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/*
* Adapted from code copyright 2009-2010 NVIDIA Corporation
* Modifications Copyright 2011, Blender Foundation.
*
* 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.
*/
#include "bvh/bvh4.h"
#include "render/mesh.h"
#include "render/object.h"
#include "bvh/bvh_node.h"
#include "bvh/bvh_unaligned.h"
CCL_NAMESPACE_BEGIN
/* Can we avoid this somehow or make more generic?
*
* Perhaps we can merge nodes in actual tree and make our
* life easier all over the place.
*/
BVH4::BVH4(const BVHParams ¶ms_,
const vector<Mesh *> &meshes_,
const vector<Object *> &objects_)
: BVH(params_, meshes_, objects_)
{
params.bvh_layout = BVH_LAYOUT_BVH4;
}
namespace {
BVHNode *bvh_node_merge_children_recursively(const BVHNode *node)
{
if (node->is_leaf()) {
return new LeafNode(*reinterpret_cast<const LeafNode *>(node));
}
/* Collect nodes of one layer deeper, allowing us to have more children in an inner layer. */
assert(node->num_children() <= 2);
const BVHNode *children[4];
const BVHNode *child0 = node->get_child(0);
const BVHNode *child1 = node->get_child(1);
int num_children = 0;
if (child0->is_leaf()) {
children[num_children++] = child0;
}
else {
children[num_children++] = child0->get_child(0);
children[num_children++] = child0->get_child(1);
}
if (child1->is_leaf()) {
children[num_children++] = child1;
}
else {
children[num_children++] = child1->get_child(0);
children[num_children++] = child1->get_child(1);
}
/* Merge children in subtrees. */
BVHNode *children4[4];
for (int i = 0; i < num_children; ++i) {
children4[i] = bvh_node_merge_children_recursively(children[i]);
}
/* Allocate new node. */
BVHNode *node4 = new InnerNode(node->bounds, children4, num_children);
/* TODO(sergey): Consider doing this from the InnerNode() constructor.
* But in order to do this nicely need to think of how to pass all the
* parameters there. */
if (node->is_unaligned) {
node4->is_unaligned = true;
node4->aligned_space = new Transform();
*node4->aligned_space = *node->aligned_space;
}
return node4;
}
} // namespace
BVHNode *BVH4::widen_children_nodes(const BVHNode *root)
{
if (root == NULL) {
return NULL;
}
if (root->is_leaf()) {
return const_cast<BVHNode *>(root);
}
BVHNode *root4 = bvh_node_merge_children_recursively(root);
/* TODO(sergey): Pack children nodes to parents which has less that 4
* children. */
return root4;
}
void BVH4::pack_leaf(const BVHStackEntry &e, const LeafNode *leaf)
{
float4 data[BVH_QNODE_LEAF_SIZE];
memset(data, 0, sizeof(data));
if (leaf->num_triangles() == 1 && pack.prim_index[leaf->lo] == -1) {
/* object */
data[0].x = __int_as_float(~(leaf->lo));
data[0].y = __int_as_float(0);
}
else {
/* triangle */
data[0].x = __int_as_float(leaf->lo);
data[0].y = __int_as_float(leaf->hi);
}
data[0].z = __uint_as_float(leaf->visibility);
if (leaf->num_triangles() != 0) {
data[0].w = __uint_as_float(pack.prim_type[leaf->lo]);
}
memcpy(&pack.leaf_nodes[e.idx], data, sizeof(float4) * BVH_QNODE_LEAF_SIZE);
}
void BVH4::pack_inner(const BVHStackEntry &e, const BVHStackEntry *en, int num)
{
bool has_unaligned = false;
/* Check whether we have to create unaligned node or all nodes are aligned
* and we can cut some corner here.
*/
if (params.use_unaligned_nodes) {
for (int i = 0; i < num; i++) {
if (en[i].node->is_unaligned) {
has_unaligned = true;
break;
}
}
}
if (has_unaligned) {
/* There's no unaligned children, pack into AABB node. */
pack_unaligned_inner(e, en, num);
}
else {
/* Create unaligned node with orientation transform for each of the
* children.
*/
pack_aligned_inner(e, en, num);
}
}
void BVH4::pack_aligned_inner(const BVHStackEntry &e, const BVHStackEntry *en, int num)
{
BoundBox bounds[4];
int child[4];
for (int i = 0; i < num; ++i) {
bounds[i] = en[i].node->bounds;
child[i] = en[i].encodeIdx();
}
pack_aligned_node(
e.idx, bounds, child, e.node->visibility, e.node->time_from, e.node->time_to, num);
}
void BVH4::pack_aligned_node(int idx,
const BoundBox *bounds,
const int *child,
const uint visibility,
const float time_from,
const float time_to,
const int num)
{
float4 data[BVH_QNODE_SIZE];
memset(data, 0, sizeof(data));
data[0].x = __uint_as_float(visibility & ~PATH_RAY_NODE_UNALIGNED);
data[0].y = time_from;
data[0].z = time_to;
for (int i = 0; i < num; i++) {
float3 bb_min = bounds[i].min;
float3 bb_max = bounds[i].max;
data[1][i] = bb_min.x;
data[2][i] = bb_max.x;
data[3][i] = bb_min.y;
data[4][i] = bb_max.y;
data[5][i] = bb_min.z;
data[6][i] = bb_max.z;
data[7][i] = __int_as_float(child[i]);
}
for (int i = num; i < 4; i++) {
/* We store BB which would never be recorded as intersection
* so kernel might safely assume there are always 4 child nodes.
*/
data[1][i] = FLT_MAX;
data[2][i] = -FLT_MAX;
data[3][i] = FLT_MAX;
data[4][i] = -FLT_MAX;
data[5][i] = FLT_MAX;
data[6][i] = -FLT_MAX;
data[7][i] = __int_as_float(0);
}
memcpy(&pack.nodes[idx], data, sizeof(float4) * BVH_QNODE_SIZE);
}
void BVH4::pack_unaligned_inner(const BVHStackEntry &e, const BVHStackEntry *en, int num)
{
Transform aligned_space[4];
BoundBox bounds[4];
int child[4];
for (int i = 0; i < num; ++i) {
aligned_space[i] = en[i].node->get_aligned_space();
bounds[i] = en[i].node->bounds;
child[i] = en[i].encodeIdx();
}
pack_unaligned_node(e.idx,
aligned_space,
bounds,
child,
e.node->visibility,
e.node->time_from,
e.node->time_to,
num);
}
void BVH4::pack_unaligned_node(int idx,
const Transform *aligned_space,
const BoundBox *bounds,
const int *child,
const uint visibility,
const float time_from,
const float time_to,
const int num)
{
float4 data[BVH_UNALIGNED_QNODE_SIZE];
memset(data, 0, sizeof(data));
data[0].x = __uint_as_float(visibility | PATH_RAY_NODE_UNALIGNED);
data[0].y = time_from;
data[0].z = time_to;
for (int i = 0; i < num; i++) {
Transform space = BVHUnaligned::compute_node_transform(bounds[i], aligned_space[i]);
data[1][i] = space.x.x;
data[2][i] = space.x.y;
data[3][i] = space.x.z;
data[4][i] = space.y.x;
data[5][i] = space.y.y;
data[6][i] = space.y.z;
data[7][i] = space.z.x;
data[8][i] = space.z.y;
data[9][i] = space.z.z;
data[10][i] = space.x.w;
data[11][i] = space.y.w;
data[12][i] = space.z.w;
data[13][i] = __int_as_float(child[i]);
}
for (int i = num; i < 4; i++) {
/* We store BB which would never be recorded as intersection
* so kernel might safely assume there are always 4 child nodes.
*/
data[1][i] = NAN;
data[2][i] = NAN;
data[3][i] = NAN;
data[4][i] = NAN;
data[5][i] = NAN;
data[6][i] = NAN;
data[7][i] = NAN;
data[8][i] = NAN;
data[9][i] = NAN;
data[10][i] = NAN;
data[11][i] = NAN;
data[12][i] = NAN;
data[13][i] = __int_as_float(0);
}
memcpy(&pack.nodes[idx], data, sizeof(float4) * BVH_UNALIGNED_QNODE_SIZE);
}
/* Quad SIMD Nodes */
void BVH4::pack_nodes(const BVHNode *root)
{
/* Calculate size of the arrays required. */
const size_t num_nodes = root->getSubtreeSize(BVH_STAT_NODE_COUNT);
const size_t num_leaf_nodes = root->getSubtreeSize(BVH_STAT_LEAF_COUNT);
assert(num_leaf_nodes <= num_nodes);
const size_t num_inner_nodes = num_nodes - num_leaf_nodes;
size_t node_size;
if (params.use_unaligned_nodes) {
const size_t num_unaligned_nodes = root->getSubtreeSize(BVH_STAT_UNALIGNED_INNER_COUNT);
node_size = (num_unaligned_nodes * BVH_UNALIGNED_QNODE_SIZE) +
(num_inner_nodes - num_unaligned_nodes) * BVH_QNODE_SIZE;
}
else {
node_size = num_inner_nodes * BVH_QNODE_SIZE;
}
/* Resize arrays. */
pack.nodes.clear();
pack.leaf_nodes.clear();
/* For top level BVH, first merge existing BVH's so we know the offsets. */
if (params.top_level) {
pack_instances(node_size, num_leaf_nodes * BVH_QNODE_LEAF_SIZE);
}
else {
pack.nodes.resize(node_size);
pack.leaf_nodes.resize(num_leaf_nodes * BVH_QNODE_LEAF_SIZE);
}
int nextNodeIdx = 0, nextLeafNodeIdx = 0;
vector<BVHStackEntry> stack;
stack.reserve(BVHParams::MAX_DEPTH * 2);
if (root->is_leaf()) {
stack.push_back(BVHStackEntry(root, nextLeafNodeIdx++));
}
else {
stack.push_back(BVHStackEntry(root, nextNodeIdx));
nextNodeIdx += root->has_unaligned() ? BVH_UNALIGNED_QNODE_SIZE : BVH_QNODE_SIZE;
}
while (stack.size()) {
BVHStackEntry e = stack.back();
stack.pop_back();
if (e.node->is_leaf()) {
/* leaf node */
const LeafNode *leaf = reinterpret_cast<const LeafNode *>(e.node);
pack_leaf(e, leaf);
}
else {
/* Inner node. */
/* Collect nodes. */
const BVHNode *children[4];
const int num_children = e.node->num_children();
/* Push entries on the stack. */
for (int i = 0; i < num_children; ++i) {
int idx;
children[i] = e.node->get_child(i);
assert(children[i] != NULL);
if (children[i]->is_leaf()) {
idx = nextLeafNodeIdx++;
}
else {
idx = nextNodeIdx;
nextNodeIdx += children[i]->has_unaligned() ? BVH_UNALIGNED_QNODE_SIZE : BVH_QNODE_SIZE;
}
stack.push_back(BVHStackEntry(children[i], idx));
}
/* Set node. */
pack_inner(e, &stack[stack.size() - num_children], num_children);
}
}
assert(node_size == nextNodeIdx);
/* Root index to start traversal at, to handle case of single leaf node. */
pack.root_index = (root->is_leaf()) ? -1 : 0;
}
void BVH4::refit_nodes()
{
assert(!params.top_level);
BoundBox bbox = BoundBox::empty;
uint visibility = 0;
refit_node(0, (pack.root_index == -1) ? true : false, bbox, visibility);
}
void BVH4::refit_node(int idx, bool leaf, BoundBox &bbox, uint &visibility)
{
if (leaf) {
/* Refit leaf node. */
int4 *data = &pack.leaf_nodes[idx];
int4 c = data[0];
BVH::refit_primitives(c.x, c.y, bbox, visibility);
/* TODO(sergey): This is actually a copy of pack_leaf(),
* but this chunk of code only knows actual data and has
* no idea about BVHNode.
*
* Would be nice to de-duplicate code, but trying to make
* making code more general ends up in much nastier code
* in my opinion so far.
*
* Same applies to the inner nodes case below.
*/
float4 leaf_data[BVH_QNODE_LEAF_SIZE];
leaf_data[0].x = __int_as_float(c.x);
leaf_data[0].y = __int_as_float(c.y);
leaf_data[0].z = __uint_as_float(visibility);
leaf_data[0].w = __uint_as_float(c.w);
memcpy(&pack.leaf_nodes[idx], leaf_data, sizeof(float4) * BVH_QNODE_LEAF_SIZE);
}
else {
int4 *data = &pack.nodes[idx];
bool is_unaligned = (data[0].x & PATH_RAY_NODE_UNALIGNED) != 0;
int4 c;
if (is_unaligned) {
c = data[13];
}
else {
c = data[7];
}
/* Refit inner node, set bbox from children. */
BoundBox child_bbox[4] = {BoundBox::empty, BoundBox::empty, BoundBox::empty, BoundBox::empty};
uint child_visibility[4] = {0};
int num_nodes = 0;
for (int i = 0; i < 4; ++i) {
if (c[i] != 0) {
refit_node((c[i] < 0) ? -c[i] - 1 : c[i], (c[i] < 0), child_bbox[i], child_visibility[i]);
++num_nodes;
bbox.grow(child_bbox[i]);
visibility |= child_visibility[i];
}
}
if (is_unaligned) {
Transform aligned_space[4] = {
transform_identity(), transform_identity(), transform_identity(), transform_identity()};
pack_unaligned_node(
idx, aligned_space, child_bbox, &c[0], visibility, 0.0f, 1.0f, num_nodes);
}
else {
pack_aligned_node(idx, child_bbox, &c[0], visibility, 0.0f, 1.0f, num_nodes);
}
}
}
CCL_NAMESPACE_END
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