diff options
Diffstat (limited to 'source/blender/blenlib/intern/math_geom.c')
| -rw-r--r-- | source/blender/blenlib/intern/math_geom.c | 69 |
1 files changed, 51 insertions, 18 deletions
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c index ac9534dac25..810c15437dc 100644 --- a/source/blender/blenlib/intern/math_geom.c +++ b/source/blender/blenlib/intern/math_geom.c @@ -39,9 +39,9 @@ void cent_tri_v3(float cent[3], const float v1[3], const float v2[3], const float v3[3]) { - cent[0] = 0.33333f * (v1[0] + v2[0] + v3[0]); - cent[1] = 0.33333f * (v1[1] + v2[1] + v3[1]); - cent[2] = 0.33333f * (v1[2] + v2[2] + v3[2]); + cent[0] = (v1[0] + v2[0] + v3[0]) / 3.0f; + cent[1] = (v1[1] + v2[1] + v3[1]) / 3.0f; + cent[2] = (v1[2] + v2[2] + v3[2]) / 3.0f; } void cent_quad_v3(float cent[3], const float v1[3], const float v2[3], const float v3[3], const float v4[3]) @@ -129,6 +129,22 @@ float area_tri_v3(const float v1[3], const float v2[3], const float v3[3]) return (len / 2.0f); } +float area_tri_signed_v3(const float v1[3], const float v2[3], const float v3[3], const float normal[3]) +{ + float area, vec1[3], vec2[3], n[3]; + + sub_v3_v3v3(vec1, v3, v2); + sub_v3_v3v3(vec2, v1, v2); + cross_v3_v3v3(n, vec1, vec2); + area = len_v3(n) / 2.0f; + + /* negate area for flipped triangles */ + if (dot_v3v3(n, normal) < 0.0f) + area = -area; + + return area; +} + float area_poly_v3(int nr, float verts[][3], const float normal[3]) { int a, px, py; @@ -3578,25 +3594,42 @@ float form_factor_hemi_poly(float p[3], float n[3], float v1[3], float v2[3], fl /* evaluate if entire quad is a proper convex quad */ int is_quad_convex_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]) { - float nor[3], nor1[3], nor2[3], vec[4][2]; + float nor[3], nor_a[3], nor_b[3], vec[4][2]; float mat[3][3]; + const bool is_ok_a = (normal_tri_v3(nor_a, v1, v2, v3) > FLT_EPSILON); + const bool is_ok_b = (normal_tri_v3(nor_b, v1, v3, v4) > FLT_EPSILON); /* define projection, do both trias apart, quad is undefined! */ - normal_tri_v3(nor1, v1, v2, v3); - normal_tri_v3(nor2, v1, v3, v4); + /* check normal length incase one size is zero area */ + if (is_ok_a) { + if (is_ok_b) { + /* use both, most common outcome */ + + /* when the face is folded over as 2 tris we probably don't want to create + * a quad from it, but go ahead with the intersection test since this + * isn't a function for degenerate faces */ + if (UNLIKELY(dot_v3v3(nor_a, nor_b) < 0.0f)) { + /* flip so adding normals in the opposite direction + * doesn't give a zero length vector */ + negate_v3(nor_b); + } - /* when the face is folded over as 2 tris we probably don't want to create - * a quad from it, but go ahead with the intersection test since this - * isn't a function for degenerate faces */ - if (UNLIKELY(dot_v3v3(nor1, nor2) < 0.0f)) { - /* flip so adding normals in the opposite direction - * doesnt give a zero length vector */ - negate_v3(nor2); + add_v3_v3v3(nor, nor_a, nor_b); + normalize_v3(nor); + } + else { + copy_v3_v3(nor, nor_a); /* only 'a' */ + } + } + else { + if (is_ok_b) { + copy_v3_v3(nor, nor_b); /* only 'b' */ + } + else { + return false; /* both zero, we can't do anything useful here */ + } } - - add_v3_v3v3(nor, nor1, nor2); - normalize_v3(nor); axis_dominant_v3_to_m3(mat, nor); @@ -3606,12 +3639,12 @@ int is_quad_convex_v3(const float v1[3], const float v2[3], const float v3[3], c mul_v2_m3v3(vec[3], mat, v4); /* linetests, the 2 diagonals have to instersect to be convex */ - return (isect_line_line_v2(vec[0], vec[2], vec[1], vec[3]) > 0) ? TRUE : FALSE; + return (isect_line_line_v2(vec[0], vec[2], vec[1], vec[3]) > 0); } int 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_line_line_v2(v1, v3, v2, v4) > 0) ? TRUE : FALSE; + return (isect_line_line_v2(v1, v3, v2, v4) > 0); } |