GPU: Add Image Load Store extension support

This wraps the functionality used to speedup EEVEE volumetrics.

This touches the rendering code of EEVEE as it should fix a mis-usage of
the GL barrier. The barrier changed type and location, removing an
unused barrier.

4 files changed, 27 insertions, 0 deletions

diff --git a/source/blender/draw/intern/DRW_render.h b/source/blender/draw/intern/DRW_render.h
index 8e3562216e9..30c6f0ad4dc 100644
--- a/source/blender/draw/intern/DRW_render.h
+++ b/source/blender/draw/intern/DRW_render.h
@@ -557,6 +557,9 @@ void DRW_shgroup_uniform_ivec4(DRWShadingGroup *shgroup,
                                int arraysize);
 void DRW_shgroup_uniform_mat3(DRWShadingGroup *shgroup, const char *name, const float (*value)[3]);
 void DRW_shgroup_uniform_mat4(DRWShadingGroup *shgroup, const char *name, const float (*value)[4]);
+/* Only to be used when image load store is supported (GPU_shader_image_load_store_support()). */
+void DRW_shgroup_uniform_image(DRWShadingGroup *shgroup, const char *name, const GPUTexture *tex);
+void DRW_shgroup_uniform_image_ref(DRWShadingGroup *shgroup, const char *name, GPUTexture **tex);
 /* Store value instead of referencing it. */
 void DRW_shgroup_uniform_int_copy(DRWShadingGroup *shgroup, const char *name, const int value);
 void DRW_shgroup_uniform_ivec2_copy(DRWShadingGroup *shgroup, const char *name, const int *value);
diff --git a/source/blender/draw/intern/draw_manager.h b/source/blender/draw/intern/draw_manager.h
index c0bcb0e679f..9f6a970ea22 100644
--- a/source/blender/draw/intern/draw_manager.h
+++ b/source/blender/draw/intern/draw_manager.h
@@ -278,6 +278,8 @@ typedef enum {
   DRW_UNIFORM_FLOAT_COPY,
   DRW_UNIFORM_TEXTURE,
   DRW_UNIFORM_TEXTURE_REF,
+  DRW_UNIFORM_IMAGE,
+  DRW_UNIFORM_IMAGE_REF,
   DRW_UNIFORM_BLOCK,
   DRW_UNIFORM_BLOCK_REF,
   DRW_UNIFORM_TFEEDBACK_TARGET,
diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c
index a4fc44e9571..81842f5d2ec 100644
--- a/source/blender/draw/intern/draw_manager_data.c
+++ b/source/blender/draw/intern/draw_manager_data.c
@@ -199,10 +199,12 @@ static void drw_shgroup_uniform_create_ex(DRWShadingGroup *shgroup,
     case DRW_UNIFORM_BLOCK_REF:
       uni->block_ref = (GPUUniformBuf **)value;
       break;
+    case DRW_UNIFORM_IMAGE:
     case DRW_UNIFORM_TEXTURE:
       uni->texture = (GPUTexture *)value;
       uni->sampler_state = sampler_state;
       break;
+    case DRW_UNIFORM_IMAGE_REF:
     case DRW_UNIFORM_TEXTURE_REF:
       uni->texture_ref = (GPUTexture **)value;
       uni->sampler_state = sampler_state;
@@ -261,6 +263,20 @@ void DRW_shgroup_uniform_texture_ref(DRWShadingGroup *shgroup, const char *name,
   DRW_shgroup_uniform_texture_ref_ex(shgroup, name, tex, GPU_SAMPLER_MAX);
 }
 
+void DRW_shgroup_uniform_image(DRWShadingGroup *shgroup, const char *name, const GPUTexture *tex)
+{
+  BLI_assert(tex != NULL);
+  int loc = GPU_shader_get_texture_binding(shgroup->shader, name);
+  drw_shgroup_uniform_create_ex(shgroup, loc, DRW_UNIFORM_IMAGE, tex, 0, 0, 1);
+}
+
+void DRW_shgroup_uniform_image_ref(DRWShadingGroup *shgroup, const char *name, GPUTexture **tex)
+{
+  BLI_assert(tex != NULL);
+  int loc = GPU_shader_get_texture_binding(shgroup->shader, name);
+  drw_shgroup_uniform_create_ex(shgroup, loc, DRW_UNIFORM_IMAGE_REF, tex, 0, 0, 1);
+}
+
 void DRW_shgroup_uniform_block(DRWShadingGroup *shgroup,
                                const char *name,
                                const GPUUniformBuf *ubo)
diff --git a/source/blender/draw/intern/draw_manager_exec.c b/source/blender/draw/intern/draw_manager_exec.c
index 79d74e1f67d..84f618c1c15 100644
--- a/source/blender/draw/intern/draw_manager_exec.c
+++ b/source/blender/draw/intern/draw_manager_exec.c
@@ -596,6 +596,12 @@ static void draw_update_uniforms(DRWShadingGroup *shgroup,
         case DRW_UNIFORM_TEXTURE_REF:
           GPU_texture_bind_ex(*uni->texture_ref, uni->sampler_state, uni->location, false);
           break;
+        case DRW_UNIFORM_IMAGE:
+          GPU_texture_image_bind(uni->texture, uni->location);
+          break;
+        case DRW_UNIFORM_IMAGE_REF:
+          GPU_texture_image_bind(*uni->texture_ref, uni->location);
+          break;
         case DRW_UNIFORM_BLOCK:
           GPU_uniformbuf_bind(uni->block, uni->location);
           break;