EEVEE: Viewport Renderpasses

This patch will allow the user to select the EEVEE renderpass to be
shown in the viewport by default the combined pass will be shown.

Limitations:

* Viewport rendering stores the result in a `RenderResult`. RenderResult
  is not aware of the type of data it holds. In many places where RenderResult
  is used it is assumed that it stores a combined pass and the display+view
  transform are applied.

  I will propose to fix this in a future patch. But that is still being
  designed and discussed.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D6319

1 files changed, 4 insertions, 2 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_occlusion.c b/source/blender/draw/engines/eevee/eevee_occlusion.c
index 0a7d1db1061..6ba518b3a28 100644
--- a/source/blender/draw/engines/eevee/eevee_occlusion.c
+++ b/source/blender/draw/engines/eevee/eevee_occlusion.c
@@ -155,8 +155,10 @@ void EEVEE_occlusion_output_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata
                                   {GPU_ATTACHMENT_NONE, GPU_ATTACHMENT_TEXTURE(txl->ao_accum)});
 
     /* Clear texture. */
-    GPU_framebuffer_bind(fbl->ao_accum_fb);
-    GPU_framebuffer_clear_color(fbl->ao_accum_fb, clear);
+    if (DRW_state_is_image_render() || effects->taa_current_sample == 1) {
+      GPU_framebuffer_bind(fbl->ao_accum_fb);
+      GPU_framebuffer_clear_color(fbl->ao_accum_fb, clear);
+    }
 
     /* Accumulation pass */
     DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_ADD;