Fix T47848: Fix regression in sequencer GL render

Own changes in 2.77 broke off-screen render with scene render size doesn't match output.

1 files changed, 7 insertions, 1 deletions

diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 4d7cc28ca3f..8c2d7877c8c 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -3309,13 +3309,19 @@ ImBuf *ED_view3d_draw_offscreen_imbuf(
 	RegionView3D *rv3d = ar->regiondata;
 	ImBuf *ibuf;
 	const bool draw_sky = (alpha_mode == R_ADDSKY);
-	const bool own_ofs = (ofs == NULL);
 
 	/* view state */
 	GPUFXSettings fx_settings = v3d->fx_settings;
 	bool is_ortho = false;
 	float winmat[4][4];
 
+	if (ofs && ((GPU_offscreen_width(ofs) != sizex) || (GPU_offscreen_height(ofs) != sizey))) {
+		/* sizes differ, can't reuse */
+		ofs = NULL;
+	}
+
+	const bool own_ofs = (ofs == NULL);
+
 	if (own_ofs) {
 		/* bind */
 		ofs = GPU_offscreen_create(sizex, sizey, full_samples ? 0 : samples, err_out);