Image: support storing full image buffers for each undo step

Update image undo to store buffers for each step:

- Undo buffers share tiles to avoid using too much memory.
- Undo support for different sized buffers
  allowing operations such as crop or resize.
- Paint tiles have been split into separate API/storage.
- Painting speed wont be impacted significantly
  since storing the extra tiles is done after the stroke & only
  for the first undo step.

Resolves T61263, see D5939 for details.

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/editors/include/ED_paint.h b/source/blender/editors/include/ED_paint.h
index 88cc8a85897..81252ad2516 100644
--- a/source/blender/editors/include/ED_paint.h
+++ b/source/blender/editors/include/ED_paint.h
@@ -42,6 +42,10 @@ void ED_imapaint_bucket_fill(struct bContext *C, float color[3], struct wmOperat
 
 /* paint_image_undo.c */
 void ED_image_undo_push_begin(const char *name, int paint_mode);
+void ED_image_undo_push_begin_with_image(const char *name,
+                                         struct Image *image,
+                                         struct ImBuf *ibuf);
+
 void ED_image_undo_push_end(void);
 void ED_image_undo_restore(struct UndoStep *us);