1 files changed, 57 insertions, 0 deletions
diff --git a/source/blender/draw/intern/shaders/common_subdiv_ibo_lines_comp.glsl b/source/blender/draw/intern/shaders/common_subdiv_ibo_lines_comp.glsl
new file mode 100644
index 00000000000..f11c0f6427e
--- /dev/null
+++ b/source/blender/draw/intern/shaders/common_subdiv_ibo_lines_comp.glsl
@@ -0,0 +1,57 @@
+
+/* To be compile with common_subdiv_lib.glsl */
+
+layout(std430, binding = 0) readonly buffer inputEdgeOrigIndex
+{
+  int input_origindex[];
+};
+
+layout(std430, binding = 1) writeonly buffer outputLinesIndices
+{
+  uint output_lines[];
+};
+
+#ifndef LINES_LOOSE
+void emit_line(uint line_offset, uint start_loop_index, uint corner_index)
+{
+  uint vertex_index = start_loop_index + corner_index;
+
+  if (input_origindex[vertex_index] == ORIGINDEX_NONE && optimal_display) {
+    output_lines[line_offset + 0] = 0xffffffff;
+    output_lines[line_offset + 1] = 0xffffffff;
+  }
+  else {
+    /* Mod 4 so we loop back at the first vertex on the last loop index (3). */
+    uint next_vertex_index = start_loop_index + (corner_index + 1) % 4;
+
+    output_lines[line_offset + 0] = vertex_index;
+    output_lines[line_offset + 1] = next_vertex_index;
+  }
+}
+#endif
+
+void main()
+{
+  uint index = get_global_invocation_index();
+  if (index >= total_dispatch_size) {
+    return;
+  }
+
+#ifdef LINES_LOOSE
+  /* In the loose lines case, we execute for each line, with two vertices per line. */
+  uint line_offset = edge_loose_offset + index * 2;
+  uint loop_index = num_subdiv_loops + index * 2;
+  output_lines[line_offset] = loop_index;
+  output_lines[line_offset + 1] = loop_index + 1;
+#else
+  /* We execute for each quad, so the start index of the loop is quad_index * 4. */
+  uint start_loop_index = index * 4;
+  /* We execute for each quad, so the start index of the line is quad_index * 8 (with 2 vertices
+   * per line). */
+  uint start_line_index = index * 8;
+
+  for (int i = 0; i < 4; i++) {
+    emit_line(start_line_index + i * 2, start_loop_index, i);
+  }
+#endif
+}