DRW: DebugDraw: Port module to C++ and add GPU capabilities

This is a complete rewrite of the draw debug drawing module in C++.
It uses `GPUStorageBuf` to store the data to be drawn and use indirect
drawing. This makes it easier to do a mirror API for GPU shaders.

The C++ API class is exposed through `draw_debug.hh` and should be used
when possible in new code.

However, the debug drawing will not work for platform not yet supporting
`GPUStorageBuf`. Also keep in mind that this module must only be used
in debug build for performance and compatibility reasons.

1 files changed, 20 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_shader.cc b/source/blender/draw/intern/draw_shader.cc
index 001ceb0ae8d..ecb30d54b64 100644
--- a/source/blender/draw/intern/draw_shader.cc
+++ b/source/blender/draw/intern/draw_shader.cc
@@ -24,6 +24,8 @@ extern "C" char datatoc_gpu_shader_3D_smooth_color_frag_glsl[];
 
 static struct {
   struct GPUShader *hair_refine_sh[PART_REFINE_MAX_SHADER];
+  struct GPUShader *debug_print_display_sh;
+  struct GPUShader *debug_draw_display_sh;
 } e_data = {{nullptr}};
 
 /* -------------------------------------------------------------------- */
@@ -109,6 +111,22 @@ GPUShader *DRW_shader_curves_refine_get(CurvesEvalShader type, eParticleRefineSh
   return e_data.hair_refine_sh[type];
 }
 
+GPUShader *DRW_shader_debug_print_display_get()
+{
+  if (e_data.debug_print_display_sh == nullptr) {
+    e_data.debug_print_display_sh = GPU_shader_create_from_info_name("draw_debug_print_display");
+  }
+  return e_data.debug_print_display_sh;
+}
+
+GPUShader *DRW_shader_debug_draw_display_get()
+{
+  if (e_data.debug_draw_display_sh == nullptr) {
+    e_data.debug_draw_display_sh = GPU_shader_create_from_info_name("draw_debug_draw_display");
+  }
+  return e_data.debug_draw_display_sh;
+}
+
 /** \} */
 
 void DRW_shaders_free()
@@ -116,4 +134,6 @@ void DRW_shaders_free()
   for (int i = 0; i < PART_REFINE_MAX_SHADER; i++) {
     DRW_SHADER_FREE_SAFE(e_data.hair_refine_sh[i]);
   }
+  DRW_SHADER_FREE_SAFE(e_data.debug_print_display_sh);
+  DRW_SHADER_FREE_SAFE(e_data.debug_draw_display_sh);
 }