Draw checker backdrop for sequencer when in RGBA mode

1 files changed, 12 insertions, 9 deletions

diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 1a4d461c3c1..3c2c715efc2 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -1050,6 +1050,17 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 	/* setting up the view - actual drawing starts here */
 	UI_view2d_view_ortho(v2d);
 
+	/* only draw alpha for main buffer */
+	if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
+		if (sseq->flag & SEQ_USE_ALPHA) {
+			glEnable(GL_BLEND);
+			glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+			fdrawcheckerboard(v2d->tot.xmin, v2d->tot.ymin, v2d->tot.xmax, v2d->tot.ymax);
+			glColor4f(1.0, 1.0, 1.0, 1.0);
+		}
+	}
+
 	last_texid = glaGetOneInteger(GL_TEXTURE_2D);
 	glEnable(GL_TEXTURE_2D);
 	glGenTextures(1, (GLuint *)&texid);
@@ -1061,14 +1072,6 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, ibuf->x, ibuf->y, 0, GL_RGBA, GL_UNSIGNED_BYTE, display_buffer);
 
-	/* only draw alpha for main buffer */
-	if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
-		if (sseq->flag & SEQ_USE_ALPHA) {
-			glEnable(GL_BLEND);
-			glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-		}
-	}
-
 	glBegin(GL_QUADS);
 
 	if (draw_overlay) {
@@ -1100,7 +1103,7 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 	glEnd();
 	glBindTexture(GL_TEXTURE_2D, last_texid);
 	glDisable(GL_TEXTURE_2D);
-	if (sseq->flag & SEQ_USE_ALPHA)
+	if (sseq->mainb == SEQ_DRAW_IMG_IMBUF && sseq->flag & SEQ_USE_ALPHA)
 		glDisable(GL_BLEND);
 	glDeleteTextures(1, &texid);