Realtime Compositor: Add evaluator and engine

This patch adds the core realtime compositor evaluator as well as a
compositor draw engine powered by the evaluator that operates in the
viewport. The realtime compositor is a new GPU accelerated compositor
that will be used to power the viewport compositor imminently as well as
the existing compositor in the future.

This patch only adds the evaluator and engine as an experimental
feature, the implementation of the nodes themselves will be committed
separately.

See T99210.

Differential Revision: https://developer.blender.org/D15206

Reviewed By: Clement Foucault

1 files changed, 33 insertions, 1 deletions

diff --git a/source/blender/draw/intern/draw_manager.c b/source/blender/draw/intern/draw_manager.c
index 63c7cc667cb..b965045a424 100644
--- a/source/blender/draw/intern/draw_manager.c
+++ b/source/blender/draw/intern/draw_manager.c
@@ -43,6 +43,7 @@
 #include "DNA_camera_types.h"
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
+#include "DNA_userdef_types.h"
 #include "DNA_world_types.h"
 
 #include "ED_gpencil.h"
@@ -84,6 +85,7 @@
 #include "draw_cache_impl.h"
 
 #include "engines/basic/basic_engine.h"
+#include "engines/compositor/compositor_engine.h"
 #include "engines/eevee/eevee_engine.h"
 #include "engines/eevee_next/eevee_engine.h"
 #include "engines/external/external_engine.h"
@@ -1214,6 +1216,31 @@ static void drw_engines_enable_editors(void)
   }
 }
 
+static bool is_compositor_enabled(void)
+{
+  if (!U.experimental.use_realtime_compositor) {
+    return false;
+  }
+
+  if (!(DST.draw_ctx.v3d->shading.flag & V3D_SHADING_COMPOSITOR)) {
+    return false;
+  }
+
+  if (!(DST.draw_ctx.v3d->shading.type > OB_MATERIAL)) {
+    return false;
+  }
+
+  if (!DST.draw_ctx.scene->use_nodes) {
+    return false;
+  }
+
+  if (!DST.draw_ctx.scene->nodetree) {
+    return false;
+  }
+
+  return true;
+}
+
 static void drw_engines_enable(ViewLayer *UNUSED(view_layer),
                                RenderEngineType *engine_type,
                                bool gpencil_engine_needed)
@@ -1226,6 +1253,11 @@ static void drw_engines_enable(ViewLayer *UNUSED(view_layer),
   if (gpencil_engine_needed && ((drawtype >= OB_SOLID) || !use_xray)) {
     use_drw_engine(&draw_engine_gpencil_type);
   }
+
+  if (is_compositor_enabled()) {
+    use_drw_engine(&draw_engine_compositor_type);
+  }
+
   drw_engines_enable_overlays();
 
 #ifdef WITH_DRAW_DEBUG
@@ -1597,7 +1629,6 @@ void DRW_draw_render_loop_ex(struct Depsgraph *depsgraph,
                              GPUViewport *viewport,
                              const bContext *evil_C)
 {
-
   Scene *scene = DEG_get_evaluated_scene(depsgraph);
   ViewLayer *view_layer = DEG_get_evaluated_view_layer(depsgraph);
   RegionView3D *rv3d = region->regiondata;
@@ -2948,6 +2979,7 @@ void DRW_engines_register(void)
   DRW_engine_register(&draw_engine_overlay_type);
   DRW_engine_register(&draw_engine_select_type);
   DRW_engine_register(&draw_engine_basic_type);
+  DRW_engine_register(&draw_engine_compositor_type);
 #ifdef WITH_DRAW_DEBUG
   DRW_engine_register(&draw_engine_debug_select_type);
 #endif