Sequencer: disabled sequencer recursion and corrected rendered preview mode

Sequencer recursion was never actually supported and only gives lots of
issues. Disabled it now, so users are not getting confused by semi-working
stuff.

Also made a correction to rendered sequencer preview, so now using scene
strip in it's own sequencer will work properly (it produced black frames
before).

This required killing compositor jobs since they could be using the same
render result as renderer called from sequencer uses.

Small improvements could be:
- Add slight delay before compositor job starts handling nodes so killing
  this job would be fast
- Tag compositor to be updated after preview was fully rendered.

1 files changed, 10 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index af0cab98fe0..a947a48938e 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -2344,6 +2344,7 @@ static ImBuf *seq_render_scene_strip(SeqRenderData context, Sequence *seq, float
 	int do_seq;
 	int have_seq = FALSE;
 	Scene *scene;
+	int is_thread_main = BLI_thread_is_main();
 
 	/* don't refer to seq->scene above this point!, it can be NULL */
 	if (seq->scene == NULL) {
@@ -2373,7 +2374,7 @@ static ImBuf *seq_render_scene_strip(SeqRenderData context, Sequence *seq, float
 
 	/* prevent eternal loop */
 	do_seq = context.scene->r.scemode & R_DOSEQ;
-	context.scene->r.scemode &= ~R_DOSEQ;
+	scene->r.scemode &= ~R_DOSEQ;
 	
 #ifdef DURIAN_CAMERA_SWITCH
 	/* stooping to new low's in hackyness :( */
@@ -2383,9 +2384,7 @@ static ImBuf *seq_render_scene_strip(SeqRenderData context, Sequence *seq, float
 	(void)oldmarkers;
 #endif
 
-	if ((sequencer_view3d_cb && do_seq_gl && camera) &&
-	    (BLI_thread_is_main() == TRUE) &&
-	    ((have_seq == FALSE) || (scene == context.scene)))
+	if ((sequencer_view3d_cb && do_seq_gl && camera) && is_thread_main)
 	{
 		char err_out[256] = "unknown";
 		/* for old scened this can be uninitialized,
@@ -2405,8 +2404,12 @@ static ImBuf *seq_render_scene_strip(SeqRenderData context, Sequence *seq, float
 		Render *re = RE_GetRender(scene->id.name);
 		RenderResult rres;
 
-		/* XXX: this if can be removed when sequence preview rendering uses the job system */
-		if (is_rendering || context.scene != scene) {
+		/* XXX: this if can be removed when sequence preview rendering uses the job system
+		 *
+		 * disable rendered preview for sequencer while rendering -- it's very much possible
+		 * that preview render will went into conflict with final render
+		 */
+		if (!is_thread_main || is_rendering == FALSE) {
 			if (re == NULL)
 				re = RE_NewRender(scene->id.name);
 			
@@ -2440,7 +2443,7 @@ static ImBuf *seq_render_scene_strip(SeqRenderData context, Sequence *seq, float
 	}
 	
 	/* restore */
-	context.scene->r.scemode |= do_seq;
+	scene->r.scemode |= do_seq;
 	
 	scene->r.cfra = oldcfra;