Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/bvh/params.h

@@ -0,0 +1,325 @@
+/* SPDX-FileCopyrightText: 2009-2010 NVIDIA Corporation
+ * SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Adapted code from NVIDIA Corporation. */
+
+#pragma once
+
+#include "util/boundbox.h"
+#include "util/vector.h"
+
+#include "kernel/types.h"
+
+CCL_NAMESPACE_BEGIN
+
+/* Layout of BVH tree.
+ *
+ * For example, how wide BVH tree is, in terms of number of children
+ * per node.
+ */
+using BVHLayout = KernelBVHLayout;
+
+/* Type of BVH, in terms whether it is supported dynamic updates of meshes
+ * or whether modifying geometry requires full BVH rebuild.
+ */
+enum BVHType {
+  /* BVH supports dynamic updates of geometry.
+   *
+   * Faster for updating BVH tree when doing modifications in viewport,
+   * but slower for rendering.
+   */
+  BVH_TYPE_DYNAMIC = 0,
+  /* BVH tree is calculated for specific scene, updates in geometry
+   * requires full tree rebuild.
+   *
+   * Slower to update BVH tree when modifying objects in viewport, also
+   * slower to build final BVH tree but gives best possible render speed.
+   */
+  BVH_TYPE_STATIC = 1,
+
+  BVH_NUM_TYPES,
+};
+
+/* Names bit-flag type to denote which BVH layouts are supported by
+ * particular area.
+ *
+ * Bit-flags are the BVH_LAYOUT_* values.
+ */
+using BVHLayoutMask = int;
+
+/* Get human readable name of BVH layout. */
+const char *bvh_layout_name(BVHLayout layout);
+
+/* BVH Parameters */
+
+class BVHParams {
+ public:
+  /* spatial split area threshold */
+  bool use_spatial_split;
+  float spatial_split_alpha;
+
+  /* Unaligned nodes creation threshold */
+  float unaligned_split_threshold;
+
+  /* SAH costs */
+  float sah_node_cost;
+  float sah_primitive_cost;
+
+  /* number of primitives in leaf */
+  int min_leaf_size;
+  int max_triangle_leaf_size;
+  int max_motion_triangle_leaf_size;
+  int max_curve_leaf_size;
+  int max_motion_curve_leaf_size;
+  int max_point_leaf_size;
+  int max_motion_point_leaf_size;
+
+  /* object or mesh level bvh */
+  bool top_level;
+
+  /* BVH layout to be built. */
+  BVHLayout bvh_layout;
+
+  /* Use unaligned bounding boxes.
+   * Only used for curves BVH.
+   */
+  bool use_unaligned_nodes;
+
+  /* Use compact acceleration structure (Embree). */
+  bool use_compact_structure;
+
+  /* Split time range to this number of steps and create leaf node for each
+   * of this time steps.
+   *
+   * Speeds up rendering of motion primitives at the cost of higher memory usage.
+   */
+
+  /* Same as above, but for triangle primitives. */
+  int num_motion_triangle_steps;
+  int num_motion_curve_steps;
+  int num_motion_point_steps;
+
+  /* Same as in SceneParams. */
+  int bvh_type;
+
+  /* These are needed for Embree. */
+  int curve_subdivisions;
+
+  /* fixed parameters */
+  enum { MAX_DEPTH = 64, MAX_SPATIAL_DEPTH = 48, NUM_SPATIAL_BINS = 32 };
+
+  BVHParams()
+  {
+    use_spatial_split = true;
+    spatial_split_alpha = 1e-5f;
+
+    unaligned_split_threshold = 0.7f;
+
+    /* todo: see if splitting up primitive cost to be separate for triangles
+     * and curves can help. so far in tests it doesn't help, but why? */
+    sah_node_cost = 1.0f;
+    sah_primitive_cost = 1.0f;
+
+    min_leaf_size = 1;
+    max_triangle_leaf_size = 8;
+    max_motion_triangle_leaf_size = 8;
+    max_curve_leaf_size = 1;
+    max_motion_curve_leaf_size = 4;
+    max_point_leaf_size = 8;
+    max_motion_point_leaf_size = 8;
+
+    top_level = false;
+    bvh_layout = BVH_LAYOUT_BVH2;
+    use_compact_structure = false;
+    use_unaligned_nodes = false;
+
+    num_motion_curve_steps = 0;
+    num_motion_triangle_steps = 0;
+    num_motion_point_steps = 0;
+
+    bvh_type = 0;
+
+    curve_subdivisions = 4;
+  }
+
+  /* SAH costs */
+  __forceinline float cost(const int num_nodes, const int num_primitives) const
+  {
+    return node_cost(num_nodes) + primitive_cost(num_primitives);
+  }
+
+  __forceinline float primitive_cost(const int n) const
+  {
+    return n * sah_primitive_cost;
+  }
+
+  __forceinline float node_cost(const int n) const
+  {
+    return n * sah_node_cost;
+  }
+
+  __forceinline bool small_enough_for_leaf(const int size, const int level)
+  {
+    return (size <= min_leaf_size || level >= MAX_DEPTH);
+  }
+
+  bool use_motion_steps()
+  {
+    return num_motion_curve_steps > 0 || num_motion_triangle_steps > 0 ||
+           num_motion_point_steps > 0;
+  }
+
+  /* Gets best matching BVH.
+   *
+   * If the requested layout is supported by the device, it will be used.
+   * Otherwise, widest supported layout below that will be used.
+   */
+  static BVHLayout best_bvh_layout(BVHLayout requested_layout, BVHLayoutMask supported_layouts);
+};
+
+/* BVH Reference
+ *
+ * Reference to a primitive. Primitive index and object are sneakily packed
+ * into BoundBox to reduce memory usage and align nicely */
+
+class BVHReference {
+ public:
+  __forceinline BVHReference() = default;
+
+  __forceinline BVHReference(const BoundBox &bounds_,
+                             const int prim_index_,
+                             const int prim_object_,
+                             const int prim_type,
+                             float time_from = 0.0f,
+                             float time_to = 1.0f)
+      : rbounds(bounds_), time_from_(time_from), time_to_(time_to)
+  {
+    rbounds.min.w = __int_as_float(prim_index_);
+    rbounds.max.w = __int_as_float(prim_object_);
+    type = prim_type;
+  }
+
+  __forceinline const BoundBox &bounds() const
+  {
+    return rbounds;
+  }
+  __forceinline int prim_index() const
+  {
+    return __float_as_int(rbounds.min.w);
+  }
+  __forceinline int prim_object() const
+  {
+    return __float_as_int(rbounds.max.w);
+  }
+  __forceinline int prim_type() const
+  {
+    return type;
+  }
+  __forceinline float time_from() const
+  {
+    return time_from_;
+  }
+  __forceinline float time_to() const
+  {
+    return time_to_;
+  }
+
+  BVHReference &operator=(const BVHReference &arg) = default;
+
+ protected:
+  BoundBox rbounds;
+  uint type;
+  float time_from_, time_to_;
+};
+
+/* BVH Range
+ *
+ * Build range used during construction, to indicate the bounds and place in
+ * the reference array of a subset of primitives Again uses trickery to pack
+ * integers into BoundBox for alignment purposes. */
+
+class BVHRange {
+ public:
+  __forceinline BVHRange()
+  {
+    rbounds.min.w = __int_as_float(0);
+    rbounds.max.w = __int_as_float(0);
+  }
+
+  __forceinline BVHRange(const BoundBox &bounds_, int start_, int size_) : rbounds(bounds_)
+  {
+    rbounds.min.w = __int_as_float(start_);
+    rbounds.max.w = __int_as_float(size_);
+  }
+
+  __forceinline BVHRange(const BoundBox &bounds_, const BoundBox &cbounds_, int start_, int size_)
+      : rbounds(bounds_), cbounds(cbounds_)
+  {
+    rbounds.min.w = __int_as_float(start_);
+    rbounds.max.w = __int_as_float(size_);
+  }
+
+  __forceinline void set_start(const int start_)
+  {
+    rbounds.min.w = __int_as_float(start_);
+  }
+
+  __forceinline const BoundBox &bounds() const
+  {
+    return rbounds;
+  }
+  __forceinline const BoundBox &cent_bounds() const
+  {
+    return cbounds;
+  }
+  __forceinline int start() const
+  {
+    return __float_as_int(rbounds.min.w);
+  }
+  __forceinline int size() const
+  {
+    return __float_as_int(rbounds.max.w);
+  }
+  __forceinline int end() const
+  {
+    return start() + size();
+  }
+
+ protected:
+  BoundBox rbounds;
+  BoundBox cbounds;
+};
+
+/* BVH Spatial Bin */
+
+struct BVHSpatialBin {
+  BoundBox bounds;
+  int enter;
+  int exit;
+
+  __forceinline BVHSpatialBin() = default;
+};
+
+/* BVH Spatial Storage
+ *
+ * The idea of this storage is have thread-specific storage for the spatial
+ * splitters. We can pre-allocate this storage in advance and avoid heavy memory
+ * operations during split process.
+ */
+
+struct BVHSpatialStorage {
+  /* Accumulated bounds when sweeping from right to left. */
+  vector<BoundBox> right_bounds;
+
+  /* Bins used for histogram when selecting best split plane. */
+  BVHSpatialBin bins[3][BVHParams::NUM_SPATIAL_BINS];
+
+  /* Temporary storage for the new references. Used by spatial split to store
+   * new references in before they're getting inserted into actual array,
+   */
+  vector<BVHReference> new_references;
+};
+
+CCL_NAMESPACE_END