/* * ***** BEGIN GPL LICENSE BLOCK ***** * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV. * All rights reserved. * * The Original Code is: some of this file. * * ***** END GPL LICENSE BLOCK ***** * */ /** \file blender/blenlib/intern/math_geom.c * \ingroup bli */ #include "MEM_guardedalloc.h" #include "BLI_math.h" #include "BLI_math_bits.h" #include "BLI_utildefines.h" #include "BLI_strict_flags.h" /********************************** Polygons *********************************/ void cross_tri_v3(float n[3], const float v1[3], const float v2[3], const float v3[3]) { float n1[3], n2[3]; n1[0] = v1[0] - v2[0]; n2[0] = v2[0] - v3[0]; n1[1] = v1[1] - v2[1]; n2[1] = v2[1] - v3[1]; n1[2] = v1[2] - v2[2]; n2[2] = v2[2] - v3[2]; n[0] = n1[1] * n2[2] - n1[2] * n2[1]; n[1] = n1[2] * n2[0] - n1[0] * n2[2]; n[2] = n1[0] * n2[1] - n1[1] * n2[0]; } float normal_tri_v3(float n[3], const float v1[3], const float v2[3], const float v3[3]) { float n1[3], n2[3]; n1[0] = v1[0] - v2[0]; n2[0] = v2[0] - v3[0]; n1[1] = v1[1] - v2[1]; n2[1] = v2[1] - v3[1]; n1[2] = v1[2] - v2[2]; n2[2] = v2[2] - v3[2]; n[0] = n1[1] * n2[2] - n1[2] * n2[1]; n[1] = n1[2] * n2[0] - n1[0] * n2[2]; n[2] = n1[0] * n2[1] - n1[1] * n2[0]; return normalize_v3(n); } float normal_quad_v3(float n[3], const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { /* real cross! */ float n1[3], n2[3]; n1[0] = v1[0] - v3[0]; n1[1] = v1[1] - v3[1]; n1[2] = v1[2] - v3[2]; n2[0] = v2[0] - v4[0]; n2[1] = v2[1] - v4[1]; n2[2] = v2[2] - v4[2]; n[0] = n1[1] * n2[2] - n1[2] * n2[1]; n[1] = n1[2] * n2[0] - n1[0] * n2[2]; n[2] = n1[0] * n2[1] - n1[1] * n2[0]; return normalize_v3(n); } /** * Computes the normal of a planar * polygon See Graphics Gems for * computing newell normal. */ float normal_poly_v3(float n[3], const float verts[][3], unsigned int nr) { cross_poly_v3(n, verts, nr); return normalize_v3(n); } float area_quad_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { const float verts[4][3] = {{UNPACK3(v1)}, {UNPACK3(v2)}, {UNPACK3(v3)}, {UNPACK3(v4)}}; return area_poly_v3(verts, 4); } float area_squared_quad_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { const float verts[4][3] = {{UNPACK3(v1)}, {UNPACK3(v2)}, {UNPACK3(v3)}, {UNPACK3(v4)}}; return area_squared_poly_v3(verts, 4); } /* Triangles */ float area_tri_v3(const float v1[3], const float v2[3], const float v3[3]) { float n[3]; cross_tri_v3(n, v1, v2, v3); return len_v3(n) * 0.5f; } float area_squared_tri_v3(const float v1[3], const float v2[3], const float v3[3]) { float n[3]; cross_tri_v3(n, v1, v2, v3); mul_v3_fl(n, 0.5f); return len_squared_v3(n); } float area_tri_signed_v3(const float v1[3], const float v2[3], const float v3[3], const float normal[3]) { float area, n[3]; cross_tri_v3(n, v1, v2, v3); area = len_v3(n) * 0.5f; /* negate area for flipped triangles */ if (dot_v3v3(n, normal) < 0.0f) area = -area; return area; } float area_poly_v3(const float verts[][3], unsigned int nr) { float n[3]; cross_poly_v3(n, verts, nr); return len_v3(n) * 0.5f; } float area_squared_poly_v3(const float verts[][3], unsigned int nr) { float n[3]; cross_poly_v3(n, verts, nr); mul_v3_fl(n, 0.5f); return len_squared_v3(n); } /** * Scalar cross product of a 2d polygon. * * - equivalent to ``area * 2`` * - useful for checking polygon winding (a positive value is clockwise). */ float cross_poly_v2(const float verts[][2], unsigned int nr) { unsigned int a; float cross; const float *co_curr, *co_prev; /* The Trapezium Area Rule */ co_prev = verts[nr - 1]; co_curr = verts[0]; cross = 0.0f; for (a = 0; a < nr; a++) { cross += (co_curr[0] - co_prev[0]) * (co_curr[1] + co_prev[1]); co_prev = co_curr; co_curr += 2; } return cross; } void cross_poly_v3(float n[3], const float verts[][3], unsigned int nr) { const float *v_prev = verts[nr - 1]; const float *v_curr = verts[0]; unsigned int i; zero_v3(n); /* Newell's Method */ for (i = 0; i < nr; v_prev = v_curr, v_curr = verts[++i]) { add_newell_cross_v3_v3v3(n, v_prev, v_curr); } } float area_poly_v2(const float verts[][2], unsigned int nr) { return fabsf(0.5f * cross_poly_v2(verts, nr)); } float area_poly_signed_v2(const float verts[][2], unsigned int nr) { return (0.5f * cross_poly_v2(verts, nr)); } float area_squared_poly_v2(const float verts[][2], unsigned int nr) { float area = area_poly_signed_v2(verts, nr); return area * area; } float cotangent_tri_weight_v3(const float v1[3], const float v2[3], const float v3[3]) { float a[3], b[3], c[3], c_len; sub_v3_v3v3(a, v2, v1); sub_v3_v3v3(b, v3, v1); cross_v3_v3v3(c, a, b); c_len = len_v3(c); if (c_len > FLT_EPSILON) { return dot_v3v3(a, b) / c_len; } else { return 0.0f; } } /********************************* Planes **********************************/ /** * Calculate a plane from a point and a direction, * \note \a point_no isn't required to be normalized. */ void plane_from_point_normal_v3(float r_plane[4], const float plane_co[3], const float plane_no[3]) { copy_v3_v3(r_plane, plane_no); r_plane[3] = -dot_v3v3(r_plane, plane_co); } /** * Get a point and a direction from a plane. */ void plane_to_point_vector_v3(const float plane[4], float r_plane_co[3], float r_plane_no[3]) { mul_v3_v3fl(r_plane_co, plane, (-plane[3] / len_squared_v3(plane))); copy_v3_v3(r_plane_no, plane); } /** * version of #plane_to_point_vector_v3 that gets a unit length vector. */ void plane_to_point_vector_v3_normalized(const float plane[4], float r_plane_co[3], float r_plane_no[3]) { const float length = normalize_v3_v3(r_plane_no, plane); mul_v3_v3fl(r_plane_co, r_plane_no, (-plane[3] / length)); } /********************************* Volume **********************************/ /** * The volume from a tetrahedron, points can be in any order */ float volume_tetrahedron_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { float m[3][3]; sub_v3_v3v3(m[0], v1, v2); sub_v3_v3v3(m[1], v2, v3); sub_v3_v3v3(m[2], v3, v4); return fabsf(determinant_m3_array(m)) / 6.0f; } /** * The volume from a tetrahedron, normal pointing inside gives negative volume */ float volume_tetrahedron_signed_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { float m[3][3]; sub_v3_v3v3(m[0], v1, v2); sub_v3_v3v3(m[1], v2, v3); sub_v3_v3v3(m[2], v3, v4); return determinant_m3_array(m) / 6.0f; } /********************************* Distance **********************************/ /* distance p to line v1-v2 * using Hesse formula, NO LINE PIECE! */ float dist_squared_to_line_v2(const float p[2], const float l1[2], const float l2[2]) { float closest[2]; closest_to_line_v2(closest, p, l1, l2); return len_squared_v2v2(closest, p); } float dist_to_line_v2(const float p[2], const float l1[2], const float l2[2]) { return sqrtf(dist_squared_to_line_v2(p, l1, l2)); } /* distance p to line-piece v1-v2 */ float dist_squared_to_line_segment_v2(const float p[2], const float l1[2], const float l2[2]) { float closest[2]; closest_to_line_segment_v2(closest, p, l1, l2); return len_squared_v2v2(closest, p); } float dist_to_line_segment_v2(const float p[2], const float l1[2], const float l2[2]) { return sqrtf(dist_squared_to_line_segment_v2(p, l1, l2)); } /* point closest to v1 on line v2-v3 in 2D */ void closest_to_line_segment_v2(float r_close[2], const float p[2], const float l1[2], const float l2[2]) { float lambda, cp[2]; lambda = closest_to_line_v2(cp, p, l1, l2); /* flip checks for !finite case (when segment is a point) */ if (!(lambda > 0.0f)) { copy_v2_v2(r_close, l1); } else if (!(lambda < 1.0f)) { copy_v2_v2(r_close, l2); } else { copy_v2_v2(r_close, cp); } } /* point closest to v1 on line v2-v3 in 3D */ void closest_to_line_segment_v3(float r_close[3], const float p[3], const float l1[3], const float l2[3]) { float lambda, cp[3]; lambda = closest_to_line_v3(cp, p, l1, l2); /* flip checks for !finite case (when segment is a point) */ if (!(lambda > 0.0f)) { copy_v3_v3(r_close, l1); } else if (!(lambda < 1.0f)) { copy_v3_v3(r_close, l2); } else { copy_v3_v3(r_close, cp); } } /** * Find the closest point on a plane. * * \param r_close Return coordinate * \param plane The plane to test against. * \param pt The point to find the nearest of * * \note non-unit-length planes are supported. */ void closest_to_plane_v3(float r_close[3], const float plane[4], const float pt[3]) { const float len_sq = len_squared_v3(plane); const float side = plane_point_side_v3(plane, pt); madd_v3_v3v3fl(r_close, pt, plane, -side / len_sq); } void closest_to_plane_normalized_v3(float r_close[3], const float plane[4], const float pt[3]) { const float side = plane_point_side_v3(plane, pt); BLI_ASSERT_UNIT_V3(plane); madd_v3_v3v3fl(r_close, pt, plane, -side); } void closest_to_plane3_v3(float r_close[3], const float plane[3], const float pt[3]) { const float len_sq = len_squared_v3(plane); const float side = dot_v3v3(plane, pt); madd_v3_v3v3fl(r_close, pt, plane, -side / len_sq); } void closest_to_plane3_normalized_v3(float r_close[3], const float plane[3], const float pt[3]) { const float side = dot_v3v3(plane, pt); BLI_ASSERT_UNIT_V3(plane); madd_v3_v3v3fl(r_close, pt, plane, -side); } float dist_signed_squared_to_plane_v3(const float pt[3], const float plane[4]) { const float len_sq = len_squared_v3(plane); const float side = plane_point_side_v3(plane, pt); const float fac = side / len_sq; return copysignf(len_sq * (fac * fac), side); } float dist_squared_to_plane_v3(const float pt[3], const float plane[4]) { const float len_sq = len_squared_v3(plane); const float side = plane_point_side_v3(plane, pt); const float fac = side / len_sq; /* only difference to code above - no 'copysignf' */ return len_sq * (fac * fac); } float dist_signed_squared_to_plane3_v3(const float pt[3], const float plane[3]) { const float len_sq = len_squared_v3(plane); const float side = dot_v3v3(plane, pt); /* only difference with 'plane[4]' version */ const float fac = side / len_sq; return copysignf(len_sq * (fac * fac), side); } float dist_squared_to_plane3_v3(const float pt[3], const float plane[3]) { const float len_sq = len_squared_v3(plane); const float side = dot_v3v3(plane, pt); /* only difference with 'plane[4]' version */ const float fac = side / len_sq; /* only difference to code above - no 'copysignf' */ return len_sq * (fac * fac); } /** * Return the signed distance from the point to the plane. */ float dist_signed_to_plane_v3(const float pt[3], const float plane[4]) { const float len_sq = len_squared_v3(plane); const float side = plane_point_side_v3(plane, pt); const float fac = side / len_sq; return sqrtf(len_sq) * fac; } float dist_to_plane_v3(const float pt[3], const float plane[4]) { return fabsf(dist_signed_to_plane_v3(pt, plane)); } float dist_signed_to_plane3_v3(const float pt[3], const float plane[3]) { const float len_sq = len_squared_v3(plane); const float side = dot_v3v3(plane, pt); /* only difference with 'plane[4]' version */ const float fac = side / len_sq; return sqrtf(len_sq) * fac; } float dist_to_plane3_v3(const float pt[3], const float plane[3]) { return fabsf(dist_signed_to_plane3_v3(pt, plane)); } /* distance v1 to line-piece l1-l2 in 3D */ float dist_squared_to_line_segment_v3(const float p[3], const float l1[3], const float l2[3]) { float closest[3]; closest_to_line_segment_v3(closest, p, l1, l2); return len_squared_v3v3(closest, p); } float dist_to_line_segment_v3(const float p[3], const float l1[3], const float l2[3]) { return sqrtf(dist_squared_to_line_segment_v3(p, l1, l2)); } float dist_squared_to_line_v3(const float p[3], const float l1[3], const float l2[3]) { float closest[3]; closest_to_line_v3(closest, p, l1, l2); return len_squared_v3v3(closest, p); } float dist_to_line_v3(const float p[3], const float l1[3], const float l2[3]) { return sqrtf(dist_squared_to_line_v3(p, l1, l2)); } /** * Check if \a p is inside the 2x planes defined by ``(v1, v2, v3)`` * where the 3x points define 2x planes. * * \param axis_ref used when v1,v2,v3 form a line and to check if the corner is concave/convex. * * \note the distance from \a v1 & \a v3 to \a v2 doesnt matter * (it just defines the planes). * * \return the lowest squared distance to either of the planes. * where ``(return < 0.0)`` is outside. * *
 *            v1
 *            +
 *           /
 * x - out  /  x - inside
 *         /
 *        +----+
 *        v2   v3
 *           x - also outside
 * 
*/ float dist_signed_squared_to_corner_v3v3v3( const float p[3], const float v1[3], const float v2[3], const float v3[3], const float axis_ref[3]) { float dir_a[3], dir_b[3]; float plane_a[3], plane_b[3]; float dist_a, dist_b; float axis[3]; float s_p_v2[3]; bool flip = false; sub_v3_v3v3(dir_a, v1, v2); sub_v3_v3v3(dir_b, v3, v2); cross_v3_v3v3(axis, dir_a, dir_b); if ((len_squared_v3(axis) < FLT_EPSILON)) { copy_v3_v3(axis, axis_ref); } else if (dot_v3v3(axis, axis_ref) < 0.0f) { /* concave */ flip = true; negate_v3(axis); } cross_v3_v3v3(plane_a, dir_a, axis); cross_v3_v3v3(plane_b, axis, dir_b); #if 0 plane_from_point_normal_v3(plane_a, v2, plane_a); plane_from_point_normal_v3(plane_b, v2, plane_b); dist_a = dist_signed_squared_to_plane_v3(p, plane_a); dist_b = dist_signed_squared_to_plane_v3(p, plane_b); #else /* calculate without the planes 4th component to avoid float precision issues */ sub_v3_v3v3(s_p_v2, p, v2); dist_a = dist_signed_squared_to_plane3_v3(s_p_v2, plane_a); dist_b = dist_signed_squared_to_plane3_v3(s_p_v2, plane_b); #endif if (flip) { return min_ff(dist_a, dist_b); } else { return max_ff(dist_a, dist_b); } } /** * return the distance squared of a point to a ray. */ float dist_squared_to_ray_v3( const float ray_origin[3], const float ray_direction[3], const float co[3], float *r_depth) { float dvec[3]; sub_v3_v3v3(dvec, co, ray_origin); *r_depth = dot_v3v3(dvec, ray_direction); return len_squared_v3(dvec) - SQUARE(*r_depth); } /** * Find the closest point in a seg to a ray and return the distance squared. * \param r_point : Is the point on segment closest to ray (or to ray_origin if the ray and the segment are parallel). * \param depth: the distance of r_point projection on ray to the ray_origin. */ float dist_squared_ray_to_seg_v3( const float ray_origin[3], const float ray_direction[3], const float v0[3], const float v1[3], float r_point[3], float *r_depth) { float a[3], t[3], n[3], lambda; sub_v3_v3v3(a, v1, v0); sub_v3_v3v3(t, v0, ray_origin); cross_v3_v3v3(n, a, ray_direction); const float nlen = len_squared_v3(n); /* if (nlen == 0.0f) the lines are parallel, * has no nearest point, only distance squared.*/ if (nlen == 0.0f) { /* Calculate the distance to the point v0 then */ copy_v3_v3(r_point, v0); *r_depth = dot_v3v3(t, ray_direction); } else { float c[3], cray[3]; sub_v3_v3v3(c, n, t); cross_v3_v3v3(cray, c, ray_direction); lambda = dot_v3v3(cray, n) / nlen; if (lambda <= 0) { copy_v3_v3(r_point, v0); *r_depth = dot_v3v3(t, ray_direction); } else if (lambda >= 1) { copy_v3_v3(r_point, v1); sub_v3_v3v3(t, v1, ray_origin); *r_depth = dot_v3v3(t, ray_direction); } else { madd_v3_v3v3fl(r_point, v0, a, lambda); sub_v3_v3v3(t, r_point, ray_origin); *r_depth = dot_v3v3(t, ray_direction); } } return len_squared_v3(t) - SQUARE(*r_depth); } /* Adapted from "Real-Time Collision Detection" by Christer Ericson, * published by Morgan Kaufmann Publishers, copyright 2005 Elsevier Inc. * * Set 'r' to the point in triangle (a, b, c) closest to point 'p' */ void closest_on_tri_to_point_v3(float r[3], const float p[3], const float a[3], const float b[3], const float c[3]) { float ab[3], ac[3], ap[3], d1, d2; float bp[3], d3, d4, vc, cp[3], d5, d6, vb, va; float denom, v, w; /* Check if P in vertex region outside A */ sub_v3_v3v3(ab, b, a); sub_v3_v3v3(ac, c, a); sub_v3_v3v3(ap, p, a); d1 = dot_v3v3(ab, ap); d2 = dot_v3v3(ac, ap); if (d1 <= 0.0f && d2 <= 0.0f) { /* barycentric coordinates (1,0,0) */ copy_v3_v3(r, a); return; } /* Check if P in vertex region outside B */ sub_v3_v3v3(bp, p, b); d3 = dot_v3v3(ab, bp); d4 = dot_v3v3(ac, bp); if (d3 >= 0.0f && d4 <= d3) { /* barycentric coordinates (0,1,0) */ copy_v3_v3(r, b); return; } /* Check if P in edge region of AB, if so return projection of P onto AB */ vc = d1 * d4 - d3 * d2; if (vc <= 0.0f && d1 >= 0.0f && d3 <= 0.0f) { v = d1 / (d1 - d3); /* barycentric coordinates (1-v,v,0) */ madd_v3_v3v3fl(r, a, ab, v); return; } /* Check if P in vertex region outside C */ sub_v3_v3v3(cp, p, c); d5 = dot_v3v3(ab, cp); d6 = dot_v3v3(ac, cp); if (d6 >= 0.0f && d5 <= d6) { /* barycentric coordinates (0,0,1) */ copy_v3_v3(r, c); return; } /* Check if P in edge region of AC, if so return projection of P onto AC */ vb = d5 * d2 - d1 * d6; if (vb <= 0.0f && d2 >= 0.0f && d6 <= 0.0f) { w = d2 / (d2 - d6); /* barycentric coordinates (1-w,0,w) */ madd_v3_v3v3fl(r, a, ac, w); return; } /* Check if P in edge region of BC, if so return projection of P onto BC */ va = d3 * d6 - d5 * d4; if (va <= 0.0f && (d4 - d3) >= 0.0f && (d5 - d6) >= 0.0f) { w = (d4 - d3) / ((d4 - d3) + (d5 - d6)); /* barycentric coordinates (0,1-w,w) */ sub_v3_v3v3(r, c, b); mul_v3_fl(r, w); add_v3_v3(r, b); return; } /* P inside face region. Compute Q through its barycentric coordinates (u,v,w) */ denom = 1.0f / (va + vb + vc); v = vb * denom; w = vc * denom; /* = u*a + v*b + w*c, u = va * denom = 1.0f - v - w */ /* ac * w */ mul_v3_fl(ac, w); /* a + ab * v */ madd_v3_v3v3fl(r, a, ab, v); /* a + ab * v + ac * w */ add_v3_v3(r, ac); } /******************************* Intersection ********************************/ /* intersect Line-Line, shorts */ int isect_seg_seg_v2_int(const int v1[2], const int v2[2], const int v3[2], const int v4[2]) { float div, lambda, mu; div = (float)((v2[0] - v1[0]) * (v4[1] - v3[1]) - (v2[1] - v1[1]) * (v4[0] - v3[0])); if (div == 0.0f) return ISECT_LINE_LINE_COLINEAR; lambda = (float)((v1[1] - v3[1]) * (v4[0] - v3[0]) - (v1[0] - v3[0]) * (v4[1] - v3[1])) / div; mu = (float)((v1[1] - v3[1]) * (v2[0] - v1[0]) - (v1[0] - v3[0]) * (v2[1] - v1[1])) / div; if (lambda >= 0.0f && lambda <= 1.0f && mu >= 0.0f && mu <= 1.0f) { if (lambda == 0.0f || lambda == 1.0f || mu == 0.0f || mu == 1.0f) return ISECT_LINE_LINE_EXACT; return ISECT_LINE_LINE_CROSS; } return ISECT_LINE_LINE_NONE; } /* intersect Line-Line, floats - gives intersection point */ int isect_line_line_v2_point(const float v0[2], const float v1[2], const float v2[2], const float v3[2], float r_vi[2]) { float s10[2], s32[2]; float div; sub_v2_v2v2(s10, v1, v0); sub_v2_v2v2(s32, v3, v2); div = cross_v2v2(s10, s32); if (div != 0.0f) { const float u = cross_v2v2(v1, v0); const float v = cross_v2v2(v3, v2); r_vi[0] = ((s32[0] * u) - (s10[0] * v)) / div; r_vi[1] = ((s32[1] * u) - (s10[1] * v)) / div; return ISECT_LINE_LINE_CROSS; } else { return ISECT_LINE_LINE_COLINEAR; } } /* intersect Line-Line, floats */ int isect_seg_seg_v2(const float v1[2], const float v2[2], const float v3[2], const float v4[2]) { float div, lambda, mu; div = (v2[0] - v1[0]) * (v4[1] - v3[1]) - (v2[1] - v1[1]) * (v4[0] - v3[0]); if (div == 0.0f) return ISECT_LINE_LINE_COLINEAR; lambda = ((float)(v1[1] - v3[1]) * (v4[0] - v3[0]) - (v1[0] - v3[0]) * (v4[1] - v3[1])) / div; mu = ((float)(v1[1] - v3[1]) * (v2[0] - v1[0]) - (v1[0] - v3[0]) * (v2[1] - v1[1])) / div; if (lambda >= 0.0f && lambda <= 1.0f && mu >= 0.0f && mu <= 1.0f) { if (lambda == 0.0f || lambda == 1.0f || mu == 0.0f || mu == 1.0f) return ISECT_LINE_LINE_EXACT; return ISECT_LINE_LINE_CROSS; } return ISECT_LINE_LINE_NONE; } /* get intersection point of two 2D segments and return intersection type: * -1: collinear * 1: intersection */ int isect_seg_seg_v2_point( const float v0[2], const float v1[2], const float v2[2], const float v3[2], float r_vi[2]) { float s10[2], s32[2], s30[2], d; const float eps = 1e-6f; const float eps_sq = eps * eps; sub_v2_v2v2(s10, v1, v0); sub_v2_v2v2(s32, v3, v2); sub_v2_v2v2(s30, v3, v0); d = cross_v2v2(s10, s32); if (d != 0) { float u, v; u = cross_v2v2(s30, s32) / d; v = cross_v2v2(s10, s30) / d; if ((u >= -eps && u <= 1.0f + eps) && (v >= -eps && v <= 1.0f + eps)) { /* intersection */ float vi_test[2]; float s_vi_v2[2]; madd_v2_v2v2fl(vi_test, v0, s10, u); /* When 'd' approaches zero, float precision lets non-overlapping co-linear segments * detect as an intersection. So re-calculate 'v' to ensure the point overlaps both. * see T45123 */ /* inline since we have most vars already */ #if 0 v = line_point_factor_v2(ix_test, v2, v3); #else sub_v2_v2v2(s_vi_v2, vi_test, v2); v = (dot_v2v2(s32, s_vi_v2) / dot_v2v2(s32, s32)); #endif if (v >= -eps && v <= 1.0f + eps) { copy_v2_v2(r_vi, vi_test); return 1; } } /* out of segment intersection */ return -1; } else { if ((cross_v2v2(s10, s30) == 0.0f) && (cross_v2v2(s32, s30) == 0.0f)) { /* equal lines */ float s20[2]; float u_a, u_b; if (equals_v2v2(v0, v1)) { if (len_squared_v2v2(v2, v3) > eps_sq) { /* use non-point segment as basis */ SWAP(const float *, v0, v2); SWAP(const float *, v1, v3); sub_v2_v2v2(s10, v1, v0); sub_v2_v2v2(s30, v3, v0); } else { /* both of segments are points */ if (equals_v2v2(v0, v2)) { /* points are equal */ copy_v2_v2(r_vi, v0); return 1; } /* two different points */ return -1; } } sub_v2_v2v2(s20, v2, v0); u_a = dot_v2v2(s20, s10) / dot_v2v2(s10, s10); u_b = dot_v2v2(s30, s10) / dot_v2v2(s10, s10); if (u_a > u_b) SWAP(float, u_a, u_b); if (u_a > 1.0f + eps || u_b < -eps) { /* non-overlapping segments */ return -1; } else if (max_ff(0.0f, u_a) == min_ff(1.0f, u_b)) { /* one common point: can return result */ madd_v2_v2v2fl(r_vi, v0, s10, max_ff(0, u_a)); return 1; } } /* lines are collinear */ return -1; } } bool isect_seg_seg_v2_simple(const float v1[2], const float v2[2], const float v3[2], const float v4[2]) { #define CCW(A, B, C) \ ((C[1] - A[1]) * (B[0] - A[0]) > \ (B[1] - A[1]) * (C[0] - A[0])) return CCW(v1, v3, v4) != CCW(v2, v3, v4) && CCW(v1, v2, v3) != CCW(v1, v2, v4); #undef CCW } /** * \param l1, l2: Coordinates (point of line). * \param sp, r: Coordinate and radius (sphere). * \return r_p1, r_p2: Intersection coordinates. * * \note The order of assignment for intersection points (\a r_p1, \a r_p2) is predictable, * based on the direction defined by ``l2 - l1``, * this direction compared with the normal of each point on the sphere: * \a r_p1 always has a >= 0.0 dot product. * \a r_p2 always has a <= 0.0 dot product. * For example, when \a l1 is inside the sphere and \a l2 is outside, * \a r_p1 will always be between \a l1 and \a l2. */ int isect_line_sphere_v3(const float l1[3], const float l2[3], const float sp[3], const float r, float r_p1[3], float r_p2[3]) { /* adapted for use in blender by Campbell Barton - 2011 * * atelier iebele abel - 2001 * atelier@iebele.nl * http://www.iebele.nl * * sphere_line_intersection function adapted from: * http://astronomy.swin.edu.au/pbourke/geometry/sphereline * Paul Bourke pbourke@swin.edu.au */ const float ldir[3] = { l2[0] - l1[0], l2[1] - l1[1], l2[2] - l1[2] }; const float a = len_squared_v3(ldir); const float b = 2.0f * (ldir[0] * (l1[0] - sp[0]) + ldir[1] * (l1[1] - sp[1]) + ldir[2] * (l1[2] - sp[2])); const float c = len_squared_v3(sp) + len_squared_v3(l1) - (2.0f * dot_v3v3(sp, l1)) - (r * r); const float i = b * b - 4.0f * a * c; float mu; if (i < 0.0f) { /* no intersections */ return 0; } else if (i == 0.0f) { /* one intersection */ mu = -b / (2.0f * a); madd_v3_v3v3fl(r_p1, l1, ldir, mu); return 1; } else if (i > 0.0f) { const float i_sqrt = sqrtf(i); /* avoid calc twice */ /* first intersection */ mu = (-b + i_sqrt) / (2.0f * a); madd_v3_v3v3fl(r_p1, l1, ldir, mu); /* second intersection */ mu = (-b - i_sqrt) / (2.0f * a); madd_v3_v3v3fl(r_p2, l1, ldir, mu); return 2; } else { /* math domain error - nan */ return -1; } } /* keep in sync with isect_line_sphere_v3 */ int isect_line_sphere_v2(const float l1[2], const float l2[2], const float sp[2], const float r, float r_p1[2], float r_p2[2]) { const float ldir[2] = {l2[0] - l1[0], l2[1] - l1[1]}; const float a = dot_v2v2(ldir, ldir); const float b = 2.0f * (ldir[0] * (l1[0] - sp[0]) + ldir[1] * (l1[1] - sp[1])); const float c = dot_v2v2(sp, sp) + dot_v2v2(l1, l1) - (2.0f * dot_v2v2(sp, l1)) - (r * r); const float i = b * b - 4.0f * a * c; float mu; if (i < 0.0f) { /* no intersections */ return 0; } else if (i == 0.0f) { /* one intersection */ mu = -b / (2.0f * a); madd_v2_v2v2fl(r_p1, l1, ldir, mu); return 1; } else if (i > 0.0f) { const float i_sqrt = sqrtf(i); /* avoid calc twice */ /* first intersection */ mu = (-b + i_sqrt) / (2.0f * a); madd_v2_v2v2fl(r_p1, l1, ldir, mu); /* second intersection */ mu = (-b - i_sqrt) / (2.0f * a); madd_v2_v2v2fl(r_p2, l1, ldir, mu); return 2; } else { /* math domain error - nan */ return -1; } } /* point in polygon (keep float and int versions in sync) */ #if 0 bool isect_point_poly_v2(const float pt[2], const float verts[][2], const unsigned int nr, const bool use_holes) { /* we do the angle rule, define that all added angles should be about zero or (2 * PI) */ float angletot = 0.0; float fp1[2], fp2[2]; unsigned int i; const float *p1, *p2; p1 = verts[nr - 1]; /* first vector */ fp1[0] = (float)(p1[0] - pt[0]); fp1[1] = (float)(p1[1] - pt[1]); for (i = 0; i < nr; i++) { p2 = verts[i]; /* second vector */ fp2[0] = (float)(p2[0] - pt[0]); fp2[1] = (float)(p2[1] - pt[1]); /* dot and angle and cross */ angletot += angle_signed_v2v2(fp1, fp2); /* circulate */ copy_v2_v2(fp1, fp2); p1 = p2; } angletot = fabsf(angletot); if (use_holes) { const float nested = floorf((angletot / (float)(M_PI * 2.0)) + 0.00001f); angletot -= nested * (float)(M_PI * 2.0); return (angletot > 4.0f) != ((int)nested % 2); } else { return (angletot > 4.0f); } } bool isect_point_poly_v2_int(const int pt[2], const int verts[][2], const unsigned int nr, const bool use_holes) { /* we do the angle rule, define that all added angles should be about zero or (2 * PI) */ float angletot = 0.0; float fp1[2], fp2[2]; unsigned int i; const int *p1, *p2; p1 = verts[nr - 1]; /* first vector */ fp1[0] = (float)(p1[0] - pt[0]); fp1[1] = (float)(p1[1] - pt[1]); for (i = 0; i < nr; i++) { p2 = verts[i]; /* second vector */ fp2[0] = (float)(p2[0] - pt[0]); fp2[1] = (float)(p2[1] - pt[1]); /* dot and angle and cross */ angletot += angle_signed_v2v2(fp1, fp2); /* circulate */ copy_v2_v2(fp1, fp2); p1 = p2; } angletot = fabsf(angletot); if (use_holes) { const float nested = floorf((angletot / (float)(M_PI * 2.0)) + 0.00001f); angletot -= nested * (float)(M_PI * 2.0); return (angletot > 4.0f) != ((int)nested % 2); } else { return (angletot > 4.0f); } } #else bool isect_point_poly_v2(const float pt[2], const float verts[][2], const unsigned int nr, const bool UNUSED(use_holes)) { unsigned int i, j; bool isect = false; for (i = 0, j = nr - 1; i < nr; j = i++) { if (((verts[i][1] > pt[1]) != (verts[j][1] > pt[1])) && (pt[0] < (verts[j][0] - verts[i][0]) * (pt[1] - verts[i][1]) / (verts[j][1] - verts[i][1]) + verts[i][0])) { isect = !isect; } } return isect; } bool isect_point_poly_v2_int(const int pt[2], const int verts[][2], const unsigned int nr, const bool UNUSED(use_holes)) { unsigned int i, j; bool isect = false; for (i = 0, j = nr - 1; i < nr; j = i++) { if (((verts[i][1] > pt[1]) != (verts[j][1] > pt[1])) && (pt[0] < (verts[j][0] - verts[i][0]) * (pt[1] - verts[i][1]) / (verts[j][1] - verts[i][1]) + verts[i][0])) { isect = !isect; } } return isect; } #endif /* point in tri */ /* only single direction */ bool isect_point_tri_v2_cw(const float pt[2], const float v1[2], const float v2[2], const float v3[2]) { if (line_point_side_v2(v1, v2, pt) >= 0.0f) { if (line_point_side_v2(v2, v3, pt) >= 0.0f) { if (line_point_side_v2(v3, v1, pt) >= 0.0f) { return true; } } } return false; } int isect_point_tri_v2(const float pt[2], const float v1[2], const float v2[2], const float v3[2]) { if (line_point_side_v2(v1, v2, pt) >= 0.0f) { if (line_point_side_v2(v2, v3, pt) >= 0.0f) { if (line_point_side_v2(v3, v1, pt) >= 0.0f) { return 1; } } } else { if (!(line_point_side_v2(v2, v3, pt) >= 0.0f)) { if (!(line_point_side_v2(v3, v1, pt) >= 0.0f)) { return -1; } } } return 0; } /* point in quad - only convex quads */ int isect_point_quad_v2(const float pt[2], const float v1[2], const float v2[2], const float v3[2], const float v4[2]) { if (line_point_side_v2(v1, v2, pt) >= 0.0f) { if (line_point_side_v2(v2, v3, pt) >= 0.0f) { if (line_point_side_v2(v3, v4, pt) >= 0.0f) { if (line_point_side_v2(v4, v1, pt) >= 0.0f) { return 1; } } } } else { if (!(line_point_side_v2(v2, v3, pt) >= 0.0f)) { if (!(line_point_side_v2(v3, v4, pt) >= 0.0f)) { if (!(line_point_side_v2(v4, v1, pt) >= 0.0f)) { return -1; } } } } return 0; } /* moved from effect.c * test if the line starting at p1 ending at p2 intersects the triangle v0..v2 * return non zero if it does */ bool isect_line_segment_tri_v3( const float p1[3], const float p2[3], const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]) { float p[3], s[3], d[3], e1[3], e2[3], q[3]; float a, f, u, v; sub_v3_v3v3(e1, v1, v0); sub_v3_v3v3(e2, v2, v0); sub_v3_v3v3(d, p2, p1); cross_v3_v3v3(p, d, e2); a = dot_v3v3(e1, p); if (a == 0.0f) return false; f = 1.0f / a; sub_v3_v3v3(s, p1, v0); u = f * dot_v3v3(s, p); if ((u < 0.0f) || (u > 1.0f)) return false; cross_v3_v3v3(q, s, e1); v = f * dot_v3v3(d, q); if ((v < 0.0f) || ((u + v) > 1.0f)) return false; *r_lambda = f * dot_v3v3(e2, q); if ((*r_lambda < 0.0f) || (*r_lambda > 1.0f)) return false; if (r_uv) { r_uv[0] = u; r_uv[1] = v; } return true; } /* like isect_line_segment_tri_v3, but allows epsilon tolerance around triangle */ bool isect_line_segment_tri_epsilon_v3( const float p1[3], const float p2[3], const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2], const float epsilon) { float p[3], s[3], d[3], e1[3], e2[3], q[3]; float a, f, u, v; sub_v3_v3v3(e1, v1, v0); sub_v3_v3v3(e2, v2, v0); sub_v3_v3v3(d, p2, p1); cross_v3_v3v3(p, d, e2); a = dot_v3v3(e1, p); if (a == 0.0f) return false; f = 1.0f / a; sub_v3_v3v3(s, p1, v0); u = f * dot_v3v3(s, p); if ((u < -epsilon) || (u > 1.0f + epsilon)) return false; cross_v3_v3v3(q, s, e1); v = f * dot_v3v3(d, q); if ((v < -epsilon) || ((u + v) > 1.0f + epsilon)) return false; *r_lambda = f * dot_v3v3(e2, q); if ((*r_lambda < 0.0f) || (*r_lambda > 1.0f)) return false; if (r_uv) { r_uv[0] = u; r_uv[1] = v; } return true; } /* moved from effect.c * test if the ray starting at p1 going in d direction intersects the triangle v0..v2 * return non zero if it does */ bool isect_ray_tri_v3( const float ray_origin[3], const float ray_direction[3], const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]) { /* note: these values were 0.000001 in 2.4x but for projection snapping on * a human head (1BU == 1m), subsurf level 2, this gave many errors - campbell */ const float epsilon = 0.00000001f; float p[3], s[3], e1[3], e2[3], q[3]; float a, f, u, v; sub_v3_v3v3(e1, v1, v0); sub_v3_v3v3(e2, v2, v0); cross_v3_v3v3(p, ray_direction, e2); a = dot_v3v3(e1, p); if ((a > -epsilon) && (a < epsilon)) return false; f = 1.0f / a; sub_v3_v3v3(s, ray_origin, v0); u = f * dot_v3v3(s, p); if ((u < 0.0f) || (u > 1.0f)) return false; cross_v3_v3v3(q, s, e1); v = f * dot_v3v3(ray_direction, q); if ((v < 0.0f) || ((u + v) > 1.0f)) return false; *r_lambda = f * dot_v3v3(e2, q); if ((*r_lambda < 0.0f)) return false; if (r_uv) { r_uv[0] = u; r_uv[1] = v; } return true; } /** * if clip is nonzero, will only return true if lambda is >= 0.0 * (i.e. intersection point is along positive \a ray_direction) * * \note #line_plane_factor_v3() shares logic. */ bool isect_ray_plane_v3( const float ray_origin[3], const float ray_direction[3], const float plane[4], float *r_lambda, const bool clip) { float h[3], plane_co[3]; float dot; dot = dot_v3v3(plane, ray_direction); if (dot == 0.0f) { return false; } mul_v3_v3fl(plane_co, plane, (-plane[3] / len_squared_v3(plane))); sub_v3_v3v3(h, ray_origin, plane_co); *r_lambda = -dot_v3v3(plane, h) / dot; if (clip && (*r_lambda < 0.0f)) { return false; } return true; } bool isect_ray_tri_epsilon_v3( const float ray_origin[3], const float ray_direction[3], const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2], const float epsilon) { float p[3], s[3], e1[3], e2[3], q[3]; float a, f, u, v; sub_v3_v3v3(e1, v1, v0); sub_v3_v3v3(e2, v2, v0); cross_v3_v3v3(p, ray_direction, e2); a = dot_v3v3(e1, p); if (a == 0.0f) return false; f = 1.0f / a; sub_v3_v3v3(s, ray_origin, v0); u = f * dot_v3v3(s, p); if ((u < -epsilon) || (u > 1.0f + epsilon)) return false; cross_v3_v3v3(q, s, e1); v = f * dot_v3v3(ray_direction, q); if ((v < -epsilon) || ((u + v) > 1.0f + epsilon)) return false; *r_lambda = f * dot_v3v3(e2, q); if ((*r_lambda < 0.0f)) return false; if (r_uv) { r_uv[0] = u; r_uv[1] = v; } return true; } void isect_ray_tri_watertight_v3_precalc(struct IsectRayPrecalc *isect_precalc, const float ray_direction[3]) { float inv_dir_z; /* Calculate dimension where the ray direction is maximal. */ int kz = axis_dominant_v3_single(ray_direction); int kx = (kz != 2) ? (kz + 1) : 0; int ky = (kx != 2) ? (kx + 1) : 0; /* Swap kx and ky dimensions to preserve winding direction of triangles. */ if (ray_direction[kz] < 0.0f) { SWAP(int, kx, ky); } /* Calculate the shear constants. */ inv_dir_z = 1.0f / ray_direction[kz]; isect_precalc->sx = ray_direction[kx] * inv_dir_z; isect_precalc->sy = ray_direction[ky] * inv_dir_z; isect_precalc->sz = inv_dir_z; /* Store the dimensions. */ isect_precalc->kx = kx; isect_precalc->ky = ky; isect_precalc->kz = kz; } bool isect_ray_tri_watertight_v3( const float ray_origin[3], const struct IsectRayPrecalc *isect_precalc, const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]) { const int kx = isect_precalc->kx; const int ky = isect_precalc->ky; const int kz = isect_precalc->kz; const float sx = isect_precalc->sx; const float sy = isect_precalc->sy; const float sz = isect_precalc->sz; /* Calculate vertices relative to ray origin. */ const float a[3] = {v0[0] - ray_origin[0], v0[1] - ray_origin[1], v0[2] - ray_origin[2]}; const float b[3] = {v1[0] - ray_origin[0], v1[1] - ray_origin[1], v1[2] - ray_origin[2]}; const float c[3] = {v2[0] - ray_origin[0], v2[1] - ray_origin[1], v2[2] - ray_origin[2]}; const float a_kx = a[kx], a_ky = a[ky], a_kz = a[kz]; const float b_kx = b[kx], b_ky = b[ky], b_kz = b[kz]; const float c_kx = c[kx], c_ky = c[ky], c_kz = c[kz]; /* Perform shear and scale of vertices. */ const float ax = a_kx - sx * a_kz; const float ay = a_ky - sy * a_kz; const float bx = b_kx - sx * b_kz; const float by = b_ky - sy * b_kz; const float cx = c_kx - sx * c_kz; const float cy = c_ky - sy * c_kz; /* Calculate scaled barycentric coordinates. */ const float u = cx * by - cy * bx; const float v = ax * cy - ay * cx; const float w = bx * ay - by * ax; float det; if ((u < 0.0f || v < 0.0f || w < 0.0f) && (u > 0.0f || v > 0.0f || w > 0.0f)) { return false; } /* Calculate determinant. */ det = u + v + w; if (UNLIKELY(det == 0.0f)) { return false; } else { /* Calculate scaled z-coordinates of vertices and use them to calculate * the hit distance. */ const int sign_det = (float_as_int(det) & (int)0x80000000); const float t = (u * a_kz + v * b_kz + w * c_kz) * sz; const float sign_t = xor_fl(t, sign_det); if ((sign_t < 0.0f) /* differ from Cycles, don't read r_lambda's original value * otherwise we won't match any of the other intersect functions here... * which would be confusing */ #if 0 || (sign_T > *r_lambda * xor_signmask(det, sign_mask)) #endif ) { return false; } else { /* Normalize u, v and t. */ const float inv_det = 1.0f / det; if (r_uv) { r_uv[0] = u * inv_det; r_uv[1] = v * inv_det; } *r_lambda = t * inv_det; return true; } } } bool isect_ray_tri_watertight_v3_simple( const float ray_origin[3], const float ray_direction[3], const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]) { struct IsectRayPrecalc isect_precalc; isect_ray_tri_watertight_v3_precalc(&isect_precalc, ray_direction); return isect_ray_tri_watertight_v3(ray_origin, &isect_precalc, v0, v1, v2, r_lambda, r_uv); } #if 0 /* UNUSED */ /** * A version of #isect_ray_tri_v3 which takes a threshold argument * so rays slightly outside the triangle to be considered as intersecting. */ bool isect_ray_tri_threshold_v3( const float ray_origin[3], const float ray_direction[3], const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2], const float threshold) { const float epsilon = 0.00000001f; float p[3], s[3], e1[3], e2[3], q[3]; float a, f, u, v; float du, dv; sub_v3_v3v3(e1, v1, v0); sub_v3_v3v3(e2, v2, v0); cross_v3_v3v3(p, ray_direction, e2); a = dot_v3v3(e1, p); if ((a > -epsilon) && (a < epsilon)) return false; f = 1.0f / a; sub_v3_v3v3(s, ray_origin, v0); cross_v3_v3v3(q, s, e1); *r_lambda = f * dot_v3v3(e2, q); if ((*r_lambda < 0.0f)) return false; u = f * dot_v3v3(s, p); v = f * dot_v3v3(ray_direction, q); if (u > 0 && v > 0 && u + v > 1) { float t = (u + v - 1) / 2; du = u - t; dv = v - t; } else { if (u < 0) du = u; else if (u > 1) du = u - 1; else du = 0.0f; if (v < 0) dv = v; else if (v > 1) dv = v - 1; else dv = 0.0f; } mul_v3_fl(e1, du); mul_v3_fl(e2, dv); if (len_squared_v3(e1) + len_squared_v3(e2) > threshold * threshold) { return false; } if (r_uv) { r_uv[0] = u; r_uv[1] = v; } return true; } #endif bool isect_ray_seg_v2( const float ray_origin[2], const float ray_direction[2], const float v0[2], const float v1[2], float *r_lambda, float *r_u) { float v0_local[2], v1_local[2]; sub_v2_v2v2(v0_local, v0, ray_origin); sub_v2_v2v2(v1_local, v1, ray_origin); float s10[2]; float det; sub_v2_v2v2(s10, v1_local, v0_local); det = cross_v2v2(ray_direction, s10); if (det != 0.0f) { const float v = cross_v2v2(v0_local, v1_local); float p[2] = {(ray_direction[0] * v) / det, (ray_direction[1] * v) / det}; const float t = (dot_v2v2(p, ray_direction) / dot_v2v2(ray_direction, ray_direction)); if ((t >= 0.0f) == 0) { return false; } float h[2]; sub_v2_v2v2(h, v1_local, p); const float u = (dot_v2v2(s10, h) / dot_v2v2(s10, s10)); if ((u >= 0.0f && u <= 1.0f) == 0) { return false; } if (r_lambda) { *r_lambda = t; } if (r_u) { *r_u = u; } return true; } return false; } /** * Check if a point is behind all planes. */ bool isect_point_planes_v3(float (*planes)[4], int totplane, const float p[3]) { int i; for (i = 0; i < totplane; i++) { if (plane_point_side_v3(planes[i], p) > 0.0f) { return false; } } return true; } /** * Intersect line/plane. * * \param r_isect_co The intersection point. * \param l1 The first point of the line. * \param l2 The second point of the line. * \param plane_co A point on the plane to intersect with. * \param plane_no The direction of the plane (does not need to be normalized). * * \note #line_plane_factor_v3() shares logic. */ bool isect_line_plane_v3( float r_isect_co[3], const float l1[3], const float l2[3], const float plane_co[3], const float plane_no[3]) { float u[3], h[3]; float dot; sub_v3_v3v3(u, l2, l1); sub_v3_v3v3(h, l1, plane_co); dot = dot_v3v3(plane_no, u); if (fabsf(dot) > FLT_EPSILON) { float lambda = -dot_v3v3(plane_no, h) / dot; madd_v3_v3v3fl(r_isect_co, l1, u, lambda); return true; } else { /* The segment is parallel to plane */ return false; } } /** * Intersect three planes, return the point where all 3 meet. * See Graphics Gems 1 pg 305 * * \param plane_a, plane_b, plane_c: Planes. * \param r_isect_co: The resulting intersection point. */ bool isect_plane_plane_plane_v3( const float plane_a[4], const float plane_b[4], const float plane_c[4], float r_isect_co[3]) { float det; det = determinant_m3(UNPACK3(plane_a), UNPACK3(plane_b), UNPACK3(plane_c)); if (det != 0.0f) { float tmp[3]; /* (plane_b.xyz.cross(plane_c.xyz) * -plane_a[3] + * plane_c.xyz.cross(plane_a.xyz) * -plane_b[3] + * plane_a.xyz.cross(plane_b.xyz) * -plane_c[3]) / det; */ cross_v3_v3v3(tmp, plane_c, plane_b); mul_v3_v3fl(r_isect_co, tmp, plane_a[3]); cross_v3_v3v3(tmp, plane_a, plane_c); madd_v3_v3fl(r_isect_co, tmp, plane_b[3]); cross_v3_v3v3(tmp, plane_b, plane_a); madd_v3_v3fl(r_isect_co, tmp, plane_c[3]); mul_v3_fl(r_isect_co, 1.0f / det); return true; } else { return false; } } /** * Intersect two planes, return a point on the intersection and a vector * that runs on the direction of the intersection. * * * \note this is a slightly reduced version of #isect_plane_plane_plane_v3 * * \param plane_a, plane_b: Planes. * \param r_isect_co: The resulting intersection point. * \param r_isect_no: The resulting vector of the intersection. * * \note \a r_isect_no isn't unit length. */ bool isect_plane_plane_v3( const float plane_a[4], const float plane_b[4], float r_isect_co[3], float r_isect_no[3]) { float det, plane_c[3]; /* direction is simply the cross product */ cross_v3_v3v3(plane_c, plane_a, plane_b); /* in this case we don't need to use 'determinant_m3' */ det = len_squared_v3(plane_c); if (det != 0.0f) { float tmp[3]; /* (plane_b.xyz.cross(plane_c.xyz) * -plane_a[3] + * plane_c.xyz.cross(plane_a.xyz) * -plane_b[3]) / det; */ cross_v3_v3v3(tmp, plane_c, plane_b); mul_v3_v3fl(r_isect_co, tmp, plane_a[3]); cross_v3_v3v3(tmp, plane_a, plane_c); madd_v3_v3fl(r_isect_co, tmp, plane_b[3]); mul_v3_fl(r_isect_co, 1.0f / det); copy_v3_v3(r_isect_no, plane_c); return true; } else { return false; } } /** * Intersect two triangles. * * \param r_i1, r_i2: Optional arguments to retrieve the overlapping edge between the 2 triangles. * \return true when the triangles intersect. * * \note intersections between coplanar triangles are currently undetected. */ bool isect_tri_tri_epsilon_v3( const float t_a0[3], const float t_a1[3], const float t_a2[3], const float t_b0[3], const float t_b1[3], const float t_b2[3], float r_i1[3], float r_i2[3], const float epsilon) { const float *tri_pair[2][3] = {{t_a0, t_a1, t_a2}, {t_b0, t_b1, t_b2}}; float plane_a[4], plane_b[4]; float plane_co[3], plane_no[3]; BLI_assert((r_i1 != NULL) == (r_i2 != NULL)); /* normalizing is needed for small triangles T46007 */ normal_tri_v3(plane_a, UNPACK3(tri_pair[0])); normal_tri_v3(plane_b, UNPACK3(tri_pair[1])); plane_a[3] = -dot_v3v3(plane_a, t_a0); plane_b[3] = -dot_v3v3(plane_b, t_b0); if (isect_plane_plane_v3(plane_a, plane_b, plane_co, plane_no) && (normalize_v3(plane_no) > epsilon)) { /** * Implementation note: its simpler to project the triangles onto the intersection plane * before intersecting their edges with the ray, defined by 'isect_plane_plane_v3'. * This way we can use 'line_point_factor_v3_ex' to see if an edge crosses 'co_proj', * then use the factor to calculate the world-space point. */ struct { float min, max; } range[2] = {{FLT_MAX, -FLT_MAX}, {FLT_MAX, -FLT_MAX}}; int t; float co_proj[3]; closest_to_plane3_normalized_v3(co_proj, plane_no, plane_co); /* For both triangles, find the overlap with the line defined by the ray [co_proj, plane_no]. * When the ranges overlap we know the triangles do too. */ for (t = 0; t < 2; t++) { int j, j_prev; float tri_proj[3][3]; closest_to_plane3_normalized_v3(tri_proj[0], plane_no, tri_pair[t][0]); closest_to_plane3_normalized_v3(tri_proj[1], plane_no, tri_pair[t][1]); closest_to_plane3_normalized_v3(tri_proj[2], plane_no, tri_pair[t][2]); for (j = 0, j_prev = 2; j < 3; j_prev = j++) { /* note that its important to have a very small nonzero epsilon here * otherwise this fails for very small faces. * However if its too small, large adjacent faces will count as intersecting */ const float edge_fac = line_point_factor_v3_ex(co_proj, tri_proj[j_prev], tri_proj[j], 1e-10f, -1.0f); /* ignore collinear lines, they are either an edge shared between 2 tri's * (which runs along [co_proj, plane_no], but can be safely ignored). * * or a collinear edge placed away from the ray - which we don't intersect with & can ignore. */ if (UNLIKELY(edge_fac == -1.0f)) { /* pass */ } else if (edge_fac > 0.0f && edge_fac < 1.0f) { float ix_tri[3]; float span_fac; interp_v3_v3v3(ix_tri, tri_pair[t][j_prev], tri_pair[t][j], edge_fac); /* the actual distance, since 'plane_no' is normalized */ span_fac = dot_v3v3(plane_no, ix_tri); range[t].min = min_ff(range[t].min, span_fac); range[t].max = max_ff(range[t].max, span_fac); } } if (range[t].min == FLT_MAX) { return false; } } if (((range[0].min > range[1].max) || (range[0].max < range[1].min)) == 0) { if (r_i1 && r_i2) { project_plane_v3_v3v3(plane_co, plane_co, plane_no); madd_v3_v3v3fl(r_i1, plane_co, plane_no, max_ff(range[0].min, range[1].min)); madd_v3_v3v3fl(r_i2, plane_co, plane_no, min_ff(range[0].max, range[1].max)); } return true; } } return false; } /* Adapted from the paper by Kasper Fauerby */ /* "Improved Collision detection and Response" */ static bool getLowestRoot(const float a, const float b, const float c, const float maxR, float *root) { /* Check if a solution exists */ const float determinant = b * b - 4.0f * a * c; /* If determinant is negative it means no solutions. */ if (determinant >= 0.0f) { /* calculate the two roots: (if determinant == 0 then * x1==x2 but lets disregard that slight optimization) */ const float sqrtD = sqrtf(determinant); float r1 = (-b - sqrtD) / (2.0f * a); float r2 = (-b + sqrtD) / (2.0f * a); /* Sort so x1 <= x2 */ if (r1 > r2) SWAP(float, r1, r2); /* Get lowest root: */ if (r1 > 0.0f && r1 < maxR) { *root = r1; return true; } /* It is possible that we want x2 - this can happen */ /* if x1 < 0 */ if (r2 > 0.0f && r2 < maxR) { *root = r2; return true; } } /* No (valid) solutions */ return false; } bool isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const float radius, const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float ipoint[3]) { float e1[3], e2[3], e3[3], point[3], vel[3], /*dist[3],*/ nor[3], temp[3], bv[3]; float a, b, c, d, e, x, y, z, radius2 = radius * radius; float elen2, edotv, edotbv, nordotv; float newLambda; bool found_by_sweep = false; sub_v3_v3v3(e1, v1, v0); sub_v3_v3v3(e2, v2, v0); sub_v3_v3v3(vel, p2, p1); /*---test plane of tri---*/ cross_v3_v3v3(nor, e1, e2); normalize_v3(nor); /* flip normal */ if (dot_v3v3(nor, vel) > 0.0f) negate_v3(nor); a = dot_v3v3(p1, nor) - dot_v3v3(v0, nor); nordotv = dot_v3v3(nor, vel); if (fabsf(nordotv) < 0.000001f) { if (fabsf(a) >= radius) { return false; } } else { float t0 = (-a + radius) / nordotv; float t1 = (-a - radius) / nordotv; if (t0 > t1) SWAP(float, t0, t1); if (t0 > 1.0f || t1 < 0.0f) return false; /* clamp to [0, 1] */ CLAMP(t0, 0.0f, 1.0f); CLAMP(t1, 0.0f, 1.0f); /*---test inside of tri---*/ /* plane intersection point */ point[0] = p1[0] + vel[0] * t0 - nor[0] * radius; point[1] = p1[1] + vel[1] * t0 - nor[1] * radius; point[2] = p1[2] + vel[2] * t0 - nor[2] * radius; /* is the point in the tri? */ a = dot_v3v3(e1, e1); b = dot_v3v3(e1, e2); c = dot_v3v3(e2, e2); sub_v3_v3v3(temp, point, v0); d = dot_v3v3(temp, e1); e = dot_v3v3(temp, e2); x = d * c - e * b; y = e * a - d * b; z = x + y - (a * c - b * b); if (z <= 0.0f && (x >= 0.0f && y >= 0.0f)) { //(((unsigned int)z)& ~(((unsigned int)x)|((unsigned int)y))) & 0x80000000) { *r_lambda = t0; copy_v3_v3(ipoint, point); return true; } } *r_lambda = 1.0f; /*---test points---*/ a = dot_v3v3(vel, vel); /*v0*/ sub_v3_v3v3(temp, p1, v0); b = 2.0f * dot_v3v3(vel, temp); c = dot_v3v3(temp, temp) - radius2; if (getLowestRoot(a, b, c, *r_lambda, r_lambda)) { copy_v3_v3(ipoint, v0); found_by_sweep = true; } /*v1*/ sub_v3_v3v3(temp, p1, v1); b = 2.0f * dot_v3v3(vel, temp); c = dot_v3v3(temp, temp) - radius2; if (getLowestRoot(a, b, c, *r_lambda, r_lambda)) { copy_v3_v3(ipoint, v1); found_by_sweep = true; } /*v2*/ sub_v3_v3v3(temp, p1, v2); b = 2.0f * dot_v3v3(vel, temp); c = dot_v3v3(temp, temp) - radius2; if (getLowestRoot(a, b, c, *r_lambda, r_lambda)) { copy_v3_v3(ipoint, v2); found_by_sweep = true; } /*---test edges---*/ sub_v3_v3v3(e3, v2, v1); /* wasnt yet calculated */ /*e1*/ sub_v3_v3v3(bv, v0, p1); elen2 = dot_v3v3(e1, e1); edotv = dot_v3v3(e1, vel); edotbv = dot_v3v3(e1, bv); a = elen2 * (-dot_v3v3(vel, vel)) + edotv * edotv; b = 2.0f * (elen2 * dot_v3v3(vel, bv) - edotv * edotbv); c = elen2 * (radius2 - dot_v3v3(bv, bv)) + edotbv * edotbv; if (getLowestRoot(a, b, c, *r_lambda, &newLambda)) { e = (edotv * newLambda - edotbv) / elen2; if (e >= 0.0f && e <= 1.0f) { *r_lambda = newLambda; copy_v3_v3(ipoint, e1); mul_v3_fl(ipoint, e); add_v3_v3(ipoint, v0); found_by_sweep = true; } } /*e2*/ /*bv is same*/ elen2 = dot_v3v3(e2, e2); edotv = dot_v3v3(e2, vel); edotbv = dot_v3v3(e2, bv); a = elen2 * (-dot_v3v3(vel, vel)) + edotv * edotv; b = 2.0f * (elen2 * dot_v3v3(vel, bv) - edotv * edotbv); c = elen2 * (radius2 - dot_v3v3(bv, bv)) + edotbv * edotbv; if (getLowestRoot(a, b, c, *r_lambda, &newLambda)) { e = (edotv * newLambda - edotbv) / elen2; if (e >= 0.0f && e <= 1.0f) { *r_lambda = newLambda; copy_v3_v3(ipoint, e2); mul_v3_fl(ipoint, e); add_v3_v3(ipoint, v0); found_by_sweep = true; } } /*e3*/ /* sub_v3_v3v3(bv, v0, p1); */ /* UNUSED */ /* elen2 = dot_v3v3(e1, e1); */ /* UNUSED */ /* edotv = dot_v3v3(e1, vel); */ /* UNUSED */ /* edotbv = dot_v3v3(e1, bv); */ /* UNUSED */ sub_v3_v3v3(bv, v1, p1); elen2 = dot_v3v3(e3, e3); edotv = dot_v3v3(e3, vel); edotbv = dot_v3v3(e3, bv); a = elen2 * (-dot_v3v3(vel, vel)) + edotv * edotv; b = 2.0f * (elen2 * dot_v3v3(vel, bv) - edotv * edotbv); c = elen2 * (radius2 - dot_v3v3(bv, bv)) + edotbv * edotbv; if (getLowestRoot(a, b, c, *r_lambda, &newLambda)) { e = (edotv * newLambda - edotbv) / elen2; if (e >= 0.0f && e <= 1.0f) { *r_lambda = newLambda; copy_v3_v3(ipoint, e3); mul_v3_fl(ipoint, e); add_v3_v3(ipoint, v1); found_by_sweep = true; } } return found_by_sweep; } bool isect_axial_line_segment_tri_v3( const int axis, const float p1[3], const float p2[3], const float v0[3], const float v1[3], const float v2[3], float *r_lambda) { const float epsilon = 0.000001f; float p[3], e1[3], e2[3]; float u, v, f; int a0 = axis, a1 = (axis + 1) % 3, a2 = (axis + 2) % 3; #if 0 return isect_line_segment_tri_v3(p1, p2, v0, v1, v2, lambda); /* first a simple bounding box test */ if (min_fff(v0[a1], v1[a1], v2[a1]) > p1[a1]) return false; if (min_fff(v0[a2], v1[a2], v2[a2]) > p1[a2]) return false; if (max_fff(v0[a1], v1[a1], v2[a1]) < p1[a1]) return false; if (max_fff(v0[a2], v1[a2], v2[a2]) < p1[a2]) return false; /* then a full intersection test */ #endif sub_v3_v3v3(e1, v1, v0); sub_v3_v3v3(e2, v2, v0); sub_v3_v3v3(p, v0, p1); f = (e2[a1] * e1[a2] - e2[a2] * e1[a1]); if ((f > -epsilon) && (f < epsilon)) return false; v = (p[a2] * e1[a1] - p[a1] * e1[a2]) / f; if ((v < 0.0f) || (v > 1.0f)) return false; f = e1[a1]; if ((f > -epsilon) && (f < epsilon)) { f = e1[a2]; if ((f > -epsilon) && (f < epsilon)) return false; u = (-p[a2] - v * e2[a2]) / f; } else u = (-p[a1] - v * e2[a1]) / f; if ((u < 0.0f) || ((u + v) > 1.0f)) return false; *r_lambda = (p[a0] + u * e1[a0] + v * e2[a0]) / (p2[a0] - p1[a0]); if ((*r_lambda < 0.0f) || (*r_lambda > 1.0f)) return false; return true; } /** * \return The number of point of interests * 0 - lines are collinear * 1 - lines are coplanar, i1 is set to intersection * 2 - i1 and i2 are the nearest points on line 1 (v1, v2) and line 2 (v3, v4) respectively */ int isect_line_line_epsilon_v3( const float v1[3], const float v2[3], const float v3[3], const float v4[3], float r_i1[3], float r_i2[3], const float epsilon) { float a[3], b[3], c[3], ab[3], cb[3]; float d, div; sub_v3_v3v3(c, v3, v1); sub_v3_v3v3(a, v2, v1); sub_v3_v3v3(b, v4, v3); cross_v3_v3v3(ab, a, b); d = dot_v3v3(c, ab); div = dot_v3v3(ab, ab); /* important not to use an epsilon here, see: T45919 */ /* test zero length line */ if (UNLIKELY(div == 0.0f)) { return 0; } /* test if the two lines are coplanar */ else if (UNLIKELY(fabsf(d) <= epsilon)) { cross_v3_v3v3(cb, c, b); mul_v3_fl(a, dot_v3v3(cb, ab) / div); add_v3_v3v3(r_i1, v1, a); copy_v3_v3(r_i2, r_i1); return 1; /* one intersection only */ } /* if not */ else { float n[3], t[3]; float v3t[3], v4t[3]; sub_v3_v3v3(t, v1, v3); /* offset between both plane where the lines lies */ cross_v3_v3v3(n, a, b); project_v3_v3v3(t, t, n); /* for the first line, offset the second line until it is coplanar */ add_v3_v3v3(v3t, v3, t); add_v3_v3v3(v4t, v4, t); sub_v3_v3v3(c, v3t, v1); sub_v3_v3v3(a, v2, v1); sub_v3_v3v3(b, v4t, v3t); cross_v3_v3v3(ab, a, b); cross_v3_v3v3(cb, c, b); mul_v3_fl(a, dot_v3v3(cb, ab) / dot_v3v3(ab, ab)); add_v3_v3v3(r_i1, v1, a); /* for the second line, just substract the offset from the first intersection point */ sub_v3_v3v3(r_i2, r_i1, t); return 2; /* two nearest points */ } } int isect_line_line_v3( const float v1[3], const float v2[3], const float v3[3], const float v4[3], float r_i1[3], float r_i2[3]) { const float epsilon = 0.000001f; return isect_line_line_epsilon_v3(v1, v2, v3, v4, r_i1, r_i2, epsilon); } /** Intersection point strictly between the two lines * \return false when no intersection is found */ bool isect_line_line_strict_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3], float vi[3], float *r_lambda) { const float epsilon = 0.000001f; float a[3], b[3], c[3], ab[3], cb[3], ca[3]; float d, div; sub_v3_v3v3(c, v3, v1); sub_v3_v3v3(a, v2, v1); sub_v3_v3v3(b, v4, v3); cross_v3_v3v3(ab, a, b); d = dot_v3v3(c, ab); div = dot_v3v3(ab, ab); /* important not to use an epsilon here, see: T45919 */ /* test zero length line */ if (UNLIKELY(div == 0.0f)) { return false; } /* test if the two lines are coplanar */ else if (UNLIKELY(fabsf(d) < epsilon)) { return false; } else { float f1, f2; cross_v3_v3v3(cb, c, b); cross_v3_v3v3(ca, c, a); f1 = dot_v3v3(cb, ab) / div; f2 = dot_v3v3(ca, ab) / div; if (f1 >= 0 && f1 <= 1 && f2 >= 0 && f2 <= 1) { mul_v3_fl(a, f1); add_v3_v3v3(vi, v1, a); if (r_lambda) *r_lambda = f1; return true; /* intersection found */ } else { return false; } } } bool isect_aabb_aabb_v3(const float min1[3], const float max1[3], const float min2[3], const float max2[3]) { return (min1[0] < max2[0] && min1[1] < max2[1] && min1[2] < max2[2] && min2[0] < max1[0] && min2[1] < max1[1] && min2[2] < max1[2]); } void isect_ray_aabb_v3_precalc( struct IsectRayAABB_Precalc *data, const float ray_origin[3], const float ray_direction[3]) { copy_v3_v3(data->ray_origin, ray_origin); data->ray_inv_dir[0] = 1.0f / ray_direction[0]; data->ray_inv_dir[1] = 1.0f / ray_direction[1]; data->ray_inv_dir[2] = 1.0f / ray_direction[2]; data->sign[0] = data->ray_inv_dir[0] < 0.0f; data->sign[1] = data->ray_inv_dir[1] < 0.0f; data->sign[2] = data->ray_inv_dir[2] < 0.0f; } /* Adapted from http://www.gamedev.net/community/forums/topic.asp?topic_id=459973 */ bool isect_ray_aabb_v3( const struct IsectRayAABB_Precalc *data, const float bb_min[3], const float bb_max[3], float *tmin_out) { float bbox[2][3]; copy_v3_v3(bbox[0], bb_min); copy_v3_v3(bbox[1], bb_max); float tmin = (bbox[data->sign[0]][0] - data->ray_origin[0]) * data->ray_inv_dir[0]; float tmax = (bbox[1 - data->sign[0]][0] - data->ray_origin[0]) * data->ray_inv_dir[0]; const float tymin = (bbox[data->sign[1]][1] - data->ray_origin[1]) * data->ray_inv_dir[1]; const float tymax = (bbox[1 - data->sign[1]][1] - data->ray_origin[1]) * data->ray_inv_dir[1]; if ((tmin > tymax) || (tymin > tmax)) return false; if (tymin > tmin) tmin = tymin; if (tymax < tmax) tmax = tymax; const float tzmin = (bbox[data->sign[2]][2] - data->ray_origin[2]) * data->ray_inv_dir[2]; const float tzmax = (bbox[1 - data->sign[2]][2] - data->ray_origin[2]) * data->ray_inv_dir[2]; if ((tmin > tzmax) || (tzmin > tmax)) return false; if (tzmin > tmin) tmin = tzmin; /* Note: tmax does not need to be updated since we don't use it * keeping this here for future reference - jwilkins */ //if (tzmax < tmax) tmax = tzmax; if (tmin_out) (*tmin_out) = tmin; return true; } /* * Test a bounding box (AABB) for ray intersection * assumes the ray is already local to the boundbox space */ bool isect_ray_aabb_v3_simple( const float orig[3], const float dir[3], const float bb_min[3], const float bb_max[3], float *tmin, float *tmax) { double t[7]; float hit_dist[2]; t[1] = (double)(bb_min[0] - orig[0]) / dir[0]; t[2] = (double)(bb_max[0] - orig[0]) / dir[0]; t[3] = (double)(bb_min[1] - orig[1]) / dir[1]; t[4] = (double)(bb_max[1] - orig[1]) / dir[1]; t[5] = (double)(bb_min[2] - orig[2]) / dir[2]; t[6] = (double)(bb_max[2] - orig[2]) / dir[2]; hit_dist[0] = (float)fmax(fmax(fmin(t[1], t[2]), fmin(t[3], t[4])), fmin(t[5], t[6])); hit_dist[1] = (float)fmin(fmin(fmax(t[1], t[2]), fmax(t[3], t[4])), fmax(t[5], t[6])); if ((hit_dist[1] < 0 || hit_dist[0] > hit_dist[1])) return false; else { if (tmin) *tmin = hit_dist[0]; if (tmax) *tmax = hit_dist[1]; return true; } } /* find closest point to p on line through (l1, l2) and return lambda, * where (0 <= lambda <= 1) when cp is in the line segment (l1, l2) */ float closest_to_line_v3(float r_close[3], const float p[3], const float l1[3], const float l2[3]) { float h[3], u[3], lambda; sub_v3_v3v3(u, l2, l1); sub_v3_v3v3(h, p, l1); lambda = dot_v3v3(u, h) / dot_v3v3(u, u); r_close[0] = l1[0] + u[0] * lambda; r_close[1] = l1[1] + u[1] * lambda; r_close[2] = l1[2] + u[2] * lambda; return lambda; } float closest_to_line_v2(float r_close[2], const float p[2], const float l1[2], const float l2[2]) { float h[2], u[2], lambda; sub_v2_v2v2(u, l2, l1); sub_v2_v2v2(h, p, l1); lambda = dot_v2v2(u, h) / dot_v2v2(u, u); r_close[0] = l1[0] + u[0] * lambda; r_close[1] = l1[1] + u[1] * lambda; return lambda; } float ray_point_factor_v3_ex( const float p[3], const float ray_origin[3], const float ray_direction[3], const float epsilon, const float fallback) { float p_relative[3]; sub_v3_v3v3(p_relative, p, ray_origin); const float dot = len_squared_v3(ray_direction); return (dot > epsilon) ? (dot_v3v3(ray_direction, p_relative) / dot) : fallback; } float ray_point_factor_v3( const float p[3], const float ray_origin[3], const float ray_direction[3]) { return ray_point_factor_v3_ex(p, ray_origin, ray_direction, 0.0f, 0.0f); } /** * A simplified version of #closest_to_line_v3 * we only need to return the ``lambda`` * * \param epsilon: avoid approaching divide-by-zero. * Passing a zero will just check for nonzero division. */ float line_point_factor_v3_ex( const float p[3], const float l1[3], const float l2[3], const float epsilon, const float fallback) { float h[3], u[3]; float dot; sub_v3_v3v3(u, l2, l1); sub_v3_v3v3(h, p, l1); #if 0 return (dot_v3v3(u, h) / dot_v3v3(u, u)); #else /* better check for zero */ dot = len_squared_v3(u); return (dot > epsilon) ? (dot_v3v3(u, h) / dot) : fallback; #endif } float line_point_factor_v3( const float p[3], const float l1[3], const float l2[3]) { return line_point_factor_v3_ex(p, l1, l2, 0.0f, 0.0f); } float line_point_factor_v2_ex( const float p[2], const float l1[2], const float l2[2], const float epsilon, const float fallback) { float h[2], u[2]; float dot; sub_v2_v2v2(u, l2, l1); sub_v2_v2v2(h, p, l1); #if 0 return (dot_v2v2(u, h) / dot_v2v2(u, u)); #else /* better check for zero */ dot = len_squared_v2(u); return (dot > epsilon) ? (dot_v2v2(u, h) / dot) : fallback; #endif } float line_point_factor_v2(const float p[2], const float l1[2], const float l2[2]) { return line_point_factor_v2_ex(p, l1, l2, 0.0f, 0.0f); } /** * \note #isect_line_plane_v3() shares logic */ float line_plane_factor_v3(const float plane_co[3], const float plane_no[3], const float l1[3], const float l2[3]) { float u[3], h[3]; float dot; sub_v3_v3v3(u, l2, l1); sub_v3_v3v3(h, l1, plane_co); dot = dot_v3v3(plane_no, u); return (dot != 0.0f) ? -dot_v3v3(plane_no, h) / dot : 0.0f; } /** Ensure the distance between these points is no greater than 'dist'. * If it is, scale then both into the center. */ void limit_dist_v3(float v1[3], float v2[3], const float dist) { const float dist_old = len_v3v3(v1, v2); if (dist_old > dist) { float v1_old[3]; float v2_old[3]; float fac = (dist / dist_old) * 0.5f; copy_v3_v3(v1_old, v1); copy_v3_v3(v2_old, v2); interp_v3_v3v3(v1, v1_old, v2_old, 0.5f - fac); interp_v3_v3v3(v2, v1_old, v2_old, 0.5f + fac); } } /* * x1,y2 * | \ * | \ .(a,b) * | \ * x1,y1-- x2,y1 */ int isect_point_tri_v2_int(const int x1, const int y1, const int x2, const int y2, const int a, const int b) { float v1[2], v2[2], v3[2], p[2]; v1[0] = (float)x1; v1[1] = (float)y1; v2[0] = (float)x1; v2[1] = (float)y2; v3[0] = (float)x2; v3[1] = (float)y1; p[0] = (float)a; p[1] = (float)b; return isect_point_tri_v2(p, v1, v2, v3); } static bool point_in_slice(const float p[3], const float v1[3], const float l1[3], const float l2[3]) { /* * what is a slice ? * some maths: * a line including (l1, l2) and a point not on the line * define a subset of R3 delimited by planes parallel to the line and orthogonal * to the (point --> line) distance vector, one plane on the line one on the point, * the room inside usually is rather small compared to R3 though still infinite * useful for restricting (speeding up) searches * e.g. all points of triangular prism are within the intersection of 3 'slices' * another trivial case : cube * but see a 'spat' which is a deformed cube with paired parallel planes needs only 3 slices too */ float h, rp[3], cp[3], q[3]; closest_to_line_v3(cp, v1, l1, l2); sub_v3_v3v3(q, cp, v1); sub_v3_v3v3(rp, p, v1); h = dot_v3v3(q, rp) / dot_v3v3(q, q); /* note: when 'h' is nan/-nan, this check returns false * without explicit check - covering the degenerate case */ return (h >= 0.0f && h <= 1.0f); } #if 0 /* adult sister defining the slice planes by the origin and the normal * NOTE |normal| may not be 1 but defining the thickness of the slice */ static int point_in_slice_as(float p[3], float origin[3], float normal[3]) { float h, rp[3]; sub_v3_v3v3(rp, p, origin); h = dot_v3v3(normal, rp) / dot_v3v3(normal, normal); if (h < 0.0f || h > 1.0f) return 0; return 1; } /*mama (knowing the squared length of the normal) */ static int point_in_slice_m(float p[3], float origin[3], float normal[3], float lns) { float h, rp[3]; sub_v3_v3v3(rp, p, origin); h = dot_v3v3(normal, rp) / lns; if (h < 0.0f || h > 1.0f) return 0; return 1; } #endif bool isect_point_tri_prism_v3(const float p[3], const float v1[3], const float v2[3], const float v3[3]) { if (!point_in_slice(p, v1, v2, v3)) return false; if (!point_in_slice(p, v2, v3, v1)) return false; if (!point_in_slice(p, v3, v1, v2)) return false; return true; } /** * \param r_isect_co: The point \a p projected onto the triangle. * \return True when \a p is inside the triangle. * \note Its up to the caller to check the distance between \a p and \a r_vi against an error margin. */ bool isect_point_tri_v3( const float p[3], const float v1[3], const float v2[3], const float v3[3], float r_isect_co[3]) { if (isect_point_tri_prism_v3(p, v1, v2, v3)) { float plane[4]; float no[3]; /* Could use normal_tri_v3, but doesn't have to be unit-length */ cross_tri_v3(no, v1, v2, v3); BLI_assert(len_squared_v3(no) != 0.0f); plane_from_point_normal_v3(plane, v1, no); closest_to_plane_v3(r_isect_co, plane, p); return true; } else { return false; } } bool clip_segment_v3_plane( const float p1[3], const float p2[3], const float plane[4], float r_p1[3], float r_p2[3]) { float dp[3], div; sub_v3_v3v3(dp, p2, p1); div = dot_v3v3(dp, plane); if (div == 0.0f) /* parallel */ return true; float t = -plane_point_side_v3(plane, p1); if (div > 0.0f) { /* behind plane, completely clipped */ if (t >= div) { return false; } else if (t > 0.0f) { const float p1_copy[3] = {UNPACK3(p1)}; copy_v3_v3(r_p2, p2); madd_v3_v3v3fl(r_p1, p1_copy, dp, t / div); return true; } } else { /* behind plane, completely clipped */ if (t >= 0.0f) { return false; } else if (t > div) { const float p1_copy[3] = {UNPACK3(p1)}; copy_v3_v3(r_p1, p1); madd_v3_v3v3fl(r_p2, p1_copy, dp, t / div); return true; } } /* incase input/output values match (above also) */ const float p1_copy[3] = {UNPACK3(p1)}; copy_v3_v3(r_p2, p2); copy_v3_v3(r_p1, p1_copy); return true; } bool clip_segment_v3_plane_n( const float p1[3], const float p2[3], const float plane_array[][4], const int plane_tot, float r_p1[3], float r_p2[3]) { /* intersect from both directions */ float p1_fac = 0.0f, p2_fac = 1.0f; float dp[3]; sub_v3_v3v3(dp, p2, p1); for (int i = 0; i < plane_tot; i++) { const float *plane = plane_array[i]; const float div = dot_v3v3(dp, plane); if (div != 0.0f) { float t = -plane_point_side_v3(plane, p1); if (div > 0.0f) { /* clip p1 lower bounds */ if (t >= div) { return false; } else if (t > 0.0f) { t /= div; if (t > p1_fac) { p1_fac = t; if (p1_fac > p2_fac) { return false; } } } } else if (div < 0.0f) { /* clip p2 upper bounds */ if (t >= 0.0f) { return false; } else if (t > div) { t /= div; if (t < p2_fac) { p2_fac = t; if (p1_fac > p2_fac) { return false; } } } } } } /* incase input/output values match */ const float p1_copy[3] = {UNPACK3(p1)}; madd_v3_v3v3fl(r_p1, p1_copy, dp, p1_fac); madd_v3_v3v3fl(r_p2, p1_copy, dp, p2_fac); return true; } /****************************** Axis Utils ********************************/ /** * \brief Normal to x,y matrix * * Creates a 3x3 matrix from a normal. * This matrix can be applied to vectors so their 'z' axis runs along \a normal. * In practice it means you can use x,y as 2d coords. \see * * \param r_mat The matrix to return. * \param normal A unit length vector. */ void axis_dominant_v3_to_m3(float r_mat[3][3], const float normal[3]) { BLI_ASSERT_UNIT_V3(normal); copy_v3_v3(r_mat[2], normal); ortho_basis_v3v3_v3(r_mat[0], r_mat[1], r_mat[2]); BLI_ASSERT_UNIT_V3(r_mat[0]); BLI_ASSERT_UNIT_V3(r_mat[1]); transpose_m3(r_mat); BLI_assert(!is_negative_m3(r_mat)); BLI_assert((fabsf(dot_m3_v3_row_z(r_mat, normal) - 1.0f) < BLI_ASSERT_UNIT_EPSILON) || is_zero_v3(normal)); } /** * Same as axis_dominant_v3_to_m3, but flips the normal */ void axis_dominant_v3_to_m3_negate(float r_mat[3][3], const float normal[3]) { BLI_ASSERT_UNIT_V3(normal); negate_v3_v3(r_mat[2], normal); ortho_basis_v3v3_v3(r_mat[0], r_mat[1], r_mat[2]); BLI_ASSERT_UNIT_V3(r_mat[0]); BLI_ASSERT_UNIT_V3(r_mat[1]); transpose_m3(r_mat); BLI_assert(!is_negative_m3(r_mat)); BLI_assert((dot_m3_v3_row_z(r_mat, normal) < BLI_ASSERT_UNIT_EPSILON) || is_zero_v3(normal)); } /****************************** Interpolation ********************************/ static float tri_signed_area(const float v1[3], const float v2[3], const float v3[3], const int i, const int j) { return 0.5f * ((v1[i] - v2[i]) * (v2[j] - v3[j]) + (v1[j] - v2[j]) * (v3[i] - v2[i])); } /* return 1 when degenerate */ static bool barycentric_weights(const float v1[3], const float v2[3], const float v3[3], const float co[3], const float n[3], float w[3]) { float wtot; int i, j; axis_dominant_v3(&i, &j, n); w[0] = tri_signed_area(v2, v3, co, i, j); w[1] = tri_signed_area(v3, v1, co, i, j); w[2] = tri_signed_area(v1, v2, co, i, j); wtot = w[0] + w[1] + w[2]; if (fabsf(wtot) > FLT_EPSILON) { mul_v3_fl(w, 1.0f / wtot); return false; } else { /* zero area triangle */ copy_v3_fl(w, 1.0f / 3.0f); return true; } } void interp_weights_tri_v3(float w[3], const float v1[3], const float v2[3], const float v3[3], const float co[3]) { float n[3]; normal_tri_v3(n, v1, v2, v3); barycentric_weights(v1, v2, v3, co, n, w); } void interp_weights_quad_v3(float w[4], const float v1[3], const float v2[3], const float v3[3], const float v4[3], const float co[3]) { float w2[3]; w[0] = w[1] = w[2] = w[3] = 0.0f; /* first check for exact match */ if (equals_v3v3(co, v1)) w[0] = 1.0f; else if (equals_v3v3(co, v2)) w[1] = 1.0f; else if (equals_v3v3(co, v3)) w[2] = 1.0f; else if (equals_v3v3(co, v4)) w[3] = 1.0f; else { /* otherwise compute barycentric interpolation weights */ float n1[3], n2[3], n[3]; bool degenerate; sub_v3_v3v3(n1, v1, v3); sub_v3_v3v3(n2, v2, v4); cross_v3_v3v3(n, n1, n2); degenerate = barycentric_weights(v1, v2, v4, co, n, w); SWAP(float, w[2], w[3]); if (degenerate || (w[0] < 0.0f)) { /* if w[1] is negative, co is on the other side of the v1-v3 edge, * so we interpolate using the other triangle */ degenerate = barycentric_weights(v2, v3, v4, co, n, w2); if (!degenerate) { w[0] = 0.0f; w[1] = w2[0]; w[2] = w2[1]; w[3] = w2[2]; } } } } /* return 1 of point is inside triangle, 2 if it's on the edge, 0 if point is outside of triangle */ int barycentric_inside_triangle_v2(const float w[3]) { if (IN_RANGE(w[0], 0.0f, 1.0f) && IN_RANGE(w[1], 0.0f, 1.0f) && IN_RANGE(w[2], 0.0f, 1.0f)) { return 1; } else if (IN_RANGE_INCL(w[0], 0.0f, 1.0f) && IN_RANGE_INCL(w[1], 0.0f, 1.0f) && IN_RANGE_INCL(w[2], 0.0f, 1.0f)) { return 2; } return 0; } /* returns 0 for degenerated triangles */ bool barycentric_coords_v2(const float v1[2], const float v2[2], const float v3[2], const float co[2], float w[3]) { const float x = co[0], y = co[1]; const float x1 = v1[0], y1 = v1[1]; const float x2 = v2[0], y2 = v2[1]; const float x3 = v3[0], y3 = v3[1]; const float det = (y2 - y3) * (x1 - x3) + (x3 - x2) * (y1 - y3); if (fabsf(det) > FLT_EPSILON) { w[0] = ((y2 - y3) * (x - x3) + (x3 - x2) * (y - y3)) / det; w[1] = ((y3 - y1) * (x - x3) + (x1 - x3) * (y - y3)) / det; w[2] = 1.0f - w[0] - w[1]; return true; } return false; } /** * \note: using #cross_tri_v2 means locations outside the triangle are correctly weighted * * \note This is *exactly* the same calculation as #resolve_tri_uv_v2, * although it has double precision and is used for texture baking, so keep both. */ void barycentric_weights_v2(const float v1[2], const float v2[2], const float v3[2], const float co[2], float w[3]) { float wtot; w[0] = cross_tri_v2(v2, v3, co); w[1] = cross_tri_v2(v3, v1, co); w[2] = cross_tri_v2(v1, v2, co); wtot = w[0] + w[1] + w[2]; if (wtot != 0.0f) { mul_v3_fl(w, 1.0f / wtot); } else { /* dummy values for zero area face */ copy_v3_fl(w, 1.0f / 3.0f); } } /** * still use 2D X,Y space but this works for verts transformed by a perspective matrix, * using their 4th component as a weight */ void barycentric_weights_v2_persp(const float v1[4], const float v2[4], const float v3[4], const float co[2], float w[3]) { float wtot; w[0] = cross_tri_v2(v2, v3, co) / v1[3]; w[1] = cross_tri_v2(v3, v1, co) / v2[3]; w[2] = cross_tri_v2(v1, v2, co) / v3[3]; wtot = w[0] + w[1] + w[2]; if (wtot != 0.0f) { mul_v3_fl(w, 1.0f / wtot); } else { /* dummy values for zero area face */ w[0] = w[1] = w[2] = 1.0f / 3.0f; } } /** * same as #barycentric_weights_v2 but works with a quad, * note: untested for values outside the quad's bounds * this is #interp_weights_poly_v2 expanded for quads only */ void barycentric_weights_v2_quad(const float v1[2], const float v2[2], const float v3[2], const float v4[2], const float co[2], float w[4]) { /* note: fabsf() here is not needed for convex quads (and not used in interp_weights_poly_v2). * but in the case of concave/bow-tie quads for the mask rasterizer it gives unreliable results * without adding absf(). If this becomes an issue for more general usage we could have * this optional or use a different function - Campbell */ #define MEAN_VALUE_HALF_TAN_V2(_area, i1, i2) \ ((_area = cross_v2v2(dirs[i1], dirs[i2])) != 0.0f ? \ fabsf(((lens[i1] * lens[i2]) - dot_v2v2(dirs[i1], dirs[i2])) / _area) : 0.0f) const float dirs[4][2] = { {v1[0] - co[0], v1[1] - co[1]}, {v2[0] - co[0], v2[1] - co[1]}, {v3[0] - co[0], v3[1] - co[1]}, {v4[0] - co[0], v4[1] - co[1]}, }; const float lens[4] = { len_v2(dirs[0]), len_v2(dirs[1]), len_v2(dirs[2]), len_v2(dirs[3]), }; /* avoid divide by zero */ if (UNLIKELY(lens[0] < FLT_EPSILON)) { w[0] = 1.0f; w[1] = w[2] = w[3] = 0.0f; } else if (UNLIKELY(lens[1] < FLT_EPSILON)) { w[1] = 1.0f; w[0] = w[2] = w[3] = 0.0f; } else if (UNLIKELY(lens[2] < FLT_EPSILON)) { w[2] = 1.0f; w[0] = w[1] = w[3] = 0.0f; } else if (UNLIKELY(lens[3] < FLT_EPSILON)) { w[3] = 1.0f; w[0] = w[1] = w[2] = 0.0f; } else { float wtot, area; /* variable 'area' is just for storage, * the order its initialized doesn't matter */ #ifdef __clang__ # pragma clang diagnostic push # pragma clang diagnostic ignored "-Wunsequenced" #endif /* inline mean_value_half_tan four times here */ const float t[4] = { MEAN_VALUE_HALF_TAN_V2(area, 0, 1), MEAN_VALUE_HALF_TAN_V2(area, 1, 2), MEAN_VALUE_HALF_TAN_V2(area, 2, 3), MEAN_VALUE_HALF_TAN_V2(area, 3, 0), }; #ifdef __clang__ # pragma clang diagnostic pop #endif #undef MEAN_VALUE_HALF_TAN_V2 w[0] = (t[3] + t[0]) / lens[0]; w[1] = (t[0] + t[1]) / lens[1]; w[2] = (t[1] + t[2]) / lens[2]; w[3] = (t[2] + t[3]) / lens[3]; wtot = w[0] + w[1] + w[2] + w[3]; if (wtot != 0.0f) { mul_v4_fl(w, 1.0f / wtot); } else { /* dummy values for zero area face */ copy_v4_fl(w, 1.0f / 4.0f); } } } /* given 2 triangles in 3D space, and a point in relation to the first triangle. * calculate the location of a point in relation to the second triangle. * Useful for finding relative positions with geometry */ void transform_point_by_tri_v3( float pt_tar[3], float const pt_src[3], const float tri_tar_p1[3], const float tri_tar_p2[3], const float tri_tar_p3[3], const float tri_src_p1[3], const float tri_src_p2[3], const float tri_src_p3[3]) { /* this works by moving the source triangle so its normal is pointing on the Z * axis where its barycentric weights can be calculated in 2D and its Z offset can * be re-applied. The weights are applied directly to the targets 3D points and the * z-depth is used to scale the targets normal as an offset. * This saves transforming the target into its Z-Up orientation and back (which could also work) */ float no_tar[3], no_src[3]; float mat_src[3][3]; float pt_src_xy[3]; float tri_xy_src[3][3]; float w_src[3]; float area_tar, area_src; float z_ofs_src; normal_tri_v3(no_tar, tri_tar_p1, tri_tar_p2, tri_tar_p3); normal_tri_v3(no_src, tri_src_p1, tri_src_p2, tri_src_p3); axis_dominant_v3_to_m3(mat_src, no_src); /* make the source tri xy space */ mul_v3_m3v3(pt_src_xy, mat_src, pt_src); mul_v3_m3v3(tri_xy_src[0], mat_src, tri_src_p1); mul_v3_m3v3(tri_xy_src[1], mat_src, tri_src_p2); mul_v3_m3v3(tri_xy_src[2], mat_src, tri_src_p3); barycentric_weights_v2(tri_xy_src[0], tri_xy_src[1], tri_xy_src[2], pt_src_xy, w_src); interp_v3_v3v3v3(pt_tar, tri_tar_p1, tri_tar_p2, tri_tar_p3, w_src); area_tar = sqrtf(area_tri_v3(tri_tar_p1, tri_tar_p2, tri_tar_p3)); area_src = sqrtf(area_tri_v2(tri_xy_src[0], tri_xy_src[1], tri_xy_src[2])); z_ofs_src = pt_src_xy[2] - tri_xy_src[0][2]; madd_v3_v3v3fl(pt_tar, pt_tar, no_tar, (z_ofs_src / area_src) * area_tar); } /** * Simply re-interpolates, * assumes p_src is between \a l_src_p1-l_src_p2 */ void transform_point_by_seg_v3( float p_dst[3], const float p_src[3], const float l_dst_p1[3], const float l_dst_p2[3], const float l_src_p1[3], const float l_src_p2[3]) { float t = line_point_factor_v3(p_src, l_src_p1, l_src_p2); interp_v3_v3v3(p_dst, l_dst_p1, l_dst_p2, t); } /* given an array with some invalid values this function interpolates valid values * replacing the invalid ones */ int interp_sparse_array(float *array, const int list_size, const float skipval) { int found_invalid = 0; int found_valid = 0; int i; for (i = 0; i < list_size; i++) { if (array[i] == skipval) found_invalid = 1; else found_valid = 1; } if (found_valid == 0) { return -1; } else if (found_invalid == 0) { return 0; } else { /* found invalid depths, interpolate */ float valid_last = skipval; int valid_ofs = 0; float *array_up = MEM_callocN(sizeof(float) * (size_t)list_size, "interp_sparse_array up"); float *array_down = MEM_callocN(sizeof(float) * (size_t)list_size, "interp_sparse_array up"); int *ofs_tot_up = MEM_callocN(sizeof(int) * (size_t)list_size, "interp_sparse_array tup"); int *ofs_tot_down = MEM_callocN(sizeof(int) * (size_t)list_size, "interp_sparse_array tdown"); for (i = 0; i < list_size; i++) { if (array[i] == skipval) { array_up[i] = valid_last; ofs_tot_up[i] = ++valid_ofs; } else { valid_last = array[i]; valid_ofs = 0; } } valid_last = skipval; valid_ofs = 0; for (i = list_size - 1; i >= 0; i--) { if (array[i] == skipval) { array_down[i] = valid_last; ofs_tot_down[i] = ++valid_ofs; } else { valid_last = array[i]; valid_ofs = 0; } } /* now blend */ for (i = 0; i < list_size; i++) { if (array[i] == skipval) { if (array_up[i] != skipval && array_down[i] != skipval) { array[i] = ((array_up[i] * (float)ofs_tot_down[i]) + (array_down[i] * (float)ofs_tot_up[i])) / (float)(ofs_tot_down[i] + ofs_tot_up[i]); } else if (array_up[i] != skipval) { array[i] = array_up[i]; } else if (array_down[i] != skipval) { array[i] = array_down[i]; } } } MEM_freeN(array_up); MEM_freeN(array_down); MEM_freeN(ofs_tot_up); MEM_freeN(ofs_tot_down); } return 1; } /** \name interp_weights_poly_v2, v3 * \{ */ #define IS_POINT_IX (1 << 0) #define IS_SEGMENT_IX (1 << 1) #define DIR_V3_SET(d_len, va, vb) { \ sub_v3_v3v3((d_len)->dir, va, vb); \ (d_len)->len = len_v3((d_len)->dir); \ } (void)0 #define DIR_V2_SET(d_len, va, vb) { \ sub_v2_v2v2((d_len)->dir, va, vb); \ (d_len)->len = len_v2((d_len)->dir); \ } (void)0 struct Float3_Len { float dir[3], len; }; struct Float2_Len { float dir[2], len; }; /* Mean value weights - smooth interpolation weights for polygons with * more than 3 vertices */ static float mean_value_half_tan_v3(const struct Float3_Len *d_curr, const struct Float3_Len *d_next) { float cross[3], area; cross_v3_v3v3(cross, d_curr->dir, d_next->dir); area = len_v3(cross); if (LIKELY(fabsf(area) > FLT_EPSILON)) { const float dot = dot_v3v3(d_curr->dir, d_next->dir); const float len = d_curr->len * d_next->len; return (len - dot) / area; } else { return 0.0f; } } static float mean_value_half_tan_v2(const struct Float2_Len *d_curr, const struct Float2_Len *d_next) { float area; /* different from the 3d version but still correct */ area = cross_v2v2(d_curr->dir, d_next->dir); if (LIKELY(fabsf(area) > FLT_EPSILON)) { const float dot = dot_v2v2(d_curr->dir, d_next->dir); const float len = d_curr->len * d_next->len; return (len - dot) / area; } else { return 0.0f; } } void interp_weights_poly_v3(float *w, float v[][3], const int n, const float co[3]) { const float eps = 1e-5f; /* take care, low values cause [#36105] */ const float eps_sq = eps * eps; const float *v_curr, *v_next; float ht_prev, ht; /* half tangents */ float totweight = 0.0f; int i_curr, i_next; char ix_flag = 0; struct Float3_Len d_curr, d_next; /* loop over 'i_next' */ i_curr = n - 1; i_next = 0; v_curr = v[i_curr]; v_next = v[i_next]; DIR_V3_SET(&d_curr, v_curr - 3 /* v[n - 2] */, co); DIR_V3_SET(&d_next, v_curr /* v[n - 1] */, co); ht_prev = mean_value_half_tan_v3(&d_curr, &d_next); while (i_next < n) { /* Mark Mayer et al algorithm that is used here does not operate well if vertex is close * to borders of face. In that case, do simple linear interpolation between the two edge vertices */ /* 'd_next.len' is infact 'd_curr.len', just avoid copy to begin with */ if (UNLIKELY(d_next.len < eps)) { ix_flag = IS_POINT_IX; break; } else if (UNLIKELY(dist_squared_to_line_segment_v3(co, v_curr, v_next) < eps_sq)) { ix_flag = IS_SEGMENT_IX; break; } d_curr = d_next; DIR_V3_SET(&d_next, v_next, co); ht = mean_value_half_tan_v3(&d_curr, &d_next); w[i_curr] = (ht_prev + ht) / d_curr.len; totweight += w[i_curr]; /* step */ i_curr = i_next++; v_curr = v_next; v_next = v[i_next]; ht_prev = ht; } if (ix_flag) { memset(w, 0, sizeof(*w) * (size_t)n); if (ix_flag & IS_POINT_IX) { w[i_curr] = 1.0f; } else { float fac = line_point_factor_v3(co, v_curr, v_next); CLAMP(fac, 0.0f, 1.0f); w[i_curr] = 1.0f - fac; w[i_next] = fac; } } else { if (totweight != 0.0f) { for (i_curr = 0; i_curr < n; i_curr++) { w[i_curr] /= totweight; } } } } void interp_weights_poly_v2(float *w, float v[][2], const int n, const float co[2]) { const float eps = 1e-5f; /* take care, low values cause [#36105] */ const float eps_sq = eps * eps; const float *v_curr, *v_next; float ht_prev, ht; /* half tangents */ float totweight = 0.0f; int i_curr, i_next; char ix_flag = 0; struct Float2_Len d_curr, d_next; /* loop over 'i_next' */ i_curr = n - 1; i_next = 0; v_curr = v[i_curr]; v_next = v[i_next]; DIR_V2_SET(&d_curr, v_curr - 2 /* v[n - 2] */, co); DIR_V2_SET(&d_next, v_curr /* v[n - 1] */, co); ht_prev = mean_value_half_tan_v2(&d_curr, &d_next); while (i_next < n) { /* Mark Mayer et al algorithm that is used here does not operate well if vertex is close * to borders of face. In that case, do simple linear interpolation between the two edge vertices */ /* 'd_next.len' is infact 'd_curr.len', just avoid copy to begin with */ if (UNLIKELY(d_next.len < eps)) { ix_flag = IS_POINT_IX; break; } else if (UNLIKELY(dist_squared_to_line_segment_v2(co, v_curr, v_next) < eps_sq)) { ix_flag = IS_SEGMENT_IX; break; } d_curr = d_next; DIR_V2_SET(&d_next, v_next, co); ht = mean_value_half_tan_v2(&d_curr, &d_next); w[i_curr] = (ht_prev + ht) / d_curr.len; totweight += w[i_curr]; /* step */ i_curr = i_next++; v_curr = v_next; v_next = v[i_next]; ht_prev = ht; } if (ix_flag) { memset(w, 0, sizeof(*w) * (size_t)n); if (ix_flag & IS_POINT_IX) { w[i_curr] = 1.0f; } else { float fac = line_point_factor_v2(co, v_curr, v_next); CLAMP(fac, 0.0f, 1.0f); w[i_curr] = 1.0f - fac; w[i_next] = fac; } } else { if (totweight != 0.0f) { for (i_curr = 0; i_curr < n; i_curr++) { w[i_curr] /= totweight; } } } } #undef IS_POINT_IX #undef IS_SEGMENT_IX #undef DIR_V3_SET #undef DIR_V2_SET /** \} */ /* (x1, v1)(t1=0)------(x2, v2)(t2=1), 0 (x, v)(t) */ void interp_cubic_v3(float x[3], float v[3], const float x1[3], const float v1[3], const float x2[3], const float v2[3], const float t) { float a[3], b[3]; const float t2 = t * t; const float t3 = t2 * t; /* cubic interpolation */ a[0] = v1[0] + v2[0] + 2 * (x1[0] - x2[0]); a[1] = v1[1] + v2[1] + 2 * (x1[1] - x2[1]); a[2] = v1[2] + v2[2] + 2 * (x1[2] - x2[2]); b[0] = -2 * v1[0] - v2[0] - 3 * (x1[0] - x2[0]); b[1] = -2 * v1[1] - v2[1] - 3 * (x1[1] - x2[1]); b[2] = -2 * v1[2] - v2[2] - 3 * (x1[2] - x2[2]); x[0] = a[0] * t3 + b[0] * t2 + v1[0] * t + x1[0]; x[1] = a[1] * t3 + b[1] * t2 + v1[1] * t + x1[1]; x[2] = a[2] * t3 + b[2] * t2 + v1[2] * t + x1[2]; v[0] = 3 * a[0] * t2 + 2 * b[0] * t + v1[0]; v[1] = 3 * a[1] * t2 + 2 * b[1] * t + v1[1]; v[2] = 3 * a[2] * t2 + 2 * b[2] * t + v1[2]; } /* unfortunately internal calculations have to be done at double precision to achieve correct/stable results. */ #define IS_ZERO(x) ((x > (-DBL_EPSILON) && x < DBL_EPSILON) ? 1 : 0) /** * Barycentric reverse * * Compute coordinates (u, v) for point \a st with respect to triangle (\a st0, \a st1, \a st2) * * \note same basic result as #barycentric_weights_v2, see it's comment for details. */ void resolve_tri_uv_v2(float r_uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2]) { /* find UV such that * t = u * t0 + v * t1 + (1 - u - v) * t2 * u * (t0 - t2) + v * (t1 - t2) = t - t2 */ const double a = st0[0] - st2[0], b = st1[0] - st2[0]; const double c = st0[1] - st2[1], d = st1[1] - st2[1]; const double det = a * d - c * b; /* det should never be zero since the determinant is the signed ST area of the triangle. */ if (IS_ZERO(det) == 0) { const double x[2] = {st[0] - st2[0], st[1] - st2[1]}; r_uv[0] = (float)((d * x[0] - b * x[1]) / det); r_uv[1] = (float)(((-c) * x[0] + a * x[1]) / det); } else { zero_v2(r_uv); } } /** * Barycentric reverse 3d * * Compute coordinates (u, v) for point \a st with respect to triangle (\a st0, \a st1, \a st2) */ void resolve_tri_uv_v3(float r_uv[2], const float st[3], const float st0[3], const float st1[3], const float st2[3]) { float v0[3], v1[3], v2[3]; double d00, d01, d11, d20, d21, det; sub_v3_v3v3(v0, st1, st0); sub_v3_v3v3(v1, st2, st0); sub_v3_v3v3(v2, st, st0); d00 = dot_v3v3(v0, v0); d01 = dot_v3v3(v0, v1); d11 = dot_v3v3(v1, v1); d20 = dot_v3v3(v2, v0); d21 = dot_v3v3(v2, v1); det = d00 * d11 - d01 * d01; /* det should never be zero since the determinant is the signed ST area of the triangle. */ if (IS_ZERO(det) == 0) { float w; w = (float)((d00 * d21 - d01 * d20) / det); r_uv[1] = (float)((d11 * d20 - d01 * d21) / det); r_uv[0] = 1.0f - r_uv[1] - w; } else { zero_v2(r_uv); } } /* bilinear reverse */ void resolve_quad_uv_v2(float r_uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2]) { resolve_quad_uv_v2_deriv(r_uv, NULL, st, st0, st1, st2, st3); } /* bilinear reverse with derivatives */ void resolve_quad_uv_v2_deriv(float r_uv[2], float r_deriv[2][2], const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2]) { const double signed_area = (st0[0] * st1[1] - st0[1] * st1[0]) + (st1[0] * st2[1] - st1[1] * st2[0]) + (st2[0] * st3[1] - st2[1] * st3[0]) + (st3[0] * st0[1] - st3[1] * st0[0]); /* X is 2D cross product (determinant) * A = (p0 - p) X (p0 - p3)*/ const double a = (st0[0] - st[0]) * (st0[1] - st3[1]) - (st0[1] - st[1]) * (st0[0] - st3[0]); /* B = ( (p0 - p) X (p1 - p2) + (p1 - p) X (p0 - p3) ) / 2 */ const double b = 0.5 * (double)(((st0[0] - st[0]) * (st1[1] - st2[1]) - (st0[1] - st[1]) * (st1[0] - st2[0])) + ((st1[0] - st[0]) * (st0[1] - st3[1]) - (st1[1] - st[1]) * (st0[0] - st3[0]))); /* C = (p1-p) X (p1-p2) */ const double fC = (st1[0] - st[0]) * (st1[1] - st2[1]) - (st1[1] - st[1]) * (st1[0] - st2[0]); double denom = a - 2 * b + fC; /* clear outputs */ zero_v2(r_uv); if (IS_ZERO(denom) != 0) { const double fDen = a - fC; if (IS_ZERO(fDen) == 0) r_uv[0] = (float)(a / fDen); } else { const double desc_sq = b * b - a * fC; const double desc = sqrt(desc_sq < 0.0 ? 0.0 : desc_sq); const double s = signed_area > 0 ? (-1.0) : 1.0; r_uv[0] = (float)(((a - b) + s * desc) / denom); } /* find UV such that * fST = (1-u)(1-v) * ST0 + u * (1-v) * ST1 + u * v * ST2 + (1-u) * v * ST3 */ { const double denom_s = (1 - r_uv[0]) * (st0[0] - st3[0]) + r_uv[0] * (st1[0] - st2[0]); const double denom_t = (1 - r_uv[0]) * (st0[1] - st3[1]) + r_uv[0] * (st1[1] - st2[1]); int i = 0; denom = denom_s; if (fabs(denom_s) < fabs(denom_t)) { i = 1; denom = denom_t; } if (IS_ZERO(denom) == 0) r_uv[1] = (float)((double)((1.0f - r_uv[0]) * (st0[i] - st[i]) + r_uv[0] * (st1[i] - st[i])) / denom); } if (r_deriv) { float tmp1[2], tmp2[2], s[2], t[2]; /* clear outputs */ zero_v2(r_deriv[0]); zero_v2(r_deriv[1]); sub_v2_v2v2(tmp1, st1, st0); sub_v2_v2v2(tmp2, st2, st3); interp_v2_v2v2(s, tmp1, tmp2, r_uv[1]); sub_v2_v2v2(tmp1, st3, st0); sub_v2_v2v2(tmp2, st2, st1); interp_v2_v2v2(t, tmp1, tmp2, r_uv[0]); denom = t[0] * s[1] - t[1] * s[0]; if (!IS_ZERO(denom)) { double inv_denom = 1.0 / denom; r_deriv[0][0] = (float)((double)-t[1] * inv_denom); r_deriv[0][1] = (float)((double) t[0] * inv_denom); r_deriv[1][0] = (float)((double) s[1] * inv_denom); r_deriv[1][1] = (float)((double)-s[0] * inv_denom); } } } /* a version of resolve_quad_uv_v2 that only calculates the 'u' */ float resolve_quad_u_v2( const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2]) { const double signed_area = (st0[0] * st1[1] - st0[1] * st1[0]) + (st1[0] * st2[1] - st1[1] * st2[0]) + (st2[0] * st3[1] - st2[1] * st3[0]) + (st3[0] * st0[1] - st3[1] * st0[0]); /* X is 2D cross product (determinant) * A = (p0 - p) X (p0 - p3)*/ const double a = (st0[0] - st[0]) * (st0[1] - st3[1]) - (st0[1] - st[1]) * (st0[0] - st3[0]); /* B = ( (p0 - p) X (p1 - p2) + (p1 - p) X (p0 - p3) ) / 2 */ const double b = 0.5 * (double)(((st0[0] - st[0]) * (st1[1] - st2[1]) - (st0[1] - st[1]) * (st1[0] - st2[0])) + ((st1[0] - st[0]) * (st0[1] - st3[1]) - (st1[1] - st[1]) * (st0[0] - st3[0]))); /* C = (p1-p) X (p1-p2) */ const double fC = (st1[0] - st[0]) * (st1[1] - st2[1]) - (st1[1] - st[1]) * (st1[0] - st2[0]); double denom = a - 2 * b + fC; if (IS_ZERO(denom) != 0) { const double fDen = a - fC; if (IS_ZERO(fDen) == 0) return (float)(a / fDen); else return 0.0f; } else { const double desc_sq = b * b - a * fC; const double desc = sqrt(desc_sq < 0.0 ? 0.0 : desc_sq); const double s = signed_area > 0 ? (-1.0) : 1.0; return (float)(((a - b) + s * desc) / denom); } } #undef IS_ZERO /* reverse of the functions above */ void interp_bilinear_quad_v3(float data[4][3], float u, float v, float res[3]) { float vec[3]; copy_v3_v3(res, data[0]); mul_v3_fl(res, (1 - u) * (1 - v)); copy_v3_v3(vec, data[1]); mul_v3_fl(vec, u * (1 - v)); add_v3_v3(res, vec); copy_v3_v3(vec, data[2]); mul_v3_fl(vec, u * v); add_v3_v3(res, vec); copy_v3_v3(vec, data[3]); mul_v3_fl(vec, (1 - u) * v); add_v3_v3(res, vec); } void interp_barycentric_tri_v3(float data[3][3], float u, float v, float res[3]) { float vec[3]; copy_v3_v3(res, data[0]); mul_v3_fl(res, u); copy_v3_v3(vec, data[1]); mul_v3_fl(vec, v); add_v3_v3(res, vec); copy_v3_v3(vec, data[2]); mul_v3_fl(vec, 1.0f - u - v); add_v3_v3(res, vec); } /***************************** View & Projection *****************************/ /** * Matches `glOrtho` result. */ void orthographic_m4(float matrix[4][4], const float left, const float right, const float bottom, const float top, const float nearClip, const float farClip) { float Xdelta, Ydelta, Zdelta; Xdelta = right - left; Ydelta = top - bottom; Zdelta = farClip - nearClip; if (Xdelta == 0.0f || Ydelta == 0.0f || Zdelta == 0.0f) { return; } unit_m4(matrix); matrix[0][0] = 2.0f / Xdelta; matrix[3][0] = -(right + left) / Xdelta; matrix[1][1] = 2.0f / Ydelta; matrix[3][1] = -(top + bottom) / Ydelta; matrix[2][2] = -2.0f / Zdelta; /* note: negate Z */ matrix[3][2] = -(farClip + nearClip) / Zdelta; } /** * Matches `glFrustum` result. */ void perspective_m4(float mat[4][4], const float left, const float right, const float bottom, const float top, const float nearClip, const float farClip) { const float Xdelta = right - left; const float Ydelta = top - bottom; const float Zdelta = farClip - nearClip; if (Xdelta == 0.0f || Ydelta == 0.0f || Zdelta == 0.0f) { return; } mat[0][0] = nearClip * 2.0f / Xdelta; mat[1][1] = nearClip * 2.0f / Ydelta; mat[2][0] = (right + left) / Xdelta; /* note: negate Z */ mat[2][1] = (top + bottom) / Ydelta; mat[2][2] = -(farClip + nearClip) / Zdelta; mat[2][3] = -1.0f; mat[3][2] = (-2.0f * nearClip * farClip) / Zdelta; mat[0][1] = mat[0][2] = mat[0][3] = mat[1][0] = mat[1][2] = mat[1][3] = mat[3][0] = mat[3][1] = mat[3][3] = 0.0f; } /* translate a matrix created by orthographic_m4 or perspective_m4 in XY coords (used to jitter the view) */ void window_translate_m4(float winmat[4][4], float perspmat[4][4], const float x, const float y) { if (winmat[2][3] == -1.0f) { /* in the case of a win-matrix, this means perspective always */ float v1[3]; float v2[3]; float len1, len2; v1[0] = perspmat[0][0]; v1[1] = perspmat[1][0]; v1[2] = perspmat[2][0]; v2[0] = perspmat[0][1]; v2[1] = perspmat[1][1]; v2[2] = perspmat[2][1]; len1 = (1.0f / len_v3(v1)); len2 = (1.0f / len_v3(v2)); winmat[2][0] += len1 * winmat[0][0] * x; winmat[2][1] += len2 * winmat[1][1] * y; } else { winmat[3][0] += x; winmat[3][1] += y; } } /** * Frustum planes extraction from a projection matrix (homogeneous 4d vector representations of planes). * * plane parameters can be NULL if you do not need them. */ void planes_from_projmat(float mat[4][4], float left[4], float right[4], float top[4], float bottom[4], float near[4], float far[4]) { /* References: * * https://fgiesen.wordpress.com/2012/08/31/frustum-planes-from-the-projection-matrix/ * http://www8.cs.umu.se/kurser/5DV051/HT12/lab/plane_extraction.pdf */ int i; if (left) { for (i = 4; i--; ) { left[i] = mat[i][3] + mat[i][0]; } } if (right) { for (i = 4; i--; ) { right[i] = mat[i][3] - mat[i][0]; } } if (bottom) { for (i = 4; i--; ) { bottom[i] = mat[i][3] + mat[i][1]; } } if (top) { for (i = 4; i--; ) { top[i] = mat[i][3] - mat[i][1]; } } if (near) { for (i = 4; i--; ) { near[i] = mat[i][3] + mat[i][2]; } } if (far) { for (i = 4; i--; ) { far[i] = mat[i][3] - mat[i][2]; } } } static void i_multmatrix(float icand[4][4], float Vm[4][4]) { int row, col; float temp[4][4]; for (row = 0; row < 4; row++) for (col = 0; col < 4; col++) temp[row][col] = (icand[row][0] * Vm[0][col] + icand[row][1] * Vm[1][col] + icand[row][2] * Vm[2][col] + icand[row][3] * Vm[3][col]); copy_m4_m4(Vm, temp); } void polarview_m4(float Vm[4][4], float dist, float azimuth, float incidence, float twist) { unit_m4(Vm); translate_m4(Vm, 0.0, 0.0, -dist); rotate_m4(Vm, 'Z', -twist); rotate_m4(Vm, 'X', -incidence); rotate_m4(Vm, 'Z', -azimuth); } void lookat_m4(float mat[4][4], float vx, float vy, float vz, float px, float py, float pz, float twist) { float sine, cosine, hyp, hyp1, dx, dy, dz; float mat1[4][4]; unit_m4(mat1); axis_angle_to_mat4_single(mat, 'Z', -twist); dx = px - vx; dy = py - vy; dz = pz - vz; hyp = dx * dx + dz * dz; /* hyp squared */ hyp1 = sqrtf(dy * dy + hyp); hyp = sqrtf(hyp); /* the real hyp */ if (hyp1 != 0.0f) { /* rotate X */ sine = -dy / hyp1; cosine = hyp / hyp1; } else { sine = 0.0f; cosine = 1.0f; } mat1[1][1] = cosine; mat1[1][2] = sine; mat1[2][1] = -sine; mat1[2][2] = cosine; i_multmatrix(mat1, mat); mat1[1][1] = mat1[2][2] = 1.0f; /* be careful here to reinit */ mat1[1][2] = mat1[2][1] = 0.0f; /* those modified by the last */ /* paragraph */ if (hyp != 0.0f) { /* rotate Y */ sine = dx / hyp; cosine = -dz / hyp; } else { sine = 0.0f; cosine = 1.0f; } mat1[0][0] = cosine; mat1[0][2] = -sine; mat1[2][0] = sine; mat1[2][2] = cosine; i_multmatrix(mat1, mat); translate_m4(mat, -vx, -vy, -vz); /* translate viewpoint to origin */ } int box_clip_bounds_m4(float boundbox[2][3], const float bounds[4], float winmat[4][4]) { float mat[4][4], vec[4]; int a, fl, flag = -1; copy_m4_m4(mat, winmat); for (a = 0; a < 8; a++) { vec[0] = (a & 1) ? boundbox[0][0] : boundbox[1][0]; vec[1] = (a & 2) ? boundbox[0][1] : boundbox[1][1]; vec[2] = (a & 4) ? boundbox[0][2] : boundbox[1][2]; vec[3] = 1.0; mul_m4_v4(mat, vec); fl = 0; if (bounds) { if (vec[0] > bounds[1] * vec[3]) fl |= 1; if (vec[0] < bounds[0] * vec[3]) fl |= 2; if (vec[1] > bounds[3] * vec[3]) fl |= 4; if (vec[1] < bounds[2] * vec[3]) fl |= 8; } else { if (vec[0] < -vec[3]) fl |= 1; if (vec[0] > vec[3]) fl |= 2; if (vec[1] < -vec[3]) fl |= 4; if (vec[1] > vec[3]) fl |= 8; } if (vec[2] < -vec[3]) fl |= 16; if (vec[2] > vec[3]) fl |= 32; flag &= fl; if (flag == 0) return 0; } return flag; } void box_minmax_bounds_m4(float min[3], float max[3], float boundbox[2][3], float mat[4][4]) { float mn[3], mx[3], vec[3]; int a; copy_v3_v3(mn, min); copy_v3_v3(mx, max); for (a = 0; a < 8; a++) { vec[0] = (a & 1) ? boundbox[0][0] : boundbox[1][0]; vec[1] = (a & 2) ? boundbox[0][1] : boundbox[1][1]; vec[2] = (a & 4) ? boundbox[0][2] : boundbox[1][2]; mul_m4_v3(mat, vec); minmax_v3v3_v3(mn, mx, vec); } copy_v3_v3(min, mn); copy_v3_v3(max, mx); } /********************************** Mapping **********************************/ void map_to_tube(float *r_u, float *r_v, const float x, const float y, const float z) { float len; *r_v = (z + 1.0f) / 2.0f; len = sqrtf(x * x + y * y); if (len > 0.0f) { *r_u = (1.0f - (atan2f(x / len, y / len) / (float)M_PI)) / 2.0f; } else { *r_v = *r_u = 0.0f; /* to avoid un-initialized variables */ } } void map_to_sphere(float *r_u, float *r_v, const float x, const float y, const float z) { float len; len = sqrtf(x * x + y * y + z * z); if (len > 0.0f) { if (UNLIKELY(x == 0.0f && y == 0.0f)) { *r_u = 0.0f; /* othwise domain error */ } else { *r_u = (1.0f - atan2f(x, y) / (float)M_PI) / 2.0f; } *r_v = 1.0f - saacos(z / len) / (float)M_PI; } else { *r_v = *r_u = 0.0f; /* to avoid un-initialized variables */ } } void map_to_plane_v2_v3v3(float r_co[2], const float co[3], const float no[3]) { float target[3] = {0.0f, 0.0f, 1.0f}; float axis[3]; cross_v3_v3v3(axis, no, target); normalize_v3(axis); map_to_plane_axis_angle_v2_v3v3fl(r_co, co, axis, angle_normalized_v3v3(no, target)); } void map_to_plane_axis_angle_v2_v3v3fl(float r_co[2], const float co[3], const float axis[3], const float angle) { float tmp[3]; rotate_normalized_v3_v3v3fl(tmp, co, axis, angle); copy_v2_v2(r_co, tmp); } /********************************* Normals **********************************/ void accumulate_vertex_normals_tri( float n1[3], float n2[3], float n3[3], const float f_no[3], const float co1[3], const float co2[3], const float co3[3]) { float vdiffs[3][3]; const int nverts = 3; /* compute normalized edge vectors */ sub_v3_v3v3(vdiffs[0], co2, co1); sub_v3_v3v3(vdiffs[1], co3, co2); sub_v3_v3v3(vdiffs[2], co1, co3); normalize_v3(vdiffs[0]); normalize_v3(vdiffs[1]); normalize_v3(vdiffs[2]); /* accumulate angle weighted face normal */ { float *vn[] = {n1, n2, n3}; const float *prev_edge = vdiffs[nverts - 1]; int i; for (i = 0; i < nverts; i++) { const float *cur_edge = vdiffs[i]; const float fac = saacos(-dot_v3v3(cur_edge, prev_edge)); /* accumulate */ madd_v3_v3fl(vn[i], f_no, fac); prev_edge = cur_edge; } } } void accumulate_vertex_normals( float n1[3], float n2[3], float n3[3], float n4[3], const float f_no[3], const float co1[3], const float co2[3], const float co3[3], const float co4[3]) { float vdiffs[4][3]; const int nverts = (n4 != NULL && co4 != NULL) ? 4 : 3; /* compute normalized edge vectors */ sub_v3_v3v3(vdiffs[0], co2, co1); sub_v3_v3v3(vdiffs[1], co3, co2); if (nverts == 3) { sub_v3_v3v3(vdiffs[2], co1, co3); } else { sub_v3_v3v3(vdiffs[2], co4, co3); sub_v3_v3v3(vdiffs[3], co1, co4); normalize_v3(vdiffs[3]); } normalize_v3(vdiffs[0]); normalize_v3(vdiffs[1]); normalize_v3(vdiffs[2]); /* accumulate angle weighted face normal */ { float *vn[] = {n1, n2, n3, n4}; const float *prev_edge = vdiffs[nverts - 1]; int i; for (i = 0; i < nverts; i++) { const float *cur_edge = vdiffs[i]; const float fac = saacos(-dot_v3v3(cur_edge, prev_edge)); /* accumulate */ madd_v3_v3fl(vn[i], f_no, fac); prev_edge = cur_edge; } } } /* Add weighted face normal component into normals of the face vertices. * Caller must pass pre-allocated vdiffs of nverts length. */ void accumulate_vertex_normals_poly(float **vertnos, const float polyno[3], const float **vertcos, float vdiffs[][3], const int nverts) { int i; /* calculate normalized edge directions for each edge in the poly */ for (i = 0; i < nverts; i++) { sub_v3_v3v3(vdiffs[i], vertcos[(i + 1) % nverts], vertcos[i]); normalize_v3(vdiffs[i]); } /* accumulate angle weighted face normal */ { const float *prev_edge = vdiffs[nverts - 1]; for (i = 0; i < nverts; i++) { const float *cur_edge = vdiffs[i]; /* calculate angle between the two poly edges incident on * this vertex */ const float fac = saacos(-dot_v3v3(cur_edge, prev_edge)); /* accumulate */ madd_v3_v3fl(vertnos[i], polyno, fac); prev_edge = cur_edge; } } } /********************************* Tangents **********************************/ void tangent_from_uv( const float uv1[2], const float uv2[2], const float uv3[3], const float co1[3], const float co2[3], const float co3[3], const float n[3], float r_tang[3]) { const float s1 = uv2[0] - uv1[0]; const float s2 = uv3[0] - uv1[0]; const float t1 = uv2[1] - uv1[1]; const float t2 = uv3[1] - uv1[1]; float det = (s1 * t2 - s2 * t1); /* otherwise 'r_tang' becomes nan */ if (det != 0.0f) { float tangv[3], ct[3], e1[3], e2[3]; det = 1.0f / det; /* normals in render are inversed... */ sub_v3_v3v3(e1, co1, co2); sub_v3_v3v3(e2, co1, co3); r_tang[0] = (t2 * e1[0] - t1 * e2[0]) * det; r_tang[1] = (t2 * e1[1] - t1 * e2[1]) * det; r_tang[2] = (t2 * e1[2] - t1 * e2[2]) * det; tangv[0] = (s1 * e2[0] - s2 * e1[0]) * det; tangv[1] = (s1 * e2[1] - s2 * e1[1]) * det; tangv[2] = (s1 * e2[2] - s2 * e1[2]) * det; cross_v3_v3v3(ct, r_tang, tangv); /* check flip */ if (dot_v3v3(ct, n) < 0.0f) { negate_v3(r_tang); } } else { zero_v3(r_tang); } } /****************************** Vector Clouds ********************************/ /* vector clouds */ /* void vcloud_estimate_transform(int list_size, float (*pos)[3], float *weight, float (*rpos)[3], float *rweight, * float lloc[3], float rloc[3], float lrot[3][3], float lscale[3][3]) * * input * ( * int list_size * 4 lists as pointer to array[list_size] * 1. current pos array of 'new' positions * 2. current weight array of 'new'weights (may be NULL pointer if you have no weights ) * 3. reference rpos array of 'old' positions * 4. reference rweight array of 'old'weights (may be NULL pointer if you have no weights ) * ) * output * ( * float lloc[3] center of mass pos * float rloc[3] center of mass rpos * float lrot[3][3] rotation matrix * float lscale[3][3] scale matrix * pointers may be NULL if not needed * ) */ void vcloud_estimate_transform(int list_size, float (*pos)[3], float *weight, float (*rpos)[3], float *rweight, float lloc[3], float rloc[3], float lrot[3][3], float lscale[3][3]) { float accu_com[3] = {0.0f, 0.0f, 0.0f}, accu_rcom[3] = {0.0f, 0.0f, 0.0f}; float accu_weight = 0.0f, accu_rweight = 0.0f; const float eps = 1e-6f; int a; /* first set up a nice default response */ if (lloc) zero_v3(lloc); if (rloc) zero_v3(rloc); if (lrot) unit_m3(lrot); if (lscale) unit_m3(lscale); /* do com for both clouds */ if (pos && rpos && (list_size > 0)) { /* paranoya check */ /* do com for both clouds */ for (a = 0; a < list_size; a++) { if (weight) { float v[3]; copy_v3_v3(v, pos[a]); mul_v3_fl(v, weight[a]); add_v3_v3(accu_com, v); accu_weight += weight[a]; } else { add_v3_v3(accu_com, pos[a]); } if (rweight) { float v[3]; copy_v3_v3(v, rpos[a]); mul_v3_fl(v, rweight[a]); add_v3_v3(accu_rcom, v); accu_rweight += rweight[a]; } else { add_v3_v3(accu_rcom, rpos[a]); } } if (!weight || !rweight) { accu_weight = accu_rweight = (float)list_size; } mul_v3_fl(accu_com, 1.0f / accu_weight); mul_v3_fl(accu_rcom, 1.0f / accu_rweight); if (lloc) copy_v3_v3(lloc, accu_com); if (rloc) copy_v3_v3(rloc, accu_rcom); if (lrot || lscale) { /* caller does not want rot nor scale, strange but legal */ /*so now do some reverse engineering and see if we can split rotation from scale ->Polardecompose*/ /* build 'projection' matrix */ float m[3][3], mr[3][3], q[3][3], qi[3][3]; float va[3], vb[3], stunt[3]; float odet, ndet; int i = 0, imax = 15; zero_m3(m); zero_m3(mr); /* build 'projection' matrix */ for (a = 0; a < list_size; a++) { sub_v3_v3v3(va, rpos[a], accu_rcom); /* mul_v3_fl(va, bp->mass); mass needs renormalzation here ?? */ sub_v3_v3v3(vb, pos[a], accu_com); /* mul_v3_fl(va, rp->mass); */ m[0][0] += va[0] * vb[0]; m[0][1] += va[0] * vb[1]; m[0][2] += va[0] * vb[2]; m[1][0] += va[1] * vb[0]; m[1][1] += va[1] * vb[1]; m[1][2] += va[1] * vb[2]; m[2][0] += va[2] * vb[0]; m[2][1] += va[2] * vb[1]; m[2][2] += va[2] * vb[2]; /* building the reference matrix on the fly * needed to scale properly later */ mr[0][0] += va[0] * va[0]; mr[0][1] += va[0] * va[1]; mr[0][2] += va[0] * va[2]; mr[1][0] += va[1] * va[0]; mr[1][1] += va[1] * va[1]; mr[1][2] += va[1] * va[2]; mr[2][0] += va[2] * va[0]; mr[2][1] += va[2] * va[1]; mr[2][2] += va[2] * va[2]; } copy_m3_m3(q, m); stunt[0] = q[0][0]; stunt[1] = q[1][1]; stunt[2] = q[2][2]; /* renormalizing for numeric stability */ mul_m3_fl(q, 1.f / len_v3(stunt)); /* this is pretty much Polardecompose 'inline' the algo based on Higham's thesis */ /* without the far case ... but seems to work here pretty neat */ odet = 0.0f; ndet = determinant_m3_array(q); while ((odet - ndet) * (odet - ndet) > eps && i < imax) { invert_m3_m3(qi, q); transpose_m3(qi); add_m3_m3m3(q, q, qi); mul_m3_fl(q, 0.5f); odet = ndet; ndet = determinant_m3_array(q); i++; } if (i) { float scale[3][3]; float irot[3][3]; if (lrot) copy_m3_m3(lrot, q); invert_m3_m3(irot, q); invert_m3_m3(qi, mr); mul_m3_m3m3(q, m, qi); mul_m3_m3m3(scale, irot, q); if (lscale) copy_m3_m3(lscale, scale); } } } } /******************************* Form Factor *********************************/ static void vec_add_dir(float r[3], const float v1[3], const float v2[3], const float fac) { r[0] = v1[0] + fac * (v2[0] - v1[0]); r[1] = v1[1] + fac * (v2[1] - v1[1]); r[2] = v1[2] + fac * (v2[2] - v1[2]); } bool form_factor_visible_quad(const float p[3], const float n[3], const float v0[3], const float v1[3], const float v2[3], float q0[3], float q1[3], float q2[3], float q3[3]) { static const float epsilon = 1e-6f; float sd[3]; const float c = dot_v3v3(n, p); /* signed distances from the vertices to the plane. */ sd[0] = dot_v3v3(n, v0) - c; sd[1] = dot_v3v3(n, v1) - c; sd[2] = dot_v3v3(n, v2) - c; if (fabsf(sd[0]) < epsilon) sd[0] = 0.0f; if (fabsf(sd[1]) < epsilon) sd[1] = 0.0f; if (fabsf(sd[2]) < epsilon) sd[2] = 0.0f; if (sd[0] > 0.0f) { if (sd[1] > 0.0f) { if (sd[2] > 0.0f) { /* +++ */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } else if (sd[2] < 0.0f) { /* ++- */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); vec_add_dir(q2, v1, v2, (sd[1] / (sd[1] - sd[2]))); vec_add_dir(q3, v0, v2, (sd[0] / (sd[0] - sd[2]))); } else { /* ++0 */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } } else if (sd[1] < 0.0f) { if (sd[2] > 0.0f) { /* +-+ */ copy_v3_v3(q0, v0); vec_add_dir(q1, v0, v1, (sd[0] / (sd[0] - sd[1]))); vec_add_dir(q2, v1, v2, (sd[1] / (sd[1] - sd[2]))); copy_v3_v3(q3, v2); } else if (sd[2] < 0.0f) { /* +-- */ copy_v3_v3(q0, v0); vec_add_dir(q1, v0, v1, (sd[0] / (sd[0] - sd[1]))); vec_add_dir(q2, v0, v2, (sd[0] / (sd[0] - sd[2]))); copy_v3_v3(q3, q2); } else { /* +-0 */ copy_v3_v3(q0, v0); vec_add_dir(q1, v0, v1, (sd[0] / (sd[0] - sd[1]))); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } } else { if (sd[2] > 0.0f) { /* +0+ */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } else if (sd[2] < 0.0f) { /* +0- */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); vec_add_dir(q2, v0, v2, (sd[0] / (sd[0] - sd[2]))); copy_v3_v3(q3, q2); } else { /* +00 */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } } } else if (sd[0] < 0.0f) { if (sd[1] > 0.0f) { if (sd[2] > 0.0f) { /* -++ */ vec_add_dir(q0, v0, v1, (sd[0] / (sd[0] - sd[1]))); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); vec_add_dir(q3, v0, v2, (sd[0] / (sd[0] - sd[2]))); } else if (sd[2] < 0.0f) { /* -+- */ vec_add_dir(q0, v0, v1, (sd[0] / (sd[0] - sd[1]))); copy_v3_v3(q1, v1); vec_add_dir(q2, v1, v2, (sd[1] / (sd[1] - sd[2]))); copy_v3_v3(q3, q2); } else { /* -+0 */ vec_add_dir(q0, v0, v1, (sd[0] / (sd[0] - sd[1]))); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } } else if (sd[1] < 0.0f) { if (sd[2] > 0.0f) { /* --+ */ vec_add_dir(q0, v0, v2, (sd[0] / (sd[0] - sd[2]))); vec_add_dir(q1, v1, v2, (sd[1] / (sd[1] - sd[2]))); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } else if (sd[2] < 0.0f) { /* --- */ return false; } else { /* --0 */ return false; } } else { if (sd[2] > 0.0f) { /* -0+ */ vec_add_dir(q0, v0, v2, (sd[0] / (sd[0] - sd[2]))); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } else if (sd[2] < 0.0f) { /* -0- */ return false; } else { /* -00 */ return false; } } } else { if (sd[1] > 0.0f) { if (sd[2] > 0.0f) { /* 0++ */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } else if (sd[2] < 0.0f) { /* 0+- */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); vec_add_dir(q2, v1, v2, (sd[1] / (sd[1] - sd[2]))); copy_v3_v3(q3, q2); } else { /* 0+0 */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } } else if (sd[1] < 0.0f) { if (sd[2] > 0.0f) { /* 0-+ */ copy_v3_v3(q0, v0); vec_add_dir(q1, v1, v2, (sd[1] / (sd[1] - sd[2]))); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } else if (sd[2] < 0.0f) { /* 0-- */ return false; } else { /* 0-0 */ return false; } } else { if (sd[2] > 0.0f) { /* 00+ */ copy_v3_v3(q0, v0); copy_v3_v3(q1, v1); copy_v3_v3(q2, v2); copy_v3_v3(q3, q2); } else if (sd[2] < 0.0f) { /* 00- */ return false; } else { /* 000 */ return false; } } } return true; } /* altivec optimization, this works, but is unused */ #if 0 #include typedef union { vFloat v; float f[4]; } vFloatResult; static vFloat vec_splat_float(float val) { return (vFloat) {val, val, val, val}; } static float ff_quad_form_factor(float *p, float *n, float *q0, float *q1, float *q2, float *q3) { vFloat vcos, rlen, vrx, vry, vrz, vsrx, vsry, vsrz, gx, gy, gz, vangle; vUInt8 rotate = (vUInt8) {4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2, 3}; vFloatResult vresult; float result; /* compute r* */ vrx = (vFloat) {q0[0], q1[0], q2[0], q3[0]} -vec_splat_float(p[0]); vry = (vFloat) {q0[1], q1[1], q2[1], q3[1]} -vec_splat_float(p[1]); vrz = (vFloat) {q0[2], q1[2], q2[2], q3[2]} -vec_splat_float(p[2]); /* normalize r* */ rlen = vec_rsqrte(vrx * vrx + vry * vry + vrz * vrz + vec_splat_float(1e-16f)); vrx = vrx * rlen; vry = vry * rlen; vrz = vrz * rlen; /* rotate r* for cross and dot */ vsrx = vec_perm(vrx, vrx, rotate); vsry = vec_perm(vry, vry, rotate); vsrz = vec_perm(vrz, vrz, rotate); /* cross product */ gx = vsry * vrz - vsrz * vry; gy = vsrz * vrx - vsrx * vrz; gz = vsrx * vry - vsry * vrx; /* normalize */ rlen = vec_rsqrte(gx * gx + gy * gy + gz * gz + vec_splat_float(1e-16f)); gx = gx * rlen; gy = gy * rlen; gz = gz * rlen; /* angle */ vcos = vrx * vsrx + vry * vsry + vrz * vsrz; vcos = vec_max(vec_min(vcos, vec_splat_float(1.0f)), vec_splat_float(-1.0f)); vangle = vacosf(vcos); /* dot */ vresult.v = (vec_splat_float(n[0]) * gx + vec_splat_float(n[1]) * gy + vec_splat_float(n[2]) * gz) * vangle; result = (vresult.f[0] + vresult.f[1] + vresult.f[2] + vresult.f[3]) * (0.5f / (float)M_PI); result = MAX2(result, 0.0f); return result; } #endif /* SSE optimization, acos code doesn't work */ #if 0 #include static __m128 sse_approx_acos(__m128 x) { /* needs a better approximation than taylor expansion of acos, since that * gives big errors for near 1.0 values, sqrt(2 * x) * acos(1 - x) should work * better, see http://www.tom.womack.net/projects/sse-fast-arctrig.html */ return _mm_set_ps1(1.0f); } static float ff_quad_form_factor(float *p, float *n, float *q0, float *q1, float *q2, float *q3) { float r0[3], r1[3], r2[3], r3[3], g0[3], g1[3], g2[3], g3[3]; float a1, a2, a3, a4, dot1, dot2, dot3, dot4, result; float fresult[4] __attribute__((aligned(16))); __m128 qx, qy, qz, rx, ry, rz, rlen, srx, sry, srz, gx, gy, gz, glen, rcos, angle, aresult; /* compute r */ qx = _mm_set_ps(q3[0], q2[0], q1[0], q0[0]); qy = _mm_set_ps(q3[1], q2[1], q1[1], q0[1]); qz = _mm_set_ps(q3[2], q2[2], q1[2], q0[2]); rx = qx - _mm_set_ps1(p[0]); ry = qy - _mm_set_ps1(p[1]); rz = qz - _mm_set_ps1(p[2]); /* normalize r */ rlen = _mm_rsqrt_ps(rx * rx + ry * ry + rz * rz + _mm_set_ps1(1e-16f)); rx = rx * rlen; ry = ry * rlen; rz = rz * rlen; /* cross product */ srx = _mm_shuffle_ps(rx, rx, _MM_SHUFFLE(0, 3, 2, 1)); sry = _mm_shuffle_ps(ry, ry, _MM_SHUFFLE(0, 3, 2, 1)); srz = _mm_shuffle_ps(rz, rz, _MM_SHUFFLE(0, 3, 2, 1)); gx = sry * rz - srz * ry; gy = srz * rx - srx * rz; gz = srx * ry - sry * rx; /* normalize g */ glen = _mm_rsqrt_ps(gx * gx + gy * gy + gz * gz + _mm_set_ps1(1e-16f)); gx = gx * glen; gy = gy * glen; gz = gz * glen; /* compute angle */ rcos = rx * srx + ry * sry + rz * srz; rcos = _mm_max_ps(_mm_min_ps(rcos, _mm_set_ps1(1.0f)), _mm_set_ps1(-1.0f)); angle = sse_approx_cos(rcos); aresult = (_mm_set_ps1(n[0]) * gx + _mm_set_ps1(n[1]) * gy + _mm_set_ps1(n[2]) * gz) * angle; /* sum together */ result = (fresult[0] + fresult[1] + fresult[2] + fresult[3]) * (0.5f / (float)M_PI); result = MAX2(result, 0.0f); return result; } #endif static void ff_normalize(float n[3]) { float d; d = dot_v3v3(n, n); if (d > 1.0e-35f) { d = 1.0f / sqrtf(d); n[0] *= d; n[1] *= d; n[2] *= d; } } float form_factor_quad(const float p[3], const float n[3], const float q0[3], const float q1[3], const float q2[3], const float q3[3]) { float r0[3], r1[3], r2[3], r3[3], g0[3], g1[3], g2[3], g3[3]; float a1, a2, a3, a4, dot1, dot2, dot3, dot4, result; sub_v3_v3v3(r0, q0, p); sub_v3_v3v3(r1, q1, p); sub_v3_v3v3(r2, q2, p); sub_v3_v3v3(r3, q3, p); ff_normalize(r0); ff_normalize(r1); ff_normalize(r2); ff_normalize(r3); cross_v3_v3v3(g0, r1, r0); ff_normalize(g0); cross_v3_v3v3(g1, r2, r1); ff_normalize(g1); cross_v3_v3v3(g2, r3, r2); ff_normalize(g2); cross_v3_v3v3(g3, r0, r3); ff_normalize(g3); a1 = saacosf(dot_v3v3(r0, r1)); a2 = saacosf(dot_v3v3(r1, r2)); a3 = saacosf(dot_v3v3(r2, r3)); a4 = saacosf(dot_v3v3(r3, r0)); dot1 = dot_v3v3(n, g0); dot2 = dot_v3v3(n, g1); dot3 = dot_v3v3(n, g2); dot4 = dot_v3v3(n, g3); result = (a1 * dot1 + a2 * dot2 + a3 * dot3 + a4 * dot4) * 0.5f / (float)M_PI; result = MAX2(result, 0.0f); return result; } float form_factor_hemi_poly(float p[3], float n[3], float v1[3], float v2[3], float v3[3], float v4[3]) { /* computes how much hemisphere defined by point and normal is * covered by a quad or triangle, cosine weighted */ float q0[3], q1[3], q2[3], q3[3], contrib = 0.0f; if (form_factor_visible_quad(p, n, v1, v2, v3, q0, q1, q2, q3)) contrib += form_factor_quad(p, n, q0, q1, q2, q3); if (v4 && form_factor_visible_quad(p, n, v1, v3, v4, q0, q1, q2, q3)) contrib += form_factor_quad(p, n, q0, q1, q2, q3); return contrib; } /** * Evaluate if entire quad is a proper convex quad */ bool is_quad_convex_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { /** * Method projects points onto a plane and checks its convex using following method: * * - Create a plane from the cross-product of both diagonal vectors. * - Project all points onto the plane. * - Subtract for direction vectors. * - Return true if all corners cross-products point the direction of the plane. */ /* non-unit length normal, used as a projection plane */ float plane[3]; { float v13[3], v24[3]; sub_v3_v3v3(v13, v1, v3); sub_v3_v3v3(v24, v2, v4); cross_v3_v3v3(plane, v13, v24); if (len_squared_v3(plane) < FLT_EPSILON) { return false; } } const float *quad_coords[4] = {v1, v2, v3, v4}; float quad_proj[4][3]; for (int i = 0; i < 4; i++) { project_plane_v3_v3v3(quad_proj[i], quad_coords[i], plane); } float quad_dirs[4][3]; for (int i = 0, j = 3; i < 4; j = i++) { sub_v3_v3v3(quad_dirs[i], quad_proj[i], quad_proj[j]); } float test_dir[3]; #define CROSS_SIGN(dir_a, dir_b) \ ((void)cross_v3_v3v3(test_dir, dir_a, dir_b), (dot_v3v3(plane, test_dir) > 0.0f)) return (CROSS_SIGN(quad_dirs[0], quad_dirs[1]) && CROSS_SIGN(quad_dirs[1], quad_dirs[2]) && CROSS_SIGN(quad_dirs[2], quad_dirs[3]) && CROSS_SIGN(quad_dirs[3], quad_dirs[0])); #undef CROSS_SIGN } bool is_quad_convex_v2(const float v1[2], const float v2[2], const float v3[2], const float v4[2]) { /* linetests, the 2 diagonals have to instersect to be convex */ return (isect_seg_seg_v2(v1, v3, v2, v4) > 0); } bool is_poly_convex_v2(const float verts[][2], unsigned int nr) { unsigned int sign_flag = 0; unsigned int a; const float *co_curr, *co_prev; float dir_curr[2], dir_prev[2]; co_prev = verts[nr - 1]; co_curr = verts[0]; sub_v2_v2v2(dir_prev, verts[nr - 2], co_prev); for (a = 0; a < nr; a++) { float cross; sub_v2_v2v2(dir_curr, co_prev, co_curr); cross = cross_v2v2(dir_prev, dir_curr); if (cross < 0.0f) { sign_flag |= 1; } else if (cross > 0.0f) { sign_flag |= 2; } if (sign_flag == (1 | 2)) { return false; } copy_v2_v2(dir_prev, dir_curr); co_prev = co_curr; co_curr += 2; } return true; } /** * Check if either of the diagonals along this quad create flipped triangles * (normals pointing away from eachother). * - (1 << 0): (v1-v3) is flipped. * - (1 << 1): (v2-v4) is flipped. */ int is_quad_flip_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { float d_12[3], d_23[3], d_34[3], d_41[3]; float cross_a[3], cross_b[3]; int ret = 0; sub_v3_v3v3(d_12, v1, v2); sub_v3_v3v3(d_23, v2, v3); sub_v3_v3v3(d_34, v3, v4); sub_v3_v3v3(d_41, v4, v1); cross_v3_v3v3(cross_a, d_12, d_23); cross_v3_v3v3(cross_b, d_34, d_41); ret |= ((dot_v3v3(cross_a, cross_b) < 0.0f) << 0); cross_v3_v3v3(cross_a, d_23, d_34); cross_v3_v3v3(cross_b, d_41, d_12); ret |= ((dot_v3v3(cross_a, cross_b) < 0.0f) << 1); return ret; } /** * Return the value which the distance between points will need to be scaled by, * to define a handle, given both points are on a perfect circle. * * Use when we want a bezier curve to match a circle as closely as possible. * * \note the return value will need to be divided by 0.75 for correct results. */ float cubic_tangent_factor_circle_v3(const float tan_l[3], const float tan_r[3]) { BLI_ASSERT_UNIT_V3(tan_l); BLI_ASSERT_UNIT_V3(tan_r); /* -7f causes instability/glitches with Bendy Bones + Custom Refs */ const float eps = 1e-5f; const float tan_dot = dot_v3v3(tan_l, tan_r); if (tan_dot > 1.0f - eps) { /* no angle difference (use fallback, length wont make any difference) */ return (1.0f / 3.0f) * 0.75f; } else if (tan_dot < -1.0f + eps) { /* parallele tangents (half-circle) */ return (1.0f / 2.0f); } else { /* non-aligned tangents, calculate handle length */ const float angle = acosf(tan_dot) / 2.0f; /* could also use 'angle_sin = len_vnvn(tan_l, tan_r, dims) / 2.0' */ const float angle_sin = sinf(angle); const float angle_cos = cosf(angle); return ((1.0f - angle_cos) / (angle_sin * 2.0f)) / angle_sin; } }