Overlay Engine: Refactor & Cleanup

This is the unification of all overlays into one overlay engine as described in T65347.

I went over all the code making it more future proof with less hacks and removing old / not relevent parts.

Goals / Acheivements:
- Remove internal shader usage (only drw shaders)
- Remove viewportSize and viewportSizeInv and put them in gloabl ubo
- Fixed some drawing issues: Missing probe option and Missing Alt+B clipping of some shader
- Remove old (legacy) shaders dependancy (not using view UBO).
- Less shader variation (less compilation time at first load and less patching needed for vulkan)
- removed some geom shaders when I could
- Remove static e_data (except shaders storage where it is OK)
- Clear the way to fix some anoying limitations (dithered transparency, background image compositing etc...)
- Wireframe drawing now uses the same batching capabilities as workbench & eevee (indirect drawing).
- Reduced complexity, removed ~3000 Lines of code in draw (also removed a lot of unused shader in GPU).
- Post AA to avoid complexity and cost of MSAA.

Remaining issues:
- ~~Armature edits, overlay toggles, (... others?) are not refreshing viewport after AA is complete~~
- FXAA is not the best for wires, maybe investigate SMAA
- Maybe do something more temporally stable for AA.
- ~~Paint overlays are not working with AA.~~
- ~~infront objects are difficult to select.~~
- ~~the infront wires sometimes goes through they solid counterpart (missing clear maybe?) (toggle overlays on-off when using infront+wireframe overlay in solid shading)~~

Note: I made some decision to change slightly the appearance of some objects to simplify their drawing. Namely the empty arrows end (which is now hollow/wire) and distance points of the cameras/spots being done by lines.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6296

1 files changed, 38 insertions, 25 deletions

diff --git a/source/blender/draw/engines/workbench/workbench_deferred.c b/source/blender/draw/engines/workbench/workbench_deferred.c
index f84bd34545c..e5872dbac50 100644
--- a/source/blender/draw/engines/workbench/workbench_deferred.c
+++ b/source/blender/draw/engines/workbench/workbench_deferred.c
@@ -74,7 +74,6 @@ static struct {
   /* TODO(fclem) move everything below to wpd and custom viewlayer data. */
   struct GPUTexture *oit_accum_tx;        /* ref only, not alloced */
   struct GPUTexture *oit_revealage_tx;    /* ref only, not alloced */
-  struct GPUTexture *ghost_depth_tx;      /* ref only, not alloced */
   struct GPUTexture *object_id_tx;        /* ref only, not alloced */
   struct GPUTexture *color_buffer_tx;     /* ref only, not alloced */
   struct GPUTexture *cavity_buffer_tx;    /* ref only, not alloced */
@@ -582,7 +581,7 @@ void workbench_deferred_engine_init(WORKBENCH_Data *vedata)
     psl->ghost_resolve_pass = DRW_pass_create("Resolve Ghost Depth",
                                               DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_ALWAYS);
     grp = DRW_shgroup_create(e_data.ghost_resolve_sh, psl->ghost_resolve_pass);
-    DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &e_data.ghost_depth_tx);
+    DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &dtxl->depth_in_front);
     DRW_shgroup_call(grp, DRW_cache_fullscreen_quad_get(), NULL);
   }
 
@@ -621,23 +620,6 @@ void workbench_deferred_engine_init(WORKBENCH_Data *vedata)
   }
 }
 
-static void workbench_setup_ghost_framebuffer(WORKBENCH_FramebufferList *fbl)
-{
-  const float *viewport_size = DRW_viewport_size_get();
-  const int size[2] = {(int)viewport_size[0], (int)viewport_size[1]};
-
-  e_data.ghost_depth_tx = DRW_texture_pool_query_2d(
-      size[0], size[1], GPU_DEPTH_COMPONENT24, &draw_engine_workbench_solid);
-
-  GPU_framebuffer_ensure_config(&fbl->ghost_prepass_fb,
-                                {
-                                    GPU_ATTACHMENT_TEXTURE(e_data.ghost_depth_tx),
-                                    GPU_ATTACHMENT_TEXTURE(e_data.color_buffer_tx),
-                                    GPU_ATTACHMENT_TEXTURE(e_data.object_id_tx),
-                                    GPU_ATTACHMENT_TEXTURE(e_data.normal_buffer_tx),
-                                });
-}
-
 void workbench_deferred_engine_free(void)
 {
   for (int sh_data_index = 0; sh_data_index < ARRAY_SIZE(e_data.sh_data); sh_data_index++) {
@@ -1217,8 +1199,33 @@ void workbench_deferred_solid_cache_populate(WORKBENCH_Data *vedata, Object *ob)
   }
 }
 
-void workbench_deferred_cache_finish(WORKBENCH_Data *UNUSED(vedata))
+void workbench_deferred_cache_finish(WORKBENCH_Data *vedata)
 {
+  WORKBENCH_PassList *psl = vedata->psl;
+  WORKBENCH_FramebufferList *fbl = vedata->fbl;
+
+  if (GHOST_ENABLED(psl)) {
+    /* HACK we allocate the infront depth here to avoid the overhead when if is not needed. */
+    DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
+    DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
+
+    DRW_texture_ensure_fullscreen_2d(&dtxl->depth_in_front, GPU_DEPTH24_STENCIL8, 0);
+
+    GPU_framebuffer_ensure_config(
+        &dfbl->default_fb,
+        {GPU_ATTACHMENT_TEXTURE(dtxl->depth), GPU_ATTACHMENT_TEXTURE(dtxl->color)});
+    GPU_framebuffer_ensure_config(
+        &dfbl->in_front_fb,
+        {GPU_ATTACHMENT_TEXTURE(dtxl->depth_in_front), GPU_ATTACHMENT_TEXTURE(dtxl->color)});
+
+    GPU_framebuffer_ensure_config(&fbl->ghost_prepass_fb,
+                                  {
+                                      GPU_ATTACHMENT_TEXTURE(dtxl->depth_in_front),
+                                      GPU_ATTACHMENT_TEXTURE(e_data.color_buffer_tx),
+                                      GPU_ATTACHMENT_TEXTURE(e_data.object_id_tx),
+                                      GPU_ATTACHMENT_TEXTURE(e_data.normal_buffer_tx),
+                                  });
+  }
 }
 
 void workbench_deferred_draw_background(WORKBENCH_Data *vedata)
@@ -1252,6 +1259,7 @@ void workbench_deferred_draw_scene(WORKBENCH_Data *vedata)
   WORKBENCH_FramebufferList *fbl = vedata->fbl;
   WORKBENCH_PrivateData *wpd = stl->g_data;
   DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
+  DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
 
   if (workbench_is_taa_enabled(wpd)) {
     workbench_taa_draw_scene_start(vedata);
@@ -1262,12 +1270,17 @@ void workbench_deferred_draw_scene(WORKBENCH_Data *vedata)
   DRW_draw_pass(psl->prepass_pass);
   DRW_draw_pass(psl->prepass_hair_pass);
 
-  if (GHOST_ENABLED(psl)) {
-    /* meh, late init to not request a depth buffer we won't use. */
-    workbench_setup_ghost_framebuffer(fbl);
-
+  if (fbl->ghost_prepass_fb) {
     GPU_framebuffer_bind(fbl->ghost_prepass_fb);
     GPU_framebuffer_clear_depth(fbl->ghost_prepass_fb, 1.0f);
+  }
+  else if (dtxl->depth_in_front) {
+    /* TODO(fclem) This clear should be done in a global place. */
+    GPU_framebuffer_bind(dfbl->in_front_fb);
+    GPU_framebuffer_clear_depth(dfbl->in_front_fb, 1.0f);
+  }
+
+  if (GHOST_ENABLED(psl)) {
     DRW_draw_pass(psl->ghost_prepass_pass);
     DRW_draw_pass(psl->ghost_prepass_hair_pass);
 
@@ -1318,6 +1331,7 @@ void workbench_deferred_draw_scene(WORKBENCH_Data *vedata)
   /* In order to not draw on top of ghost objects, we clear the stencil
    * to 0xFF and the ghost object to 0x00 and only draw overlays on top if
    * stencil is not 0. */
+  /* TODO(fclem) Remove this hack. */
   GPU_framebuffer_bind(dfbl->depth_only_fb);
   GPU_framebuffer_clear_stencil(dfbl->depth_only_fb, 0xFF);
 
@@ -1335,7 +1349,6 @@ void workbench_deferred_draw_scene(WORKBENCH_Data *vedata)
   DRW_draw_pass(psl->background_pass);
 
   if (OIT_ENABLED(wpd) && !DRW_pass_is_empty(psl->transparent_accum_pass)) {
-    DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
     /* meh, late init to not request buffers we won't use. */
     workbench_init_oit_framebuffer(fbl, dtxl);