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, 28 insertions, 7 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_engine.c b/source/blender/draw/engines/eevee/eevee_engine.c
index 173b7ff57a1..603a4787dba 100644
--- a/source/blender/draw/engines/eevee/eevee_engine.c
+++ b/source/blender/draw/engines/eevee/eevee_engine.c
@@ -27,6 +27,8 @@
 #include "BKE_object.h"
 #include "BKE_global.h" /* for G.debug_value */
 
+#include "DEG_depsgraph_query.h"
+
 #include "DNA_world_types.h"
 
 #include "eevee_private.h"
@@ -81,7 +83,9 @@ static void eevee_engine_init(void *ved)
                                                   &sldata->common_data);
   }
 
-  /* EEVEE_effects_init needs to go first for TAA */
+  /* `EEVEE_renderpasses_init` will set the active render passes used by `EEVEE_effects_init`.
+   * `EEVEE_effects_init` needs to go second for TAA. */
+  EEVEE_renderpasses_init(vedata);
   EEVEE_effects_init(sldata, vedata, camera, false);
   EEVEE_materials_init(sldata, stl, fbl);
   EEVEE_shadows_init(sldata);
@@ -147,6 +151,8 @@ static void eevee_cache_finish(void *vedata)
 {
   EEVEE_ViewLayerData *sldata = EEVEE_view_layer_data_ensure();
   EEVEE_PrivateData *g_data = ((EEVEE_Data *)vedata)->stl->g_data;
+  const DRWContextState *draw_ctx = DRW_context_state_get();
+  const Scene *scene_eval = DEG_get_evaluated_scene(draw_ctx->depsgraph);
 
   EEVEE_volumes_cache_finish(sldata, vedata);
   EEVEE_materials_cache_finish(sldata, vedata);
@@ -156,6 +162,14 @@ static void eevee_cache_finish(void *vedata)
   EEVEE_effects_draw_init(sldata, vedata);
   EEVEE_volumes_draw_init(sldata, vedata);
 
+  uint tot_samples = scene_eval->eevee.taa_render_samples;
+  if (tot_samples == 0) {
+    /* use a high number of samples so the outputs accum buffers
+     * will have the highest possible precision */
+    tot_samples = 1024;
+  }
+  EEVEE_renderpasses_output_init(sldata, vedata, tot_samples);
+
   /* Restart taa if a shader has finish compiling. */
   /* HACK We should use notification of some sort from the compilation job instead. */
   if (g_data->queued_shaders_count != g_data->queued_shaders_count_prev) {
@@ -306,6 +320,8 @@ static void eevee_draw_background(void *vedata)
     EEVEE_draw_effects(sldata, vedata);
     DRW_stats_group_end();
 
+    EEVEE_renderpasses_output_accumulate(sldata, vedata);
+
     DRW_view_set_active(NULL);
 
     if (DRW_state_is_image_render() && (stl->effects->enabled_effects & EFFECT_SSR) &&
@@ -319,14 +335,19 @@ static void eevee_draw_background(void *vedata)
     }
   }
 
-  /* Tonemapping and transfer result to default framebuffer. */
-  bool use_render_settings = stl->g_data->use_color_render_settings;
+  if ((stl->g_data->render_passes & SCE_PASS_COMBINED) > 0) {
+    /* Tonemapping and transfer result to default framebuffer. */
+    bool use_render_settings = stl->g_data->use_color_render_settings;
 
-  GPU_framebuffer_bind(dfbl->default_fb);
-  DRW_transform_to_display(stl->effects->final_tx, true, use_render_settings);
+    GPU_framebuffer_bind(dfbl->default_fb);
+    DRW_transform_to_display(stl->effects->final_tx, true, use_render_settings);
 
-  /* Draw checkerboard with alpha under. */
-  EEVEE_draw_alpha_checker(vedata);
+    /* Draw checkerboard with alpha under. */
+    EEVEE_draw_alpha_checker(vedata);
+  }
+  else {
+    EEVEE_renderpasses_draw(sldata, vedata);
+  }
 
   /* Debug : Output buffer to view. */
   switch (G.debug_value) {