forked from bartvdbraak/blender
313 lines
10 KiB
C
313 lines
10 KiB
C
/*
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* Adapted from code Copyright 2009-2010 NVIDIA Corporation,
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* and code copyright 2009-2012 Intel Corporation
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*
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* Modifications Copyright 2011-2013, Blender Foundation.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* This is a template BVH traversal function for subsurface scattering, where
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* various features can be enabled/disabled. This way we can compile optimized
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* versions for each case without new features slowing things down.
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*
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* BVH_INSTANCING: object instancing
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* BVH_MOTION: motion blur rendering
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*
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*/
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#define FEATURE(f) (((BVH_FUNCTION_FEATURES) & (f)) != 0)
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__device uint BVH_FUNCTION_NAME(KernelGlobals *kg, const Ray *ray, Intersection *isect_array,
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int subsurface_object, uint *lcg_state, int max_hits)
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{
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/* todo:
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* - test if pushing distance on the stack helps (for non shadow rays)
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* - separate version for shadow rays
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* - likely and unlikely for if() statements
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* - SSE for hair
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* - test restrict attribute for pointers
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*/
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/* traversal stack in CUDA thread-local memory */
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int traversalStack[BVH_STACK_SIZE];
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traversalStack[0] = ENTRYPOINT_SENTINEL;
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/* traversal variables in registers */
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int stackPtr = 0;
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int nodeAddr = kernel_data.bvh.root;
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/* ray parameters in registers */
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const float tmax = ray->t;
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float3 P = ray->P;
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float3 idir = bvh_inverse_direction(ray->D);
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int object = ~0;
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const uint visibility = ~0;
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uint num_hits = 0;
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#if FEATURE(BVH_MOTION)
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Transform ob_tfm;
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#endif
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#if defined(__KERNEL_SSE2__)
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const shuffle_swap_t shuf_identity = shuffle_swap_identity();
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const shuffle_swap_t shuf_swap = shuffle_swap_swap();
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const __m128i pn = _mm_set_epi32(0x80000000, 0x80000000, 0x00000000, 0x00000000);
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__m128 Psplat[3], idirsplat[3];
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Psplat[0] = _mm_set_ps1(P.x);
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Psplat[1] = _mm_set_ps1(P.y);
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Psplat[2] = _mm_set_ps1(P.z);
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idirsplat[0] = _mm_xor_ps(_mm_set_ps1(idir.x), _mm_castsi128_ps(pn));
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idirsplat[1] = _mm_xor_ps(_mm_set_ps1(idir.y), _mm_castsi128_ps(pn));
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idirsplat[2] = _mm_xor_ps(_mm_set_ps1(idir.z), _mm_castsi128_ps(pn));
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__m128 tsplat = _mm_set_ps(-tmax, -tmax, 0.0f, 0.0f);
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shuffle_swap_t shufflex = (idir.x >= 0)? shuf_identity: shuf_swap;
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shuffle_swap_t shuffley = (idir.y >= 0)? shuf_identity: shuf_swap;
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shuffle_swap_t shufflez = (idir.z >= 0)? shuf_identity: shuf_swap;
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#endif
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/* traversal loop */
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do {
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do
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{
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/* traverse internal nodes */
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while(nodeAddr >= 0 && nodeAddr != ENTRYPOINT_SENTINEL)
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{
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bool traverseChild0, traverseChild1;
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int nodeAddrChild1;
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#if !defined(__KERNEL_SSE2__)
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/* Intersect two child bounding boxes, non-SSE version */
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float t = tmax;
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/* fetch node data */
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float4 node0 = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+0);
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float4 node1 = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+1);
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float4 node2 = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+2);
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float4 cnodes = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+3);
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/* intersect ray against child nodes */
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NO_EXTENDED_PRECISION float c0lox = (node0.x - P.x) * idir.x;
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NO_EXTENDED_PRECISION float c0hix = (node0.z - P.x) * idir.x;
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NO_EXTENDED_PRECISION float c0loy = (node1.x - P.y) * idir.y;
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NO_EXTENDED_PRECISION float c0hiy = (node1.z - P.y) * idir.y;
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NO_EXTENDED_PRECISION float c0loz = (node2.x - P.z) * idir.z;
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NO_EXTENDED_PRECISION float c0hiz = (node2.z - P.z) * idir.z;
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NO_EXTENDED_PRECISION float c0min = max4(min(c0lox, c0hix), min(c0loy, c0hiy), min(c0loz, c0hiz), 0.0f);
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NO_EXTENDED_PRECISION float c0max = min4(max(c0lox, c0hix), max(c0loy, c0hiy), max(c0loz, c0hiz), t);
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NO_EXTENDED_PRECISION float c1lox = (node0.y - P.x) * idir.x;
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NO_EXTENDED_PRECISION float c1hix = (node0.w - P.x) * idir.x;
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NO_EXTENDED_PRECISION float c1loy = (node1.y - P.y) * idir.y;
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NO_EXTENDED_PRECISION float c1hiy = (node1.w - P.y) * idir.y;
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NO_EXTENDED_PRECISION float c1loz = (node2.y - P.z) * idir.z;
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NO_EXTENDED_PRECISION float c1hiz = (node2.w - P.z) * idir.z;
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NO_EXTENDED_PRECISION float c1min = max4(min(c1lox, c1hix), min(c1loy, c1hiy), min(c1loz, c1hiz), 0.0f);
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NO_EXTENDED_PRECISION float c1max = min4(max(c1lox, c1hix), max(c1loy, c1hiy), max(c1loz, c1hiz), t);
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/* decide which nodes to traverse next */
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#ifdef __VISIBILITY_FLAG__
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/* this visibility test gives a 5% performance hit, how to solve? */
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traverseChild0 = (c0max >= c0min) && (__float_as_uint(cnodes.z) & visibility);
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traverseChild1 = (c1max >= c1min) && (__float_as_uint(cnodes.w) & visibility);
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#else
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traverseChild0 = (c0max >= c0min);
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traverseChild1 = (c1max >= c1min);
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#endif
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#else // __KERNEL_SSE2__
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/* Intersect two child bounding boxes, SSE3 version adapted from Embree */
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/* fetch node data */
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__m128 *bvh_nodes = (__m128*)kg->__bvh_nodes.data + nodeAddr*BVH_NODE_SIZE;
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float4 cnodes = ((float4*)bvh_nodes)[3];
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/* intersect ray against child nodes */
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const __m128 tminmaxx = _mm_mul_ps(_mm_sub_ps(shuffle_swap(bvh_nodes[0], shufflex), Psplat[0]), idirsplat[0]);
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const __m128 tminmaxy = _mm_mul_ps(_mm_sub_ps(shuffle_swap(bvh_nodes[1], shuffley), Psplat[1]), idirsplat[1]);
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const __m128 tminmaxz = _mm_mul_ps(_mm_sub_ps(shuffle_swap(bvh_nodes[2], shufflez), Psplat[2]), idirsplat[2]);
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const __m128 tminmax = _mm_xor_ps(_mm_max_ps(_mm_max_ps(tminmaxx, tminmaxy), _mm_max_ps(tminmaxz, tsplat)), _mm_castsi128_ps(pn));
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const __m128 lrhit = _mm_cmple_ps(tminmax, shuffle_swap(tminmax, shuf_swap));
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/* decide which nodes to traverse next */
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#ifdef __VISIBILITY_FLAG__
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/* this visibility test gives a 5% performance hit, how to solve? */
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traverseChild0 = (_mm_movemask_ps(lrhit) & 1) && (__float_as_uint(cnodes.z) & visibility);
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traverseChild1 = (_mm_movemask_ps(lrhit) & 2) && (__float_as_uint(cnodes.w) & visibility);
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#else
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traverseChild0 = (_mm_movemask_ps(lrhit) & 1);
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traverseChild1 = (_mm_movemask_ps(lrhit) & 2);
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#endif
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#endif // __KERNEL_SSE2__
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nodeAddr = __float_as_int(cnodes.x);
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nodeAddrChild1 = __float_as_int(cnodes.y);
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if(traverseChild0 && traverseChild1) {
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/* both children were intersected, push the farther one */
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#if !defined(__KERNEL_SSE2__)
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bool closestChild1 = (c1min < c0min);
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#else
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union { __m128 m128; float v[4]; } uminmax;
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uminmax.m128 = tminmax;
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bool closestChild1 = uminmax.v[1] < uminmax.v[0];
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#endif
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if(closestChild1) {
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int tmp = nodeAddr;
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nodeAddr = nodeAddrChild1;
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nodeAddrChild1 = tmp;
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}
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++stackPtr;
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traversalStack[stackPtr] = nodeAddrChild1;
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}
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else {
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/* one child was intersected */
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if(traverseChild1) {
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nodeAddr = nodeAddrChild1;
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}
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else if(!traverseChild0) {
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/* neither child was intersected */
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nodeAddr = traversalStack[stackPtr];
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--stackPtr;
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}
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}
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}
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/* if node is leaf, fetch triangle list */
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if(nodeAddr < 0) {
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float4 leaf = kernel_tex_fetch(__bvh_nodes, (-nodeAddr-1)*BVH_NODE_SIZE+(BVH_NODE_SIZE-1));
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int primAddr = __float_as_int(leaf.x);
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#if FEATURE(BVH_INSTANCING)
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if(primAddr >= 0) {
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#endif
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int primAddr2 = __float_as_int(leaf.y);
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/* pop */
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nodeAddr = traversalStack[stackPtr];
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--stackPtr;
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/* primitive intersection */
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for(; primAddr < primAddr2; primAddr++) {
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#if FEATURE(BVH_HAIR)
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uint segment = kernel_tex_fetch(__prim_segment, primAddr);
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if(segment != ~0)
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continue;
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#endif
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/* only primitives from the same object */
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uint tri_object = (object == ~0)? kernel_tex_fetch(__prim_object, primAddr): object;
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if(tri_object == subsurface_object) {
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/* intersect ray against primitive */
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bvh_triangle_intersect_subsurface(kg, isect_array, P, idir, object, primAddr, tmax, &num_hits, lcg_state, max_hits);
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}
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}
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}
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#if FEATURE(BVH_INSTANCING)
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else {
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/* instance push */
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if(subsurface_object == kernel_tex_fetch(__prim_object, -primAddr-1)) {
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object = subsurface_object;
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float t_ignore = FLT_MAX;
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#if FEATURE(BVH_MOTION)
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bvh_instance_motion_push(kg, object, ray, &P, &idir, &t_ignore, &ob_tfm, tmax);
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#else
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bvh_instance_push(kg, object, ray, &P, &idir, &t_ignore, tmax);
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#endif
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#if defined(__KERNEL_SSE2__)
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Psplat[0] = _mm_set_ps1(P.x);
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Psplat[1] = _mm_set_ps1(P.y);
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Psplat[2] = _mm_set_ps1(P.z);
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idirsplat[0] = _mm_xor_ps(_mm_set_ps1(idir.x), _mm_castsi128_ps(pn));
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idirsplat[1] = _mm_xor_ps(_mm_set_ps1(idir.y), _mm_castsi128_ps(pn));
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idirsplat[2] = _mm_xor_ps(_mm_set_ps1(idir.z), _mm_castsi128_ps(pn));
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tsplat = _mm_set_ps(-tmax, -tmax, 0.0f, 0.0f);
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shufflex = (idir.x >= 0)? shuf_identity: shuf_swap;
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shuffley = (idir.y >= 0)? shuf_identity: shuf_swap;
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shufflez = (idir.z >= 0)? shuf_identity: shuf_swap;
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#endif
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++stackPtr;
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traversalStack[stackPtr] = ENTRYPOINT_SENTINEL;
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nodeAddr = kernel_tex_fetch(__object_node, object);
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}
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else {
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/* pop */
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nodeAddr = traversalStack[stackPtr];
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--stackPtr;
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}
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}
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}
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#endif
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} while(nodeAddr != ENTRYPOINT_SENTINEL);
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#if FEATURE(BVH_INSTANCING)
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if(stackPtr >= 0) {
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kernel_assert(object != ~0);
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/* instance pop */
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float t_ignore = FLT_MAX;
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#if FEATURE(BVH_MOTION)
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bvh_instance_motion_pop(kg, object, ray, &P, &idir, &t_ignore, &ob_tfm, tmax);
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#else
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bvh_instance_pop(kg, object, ray, &P, &idir, &t_ignore, tmax);
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#endif
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#if defined(__KERNEL_SSE2__)
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Psplat[0] = _mm_set_ps1(P.x);
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Psplat[1] = _mm_set_ps1(P.y);
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Psplat[2] = _mm_set_ps1(P.z);
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idirsplat[0] = _mm_xor_ps(_mm_set_ps1(idir.x), _mm_castsi128_ps(pn));
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idirsplat[1] = _mm_xor_ps(_mm_set_ps1(idir.y), _mm_castsi128_ps(pn));
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idirsplat[2] = _mm_xor_ps(_mm_set_ps1(idir.z), _mm_castsi128_ps(pn));
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tsplat = _mm_set_ps(-tmax, -tmax, 0.0f, 0.0f);
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shufflex = (idir.x >= 0)? shuf_identity: shuf_swap;
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shuffley = (idir.y >= 0)? shuf_identity: shuf_swap;
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shufflez = (idir.z >= 0)? shuf_identity: shuf_swap;
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#endif
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object = ~0;
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nodeAddr = traversalStack[stackPtr];
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--stackPtr;
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}
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#endif
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} while(nodeAddr != ENTRYPOINT_SENTINEL);
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return num_hits;
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}
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#undef FEATURE
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#undef BVH_FUNCTION_NAME
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#undef BVH_FUNCTION_FEATURES
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