Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/bvh/split.cpp

@@ -0,0 +1,576 @@
+/* SPDX-FileCopyrightText: 2009-2010 NVIDIA Corporation
+ * SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Adapted code from NVIDIA Corporation. */
+
+#include "bvh/split.h"
+
+#include "bvh/build.h"
+#include "bvh/sort.h"
+
+#include "scene/hair.h"
+#include "scene/mesh.h"
+#include "scene/object.h"
+#include "scene/pointcloud.h"
+
+#include "util/algorithm.h"
+
+CCL_NAMESPACE_BEGIN
+
+/* Object Split */
+
+BVHObjectSplit::BVHObjectSplit(BVHBuild *builder,
+                               BVHSpatialStorage *storage,
+                               const BVHRange &range,
+                               vector<BVHReference> &references,
+                               const float nodeSAH,
+                               const BVHUnaligned *unaligned_heuristic,
+                               const Transform *aligned_space)
+    : sah(FLT_MAX),
+      dim(0),
+      num_left(0),
+      left_bounds(BoundBox::empty),
+      right_bounds(BoundBox::empty),
+      storage_(storage),
+      references_(&references),
+      unaligned_heuristic_(unaligned_heuristic),
+      aligned_space_(aligned_space)
+{
+  const BVHReference *ref_ptr = &references_->at(range.start());
+  float min_sah = FLT_MAX;
+
+  for (int dim = 0; dim < 3; dim++) {
+    /* Sort references. */
+    bvh_reference_sort(range.start(),
+                       range.end(),
+                       &references_->at(0),
+                       dim,
+                       unaligned_heuristic_,
+                       aligned_space_);
+
+    // Resize must be called after every bvh_reference_sort, as sorting may use a task pool for
+    // large ranges. This may cause another BVHObjectSplit to use and resize the storage on the
+    // same thread.
+    storage_->right_bounds.resize(range.size());
+
+    /* sweep right to left and determine bounds. */
+    BoundBox right_bounds = BoundBox::empty;
+    for (int i = range.size() - 1; i > 0; i--) {
+      const BoundBox prim_bounds = get_prim_bounds(ref_ptr[i]);
+      right_bounds.grow(prim_bounds);
+      storage_->right_bounds[i - 1] = right_bounds;
+    }
+
+    /* sweep left to right and select lowest SAH. */
+    BoundBox left_bounds = BoundBox::empty;
+
+    for (int i = 1; i < range.size(); i++) {
+      const BoundBox prim_bounds = get_prim_bounds(ref_ptr[i - 1]);
+      left_bounds.grow(prim_bounds);
+      right_bounds = storage_->right_bounds[i - 1];
+
+      const float sah = nodeSAH + left_bounds.safe_area() * builder->params.primitive_cost(i) +
+                        right_bounds.safe_area() *
+                            builder->params.primitive_cost(range.size() - i);
+
+      if (sah < min_sah) {
+        min_sah = sah;
+
+        this->sah = sah;
+        this->dim = dim;
+        this->num_left = i;
+        this->left_bounds = left_bounds;
+        this->right_bounds = right_bounds;
+      }
+    }
+  }
+}
+
+void BVHObjectSplit::split(BVHRange &left, BVHRange &right, const BVHRange &range)
+{
+  assert(!references_->empty());
+  /* sort references according to split */
+  bvh_reference_sort(range.start(),
+                     range.end(),
+                     &references_->at(0),
+                     this->dim,
+                     unaligned_heuristic_,
+                     aligned_space_);
+
+  BoundBox effective_left_bounds;
+  BoundBox effective_right_bounds;
+  const int num_right = range.size() - this->num_left;
+  if (aligned_space_ == nullptr) {
+    effective_left_bounds = left_bounds;
+    effective_right_bounds = right_bounds;
+  }
+  else {
+    effective_left_bounds = BoundBox::empty;
+    effective_right_bounds = BoundBox::empty;
+    for (int i = 0; i < this->num_left; ++i) {
+      const BoundBox prim_boundbox = references_->at(range.start() + i).bounds();
+      effective_left_bounds.grow(prim_boundbox);
+    }
+    for (int i = 0; i < num_right; ++i) {
+      const BoundBox prim_boundbox = references_->at(range.start() + this->num_left + i).bounds();
+      effective_right_bounds.grow(prim_boundbox);
+    }
+  }
+
+  /* split node ranges */
+  left = BVHRange(effective_left_bounds, range.start(), this->num_left);
+  right = BVHRange(effective_right_bounds, left.end(), num_right);
+}
+
+/* Spatial Split */
+
+BVHSpatialSplit::BVHSpatialSplit(const BVHBuild &builder,
+                                 BVHSpatialStorage *storage,
+                                 const BVHRange &range,
+                                 vector<BVHReference> &references,
+                                 const float nodeSAH,
+                                 const BVHUnaligned *unaligned_heuristic,
+                                 const Transform *aligned_space)
+    : sah(FLT_MAX),
+      dim(0),
+      pos(0.0f),
+      storage_(storage),
+      references_(&references),
+      unaligned_heuristic_(unaligned_heuristic),
+      aligned_space_(aligned_space)
+{
+  /* initialize bins. */
+  BoundBox range_bounds;
+  if (aligned_space == nullptr) {
+    range_bounds = range.bounds();
+  }
+  else {
+    range_bounds = unaligned_heuristic->compute_aligned_boundbox(
+        range, &references_->at(0), *aligned_space);
+  }
+
+  float3 origin = range_bounds.min;
+  float3 binSize = (range_bounds.max - origin) * (1.0f / (float)BVHParams::NUM_SPATIAL_BINS);
+  const float3 invBinSize = safe_divide(make_float3(1.0f), binSize);
+
+  for (int dim = 0; dim < 3; dim++) {
+    for (int i = 0; i < BVHParams::NUM_SPATIAL_BINS; i++) {
+      BVHSpatialBin &bin = storage_->bins[dim][i];
+
+      bin.bounds = BoundBox::empty;
+      bin.enter = 0;
+      bin.exit = 0;
+    }
+  }
+
+  /* chop references into bins. */
+  for (unsigned int refIdx = range.start(); refIdx < range.end(); refIdx++) {
+    const BVHReference &ref = references_->at(refIdx);
+    const BoundBox prim_bounds = get_prim_bounds(ref);
+    const float3 firstBinf = (prim_bounds.min - origin) * invBinSize;
+    const float3 lastBinf = (prim_bounds.max - origin) * invBinSize;
+    int3 firstBin = make_int3((int)firstBinf.x, (int)firstBinf.y, (int)firstBinf.z);
+    int3 lastBin = make_int3((int)lastBinf.x, (int)lastBinf.y, (int)lastBinf.z);
+
+    firstBin = clamp(firstBin, 0, BVHParams::NUM_SPATIAL_BINS - 1);
+    lastBin = clamp(lastBin, firstBin, BVHParams::NUM_SPATIAL_BINS - 1);
+
+    for (int dim = 0; dim < 3; dim++) {
+      BVHReference currRef(
+          get_prim_bounds(ref), ref.prim_index(), ref.prim_object(), ref.prim_type());
+
+      for (int i = firstBin[dim]; i < lastBin[dim]; i++) {
+        BVHReference leftRef;
+        BVHReference rightRef;
+
+        split_reference(
+            builder, leftRef, rightRef, currRef, dim, origin[dim] + binSize[dim] * (float)(i + 1));
+        storage_->bins[dim][i].bounds.grow(leftRef.bounds());
+        currRef = rightRef;
+      }
+
+      storage_->bins[dim][lastBin[dim]].bounds.grow(currRef.bounds());
+      storage_->bins[dim][firstBin[dim]].enter++;
+      storage_->bins[dim][lastBin[dim]].exit++;
+    }
+  }
+
+  /* select best split plane. */
+  storage_->right_bounds.resize(BVHParams::NUM_SPATIAL_BINS);
+  for (int dim = 0; dim < 3; dim++) {
+    /* sweep right to left and determine bounds. */
+    BoundBox right_bounds = BoundBox::empty;
+    for (int i = BVHParams::NUM_SPATIAL_BINS - 1; i > 0; i--) {
+      right_bounds.grow(storage_->bins[dim][i].bounds);
+      storage_->right_bounds[i - 1] = right_bounds;
+    }
+
+    /* sweep left to right and select lowest SAH. */
+    BoundBox left_bounds = BoundBox::empty;
+    int leftNum = 0;
+    int rightNum = range.size();
+
+    for (int i = 1; i < BVHParams::NUM_SPATIAL_BINS; i++) {
+      left_bounds.grow(storage_->bins[dim][i - 1].bounds);
+      leftNum += storage_->bins[dim][i - 1].enter;
+      rightNum -= storage_->bins[dim][i - 1].exit;
+
+      const float sah = nodeSAH +
+                        left_bounds.safe_area() * builder.params.primitive_cost(leftNum) +
+                        storage_->right_bounds[i - 1].safe_area() *
+                            builder.params.primitive_cost(rightNum);
+
+      if (sah < this->sah) {
+        this->sah = sah;
+        this->dim = dim;
+        this->pos = origin[dim] + binSize[dim] * (float)i;
+      }
+    }
+  }
+}
+
+void BVHSpatialSplit::split(BVHBuild *builder,
+                            BVHRange &left,
+                            BVHRange &right,
+                            const BVHRange &range)
+{
+  /* Categorize references and compute bounds.
+   *
+   * Left-hand side:          [left_start, left_end[
+   * Uncategorized/split:     [left_end, right_start[
+   * Right-hand side:         [right_start, refs.size()[ */
+
+  vector<BVHReference> &refs = *references_;
+  const int left_start = range.start();
+  int left_end = left_start;
+  int right_start = range.end();
+  int right_end = range.end();
+  BoundBox left_bounds = BoundBox::empty;
+  BoundBox right_bounds = BoundBox::empty;
+
+  for (int i = left_end; i < right_start; i++) {
+    BoundBox prim_bounds = get_prim_bounds(refs[i]);
+    if (prim_bounds.max[this->dim] <= this->pos) {
+      /* entirely on the left-hand side */
+      left_bounds.grow(prim_bounds);
+      swap(refs[i], refs[left_end++]);
+    }
+    else if (prim_bounds.min[this->dim] >= this->pos) {
+      /* entirely on the right-hand side */
+      right_bounds.grow(prim_bounds);
+      swap(refs[i--], refs[--right_start]);
+    }
+  }
+
+  /* Duplicate or unsplit references intersecting both sides.
+   *
+   * Duplication happens into a temporary pre-allocated vector in order to
+   * reduce number of `memmove()` calls happening in `vector.insert()`.
+   */
+  vector<BVHReference> &new_refs = storage_->new_references;
+  new_refs.clear();
+  new_refs.reserve(right_start - left_end);
+  while (left_end < right_start) {
+    /* split reference. */
+    const BVHReference curr_ref(get_prim_bounds(refs[left_end]),
+                                refs[left_end].prim_index(),
+                                refs[left_end].prim_object(),
+                                refs[left_end].prim_type());
+    BVHReference lref;
+    BVHReference rref;
+    split_reference(*builder, lref, rref, curr_ref, this->dim, this->pos);
+
+    /* compute SAH for duplicate/unsplit candidates. */
+    BoundBox lub = left_bounds;   // Unsplit to left:     new left-hand bounds.
+    BoundBox rub = right_bounds;  // Unsplit to right:    new right-hand bounds.
+    BoundBox ldb = left_bounds;   // Duplicate:           new left-hand bounds.
+    BoundBox rdb = right_bounds;  // Duplicate:           new right-hand bounds.
+
+    lub.grow(curr_ref.bounds());
+    rub.grow(curr_ref.bounds());
+    ldb.grow(lref.bounds());
+    rdb.grow(rref.bounds());
+
+    const float lac = builder->params.primitive_cost(left_end - left_start);
+    const float rac = builder->params.primitive_cost(right_end - right_start);
+    const float lbc = builder->params.primitive_cost(left_end - left_start + 1);
+    const float rbc = builder->params.primitive_cost(right_end - right_start + 1);
+
+    const float unsplitLeftSAH = lub.safe_area() * lbc + right_bounds.safe_area() * rac;
+    const float unsplitRightSAH = left_bounds.safe_area() * lac + rub.safe_area() * rbc;
+    const float duplicateSAH = ldb.safe_area() * lbc + rdb.safe_area() * rbc;
+    const float minSAH = min(min(unsplitLeftSAH, unsplitRightSAH), duplicateSAH);
+
+    if (minSAH == unsplitLeftSAH) {
+      /* unsplit to left */
+      left_bounds = lub;
+      left_end++;
+    }
+    else if (minSAH == unsplitRightSAH) {
+      /* unsplit to right */
+      right_bounds = rub;
+      swap(refs[left_end], refs[--right_start]);
+    }
+    else {
+      /* duplicate */
+      left_bounds = ldb;
+      right_bounds = rdb;
+      refs[left_end++] = lref;
+      new_refs.push_back(rref);
+      right_end++;
+    }
+  }
+  /* Insert duplicated references into actual array in one go. */
+  if (!new_refs.empty()) {
+    refs.insert(refs.begin() + (right_end - new_refs.size()), new_refs.begin(), new_refs.end());
+  }
+  if (aligned_space_ != nullptr) {
+    left_bounds = right_bounds = BoundBox::empty;
+    for (int i = left_start; i < left_end - left_start; ++i) {
+      const BoundBox prim_boundbox = references_->at(i).bounds();
+      left_bounds.grow(prim_boundbox);
+    }
+    for (int i = right_start; i < right_end - right_start; ++i) {
+      const BoundBox prim_boundbox = references_->at(i).bounds();
+      right_bounds.grow(prim_boundbox);
+    }
+  }
+  left = BVHRange(left_bounds, left_start, left_end - left_start);
+  right = BVHRange(right_bounds, right_start, right_end - right_start);
+}
+
+void BVHSpatialSplit::split_triangle_primitive(const Mesh *mesh,
+                                               const Transform *tfm,
+                                               const int prim_index,
+                                               const int dim,
+                                               const float pos,
+                                               BoundBox &left_bounds,
+                                               BoundBox &right_bounds)
+{
+  const Mesh::Triangle t = mesh->get_triangle(prim_index);
+  const packed_float3 *verts = mesh->get_position();
+  float3 v1 = tfm ? transform_point(tfm, verts[t.v[2]]) : float3(verts[t.v[2]]);
+  v1 = get_unaligned_point(v1);
+
+  for (int i = 0; i < 3; i++) {
+    float3 v0 = v1;
+    const int vindex = t.v[i];
+    v1 = tfm ? transform_point(tfm, verts[vindex]) : float3(verts[vindex]);
+    v1 = get_unaligned_point(v1);
+    const float v0p = v0[dim];
+    const float v1p = v1[dim];
+
+    /* insert vertex to the boxes it belongs to. */
+    if (v0p <= pos) {
+      left_bounds.grow(v0);
+    }
+
+    if (v0p >= pos) {
+      right_bounds.grow(v0);
+    }
+
+    /* edge intersects the plane => insert intersection to both boxes. */
+    if ((v0p < pos && v1p > pos) || (v0p > pos && v1p < pos)) {
+      const float3 t = mix(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f));
+      left_bounds.grow(t);
+      right_bounds.grow(t);
+    }
+  }
+}
+
+void BVHSpatialSplit::split_curve_primitive(const Hair *hair,
+                                            const Transform *tfm,
+                                            const int prim_index,
+                                            const int segment_index,
+                                            const int dim,
+                                            const float pos,
+                                            BoundBox &left_bounds,
+                                            BoundBox &right_bounds)
+{
+  /* curve split: NOTE - Currently ignores curve width and needs to be fixed. */
+  const Hair::Curve curve = hair->get_curve(prim_index);
+  const int k0 = curve.first_key + segment_index;
+  const int k1 = k0 + 1;
+  const packed_float3 *curve_keys = hair->get_position();
+  float3 v0 = curve_keys[k0];
+  float3 v1 = curve_keys[k1];
+
+  if (tfm != nullptr) {
+    v0 = transform_point(tfm, v0);
+    v1 = transform_point(tfm, v1);
+  }
+  v0 = get_unaligned_point(v0);
+  v1 = get_unaligned_point(v1);
+
+  const float v0p = v0[dim];
+  const float v1p = v1[dim];
+
+  /* insert vertex to the boxes it belongs to. */
+  if (v0p <= pos) {
+    left_bounds.grow(v0);
+  }
+
+  if (v0p >= pos) {
+    right_bounds.grow(v0);
+  }
+
+  if (v1p <= pos) {
+    left_bounds.grow(v1);
+  }
+
+  if (v1p >= pos) {
+    right_bounds.grow(v1);
+  }
+
+  /* edge intersects the plane => insert intersection to both boxes. */
+  if ((v0p < pos && v1p > pos) || (v0p > pos && v1p < pos)) {
+    const float3 t = mix(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f));
+    left_bounds.grow(t);
+    right_bounds.grow(t);
+  }
+}
+
+void BVHSpatialSplit::split_point_primitive(const PointCloud *pointcloud,
+                                            const Transform *tfm,
+                                            const int prim_index,
+                                            const int dim,
+                                            const float pos,
+                                            BoundBox &left_bounds,
+                                            BoundBox &right_bounds)
+{
+  /* No real splitting support for points, assume they are small enough for it
+   * not to matter. */
+  float3 point = float3(pointcloud->get_position()[prim_index]);
+  const float radius = pointcloud->get_radius()[prim_index];
+
+  if (tfm != nullptr) {
+    point = transform_point(tfm, point);
+  }
+  point = get_unaligned_point(point);
+
+  if (point[dim] - radius <= pos) {
+    left_bounds.grow(point, radius);
+  }
+
+  if (point[dim] + radius >= pos) {
+    right_bounds.grow(point, radius);
+  }
+}
+
+void BVHSpatialSplit::split_triangle_reference(const BVHReference &ref,
+                                               const Mesh *mesh,
+                                               const int dim,
+                                               const float pos,
+                                               BoundBox &left_bounds,
+                                               BoundBox &right_bounds)
+{
+  split_triangle_primitive(mesh, nullptr, ref.prim_index(), dim, pos, left_bounds, right_bounds);
+}
+
+void BVHSpatialSplit::split_curve_reference(const BVHReference &ref,
+                                            const Hair *hair,
+                                            const int dim,
+                                            const float pos,
+                                            BoundBox &left_bounds,
+                                            BoundBox &right_bounds)
+{
+  split_curve_primitive(hair,
+                        nullptr,
+                        ref.prim_index(),
+                        PRIMITIVE_UNPACK_SEGMENT(ref.prim_type()),
+                        dim,
+                        pos,
+                        left_bounds,
+                        right_bounds);
+}
+
+void BVHSpatialSplit::split_point_reference(const BVHReference &ref,
+                                            const PointCloud *pointcloud,
+                                            const int dim,
+                                            const float pos,
+                                            BoundBox &left_bounds,
+                                            BoundBox &right_bounds)
+{
+  split_point_primitive(
+      pointcloud, nullptr, ref.prim_index(), dim, pos, left_bounds, right_bounds);
+}
+
+void BVHSpatialSplit::split_object_reference(const Object *object,
+                                             const int dim,
+                                             const float pos,
+                                             BoundBox &left_bounds,
+                                             BoundBox &right_bounds)
+{
+  Geometry *geom = object->get_geometry();
+
+  if (geom->is_mesh() || geom->is_volume()) {
+    Mesh *mesh = static_cast<Mesh *>(geom);
+    for (int tri_idx = 0; tri_idx < mesh->num_triangles(); ++tri_idx) {
+      split_triangle_primitive(
+          mesh, &object->get_tfm(), tri_idx, dim, pos, left_bounds, right_bounds);
+    }
+  }
+  else if (geom->is_hair()) {
+    Hair *hair = static_cast<Hair *>(geom);
+    for (int curve_idx = 0; curve_idx < hair->num_curves(); ++curve_idx) {
+      const Hair::Curve curve = hair->get_curve(curve_idx);
+      for (int segment_idx = 0; segment_idx < curve.num_keys - 1; ++segment_idx) {
+        split_curve_primitive(
+            hair, &object->get_tfm(), curve_idx, segment_idx, dim, pos, left_bounds, right_bounds);
+      }
+    }
+  }
+  else if (geom->is_pointcloud()) {
+    PointCloud *pointcloud = static_cast<PointCloud *>(geom);
+    for (int point_idx = 0; point_idx < pointcloud->num_points(); ++point_idx) {
+      split_point_primitive(
+          pointcloud, &object->get_tfm(), point_idx, dim, pos, left_bounds, right_bounds);
+    }
+  }
+}
+
+void BVHSpatialSplit::split_reference(const BVHBuild &builder,
+                                      BVHReference &left,
+                                      BVHReference &right,
+                                      const BVHReference &ref,
+                                      const int dim,
+                                      const float pos)
+{
+  /* Initialize bounding-boxes. */
+  BoundBox left_bounds = BoundBox::empty;
+  BoundBox right_bounds = BoundBox::empty;
+
+  /* loop over vertices/edges. */
+  const Object *ob = builder.objects[ref.prim_object()];
+
+  if (ref.prim_type() & PRIMITIVE_TRIANGLE) {
+    Mesh *mesh = static_cast<Mesh *>(ob->get_geometry());
+    split_triangle_reference(ref, mesh, dim, pos, left_bounds, right_bounds);
+  }
+  else if (ref.prim_type() & PRIMITIVE_CURVE) {
+    Hair *hair = static_cast<Hair *>(ob->get_geometry());
+    split_curve_reference(ref, hair, dim, pos, left_bounds, right_bounds);
+  }
+  else if (ref.prim_type() & PRIMITIVE_POINT) {
+    PointCloud *pointcloud = static_cast<PointCloud *>(ob->get_geometry());
+    split_point_reference(ref, pointcloud, dim, pos, left_bounds, right_bounds);
+  }
+  else {
+    split_object_reference(ob, dim, pos, left_bounds, right_bounds);
+  }
+
+  /* intersect with original bounds. */
+  left_bounds.max[dim] = pos;
+  right_bounds.min[dim] = pos;
+
+  left_bounds.intersect(ref.bounds());
+  right_bounds.intersect(ref.bounds());
+
+  /* set references */
+  left = BVHReference(left_bounds, ref.prim_index(), ref.prim_object(), ref.prim_type());
+  right = BVHReference(right_bounds, ref.prim_index(), ref.prim_object(), ref.prim_type());
+}
+
+CCL_NAMESPACE_END