bugfix [#22638] Alpha channel not saved when using texture paint

check for alpha channel while saving images that have been painted onto.
It would be nicer to do this while in paint mode except this isn't so simple with project paint using multiple images at once.

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/editors/space_image/image_ops.c b/source/blender/editors/space_image/image_ops.c
index d2cf3365423..be917f43735 100644
--- a/source/blender/editors/space_image/image_ops.c
+++ b/source/blender/editors/space_image/image_ops.c
@@ -888,6 +888,13 @@ static void save_image_doit(bContext *C, SpaceImage *sima, Scene *scene, wmOpera
 				ibuf->depth= 24;
 			}
 		}
+		else {
+			/* TODO, better solution, if a 24bit image is painted onto it may contain alpha */
+			if(ibuf->userflags & IB_BITMAPDIRTY) { /* it has been painted onto */
+				/* checks each pixel, not ideal */
+				ibuf->depth= BKE_alphatest_ibuf(ibuf) ? 32 : 24;
+			}
+		}
 
 		if(scene->r.scemode & R_EXTENSION)  {
 			BKE_add_image_extension(path, sima->imtypenr);