[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [19869] trunk/blender/source/blender/ render/intern/source/pipeline.c: bugfix #18187

[Ton Roosendaal]

Revision: 19869
          http://projects.blender.org/plugins/scmsvn/viewcvs.php?view=rev&root=bf-blender&revision=19869
Author:   ton
Date:     2009-04-22 13:54:43 +0200 (Wed, 22 Apr 2009)

Log Message:
-----------
bugfix #18187

Using "Key Alpha" didn't work when using MBlur render. The accumulation
code was assuming regular alpha then. Now it corrects for it.

Still it's a bit of a weak spot in Blender's render system. I will look 
in the future to make this a real post process; converting all RGBA 
buffers in the system, including for all passes, to "key alpha". 
Combined with that our compositor should become alpha type aware too. 
Everything in Blender assumes premul alpha, which still just will work 
best in general...

Modified Paths:
--------------
    trunk/blender/source/blender/render/intern/source/pipeline.c

Modified: trunk/blender/source/blender/render/intern/source/pipeline.c
===================================================================
--- trunk/blender/source/blender/render/intern/source/pipeline.c	2009-04-22 10:07:12 UTC (rev 19868)
+++ trunk/blender/source/blender/render/intern/source/pipeline.c	2009-04-22 11:54:43 UTC (rev 19869)
@@ -1639,6 +1639,42 @@
 	RE_Database_Free(re);
 }
 
+/* called by blur loop, accumulate RGBA key alpha */
+static void addblur_rect_key(RenderResult *rr, float *rectf, float *rectf1, float blurfac)
+{
+	float mfac= 1.0f - blurfac;
+	int a, b, stride= 4*rr->rectx;
+	int len= stride*sizeof(float);
+	
+	for(a=0; a<rr->recty; a++) {
+		if(blurfac==1.0f) {
+			memcpy(rectf, rectf1, len);
+		}
+		else {
+			float *rf= rectf, *rf1= rectf1;
+			
+			for( b= rr->rectx; b>0; b--, rf+=4, rf1+=4) {
+				if(rf1[3]<0.01f)
+					rf[3]= mfac*rf[3];
+				else if(rf[3]<0.01f) {
+					rf[0]= rf1[0];
+					rf[1]= rf1[1];
+					rf[2]= rf1[2];
+					rf[3]= blurfac*rf1[3];
+				}
+				else {
+					rf[0]= mfac*rf[0] + blurfac*rf1[0];
+					rf[1]= mfac*rf[1] + blurfac*rf1[1];
+					rf[2]= mfac*rf[2] + blurfac*rf1[2];
+					rf[3]= mfac*rf[3] + blurfac*rf1[3];
+				}				
+			}
+		}
+		rectf+= stride;
+		rectf1+= stride;
+	}
+}
+
 /* called by blur loop, accumulate renderlayers */
 static void addblur_rect(RenderResult *rr, float *rectf, float *rectf1, float blurfac, int channels)
 {
@@ -1662,8 +1698,9 @@
 	}
 }
 
+
 /* called by blur loop, accumulate renderlayers */
-static void merge_renderresult_blur(RenderResult *rr, RenderResult *brr, float blurfac)
+static void merge_renderresult_blur(RenderResult *rr, RenderResult *brr, float blurfac, int key_alpha)
 {
 	RenderLayer *rl, *rl1;
 	RenderPass *rpass, *rpass1;
@@ -1672,8 +1709,12 @@
 	for(rl= rr->layers.first; rl && rl1; rl= rl->next, rl1= rl1->next) {
 		
 		/* combined */
-		if(rl->rectf && rl1->rectf)
-			addblur_rect(rr, rl->rectf, rl1->rectf, blurfac, 4);
+		if(rl->rectf && rl1->rectf) {
+			if(key_alpha)
+				addblur_rect_key(rr, rl->rectf, rl1->rectf, blurfac);
+			else
+				addblur_rect(rr, rl->rectf, rl1->rectf, blurfac, 4);
+		}
 		
 		/* passes are allocated in sync */
 		rpass1= rl1->passes.first;
@@ -1703,7 +1744,7 @@
 		
 		blurfac= 1.0f/(float)(re->r.osa-blur);
 		
-		merge_renderresult_blur(rres, re->result, blurfac);
+		merge_renderresult_blur(rres, re->result, blurfac, re->r.alphamode & R_ALPHAKEY);
 		if(re->test_break()) break;
 	}