EEVEE: Use Fullscreen maxZBuffer instead of halfres

This removes the need for per mipmap scalling factor and trilinear interpolation
issues. We pad the texture so that all mipmaps have pixels in the next mip.

This simplifies the downsampling shader too.

This also change the SSR radiance buffer as well in the same fashion.

1 files changed, 4 insertions, 20 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_screen_raytrace.c b/source/blender/draw/engines/eevee/eevee_screen_raytrace.c
index f9e22f5c08d..80a1c9fcbe5 100644
--- a/source/blender/draw/engines/eevee/eevee_screen_raytrace.c
+++ b/source/blender/draw/engines/eevee/eevee_screen_raytrace.c
@@ -42,29 +42,15 @@ int EEVEE_screen_raytrace_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
   EEVEE_CommonUniformBuffer *common_data = &sldata->common_data;
   EEVEE_StorageList *stl = vedata->stl;
   EEVEE_FramebufferList *fbl = vedata->fbl;
-  EEVEE_TextureList *txl = vedata->txl;
   EEVEE_EffectsInfo *effects = stl->effects;
   const float *viewport_size = DRW_viewport_size_get();
 
   const DRWContextState *draw_ctx = DRW_context_state_get();
   const Scene *scene_eval = DEG_get_evaluated_scene(draw_ctx->depsgraph);
 
-  /* Compute pixel size, (shared with contact shadows) */
-  copy_v2_v2(common_data->ssr_pixelsize, viewport_size);
-  invert_v2(common_data->ssr_pixelsize);
-
   if (scene_eval->eevee.flag & SCE_EEVEE_SSR_ENABLED) {
     const bool use_refraction = (scene_eval->eevee.flag & SCE_EEVEE_SSR_REFRACTION) != 0;
 
-    if (use_refraction) {
-      /* TODO: Opti: Could be shared. */
-      DRW_texture_ensure_fullscreen_2d(
-          &txl->refract_color, GPU_R11F_G11F_B10F, DRW_TEX_FILTER | DRW_TEX_MIPMAP);
-
-      GPU_framebuffer_ensure_config(
-          &fbl->refract_fb, {GPU_ATTACHMENT_NONE, GPU_ATTACHMENT_TEXTURE(txl->refract_color)});
-    }
-
     const bool is_persp = DRW_view_is_persp_get(NULL);
     if (effects->ssr_was_persp != is_persp) {
       effects->ssr_was_persp = is_persp;
@@ -117,8 +103,7 @@ int EEVEE_screen_raytrace_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
                                    GPU_ATTACHMENT_TEXTURE(effects->ssr_hit_output),
                                    GPU_ATTACHMENT_TEXTURE(effects->ssr_pdf_output)});
 
-    /* Enable double buffering to be able to read previous frame color */
-    return EFFECT_SSR | EFFECT_NORMAL_BUFFER | EFFECT_DOUBLE_BUFFER |
+    return EFFECT_SSR | EFFECT_NORMAL_BUFFER | EFFECT_RADIANCE_BUFFER | EFFECT_DOUBLE_BUFFER |
            ((use_refraction) ? EFFECT_REFRACT : 0);
   }
 
@@ -189,7 +174,7 @@ void EEVEE_screen_raytrace_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *v
     DRW_shgroup_uniform_texture_ref(grp, "planarDepth", &vedata->txl->planar_depth);
     DRW_shgroup_uniform_texture_ref(grp, "hitBuffer", &effects->ssr_hit_output);
     DRW_shgroup_uniform_texture_ref(grp, "pdfBuffer", &effects->ssr_pdf_output);
-    DRW_shgroup_uniform_texture_ref(grp, "prevColorBuffer", &txl->color_double_buffer);
+    DRW_shgroup_uniform_texture_ref(grp, "prevColorBuffer", &txl->filtered_radiance);
     DRW_shgroup_uniform_texture_ref(grp, "maxzBuffer", &txl->maxzbuffer);
     DRW_shgroup_uniform_texture_ref(grp, "shadowCubeTexture", &sldata->shadow_cube_pool);
     DRW_shgroup_uniform_texture_ref(grp, "shadowCascadeTexture", &sldata->shadow_cascade_pool);
@@ -216,8 +201,7 @@ void EEVEE_refraction_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *v
   EEVEE_EffectsInfo *effects = stl->effects;
 
   if ((effects->enabled_effects & EFFECT_REFRACT) != 0) {
-    GPU_framebuffer_blit(fbl->main_fb, 0, fbl->refract_fb, 0, GPU_COLOR_BIT);
-    EEVEE_downsample_buffer(vedata, txl->refract_color, 9);
+    EEVEE_effects_downsample_radiance_buffer(vedata, txl->color);
 
     /* Restore */
     GPU_framebuffer_bind(fbl->main_fb);
@@ -242,7 +226,7 @@ void EEVEE_reflection_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *v
     GPU_framebuffer_bind(fbl->screen_tracing_fb);
     DRW_draw_pass(psl->ssr_raytrace);
 
-    EEVEE_downsample_buffer(vedata, txl->color_double_buffer, 9);
+    EEVEE_effects_downsample_radiance_buffer(vedata, txl->color_double_buffer);
 
     /* Resolve at fullres */
     int samp = (DRW_state_is_image_render()) ? effects->taa_render_sample :