Fix preview render not starting in some cases, now starts the preview rendering

job if no render result is found and no preview render job is already running.

1 files changed, 5 insertions, 9 deletions

diff --git a/source/blender/editors/render/render_preview.c b/source/blender/editors/render/render_preview.c
index e8c578cb685..2e88c243df6 100644
--- a/source/blender/editors/render/render_preview.c
+++ b/source/blender/editors/render/render_preview.c
@@ -572,9 +572,6 @@ static int ed_preview_draw_rect(ScrArea *sa, int split, int first, rcti *rect, r
 			}
 		}
 	}
-	else {
-		ok = 1;
-	}
 
 	RE_ReleaseResultImage(re);
 
@@ -584,6 +581,7 @@ static int ed_preview_draw_rect(ScrArea *sa, int split, int first, rcti *rect, r
 void ED_preview_draw(const bContext *C, void *idp, void *parentp, void *slotp, rcti *rect)
 {
 	if (idp) {
+		wmWindowManager *wm = CTX_wm_manager(C);
 		ScrArea *sa = CTX_wm_area(C);
 		ID *id = (ID *)idp;
 		ID *parent = (ID *)parentp;
@@ -609,13 +607,11 @@ void ED_preview_draw(const bContext *C, void *idp, void *parentp, void *slotp, r
 		if (ok)
 			*rect = newrect;
 
-		/* check for spacetype... */
-		if (sbuts->spacetype == SPACE_BUTS && sbuts->preview) {
+		/* start a new preview render job if signalled through sbuts->preview,
+		 * or if no render result was found and no preview render job is running */
+		if ((sbuts->spacetype == SPACE_BUTS && sbuts->preview) ||
+			(!ok && !WM_jobs_test(wm, sa, WM_JOB_TYPE_RENDER_PREVIEW))) {
 			sbuts->preview = 0;
-			ok = 0;
-		}
-	
-		if (ok == 0) {
 			ED_preview_shader_job(C, sa, id, parent, slot, newx, newy, PR_BUTS_RENDER);
 		}
 	}