Image cache rewrite to using generic movie cache

Summary:
Behaves very much the same as cache for Movie Clip datablock:

- Image now have `MovieCache *cache` field which replaced
  legacy `ListBase ibufs`.

  This allows image datablock to easily keep of image
  buffers which are owned by itself. This field isn't
  saved to the file and getting restored on undo steps.

  However, cache limit is global for movies, sequences
  and image datablocks now. So overall cached image buffers
  size will not go above cache limit size in user
  preferences.

- Image buffers which are marked as BITMAPDIRTY will never
  be freed from the cache.

- Added utility function to iterate over image buffers
  saved in movie cache.

- Movie cache cleanup check callback now have ImBuf argument
  which can be used in a condition of cleanup.

- Added some utility functions which replaces legacy ibufs
  iterations with image cache iteration which happens from
  inside a lock.

- Fixed `image_mem_size()` which was only counting one of
  the buffers if both float and byte buffer present.

Additional notes:

- `BKE_image_get_first_ibuf()` is rather stupid, but direct
  access to ibufs->first was also the same stupid idea.

  Would consider avoid this function is another project.

- There are some places which doesn't look threadsafe, but
  they already were not so much threadsafe anyway before.

  So think not a big deal with solving this later.

Finally solves infinite memory usage by image sequences! :)

Reviewers: brecht, campbellbarton

Reviewed By: brecht

CC: sebastian_k

Differential Revision: http://developer.blender.org/D95

1 files changed, 6 insertions, 2 deletions

diff --git a/source/blender/gpu/intern/gpu_draw.c b/source/blender/gpu/intern/gpu_draw.c
index 0dba2cd50e8..ee59cf418bf 100644
--- a/source/blender/gpu/intern/gpu_draw.c
+++ b/source/blender/gpu/intern/gpu_draw.c
@@ -93,6 +93,7 @@ void GPU_render_text(MTFace *tface, int mode,
 {
 	if ((mode & GEMAT_TEXT) && (textlen>0) && tface->tpage) {
 		Image* ima = (Image *)tface->tpage;
+		ImBuf *first_ibuf;
 		int index, character;
 		float centerx, centery, sizex, sizey, transx, transy, movex, movey, advance;
 		float advance_tab;
@@ -117,7 +118,8 @@ void GPU_render_text(MTFace *tface, int mode,
 		glPushMatrix();
 		
 		/* get the tab width */
-		matrixGlyph((ImBuf *)ima->ibufs.first, ' ', & centerx, &centery,
+		first_ibuf = BKE_image_get_first_ibuf(ima);
+		matrixGlyph(first_ibuf, ' ', &centerx, &centery,
 			&sizex, &sizey, &transx, &transy, &movex, &movey, &advance);
 		
 		advance_tab= advance * 4; /* tab width could also be an option */
@@ -143,7 +145,7 @@ void GPU_render_text(MTFace *tface, int mode,
 			
 			// space starts at offset 1
 			// character = character - ' ' + 1;
-			matrixGlyph((ImBuf *)ima->ibufs.first, character, & centerx, &centery,
+			matrixGlyph(first_ibuf, character, & centerx, &centery,
 				&sizex, &sizey, &transx, &transy, &movex, &movey, &advance);
 
 			uv[0][0] = (tface->uv[0][0] - centerx) * sizex + transx;
@@ -184,6 +186,8 @@ void GPU_render_text(MTFace *tface, int mode,
 			line_start -= advance; /* so we can go back to the start of the line */
 		}
 		glPopMatrix();
+
+		IMB_freeImBuf(first_ibuf);
 	}
 }