Add Chromium-only Blender WebEngine parity work

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

@@ -0,0 +1,84 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0 */
+
+#pragma once
+
+/* DX11 like EdgeDice implementation, with different tessellation factors for
+ * each edge for watertight tessellation, with subpatch remapping to work with
+ * DiagSplit. For more algorithm details, see the DiagSplit paper or the
+ * ARB_tessellation_shader OpenGL extension, Section 2.X.2. */
+
+#include "util/transform.h"
+#include "util/types.h"
+
+#include "subd/subpatch.h"
+
+CCL_NAMESPACE_BEGIN
+
+class Camera;
+class Mesh;
+class Patch;
+class SubdAttributeInterpolation;
+class DiagSplit;
+
+struct SubdParams {
+  Mesh *mesh = nullptr;
+  bool ptex = false;
+
+  int test_steps = 3;
+  int split_threshold = 1;
+  float dicing_rate = 1.0f;
+  int max_level = 12;
+  Camera *camera = nullptr;
+  Transform objecttoworld = transform_identity();
+
+  SubdParams(Mesh *mesh_, bool ptex_ = false) : mesh(mesh_), ptex(ptex_) {}
+};
+
+class EdgeDice {
+ public:
+  SubdParams params;
+  SubdAttributeInterpolation &interpolation;
+  int *mesh_triangles = nullptr;
+  int *mesh_shader = nullptr;
+  bool *mesh_smooth = nullptr;
+  packed_float3 *mesh_P = nullptr;
+  packed_normal *mesh_N = nullptr;
+  float *mesh_ptex_face_id = nullptr;
+  float2 *mesh_ptex_uv = nullptr;
+
+  explicit EdgeDice(const SubdParams &params,
+                    const int num_verts,
+                    const int num_triangles,
+                    SubdAttributeInterpolation &interpolation);
+
+  void dice(const DiagSplit &split);
+
+ protected:
+  void tri_dice(const SubPatch &sub);
+  void quad_dice(const SubPatch &sub);
+
+  void set_vertex(const SubPatch &sub, const int index, const float2 uv);
+  void set_triangle(const SubPatch &sub,
+                    const int triangle_index,
+                    const int v0,
+                    const int v1,
+                    const int v2,
+                    const float2 uv0,
+                    const float2 uv1,
+                    const float2 uv2);
+
+  void add_grid_triangles_and_stitch(const SubPatch &sub, const int Mu, const int Mv);
+  void add_triangle_strip(const SubPatch &sub, const int left_edge, const int right_edge);
+
+  float3 eval_projected(const SubPatch &sub, const float2 uv);
+
+  void tri_set_sides(const SubPatch &sub);
+  void quad_set_sides(const SubPatch &sub);
+
+  float quad_area(const float3 &a, const float3 &b, const float3 &c, const float3 &d);
+  float scale_factor(const SubPatch &sub, const int Mu, const int Mv);
+};
+
+CCL_NAMESPACE_END