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

1 files changed, 2 insertions, 1 deletions

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;