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Diffstat (limited to 'intern/cycles/kernel/geom/geom_curve_intersect.h')
| -rw-r--r-- | intern/cycles/kernel/geom/geom_curve_intersect.h | 934 |
1 files changed, 934 insertions, 0 deletions
diff --git a/intern/cycles/kernel/geom/geom_curve_intersect.h b/intern/cycles/kernel/geom/geom_curve_intersect.h new file mode 100644 index 00000000000..e9a149ea1ab --- /dev/null +++ b/intern/cycles/kernel/geom/geom_curve_intersect.h @@ -0,0 +1,934 @@ +/* + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +CCL_NAMESPACE_BEGIN + +/* Curve primitive intersection functions. */ + +#ifdef __HAIR__ + +#if defined(__KERNEL_CUDA__) && (__CUDA_ARCH__ < 300) +# define ccl_device_curveintersect ccl_device +#else +# define ccl_device_curveintersect ccl_device_forceinline +#endif + +#ifdef __KERNEL_SSE2__ +ccl_device_inline ssef transform_point_T3(const ssef t[3], const ssef &a) +{ + return madd(shuffle<0>(a), t[0], madd(shuffle<1>(a), t[1], shuffle<2>(a) * t[2])); +} +#endif + +/* On CPU pass P and dir by reference to aligned vector. */ +ccl_device_curveintersect bool cardinal_curve_intersect( + KernelGlobals *kg, + Intersection *isect, + const float3 ccl_ref P, + const float3 ccl_ref dir, + uint visibility, + int object, + int curveAddr, + float time, + int type, + uint *lcg_state, + float difl, + float extmax) +{ + const bool is_curve_primitive = (type & PRIMITIVE_CURVE); + + if(!is_curve_primitive && kernel_data.bvh.use_bvh_steps) { + const float2 prim_time = kernel_tex_fetch(__prim_time, curveAddr); + if(time < prim_time.x || time > prim_time.y) { + return false; + } + } + + int segment = PRIMITIVE_UNPACK_SEGMENT(type); + float epsilon = 0.0f; + float r_st, r_en; + + int depth = kernel_data.curve.subdivisions; + int flags = kernel_data.curve.curveflags; + int prim = kernel_tex_fetch(__prim_index, curveAddr); + +#ifdef __KERNEL_SSE2__ + ssef vdir = load4f(dir); + ssef vcurve_coef[4]; + const float3 *curve_coef = (float3 *)vcurve_coef; + + { + ssef dtmp = vdir * vdir; + ssef d_ss = mm_sqrt(dtmp + shuffle<2>(dtmp)); + ssef rd_ss = load1f_first(1.0f) / d_ss; + + ssei v00vec = load4i((ssei *)&kg->__curves.data[prim]); + int2 &v00 = (int2 &)v00vec; + + int k0 = v00.x + segment; + int k1 = k0 + 1; + int ka = max(k0 - 1, v00.x); + int kb = min(k1 + 1, v00.x + v00.y - 1); + +#if defined(__KERNEL_AVX2__) && defined(__KERNEL_SSE__) && (!defined(_MSC_VER) || _MSC_VER > 1800) + avxf P_curve_0_1, P_curve_2_3; + if(is_curve_primitive) { + P_curve_0_1 = _mm256_loadu2_m128(&kg->__curve_keys.data[k0].x, &kg->__curve_keys.data[ka].x); + P_curve_2_3 = _mm256_loadu2_m128(&kg->__curve_keys.data[kb].x, &kg->__curve_keys.data[k1].x); + } + else { + int fobject = (object == OBJECT_NONE) ? kernel_tex_fetch(__prim_object, curveAddr) : object; + motion_cardinal_curve_keys_avx(kg, fobject, prim, time, ka, k0, k1, kb, &P_curve_0_1,&P_curve_2_3); + } +#else /* __KERNEL_AVX2__ */ + ssef P_curve[4]; + + if(is_curve_primitive) { + P_curve[0] = load4f(&kg->__curve_keys.data[ka].x); + P_curve[1] = load4f(&kg->__curve_keys.data[k0].x); + P_curve[2] = load4f(&kg->__curve_keys.data[k1].x); + P_curve[3] = load4f(&kg->__curve_keys.data[kb].x); + } + else { + int fobject = (object == OBJECT_NONE)? kernel_tex_fetch(__prim_object, curveAddr): object; + motion_cardinal_curve_keys(kg, fobject, prim, time, ka, k0, k1, kb, (float4*)&P_curve); + } +#endif /* __KERNEL_AVX2__ */ + + ssef rd_sgn = set_sign_bit<0, 1, 1, 1>(shuffle<0>(rd_ss)); + ssef mul_zxxy = shuffle<2, 0, 0, 1>(vdir) * rd_sgn; + ssef mul_yz = shuffle<1, 2, 1, 2>(vdir) * mul_zxxy; + ssef mul_shuf = shuffle<0, 1, 2, 3>(mul_zxxy, mul_yz); + ssef vdir0 = vdir & cast(ssei(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0)); + + ssef htfm0 = shuffle<0, 2, 0, 3>(mul_shuf, vdir0); + ssef htfm1 = shuffle<1, 0, 1, 3>(load1f_first(extract<0>(d_ss)), vdir0); + ssef htfm2 = shuffle<1, 3, 2, 3>(mul_shuf, vdir0); + +#if defined(__KERNEL_AVX2__) && defined(__KERNEL_SSE__) && (!defined(_MSC_VER) || _MSC_VER > 1800) + const avxf vPP = _mm256_broadcast_ps(&P.m128); + const avxf htfm00 = avxf(htfm0.m128, htfm0.m128); + const avxf htfm11 = avxf(htfm1.m128, htfm1.m128); + const avxf htfm22 = avxf(htfm2.m128, htfm2.m128); + + const avxf p01 = madd(shuffle<0>(P_curve_0_1 - vPP), + htfm00, + madd(shuffle<1>(P_curve_0_1 - vPP), + htfm11, + shuffle<2>(P_curve_0_1 - vPP) * htfm22)); + const avxf p23 = madd(shuffle<0>(P_curve_2_3 - vPP), + htfm00, + madd(shuffle<1>(P_curve_2_3 - vPP), + htfm11, + shuffle<2>(P_curve_2_3 - vPP)*htfm22)); + + const ssef p0 = _mm256_castps256_ps128(p01); + const ssef p1 = _mm256_extractf128_ps(p01, 1); + const ssef p2 = _mm256_castps256_ps128(p23); + const ssef p3 = _mm256_extractf128_ps(p23, 1); + + const ssef P_curve_1 = _mm256_extractf128_ps(P_curve_0_1, 1); + r_st = ((float4 &)P_curve_1).w; + const ssef P_curve_2 = _mm256_castps256_ps128(P_curve_2_3); + r_en = ((float4 &)P_curve_2).w; +#else /* __KERNEL_AVX2__ */ + ssef htfm[] = { htfm0, htfm1, htfm2 }; + ssef vP = load4f(P); + ssef p0 = transform_point_T3(htfm, P_curve[0] - vP); + ssef p1 = transform_point_T3(htfm, P_curve[1] - vP); + ssef p2 = transform_point_T3(htfm, P_curve[2] - vP); + ssef p3 = transform_point_T3(htfm, P_curve[3] - vP); + + r_st = ((float4 &)P_curve[1]).w; + r_en = ((float4 &)P_curve[2]).w; +#endif /* __KERNEL_AVX2__ */ + + float fc = 0.71f; + ssef vfc = ssef(fc); + ssef vfcxp3 = vfc * p3; + + vcurve_coef[0] = p1; + vcurve_coef[1] = vfc * (p2 - p0); + vcurve_coef[2] = madd(ssef(fc * 2.0f), p0, madd(ssef(fc - 3.0f), p1, msub(ssef(3.0f - 2.0f * fc), p2, vfcxp3))); + vcurve_coef[3] = msub(ssef(fc - 2.0f), p2 - p1, msub(vfc, p0, vfcxp3)); + + } +#else + float3 curve_coef[4]; + + /* curve Intersection check */ + /* obtain curve parameters */ + { + /* ray transform created - this should be created at beginning of intersection loop */ + Transform htfm; + float d = sqrtf(dir.x * dir.x + dir.z * dir.z); + htfm = make_transform( + dir.z / d, 0, -dir.x /d, 0, + -dir.x * dir.y /d, d, -dir.y * dir.z /d, 0, + dir.x, dir.y, dir.z, 0, + 0, 0, 0, 1); + + float4 v00 = kernel_tex_fetch(__curves, prim); + + int k0 = __float_as_int(v00.x) + segment; + int k1 = k0 + 1; + + int ka = max(k0 - 1,__float_as_int(v00.x)); + int kb = min(k1 + 1,__float_as_int(v00.x) + __float_as_int(v00.y) - 1); + + float4 P_curve[4]; + + if(is_curve_primitive) { + P_curve[0] = kernel_tex_fetch(__curve_keys, ka); + P_curve[1] = kernel_tex_fetch(__curve_keys, k0); + P_curve[2] = kernel_tex_fetch(__curve_keys, k1); + P_curve[3] = kernel_tex_fetch(__curve_keys, kb); + } + else { + int fobject = (object == OBJECT_NONE)? kernel_tex_fetch(__prim_object, curveAddr): object; + motion_cardinal_curve_keys(kg, fobject, prim, time, ka, k0, k1, kb, P_curve); + } + + float3 p0 = transform_point(&htfm, float4_to_float3(P_curve[0]) - P); + float3 p1 = transform_point(&htfm, float4_to_float3(P_curve[1]) - P); + float3 p2 = transform_point(&htfm, float4_to_float3(P_curve[2]) - P); + float3 p3 = transform_point(&htfm, float4_to_float3(P_curve[3]) - P); + + float fc = 0.71f; + curve_coef[0] = p1; + curve_coef[1] = -fc*p0 + fc*p2; + curve_coef[2] = 2.0f * fc * p0 + (fc - 3.0f) * p1 + (3.0f - 2.0f * fc) * p2 - fc * p3; + curve_coef[3] = -fc * p0 + (2.0f - fc) * p1 + (fc - 2.0f) * p2 + fc * p3; + r_st = P_curve[1].w; + r_en = P_curve[2].w; + } +#endif + + float r_curr = max(r_st, r_en); + + if((flags & CURVE_KN_RIBBONS) || !(flags & CURVE_KN_BACKFACING)) + epsilon = 2 * r_curr; + + /* find bounds - this is slow for cubic curves */ + float upper, lower; + + float zextrem[4]; + curvebounds(&lower, &upper, &zextrem[0], &zextrem[1], &zextrem[2], &zextrem[3], curve_coef[0].z, curve_coef[1].z, curve_coef[2].z, curve_coef[3].z); + if(lower - r_curr > isect->t || upper + r_curr < epsilon) + return false; + + /* minimum width extension */ + float mw_extension = min(difl * fabsf(upper), extmax); + float r_ext = mw_extension + r_curr; + + float xextrem[4]; + curvebounds(&lower, &upper, &xextrem[0], &xextrem[1], &xextrem[2], &xextrem[3], curve_coef[0].x, curve_coef[1].x, curve_coef[2].x, curve_coef[3].x); + if(lower > r_ext || upper < -r_ext) + return false; + + float yextrem[4]; + curvebounds(&lower, &upper, &yextrem[0], &yextrem[1], &yextrem[2], &yextrem[3], curve_coef[0].y, curve_coef[1].y, curve_coef[2].y, curve_coef[3].y); + if(lower > r_ext || upper < -r_ext) + return false; + + /* setup recurrent loop */ + int level = 1 << depth; + int tree = 0; + float resol = 1.0f / (float)level; + bool hit = false; + + /* begin loop */ + while(!(tree >> (depth))) { + const float i_st = tree * resol; + const float i_en = i_st + (level * resol); + +#ifdef __KERNEL_SSE2__ + ssef vi_st = ssef(i_st), vi_en = ssef(i_en); + ssef vp_st = madd(madd(madd(vcurve_coef[3], vi_st, vcurve_coef[2]), vi_st, vcurve_coef[1]), vi_st, vcurve_coef[0]); + ssef vp_en = madd(madd(madd(vcurve_coef[3], vi_en, vcurve_coef[2]), vi_en, vcurve_coef[1]), vi_en, vcurve_coef[0]); + + ssef vbmin = min(vp_st, vp_en); + ssef vbmax = max(vp_st, vp_en); + + float3 &bmin = (float3 &)vbmin, &bmax = (float3 &)vbmax; + float &bminx = bmin.x, &bminy = bmin.y, &bminz = bmin.z; + float &bmaxx = bmax.x, &bmaxy = bmax.y, &bmaxz = bmax.z; + float3 &p_st = (float3 &)vp_st, &p_en = (float3 &)vp_en; +#else + float3 p_st = ((curve_coef[3] * i_st + curve_coef[2]) * i_st + curve_coef[1]) * i_st + curve_coef[0]; + float3 p_en = ((curve_coef[3] * i_en + curve_coef[2]) * i_en + curve_coef[1]) * i_en + curve_coef[0]; + + float bminx = min(p_st.x, p_en.x); + float bmaxx = max(p_st.x, p_en.x); + float bminy = min(p_st.y, p_en.y); + float bmaxy = max(p_st.y, p_en.y); + float bminz = min(p_st.z, p_en.z); + float bmaxz = max(p_st.z, p_en.z); +#endif + + if(xextrem[0] >= i_st && xextrem[0] <= i_en) { + bminx = min(bminx,xextrem[1]); + bmaxx = max(bmaxx,xextrem[1]); + } + if(xextrem[2] >= i_st && xextrem[2] <= i_en) { + bminx = min(bminx,xextrem[3]); + bmaxx = max(bmaxx,xextrem[3]); + } + if(yextrem[0] >= i_st && yextrem[0] <= i_en) { + bminy = min(bminy,yextrem[1]); + bmaxy = max(bmaxy,yextrem[1]); + } + if(yextrem[2] >= i_st && yextrem[2] <= i_en) { + bminy = min(bminy,yextrem[3]); + bmaxy = max(bmaxy,yextrem[3]); + } + if(zextrem[0] >= i_st && zextrem[0] <= i_en) { + bminz = min(bminz,zextrem[1]); + bmaxz = max(bmaxz,zextrem[1]); + } + if(zextrem[2] >= i_st && zextrem[2] <= i_en) { + bminz = min(bminz,zextrem[3]); + bmaxz = max(bmaxz,zextrem[3]); + } + + float r1 = r_st + (r_en - r_st) * i_st; + float r2 = r_st + (r_en - r_st) * i_en; + r_curr = max(r1, r2); + + mw_extension = min(difl * fabsf(bmaxz), extmax); + float r_ext = mw_extension + r_curr; + float coverage = 1.0f; + + if(bminz - r_curr > isect->t || bmaxz + r_curr < epsilon || bminx > r_ext|| bmaxx < -r_ext|| bminy > r_ext|| bmaxy < -r_ext) { + /* the bounding box does not overlap the square centered at O */ + tree += level; + level = tree & -tree; + } + else if(level == 1) { + + /* the maximum recursion depth is reached. + * check if dP0.(Q-P0)>=0 and dPn.(Pn-Q)>=0. + * dP* is reversed if necessary.*/ + float t = isect->t; + float u = 0.0f; + float gd = 0.0f; + + if(flags & CURVE_KN_RIBBONS) { + float3 tg = (p_en - p_st); +#ifdef __KERNEL_SSE__ + const float3 tg_sq = tg * tg; + float w = tg_sq.x + tg_sq.y; +#else + float w = tg.x * tg.x + tg.y * tg.y; +#endif + if(w == 0) { + tree++; + level = tree & -tree; + continue; + } +#ifdef __KERNEL_SSE__ + const float3 p_sttg = p_st * tg; + w = -(p_sttg.x + p_sttg.y) / w; +#else + w = -(p_st.x * tg.x + p_st.y * tg.y) / w; +#endif + w = saturate(w); + + /* compute u on the curve segment */ + u = i_st * (1 - w) + i_en * w; + r_curr = r_st + (r_en - r_st) * u; + /* compare x-y distances */ + float3 p_curr = ((curve_coef[3] * u + curve_coef[2]) * u + curve_coef[1]) * u + curve_coef[0]; + + float3 dp_st = (3 * curve_coef[3] * i_st + 2 * curve_coef[2]) * i_st + curve_coef[1]; + if(dot(tg, dp_st)< 0) + dp_st *= -1; + if(dot(dp_st, -p_st) + p_curr.z * dp_st.z < 0) { + tree++; + level = tree & -tree; + continue; + } + float3 dp_en = (3 * curve_coef[3] * i_en + 2 * curve_coef[2]) * i_en + curve_coef[1]; + if(dot(tg, dp_en) < 0) + dp_en *= -1; + if(dot(dp_en, p_en) - p_curr.z * dp_en.z < 0) { + tree++; + level = tree & -tree; + continue; + } + + /* compute coverage */ + float r_ext = r_curr; + coverage = 1.0f; + if(difl != 0.0f) { + mw_extension = min(difl * fabsf(bmaxz), extmax); + r_ext = mw_extension + r_curr; +#ifdef __KERNEL_SSE__ + const float3 p_curr_sq = p_curr * p_curr; + const float3 dxxx(_mm_sqrt_ss(_mm_hadd_ps(p_curr_sq.m128, p_curr_sq.m128))); + float d = dxxx.x; +#else + float d = sqrtf(p_curr.x * p_curr.x + p_curr.y * p_curr.y); +#endif + float d0 = d - r_curr; + float d1 = d + r_curr; + float inv_mw_extension = 1.0f/mw_extension; + if(d0 >= 0) + coverage = (min(d1 * inv_mw_extension, 1.0f) - min(d0 * inv_mw_extension, 1.0f)) * 0.5f; + else // inside + coverage = (min(d1 * inv_mw_extension, 1.0f) + min(-d0 * inv_mw_extension, 1.0f)) * 0.5f; + } + + if(p_curr.x * p_curr.x + p_curr.y * p_curr.y >= r_ext * r_ext || p_curr.z <= epsilon || isect->t < p_curr.z) { + tree++; + level = tree & -tree; + continue; + } + + t = p_curr.z; + + /* stochastic fade from minimum width */ + if(difl != 0.0f && lcg_state) { + if(coverage != 1.0f && (lcg_step_float(lcg_state) > coverage)) + return hit; + } + } + else { + float l = len(p_en - p_st); + /* minimum width extension */ + float or1 = r1; + float or2 = r2; + + if(difl != 0.0f) { + mw_extension = min(len(p_st - P) * difl, extmax); + or1 = r1 < mw_extension ? mw_extension : r1; + mw_extension = min(len(p_en - P) * difl, extmax); + or2 = r2 < mw_extension ? mw_extension : r2; + } + /* --- */ + float invl = 1.0f/l; + float3 tg = (p_en - p_st) * invl; + gd = (or2 - or1) * invl; + float difz = -dot(p_st,tg); + float cyla = 1.0f - (tg.z * tg.z * (1 + gd*gd)); + float invcyla = 1.0f/cyla; + float halfb = (-p_st.z - tg.z*(difz + gd*(difz*gd + or1))); + float tcentre = -halfb*invcyla; + float zcentre = difz + (tg.z * tcentre); + float3 tdif = - p_st; + tdif.z += tcentre; + float tdifz = dot(tdif,tg); + float tb = 2*(tdif.z - tg.z*(tdifz + gd*(tdifz*gd + or1))); + float tc = dot(tdif,tdif) - tdifz * tdifz * (1 + gd*gd) - or1*or1 - 2*or1*tdifz*gd; + float td = tb*tb - 4*cyla*tc; + if(td < 0.0f) { + tree++; + level = tree & -tree; + continue; + } + + float rootd = sqrtf(td); + float correction = (-tb - rootd) * 0.5f * invcyla; + t = tcentre + correction; + + float3 dp_st = (3 * curve_coef[3] * i_st + 2 * curve_coef[2]) * i_st + curve_coef[1]; + if(dot(tg, dp_st)< 0) + dp_st *= -1; + float3 dp_en = (3 * curve_coef[3] * i_en + 2 * curve_coef[2]) * i_en + curve_coef[1]; + if(dot(tg, dp_en) < 0) + dp_en *= -1; + + if(flags & CURVE_KN_BACKFACING && (dot(dp_st, -p_st) + t * dp_st.z < 0 || dot(dp_en, p_en) - t * dp_en.z < 0 || isect->t < t || t <= 0.0f)) { + correction = (-tb + rootd) * 0.5f * invcyla; + t = tcentre + correction; + } + + if(dot(dp_st, -p_st) + t * dp_st.z < 0 || dot(dp_en, p_en) - t * dp_en.z < 0 || isect->t < t || t <= 0.0f) { + tree++; + level = tree & -tree; + continue; + } + + float w = (zcentre + (tg.z * correction)) * invl; + w = saturate(w); + /* compute u on the curve segment */ + u = i_st * (1 - w) + i_en * w; + + /* stochastic fade from minimum width */ + if(difl != 0.0f && lcg_state) { + r_curr = r1 + (r2 - r1) * w; + r_ext = or1 + (or2 - or1) * w; + coverage = r_curr/r_ext; + + if(coverage != 1.0f && (lcg_step_float(lcg_state) > coverage)) + return hit; + } + } + /* we found a new intersection */ + +#ifdef __VISIBILITY_FLAG__ + /* visibility flag test. we do it here under the assumption + * that most triangles are culled by node flags */ + if(kernel_tex_fetch(__prim_visibility, curveAddr) & visibility) +#endif + { + /* record intersection */ + isect->t = t; + isect->u = u; + isect->v = gd; + isect->prim = curveAddr; + isect->object = object; + isect->type = type; + hit = true; + } + + tree++; + level = tree & -tree; + } + else { + /* split the curve into two curves and process */ + level = level >> 1; + } + } + + return hit; +} + +ccl_device_curveintersect bool curve_intersect(KernelGlobals *kg, + Intersection *isect, + float3 P, + float3 direction, + uint visibility, + int object, + int curveAddr, + float time, + int type, + uint *lcg_state, + float difl, + float extmax) +{ + /* define few macros to minimize code duplication for SSE */ +#ifndef __KERNEL_SSE2__ +# define len3_squared(x) len_squared(x) +# define len3(x) len(x) +# define dot3(x, y) dot(x, y) +#endif + + const bool is_curve_primitive = (type & PRIMITIVE_CURVE); + + if(!is_curve_primitive && kernel_data.bvh.use_bvh_steps) { + const float2 prim_time = kernel_tex_fetch(__prim_time, curveAddr); + if(time < prim_time.x || time > prim_time.y) { + return false; + } + } + + int segment = PRIMITIVE_UNPACK_SEGMENT(type); + /* curve Intersection check */ + int flags = kernel_data.curve.curveflags; + + int prim = kernel_tex_fetch(__prim_index, curveAddr); + float4 v00 = kernel_tex_fetch(__curves, prim); + + int cnum = __float_as_int(v00.x); + int k0 = cnum + segment; + int k1 = k0 + 1; + +#ifndef __KERNEL_SSE2__ + float4 P_curve[2]; + + if(is_curve_primitive) { + P_curve[0] = kernel_tex_fetch(__curve_keys, k0); + P_curve[1] = kernel_tex_fetch(__curve_keys, k1); + } + else { + int fobject = (object == OBJECT_NONE)? kernel_tex_fetch(__prim_object, curveAddr): object; + motion_curve_keys(kg, fobject, prim, time, k0, k1, P_curve); + } + + float or1 = P_curve[0].w; + float or2 = P_curve[1].w; + float3 p1 = float4_to_float3(P_curve[0]); + float3 p2 = float4_to_float3(P_curve[1]); + + /* minimum width extension */ + float r1 = or1; + float r2 = or2; + float3 dif = P - p1; + float3 dif_second = P - p2; + if(difl != 0.0f) { + float pixelsize = min(len3(dif) * difl, extmax); + r1 = or1 < pixelsize ? pixelsize : or1; + pixelsize = min(len3(dif_second) * difl, extmax); + r2 = or2 < pixelsize ? pixelsize : or2; + } + /* --- */ + + float3 p21_diff = p2 - p1; + float3 sphere_dif1 = (dif + dif_second) * 0.5f; + float3 dir = direction; + float sphere_b_tmp = dot3(dir, sphere_dif1); + float3 sphere_dif2 = sphere_dif1 - sphere_b_tmp * dir; +#else + ssef P_curve[2]; + + if(is_curve_primitive) { + P_curve[0] = load4f(&kg->__curve_keys.data[k0].x); + P_curve[1] = load4f(&kg->__curve_keys.data[k1].x); + } + else { + int fobject = (object == OBJECT_NONE)? kernel_tex_fetch(__prim_object, curveAddr): object; + motion_curve_keys(kg, fobject, prim, time, k0, k1, (float4*)&P_curve); + } + + const ssef or12 = shuffle<3, 3, 3, 3>(P_curve[0], P_curve[1]); + + ssef r12 = or12; + const ssef vP = load4f(P); + const ssef dif = vP - P_curve[0]; + const ssef dif_second = vP - P_curve[1]; + if(difl != 0.0f) { + const ssef len1_sq = len3_squared_splat(dif); + const ssef len2_sq = len3_squared_splat(dif_second); + const ssef len12 = mm_sqrt(shuffle<0, 0, 0, 0>(len1_sq, len2_sq)); + const ssef pixelsize12 = min(len12 * difl, ssef(extmax)); + r12 = max(or12, pixelsize12); + } + float or1 = extract<0>(or12), or2 = extract<0>(shuffle<2>(or12)); + float r1 = extract<0>(r12), r2 = extract<0>(shuffle<2>(r12)); + + const ssef p21_diff = P_curve[1] - P_curve[0]; + const ssef sphere_dif1 = (dif + dif_second) * 0.5f; + const ssef dir = load4f(direction); + const ssef sphere_b_tmp = dot3_splat(dir, sphere_dif1); + const ssef sphere_dif2 = nmadd(sphere_b_tmp, dir, sphere_dif1); +#endif + + float mr = max(r1, r2); + float l = len3(p21_diff); + float invl = 1.0f / l; + float sp_r = mr + 0.5f * l; + + float sphere_b = dot3(dir, sphere_dif2); + float sdisc = sphere_b * sphere_b - len3_squared(sphere_dif2) + sp_r * sp_r; + + if(sdisc < 0.0f) + return false; + + /* obtain parameters and test midpoint distance for suitable modes */ +#ifndef __KERNEL_SSE2__ + float3 tg = p21_diff * invl; +#else + const ssef tg = p21_diff * invl; +#endif + float gd = (r2 - r1) * invl; + + float dirz = dot3(dir, tg); + float difz = dot3(dif, tg); + + float a = 1.0f - (dirz*dirz*(1 + gd*gd)); + + float halfb = dot3(dir, dif) - dirz*(difz + gd*(difz*gd + r1)); + + float tcentre = -halfb/a; + float zcentre = difz + (dirz * tcentre); + + if((tcentre > isect->t) && !(flags & CURVE_KN_ACCURATE)) + return false; + if((zcentre < 0 || zcentre > l) && !(flags & CURVE_KN_ACCURATE) && !(flags & CURVE_KN_INTERSECTCORRECTION)) + return false; + + /* test minimum separation */ +#ifndef __KERNEL_SSE2__ + float3 cprod = cross(tg, dir); + float cprod2sq = len3_squared(cross(tg, dif)); +#else + const ssef cprod = cross(tg, dir); + float cprod2sq = len3_squared(cross_zxy(tg, dif)); +#endif + float cprodsq = len3_squared(cprod); + float distscaled = dot3(cprod, dif); + + if(cprodsq == 0) + distscaled = cprod2sq; + else + distscaled = (distscaled*distscaled)/cprodsq; + + if(distscaled > mr*mr) + return false; + + /* calculate true intersection */ +#ifndef __KERNEL_SSE2__ + float3 tdif = dif + tcentre * dir; +#else + const ssef tdif = madd(ssef(tcentre), dir, dif); +#endif + float tdifz = dot3(tdif, tg); + float tdifma = tdifz*gd + r1; + float tb = 2*(dot3(dir, tdif) - dirz*(tdifz + gd*tdifma)); + float tc = dot3(tdif, tdif) - tdifz*tdifz - tdifma*tdifma; + float td = tb*tb - 4*a*tc; + + if(td < 0.0f) + return false; + + float rootd = 0.0f; + float correction = 0.0f; + if(flags & CURVE_KN_ACCURATE) { + rootd = sqrtf(td); + correction = ((-tb - rootd)/(2*a)); + } + + float t = tcentre + correction; + + if(t < isect->t) { + + if(flags & CURVE_KN_INTERSECTCORRECTION) { + rootd = sqrtf(td); + correction = ((-tb - rootd)/(2*a)); + t = tcentre + correction; + } + + float z = zcentre + (dirz * correction); + // bool backface = false; + + if(flags & CURVE_KN_BACKFACING && (t < 0.0f || z < 0 || z > l)) { + // backface = true; + correction = ((-tb + rootd)/(2*a)); + t = tcentre + correction; + z = zcentre + (dirz * correction); + } + + /* stochastic fade from minimum width */ + float adjradius = or1 + z * (or2 - or1) * invl; + adjradius = adjradius / (r1 + z * gd); + if(lcg_state && adjradius != 1.0f) { + if(lcg_step_float(lcg_state) > adjradius) + return false; + } + /* --- */ + + if(t > 0.0f && t < isect->t && z >= 0 && z <= l) { + + if(flags & CURVE_KN_ENCLOSEFILTER) { + float enc_ratio = 1.01f; + if((difz > -r1 * enc_ratio) && (dot3(dif_second, tg) < r2 * enc_ratio)) { + float a2 = 1.0f - (dirz*dirz*(1 + gd*gd*enc_ratio*enc_ratio)); + float c2 = dot3(dif, dif) - difz * difz * (1 + gd*gd*enc_ratio*enc_ratio) - r1*r1*enc_ratio*enc_ratio - 2*r1*difz*gd*enc_ratio; + if(a2*c2 < 0.0f) + return false; + } + } + +#ifdef __VISIBILITY_FLAG__ + /* visibility flag test. we do it here under the assumption + * that most triangles are culled by node flags */ + if(kernel_tex_fetch(__prim_visibility, curveAddr) & visibility) +#endif + { + /* record intersection */ + isect->t = t; + isect->u = z*invl; + isect->v = gd; + isect->prim = curveAddr; + isect->object = object; + isect->type = type; + + return true; + } + } + } + + return false; + +#ifndef __KERNEL_SSE2__ +# undef len3_squared +# undef len3 +# undef dot3 +#endif +} + +ccl_device_inline float3 curvetangent(float t, float3 p0, float3 p1, float3 p2, float3 p3) +{ + float fc = 0.71f; + float data[4]; + float t2 = t * t; + data[0] = -3.0f * fc * t2 + 4.0f * fc * t - fc; + data[1] = 3.0f * (2.0f - fc) * t2 + 2.0f * (fc - 3.0f) * t; + data[2] = 3.0f * (fc - 2.0f) * t2 + 2.0f * (3.0f - 2.0f * fc) * t + fc; + data[3] = 3.0f * fc * t2 - 2.0f * fc * t; + return data[0] * p0 + data[1] * p1 + data[2] * p2 + data[3] * p3; +} + +ccl_device_inline float3 curvepoint(float t, float3 p0, float3 p1, float3 p2, float3 p3) +{ + float data[4]; + float fc = 0.71f; + float t2 = t * t; + float t3 = t2 * t; + data[0] = -fc * t3 + 2.0f * fc * t2 - fc * t; + data[1] = (2.0f - fc) * t3 + (fc - 3.0f) * t2 + 1.0f; + data[2] = (fc - 2.0f) * t3 + (3.0f - 2.0f * fc) * t2 + fc * t; + data[3] = fc * t3 - fc * t2; + return data[0] * p0 + data[1] * p1 + data[2] * p2 + data[3] * p3; +} + +ccl_device_inline float3 curve_refine(KernelGlobals *kg, + ShaderData *sd, + const Intersection *isect, + const Ray *ray) +{ + int flag = kernel_data.curve.curveflags; + float t = isect->t; + float3 P = ray->P; + float3 D = ray->D; + + if(isect->object != OBJECT_NONE) { +#ifdef __OBJECT_MOTION__ + Transform tfm = sd->ob_itfm; +#else + Transform tfm = object_fetch_transform(kg, isect->object, OBJECT_INVERSE_TRANSFORM); +#endif + + P = transform_point(&tfm, P); + D = transform_direction(&tfm, D*t); + D = normalize_len(D, &t); + } + + int prim = kernel_tex_fetch(__prim_index, isect->prim); + float4 v00 = kernel_tex_fetch(__curves, prim); + + int k0 = __float_as_int(v00.x) + PRIMITIVE_UNPACK_SEGMENT(sd->type); + int k1 = k0 + 1; + + float3 tg; + + if(flag & CURVE_KN_INTERPOLATE) { + int ka = max(k0 - 1,__float_as_int(v00.x)); + int kb = min(k1 + 1,__float_as_int(v00.x) + __float_as_int(v00.y) - 1); + + float4 P_curve[4]; + + if(sd->type & PRIMITIVE_CURVE) { + P_curve[0] = kernel_tex_fetch(__curve_keys, ka); + P_curve[1] = kernel_tex_fetch(__curve_keys, k0); + P_curve[2] = kernel_tex_fetch(__curve_keys, k1); + P_curve[3] = kernel_tex_fetch(__curve_keys, kb); + } + else { + motion_cardinal_curve_keys(kg, sd->object, sd->prim, sd->time, ka, k0, k1, kb, P_curve); + } + + float3 p[4]; + p[0] = float4_to_float3(P_curve[0]); + p[1] = float4_to_float3(P_curve[1]); + p[2] = float4_to_float3(P_curve[2]); + p[3] = float4_to_float3(P_curve[3]); + + P = P + D*t; + +#ifdef __UV__ + sd->u = isect->u; + sd->v = 0.0f; +#endif + + tg = normalize(curvetangent(isect->u, p[0], p[1], p[2], p[3])); + + if(kernel_data.curve.curveflags & CURVE_KN_RIBBONS) { + sd->Ng = normalize(-(D - tg * (dot(tg, D)))); + } + else { + /* direction from inside to surface of curve */ + float3 p_curr = curvepoint(isect->u, p[0], p[1], p[2], p[3]); + sd->Ng = normalize(P - p_curr); + + /* adjustment for changing radius */ + float gd = isect->v; + + if(gd != 0.0f) { + sd->Ng = sd->Ng - gd * tg; + sd->Ng = normalize(sd->Ng); + } + } + + /* todo: sometimes the normal is still so that this is detected as + * backfacing even if cull backfaces is enabled */ + + sd->N = sd->Ng; + } + else { + float4 P_curve[2]; + + if(sd->type & PRIMITIVE_CURVE) { + P_curve[0]= kernel_tex_fetch(__curve_keys, k0); + P_curve[1]= kernel_tex_fetch(__curve_keys, k1); + } + else { + motion_curve_keys(kg, sd->object, sd->prim, sd->time, k0, k1, P_curve); + } + + float l = 1.0f; + tg = normalize_len(float4_to_float3(P_curve[1] - P_curve[0]), &l); + + P = P + D*t; + + float3 dif = P - float4_to_float3(P_curve[0]); + +#ifdef __UV__ + sd->u = dot(dif,tg)/l; + sd->v = 0.0f; +#endif + + if(flag & CURVE_KN_TRUETANGENTGNORMAL) { + sd->Ng = -(D - tg * dot(tg, D)); + sd->Ng = normalize(sd->Ng); + } + else { + float gd = isect->v; + + /* direction from inside to surface of curve */ + sd->Ng = (dif - tg * sd->u * l) / (P_curve[0].w + sd->u * l * gd); + + /* adjustment for changing radius */ + if(gd != 0.0f) { + sd->Ng = sd->Ng - gd * tg; + sd->Ng = normalize(sd->Ng); + } + } + + sd->N = sd->Ng; + } + +#ifdef __DPDU__ + /* dPdu/dPdv */ + sd->dPdu = tg; + sd->dPdv = cross(tg, sd->Ng); +#endif + + if(isect->object != OBJECT_NONE) { +#ifdef __OBJECT_MOTION__ + Transform tfm = sd->ob_tfm; +#else + Transform tfm = object_fetch_transform(kg, isect->object, OBJECT_TRANSFORM); +#endif + + P = transform_point(&tfm, P); + } + + return P; +} + +#endif + +CCL_NAMESPACE_END |