Three features;

- Live scanline updates while rendering
Using a timer system, each second now the tiles that are being processed
are checked if they could use display.
To make this work pretty, I had to use the threaded 'tile processor' for
a single thread too, but that's now proven to be stable.

Also note that these updates draw per layer, including ztransp progress
separately from solid render.

- Recode of ztransp OSA
Until now (since blender 1.0) the ztransp part was fully rendered and
added on top of the solid part with alpha-over. This adding was done before
the solid part applied sub-pixel sample filtering, causing the ztransp
layer to be always too blurry.

Now the ztransp layer uses same sub=pixel filter, resulting in the same
AA level (and filter results) as the solid part. Quite noticable with hair
renders.

- Vector buffer support & preliminary vector-blur Node
Using the "Render Layer" panel "Vector" pass button, the motion vectors
per pixel are calculated and stored. Accessible via the Compositor.

The vector-blur node is horrible btw! It just uses the length of the
vector to apply a filter like with current (z)blur. I'm committing it anyway,
I'll experiment with it further, and who knows some surprise code shows up!

2 files changed, 23 insertions, 6 deletions

diff --git a/source/blender/src/editnode.c b/source/blender/src/editnode.c
index 84354859067..c192d801b65 100644
--- a/source/blender/src/editnode.c
+++ b/source/blender/src/editnode.c
@@ -1178,7 +1178,7 @@ static void node_add_menu(SpaceNode *snode)
 	}
 	else if(snode->treetype==NTREE_COMPOSIT) {
 		/* compo menu, still hardcoded defines... solve */
-		event= pupmenu("Add Node%t|Render Result %x221|Composite %x222|Viewer%x201|Image %x220|RGB Curves%x209|AlphaOver %x210|Blur %x211|Filter %x212|Value %x203|Color %x202|Mix %x204|ColorRamp %x205|Color to BW %x206|Map Value %x213|Normal %x207");
+		event= pupmenu("Add Node%t|Render Result %x221|Composite %x222|Viewer%x201|Image %x220|RGB Curves%x209|AlphaOver %x210|Blur %x211|Vector Blur %x215|Filter %x212|Value %x203|Color %x202|Mix %x204|ColorRamp %x205|Color to BW %x206|Map Value %x213|Normal %x207");
 		if(event<1) return;
 	}
 	else return;
diff --git a/source/blender/src/renderwin.c b/source/blender/src/renderwin.c
index 579dc8b892a..8b2c0093b3e 100644
--- a/source/blender/src/renderwin.c
+++ b/source/blender/src/renderwin.c
@@ -721,10 +721,23 @@ static void renderwin_clear_display_cb(RenderResult *rr)
 */
 
 /* can get as well the full picture, as the parts while rendering */
-static void renderwin_progress(RenderWin *rw, RenderResult *rr, rcti *unused)
+static void renderwin_progress(RenderWin *rw, RenderResult *rr, rcti *renrect)
 {
 	rcti win_rct;
 	float *rectf, fullrect[2][2];
+	int ymin, ymax;
+	
+	/* if renrect argument, we only display scanlines */
+	if(renrect) {
+		ymin= renrect->ymin;
+		ymax= renrect->ymax-ymin;
+		if(ymax<2) return;
+		renrect->ymin= renrect->ymax;
+	}
+	else {
+		ymin= 0;
+		ymax= rr->recty-2*rr->crop;
+	}
 	
 	/* renderwindow cruft */
 	win_rct.xmin= win_rct.ymin= 0;
@@ -736,9 +749,13 @@ static void renderwin_progress(RenderWin *rw, RenderResult *rr, rcti *unused)
 	if(rr->rectf)
 		rectf= rr->rectf;
 	else {
-		RenderLayer *rl= BLI_findlink(&rr->layers, rr->actlay);
+		RenderLayer *rl= rr->renlay;
+		if(rl==NULL) return;
 		rectf= rl->rectf;
-	}	
+	}
+	/* if scanline updates... */
+	rectf+= 4*rr->rectx*ymin;
+	
 	/* when rendering more pixels than needed, we crop away cruft */
 	if(rr->crop)
 		rectf+= 4*(rr->crop*rr->rectx + rr->crop);
@@ -746,14 +763,14 @@ static void renderwin_progress(RenderWin *rw, RenderResult *rr, rcti *unused)
 	/* tilerect defines drawing offset from (0,0) */
 	/* however, tilerect (xmin, ymin) is first pixel */
 	fullrect[0][0] += (rr->tilerect.xmin+rr->crop)*rw->zoom;
-	fullrect[0][1] += (rr->tilerect.ymin+rr->crop)*rw->zoom;
+	fullrect[0][1] += (rr->tilerect.ymin+rr->crop + ymin)*rw->zoom;
 
 	glEnable(GL_SCISSOR_TEST);
 	glaDefine2DArea(&win_rct);
 
 	glDrawBuffer(GL_FRONT);
 	glPixelZoom(rw->zoom, rw->zoom);
-	glaDrawPixelsSafe(fullrect[0][0], fullrect[0][1], rr->rectx-2*rr->crop, rr->recty-2*rr->crop, rr->rectx, 
+	glaDrawPixelsSafe(fullrect[0][0], fullrect[0][1], rr->rectx-2*rr->crop, ymax, rr->rectx, 
 					  GL_RGBA, GL_FLOAT, rectf);
 	glPixelZoom(1.0, 1.0);
 	glFlush();