1 files changed, 43 insertions, 0 deletions
diff --git a/source/blender/draw/intern/shaders/common_subdiv_ibo_tris_comp.glsl b/source/blender/draw/intern/shaders/common_subdiv_ibo_tris_comp.glsl
new file mode 100644
index 00000000000..3257ebdae17
--- /dev/null
+++ b/source/blender/draw/intern/shaders/common_subdiv_ibo_tris_comp.glsl
@@ -0,0 +1,43 @@
+
+/* To be compile with common_subdiv_lib.glsl */
+
+/* Generate triangles from subdivision quads indices. */
+
+layout(std430, binding = 1) writeonly buffer outputTriangles
+{
+  uint output_tris[];
+};
+
+#ifndef SINGLE_MATERIAL
+layout(std430, binding = 2) readonly buffer inputPolygonMatOffset
+{
+  int polygon_mat_offset[];
+};
+#endif
+
+void main()
+{
+  uint quad_index = get_global_invocation_index();
+  if (quad_index >= total_dispatch_size) {
+    return;
+  }
+
+  uint loop_index = quad_index * 4;
+
+#ifdef SINGLE_MATERIAL
+  uint triangle_loop_index = quad_index * 6;
+#else
+  uint coarse_quad_index = coarse_polygon_index_from_subdiv_quad_index(quad_index,
+                                                                       coarse_poly_count);
+  int mat_offset = polygon_mat_offset[coarse_quad_index];
+
+  int triangle_loop_index = (int(quad_index) + mat_offset) * 6;
+#endif
+
+  output_tris[triangle_loop_index + 0] = loop_index + 0;
+  output_tris[triangle_loop_index + 1] = loop_index + 1;
+  output_tris[triangle_loop_index + 2] = loop_index + 2;
+  output_tris[triangle_loop_index + 3] = loop_index + 0;
+  output_tris[triangle_loop_index + 4] = loop_index + 2;
+  output_tris[triangle_loop_index + 5] = loop_index + 3;
+}