A couple of render improvements;

- Bug fix: the upper tile in a collumn for Panorama render didn't put the
  mainthread to sleep properly. Now panorama renders 25% faster if you had
  set Y-Parts to 4.

- Enabling Compositing in Scene for first time now adds a "Composite" node
  too, so render output gets applied.
- An attempt to render with "Do Composite" without "Composite" node will
  throw an error and stops rendering. In background mode it will just not
  render at all, and print errors.
- Errors that prevent rendering now give a popup menu again.
- Having MBlur or Fields option on will now normally render, but with an
  error print in console (not done yet...)

source/blender/render/extern/include/RE_pipeline.h

@@ -175,7 +175,7 @@ void RE_stats_draw_cb	(struct Render *re, void (*f)(RenderStats *rs));
 void RE_timecursor_cb	(struct Render *re, void (*f)(int));
 void RE_test_break_cb	(struct Render *re, int (*f)(void));
 void RE_test_return_cb	(struct Render *re, int (*f)(void));
-void RE_error_cb		(struct Render *re, void (*f)(const char *str));
+void RE_error_cb		(struct Render *re, void (*f)(char *str));
 
 /* should move to kernel once... still unsure on how/where */
 float RE_filter_value(int type, float x);

source/blender/render/intern/include/render_types.h

@@ -177,7 +177,7 @@ struct Render
 	
 	int (*test_break)(void);
 	int (*test_return)(void);
-	void (*error)(const char *str);
+	void (*error)(char *str);
 	
 	RenderStats i;
 };

source/blender/render/intern/source/pipeline.c

@@ -120,7 +120,7 @@ static void result_rcti_nothing(RenderResult *rr, volatile struct rcti *rect) {}
 static void stats_nothing(RenderStats *rs) {}
 static void int_nothing(int val) {}
 static int void_nothing(void) {return 0;}
-static void print_error(const char *str) {printf("ERROR: %s\n", str);}
+static void print_error(char *str) {printf("ERROR: %s\n", str);}
 
 static void stats_background(RenderStats *rs)
 {
@@ -842,7 +842,7 @@ void RE_test_return_cb(Render *re, int (*f)(void))
 {
 	re->test_return= f;
 }
-void RE_error_cb(Render *re, void (*f)(const char *str))
+void RE_error_cb(Render *re, void (*f)(char *str))
 {
 	re->error= f;
 }
@@ -1097,6 +1097,10 @@ static void threaded_tile_processor(Render *re)
 		else if(re->r.mode & R_PANORAMA) {
 			if(nextpa==NULL && BLI_available_threads(&threads)==maxthreads)
 				nextpa= find_next_pano_slice(re, &minx, &viewplane);
+			else {
+				PIL_sleep_ms(50);
+				drawtimer++;
+			}
 		}
 		else {
 			PIL_sleep_ms(50);
@@ -1179,6 +1183,7 @@ void render_one_frame(Render *re)
 	RE_Database_Free(re);
 }
 
+#if 0
 /* accumulates osa frames */
 static void do_render_blurred(Render *re, float frame)
 {
@@ -1190,6 +1195,7 @@ static void do_render_fields(Render *re)
 {
 	
 }
+#endif
 
 /* within context of current Render *re, render another scene.
    it uses current render image size and disprect, but doesn't execute composite
@@ -1222,11 +1228,11 @@ void RE_RenderScene(Render *re, Scene *sce, int cfra)
 	resc->stats_draw= re->stats_draw;
 	
 	if(resc->r.mode & R_FIELDS)
-		do_render_fields(resc);
+		printf("No field render yet...\n"); //do_render_fields(resc);
 	else if(resc->r.mode & R_MBLUR)
-		do_render_blurred(resc, resc->r.cfra);
-	else
-		render_one_frame(resc);
+		printf("No mblur render yet...\n"); //do_render_blurred(resc, resc->r.cfra);
+	//else
+	render_one_frame(resc);
 
 }
 
@@ -1316,11 +1322,11 @@ static void do_render_final(Render *re)
 			RE_SetCamera(re, re->scene->camera);
 			
 			if(re->r.mode & R_FIELDS)
-				do_render_fields(re);
+				printf("No field render yet...\n"); //do_render_fields(resc);
 			else if(re->r.mode & R_MBLUR)
-				do_render_blurred(re, re->scene->r.cfra);
-			else
-				render_one_frame(re);
+				printf("No mblur render yet...\n"); //do_render_blurred(resc, resc->r.cfra);
+													//else
+			render_one_frame(re);
 		}
 		
 		/* swap render result */
@@ -1379,6 +1385,27 @@ static int is_rendering_allowed(Render *re)
 		}
 	}
 	
+	if(re->r.scemode & R_DOCOMP) {
+		if(re->scene->use_nodes) {
+			bNodeTree *ntree= re->scene->nodetree;
+			bNode *node;
+		
+			if(ntree==NULL) {
+				re->error("No Nodetree in Scene");
+				return 0;
+			}
+		
+			for(node= ntree->nodes.first; node; node= node->next)
+				if(node->type==CMP_NODE_COMPOSITE)
+					break;
+			
+			if(node==NULL) {
+				re->error("No Render Output Node in Scene");
+				return 0;
+			}
+		}
+	}
+	
  	/* check valid camera */
 	if(re->scene->camera==NULL)
 		re->scene->camera= scene_find_camera(re->scene);

source/blender/src/editnode.c

@@ -333,7 +333,7 @@ void node_shader_default(Material *ma)
 /* called from shading buttons or header */
 void node_composit_default(Scene *sce)
 {
-	bNode *in, *out;
+	bNode *in, *out1, *out2;
 	bNodeSocket *fromsock, *tosock;
 	
 	/* but lets check it anyway */
@@ -344,27 +344,31 @@ void node_composit_default(Scene *sce)
 	
 	sce->nodetree= ntreeAddTree(NTREE_COMPOSIT);
 	
-	out= nodeAddNodeType(sce->nodetree, CMP_NODE_VIEWER, NULL);
-	out->locx= 300.0f; out->locy= 300.0f;
+	out1= nodeAddNodeType(sce->nodetree, CMP_NODE_VIEWER, NULL);
+	out1->locx= 300.0f; out1->locy= 200.0f;
+	out2= nodeAddNodeType(sce->nodetree, CMP_NODE_COMPOSITE, NULL);
+	out2->locx= 300.0f; out2->locy= 500.0f;
 	
 	in= nodeAddNodeType(sce->nodetree, CMP_NODE_R_RESULT, NULL);
-	in->locx= 10.0f; in->locy= 300.0f;
+	in->locx= 10.0f; in->locy= 400.0f;
 	nodeSetActive(sce->nodetree, in);
 	
-	/* only a link from color to color */
+	/* links from color to color */
 	fromsock= in->outputs.first;
-	tosock= out->inputs.first;
-	nodeAddLink(sce->nodetree, in, fromsock, out, tosock);
+	tosock= out1->inputs.first;
+	nodeAddLink(sce->nodetree, in, fromsock, out1, tosock);
+	tosock= out2->inputs.first;
+	nodeAddLink(sce->nodetree, in, fromsock, out2, tosock);
 	
 	ntreeSolveOrder(sce->nodetree);	/* needed for pointers */
 	
-	out->id= find_id("IM", "Compositor");
-	if(out->id==NULL) {
+	out1->id= find_id("IM", "Compositor");
+	if(out1->id==NULL) {
 		Image *ima= alloc_libblock(&G.main->image, ID_IM, "Compositor");
 		strcpy(ima->name, "Compositor");
 		ima->ok= 1;
 		ima->xrep= ima->yrep= 1;
-		out->id= &ima->id;
+		out1->id= &ima->id;
 	}
 }
 

source/blender/src/renderwin.c

@@ -80,6 +80,7 @@
 #include "BIF_renderwin.h"
 #include "BIF_resources.h"
 #include "BIF_toets.h"
+#include "BIF_toolbox.h"
 #include "BIF_writeimage.h"
 
 #include "BDR_editobject.h"
@@ -1030,6 +1031,7 @@ static void end_test_break_callback()
    - set callbacks
    - cleanup
 */
+static void error_cb(char *str){error(str);}
 
 static void do_render(int anim)
 {
@@ -1045,6 +1047,7 @@ static void do_render(int anim)
 	RE_display_init_cb(re, renderwin_init_display_cb);
 	RE_display_draw_cb(re, renderwin_progress_display_cb);
 	RE_display_clear_cb(re, renderwin_clear_display_cb);
+	RE_error_cb(re, error_cb);
 	init_test_break_callback();
 	RE_test_break_cb(re, test_break);
 	RE_timecursor_cb(re, set_timecursor);

source/blender/src/toolbox.c

@@ -221,7 +221,7 @@ void error(char *fmt, ...)
 	sprintf(nfmt, "%s", fmt);
 	
 	va_start(ap, fmt);
-	if (G.background || !G.curscreen || (G.rendering)) {
+	if (G.background || !G.curscreen) {
 		vprintf(nfmt, ap);
 		printf("\n");
 	} else {