Fix regression in sequencer overlay draw option

Drawing alpha backdrop would obscure image data behind the overlay.

diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 8e789c0f21bd71f0e30b679e1c0922f3ac06d6f0..5793c8eb7117c6aa0257b5ee3842b9e66470f105 100644 (file)
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -1070,7 +1070,8 @@ static void sequencer_draw_borders(const SpaceSeq *sseq, const View2D *v2d, cons
 }
 
 /* draws checkerboard background for transparent content */
-static void sequencer_draw_background(const SpaceSeq *sseq, View2D *v2d, const float viewrect[2])
+static void sequencer_draw_background(
+        const SpaceSeq *sseq, View2D *v2d, const float viewrect[2], const bool draw_overlay)
 {
        /* setting up the view */
        UI_view2d_totRect_set(v2d, viewrect[0] + 0.5f, viewrect[1] + 0.5f);
@@ -1079,7 +1080,7 @@ static void sequencer_draw_background(const SpaceSeq *sseq, View2D *v2d, const f
 
        /* only draw alpha for main buffer */
        if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
-               if (sseq->flag & SEQ_USE_ALPHA) {
+               if ((sseq->flag & SEQ_USE_ALPHA) && !draw_overlay) {
                        glEnable(GL_BLEND);
                        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
@@ -1146,10 +1147,10 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
            (ibuf->rect == NULL && ibuf->rect_float == NULL))
        {
                /* gpencil can also be drawn without a valid imbuf */
-               if (draw_gpencil && is_imbuf) {
+               if ((draw_gpencil && is_imbuf) && !draw_overlay) {
                        sequencer_display_size(scene, sseq, viewrect);
 
-                       sequencer_draw_background(sseq, v2d, viewrect);
+                       sequencer_draw_background(sseq, v2d, viewrect, false);
                        sequencer_draw_borders(sseq, v2d, scene);
 
                        sequencer_draw_gpencil(C);
@@ -1219,7 +1220,7 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
        }
 
        if (!draw_backdrop) {
-               sequencer_draw_background(sseq, v2d, viewrect);
+               sequencer_draw_background(sseq, v2d, viewrect, draw_overlay);
        }
 
        if (scope) {