Compositor: Full-frame base system

This patch adds the base code needed to make the full-frame system work for both current tiled/per-pixel implementation of operations and full-frame.

Two execution models:
- Tiled: Current implementation. Renders execution groups in tiles from outputs to input. Not all operations are buffered. Runs the tiled/per-pixel implementation.
- FullFrame: All operations are buffered. Fully renders operations from inputs to outputs. Runs full-frame implementation of operations if available otherwise the current tiled/per-pixel. Creates output buffers on first read and free them as soon as all its readers have finished, reducing peak memory usage of complex/long trees. Operations are multi-threaded but do not run in parallel as Tiled (will be done in another patch).

This should allow us to convert operations to full-frame in small steps with the system already working and solve the problem of high memory usage.

FullFrame breaking changes respect Tiled system, mainly:
- Translate, Rotate, Scale, and Transform take effect immediately instead of next buffered operation.
- Any sampling is always done over inputs instead of last buffered operation.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D11113

2 files changed, 10 insertions, 2 deletions

diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 58c94b6f369..0fa1d1a74ac 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -461,7 +461,6 @@ typedef struct bNodeTree {
   short is_updating;
   /** Generic temporary flag for recursion check (DFS/BFS). */
   short done;
-  char _pad2[4];
 
   /** Specific node type this tree is used for. */
   int nodetype DNA_DEPRECATED;
@@ -472,6 +471,8 @@ typedef struct bNodeTree {
   short render_quality;
   /** Tile size for compositor engine. */
   int chunksize;
+  /** Execution mode to use for compositor engine. */
+  int execution_mode;
 
   rctf viewer_border;
 
@@ -545,6 +546,12 @@ typedef enum eNodeTreeUpdate {
   NTREE_UPDATE_GROUP = (NTREE_UPDATE_GROUP_IN | NTREE_UPDATE_GROUP_OUT),
 } eNodeTreeUpdate;
 
+/* tree->execution_mode */
+typedef enum eNodeTreeExecutionMode {
+  NTREE_EXECUTION_MODE_TILED = 0,
+  NTREE_EXECUTION_MODE_FULL_FRAME = 1,
+} eNodeTreeExecutionMode;
+
 /* socket value structs for input buttons
  * DEPRECATED now using ID properties
  */
diff --git a/source/blender/makesdna/DNA_userdef_types.h b/source/blender/makesdna/DNA_userdef_types.h
index 1fed8e14bd6..61d2c04d98b 100644
--- a/source/blender/makesdna/DNA_userdef_types.h
+++ b/source/blender/makesdna/DNA_userdef_types.h
@@ -642,11 +642,12 @@ typedef struct UserDef_Experimental {
    * when the release cycle is not alpha. */
   char use_new_hair_type;
   char use_new_point_cloud_type;
+  char use_full_frame_compositor;
   char use_sculpt_vertex_colors;
   char use_sculpt_tools_tilt;
   char use_asset_browser;
   char use_override_templates;
-  char _pad[6];
+  char _pad[5];
   /** `makesdna` does not allow empty structs. */
 } UserDef_Experimental;