Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/subd/split.h

@@ -0,0 +1,107 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0 */
+
+#pragma once
+
+/* DiagSplit: Parallel, Crack-free, Adaptive Tessellation for Micro-polygon Rendering
+ * Splits up patches and determines edge tessellation factors for dicing. Patch
+ * evaluation at arbitrary points is required for this to work. See the paper
+ * for more details. */
+
+#include "scene/mesh.h"
+
+#include "subd/dice.h"
+#include "subd/subpatch.h"
+
+#include "util/set.h"
+#include "util/types.h"
+#include "util/vector.h"
+
+CCL_NAMESPACE_BEGIN
+
+class Mesh;
+class Patch;
+class SubdAttributeInterpolation;
+
+class DiagSplit {
+ private:
+  SubdParams params;
+  vector<SubPatch> subpatches;
+  vector<bool> owned_verts;
+  unordered_set<SubEdge, SubEdge::Hash, SubEdge::Equal> edges;
+  int num_verts = 0;
+  int num_triangles = 0;
+
+  /* Allocate vertices, edges and subpatches. */
+  int alloc_verts(const int num);
+  SubEdge *alloc_edge(const int v0, const int v1, const int depth, bool &was_missing);
+  void alloc_edge(SubPatch::Edge *sub_edge,
+                  const int v0,
+                  const int v1,
+                  const int depth,
+                  const bool want_to_own_edge,
+                  const bool want_to_own_vertex);
+  void alloc_subpatch(SubPatch &&sub);
+
+  /* Compute edge factors. */
+  float3 to_world(const Patch *patch, const float2 uv);
+  std::pair<int, float> T(const Patch *patch,
+                          const float2 uv_start,
+                          const float2 uv_end,
+                          const int depth,
+                          const bool recursive_resolve = false);
+  int limit_edge_factor(const Patch *patch,
+                        const float2 uv_start,
+                        const float2 uv_end,
+                        const int T);
+  void assign_edge_factor(SubEdge *edge,
+                          const Patch *patch,
+                          const float2 uv_start,
+                          const float2 uv_end,
+                          const bool recursive_resolve = false);
+  void resolve_edge_factors(const SubPatch &sub);
+
+  /* Split edge, subpatch, quad and n-gon. */
+  float2 split_edge(const Patch *patch,
+                    SubPatch::Edge *subedge,
+                    SubPatch::Edge *subedge_a,
+                    SubPatch::Edge *subedge_b,
+                    float2 uv_start,
+                    float2 uv_end);
+  void split_quad(SubPatch &&sub);
+  void split_triangle(SubPatch &&sub);
+  void split_quad_into_triangles(SubPatch &&sub);
+  void split_quad(const Mesh::SubdFace &face, const int face_index, const Patch *patch);
+  void split_ngon(const Mesh::SubdFace &face,
+                  const int face_index,
+                  const Patch *patches,
+                  const size_t patches_byte_stride);
+
+ public:
+  explicit DiagSplit(const SubdParams &params);
+
+  void split_patches(const Patch *patches, const size_t patches_byte_stride);
+
+  size_t get_num_subpatches() const
+  {
+    return subpatches.size();
+  }
+
+  const SubPatch &get_subpatch(const size_t i) const
+  {
+    return subpatches[i];
+  }
+
+  int get_num_verts() const
+  {
+    return num_verts;
+  }
+
+  int get_num_triangles() const
+  {
+    return num_triangles;
+  }
+};
+
+CCL_NAMESPACE_END