EEVEE: Lookdev: Add support for partially blurred background

This is using the GGX probe as background. This has the drawback of
having the resolution choosed in the indirect lighting setting.
The blurring is not really high-quality.

The pros is that it has a simple implementation and is fast to evaluate.

This patch also fades the background alpha to make overlay engine draw the
default background color in the correct color space. Removing one colorspace
hack.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6895

1 files changed, 23 insertions, 0 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_shaders.c b/source/blender/draw/engines/eevee/eevee_shaders.c
index 34a3e723161..2d91e4bb4bd 100644
--- a/source/blender/draw/engines/eevee/eevee_shaders.c
+++ b/source/blender/draw/engines/eevee/eevee_shaders.c
@@ -44,6 +44,7 @@ static struct {
   /* Probes */
   struct GPUShader *probe_default_sh;
   struct GPUShader *probe_default_studiolight_sh;
+  struct GPUShader *probe_background_studiolight_sh;
   struct GPUShader *probe_grid_display_sh;
   struct GPUShader *probe_cube_display_sh;
   struct GPUShader *probe_planar_display_sh;
@@ -191,6 +192,27 @@ GPUShader *EEVEE_shaders_default_studiolight_sh_get(void)
   return e_data.probe_default_studiolight_sh;
 }
 
+GPUShader *EEVEE_shaders_background_studiolight_sh_get(void)
+{
+  if (e_data.probe_background_studiolight_sh == NULL) {
+    char *frag_str = BLI_string_joinN(datatoc_octahedron_lib_glsl,
+                                      datatoc_common_uniforms_lib_glsl,
+                                      datatoc_bsdf_common_lib_glsl,
+                                      datatoc_lightprobe_lib_glsl,
+                                      datatoc_default_world_frag_glsl);
+
+    e_data.probe_background_studiolight_sh = DRW_shader_create_with_lib(
+        datatoc_background_vert_glsl,
+        NULL,
+        frag_str,
+        datatoc_common_view_lib_glsl,
+        "#define LOOKDEV_BG\n" SHADER_DEFINES);
+
+    MEM_freeN(frag_str);
+  }
+  return e_data.probe_background_studiolight_sh;
+}
+
 GPUShader *EEVEE_shaders_probe_cube_display_sh_get(void)
 {
   if (e_data.probe_cube_display_sh == NULL) {
@@ -299,6 +321,7 @@ void EEVEE_shaders_free(void)
   DRW_SHADER_FREE_SAFE(e_data.probe_grid_fill_sh);
   DRW_SHADER_FREE_SAFE(e_data.probe_planar_downsample_sh);
   DRW_SHADER_FREE_SAFE(e_data.probe_default_studiolight_sh);
+  DRW_SHADER_FREE_SAFE(e_data.probe_background_studiolight_sh);
   DRW_SHADER_FREE_SAFE(e_data.probe_grid_display_sh);
   DRW_SHADER_FREE_SAFE(e_data.probe_cube_display_sh);
   DRW_SHADER_FREE_SAFE(e_data.probe_planar_display_sh);