Fix T40939: Border render and SSS doesn't work correct in rendered viewport

There were some missing updates in the viewport render job which lead to
wrong SSS mapping on the final resolution.

There was also wrong scaling applying when border render is used.

And last but not least(?) strands render was using first level of the
resolution leading to really thick strands in the final viewport.

1 files changed, 5 insertions, 3 deletions

diff --git a/source/blender/render/intern/source/pipeline.c b/source/blender/render/intern/source/pipeline.c
index e6a9303a982..2131b820bd4 100644
--- a/source/blender/render/intern/source/pipeline.c
+++ b/source/blender/render/intern/source/pipeline.c
@@ -729,9 +729,11 @@ void RE_ChangeResolution(Render *re, int winx, int winy, rcti *disprect)
 {
 	re_init_resolution(re, NULL, winx, winy, disprect);
 
-	BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
-	render_result_rescale(re);
-	BLI_rw_mutex_unlock(&re->resultmutex);
+	if (re->result) {
+		BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
+		render_result_rescale(re);
+		BLI_rw_mutex_unlock(&re->resultmutex);
+	}
 }
 
 /* update some variables that can be animated, and otherwise wouldn't be due to