From b154b5993829f92e03233a04410b3667f2976556 Mon Sep 17 00:00:00 2001
From: Sergey Sharybin <sergey.vfx@gmail.com>
Date: Sun, 24 Jul 2011 10:26:22 +0000
Subject: New dilation function from Morten Mikkelsen (aka sparky).

This commit fixes very noticeable seams caused by margins
calculated incorrectly. This commit changes way margin is
calculated in and makes textures really seamless.

Also margin limited to 32 isn't good now -- artists are baking
really large textures nowadays so margin is now limited to 64px.

Thank you, Morten!
---
 source/blender/imbuf/intern/filter.c | 219 ++++++++++++++++++-----------------
 1 file changed, 115 insertions(+), 104 deletions(-)

(limited to 'source/blender/imbuf/intern/filter.c')

diff --git a/source/blender/imbuf/intern/filter.c b/source/blender/imbuf/intern/filter.c
index d12360e5a7e..1644e653df4 100644
--- a/source/blender/imbuf/intern/filter.c
+++ b/source/blender/imbuf/intern/filter.c
@@ -21,7 +21,7 @@
  *
  * The Original Code is: all of this file.
  *
- * Contributor(s): none yet.
+ * Contributor(s): Morten Mikkelsen.
  *
  * ***** END GPL LICENSE BLOCK *****
  * filter.c
@@ -326,121 +326,132 @@ void IMB_mask_clear(ImBuf *ibuf, char *mask, int val)
 	}
 }
 
-#define EXTEND_PIXEL(color, w) if((color)[3]) {r+= w*(color)[0]; g+= w*(color)[1]; b+= w*(color)[2]; a+= w*(color)[3]; tot+=w;}
+static int filter_make_index(const int x, const int y, const int w, const int h)
+{
+	if(x<0 || x>=w || y<0 || y>=h) return -1;	/* return bad index */
+	else return y*w+x;
+}
+
+static int check_pixel_assigned(const void *buffer, const char *mask, const int index, const int depth, const int is_float)
+{
+	int res = 0;
+
+	if(index>=0) {
+		const int alpha_index = depth*index+(depth-1);
+
+		if(mask!=NULL) {
+			res = mask[index]!=0 ? 1 : 0;
+		}
+		else if( (is_float && ((const float *) buffer)[alpha_index]!=0.0f) ||
+				(!is_float && ((const unsigned char *) buffer)[alpha_index]!=0) ) {
+			res=1;
+		}
+	}
+
+	return res;
+}
 
 /* if alpha is zero, it checks surrounding pixels and averages color. sets new alphas to 1.0
  * 
  * When a mask is given, only effect pixels with a mask value of 1, defined as BAKE_MASK_MARGIN in rendercore.c
  * */
-void IMB_filter_extend(struct ImBuf *ibuf, char *mask)
+void IMB_filter_extend(struct ImBuf *ibuf, char *mask, int filter)
 {
-	register char *row1, *row2, *row3;
-	register char *cp; 
-	int rowlen, x, y;
-	
-	rowlen= ibuf->x;
-	
-	
-	if (ibuf->rect_float) {
-		float *temprect;
-		float *row1f, *row2f, *row3f;
-		float *fp;
-		temprect= MEM_dupallocN(ibuf->rect_float);
-		
-		for(y=1; y<=ibuf->y; y++) {
-			/* setup rows */
-			row1f= (float *)(temprect + (y-2)*rowlen*4);
-			row2f= row1f + 4*rowlen;
-			row3f= row2f + 4*rowlen;
-			if(y==1)
-				row1f= row2f;
-			else if(y==ibuf->y)
-				row3f= row2f;
-			
-			fp= (float *)(ibuf->rect_float + (y-1)*rowlen*4);
-				
-			for(x=0; x<rowlen; x++) {
-				if((mask==NULL && fp[3]==0.0f) || (mask && mask[((y-1)*rowlen)+x]==1)) {
-					int tot= 0;
-					float r=0.0f, g=0.0f, b=0.0f, a=0.0f;
-					
-					EXTEND_PIXEL(row1f, 1);
-					EXTEND_PIXEL(row2f, 2);
-					EXTEND_PIXEL(row3f, 1);
-					EXTEND_PIXEL(row1f+4, 2);
-					EXTEND_PIXEL(row3f+4, 2);
-					if(x!=rowlen-1) {
-						EXTEND_PIXEL(row1f+8, 1);
-						EXTEND_PIXEL(row2f+8, 2);
-						EXTEND_PIXEL(row3f+8, 1);
-					}					
-					if(tot) {
-						fp[0]= r/tot;
-						fp[1]= g/tot;
-						fp[2]= b/tot;
-						fp[3]= a/tot;
+	const int width= ibuf->x;
+	const int height= ibuf->y;
+	const int depth= 4;		/* always 4 channels */
+	const int chsize= ibuf->rect_float ? sizeof(float) : sizeof(unsigned char);
+	const int bsize= width*height*depth*chsize;
+	const int is_float= ibuf->rect_float!=NULL;
+	void *dstbuf= (void *) MEM_dupallocN(ibuf->rect_float ? (void *) ibuf->rect_float : (void *) ibuf->rect);
+	char *dstmask= mask==NULL ? NULL : (char *) MEM_dupallocN(mask);
+	void *srcbuf= ibuf->rect_float ? (void *) ibuf->rect_float : (void *) ibuf->rect;
+	char *srcmask= mask;
+	int cannot_early_out= 1, r, n, k, i, j, c;
+	float weight[25];
+
+	/* build a weights buffer */
+	n= 2;
+	k= 0;
+	for(i = -n; i <= n; i++)
+		for(j = -n; j <= n; j++)
+			weight[k++] = sqrt((float) i * i + j * j);
+
+	/* run passes */
+	for(r = 0; cannot_early_out == 1 && r < filter; r++) {
+		int x, y;
+		cannot_early_out = 0;
+
+		for(y= 0; y<height; y++) {
+			for(x= 0; x<width; x++) {
+				const int index= filter_make_index(x, y, width, height);
+
+				/* only update unassigned pixels */
+				if(!check_pixel_assigned(srcbuf, srcmask, index, depth, is_float)) {
+					float tmp[4];
+					float wsum=0;
+					float acc[4]={0,0,0,0};
+					k = 0;
+
+					if (check_pixel_assigned(srcbuf, srcmask, filter_make_index(x-1, y, width, height), depth, is_float) ||
+						check_pixel_assigned(srcbuf, srcmask, filter_make_index(x+1, y, width, height), depth, is_float) ||
+						check_pixel_assigned(srcbuf, srcmask, filter_make_index(x, y-1, width, height), depth, is_float) ||
+						check_pixel_assigned(srcbuf, srcmask, filter_make_index(x, y+1, width, height), depth, is_float)) {
+						for(i= -n; i<=n; i++) {
+							for(j=-n; j<=n; j++) {
+								if(i != 0 || j != 0) {
+									const int tmpindex= filter_make_index(x+i, y+j, width, height);
+
+									if(check_pixel_assigned(srcbuf, srcmask, tmpindex, depth, is_float))	{ 
+										if(is_float) {
+											for(c=0; c<depth; c++)
+												tmp[c] = ((const float *) srcbuf)[depth*tmpindex+c];
+										}
+										else {
+											for(c=0; c<depth; c++)
+												tmp[c] = (float) ((const unsigned char *) srcbuf)[depth*tmpindex+c];
+										}
+
+										wsum+= weight[k];
+
+										for(c=0; c<depth; c++)
+											acc[c]+= weight[k] * tmp[c];
+									}
+								}
+								k++;
+							}
+						}
+
+						if(wsum!=0) {
+							for(c=0; c<depth; c++)
+								acc[c]/= wsum;
+
+							if(is_float) {
+								for(c=0; c<depth; c++)
+									((float *) dstbuf)[depth*index+c] = acc[c];
+							}
+							else {
+								for(c=0; c<depth; c++) {
+									((unsigned char *) dstbuf)[depth*index+c]= acc[c] > 255 ? 255 : (acc[c] < 0 ? 0 : ((unsigned char) (acc[c]+0.5f)));
+								}
+							}
+
+							if(dstmask!=NULL) dstmask[index]=FILTER_MASK_MARGIN;	/* assigned */
+							cannot_early_out = 1;
+						}
 					}
 				}
-				fp+=4; 
-				
-				if(x!=0) {
-					row1f+=4; row2f+=4; row3f+=4;
-				}
 			}
 		}
 
-		MEM_freeN(temprect);
-	}
-	else if(ibuf->rect) {
-		int *temprect;
-		
-		/* make a copy, to prevent flooding */
-		temprect= MEM_dupallocN(ibuf->rect);
-		
-		for(y=1; y<=ibuf->y; y++) {
-			/* setup rows */
-			row1= (char *)(temprect + (y-2)*rowlen);
-			row2= row1 + 4*rowlen;
-			row3= row2 + 4*rowlen;
-			if(y==1)
-				row1= row2;
-			else if(y==ibuf->y)
-				row3= row2;
-			
-			cp= (char *)(ibuf->rect + (y-1)*rowlen);
-			
-			for(x=0; x<rowlen; x++) {
-				/*if(cp[3]==0) {*/
-				if((mask==NULL && cp[3]==0) || (mask && mask[((y-1)*rowlen)+x]==1)) {
-					int tot= 0, r=0, g=0, b=0, a=0;
-					
-					EXTEND_PIXEL(row1, 1);
-					EXTEND_PIXEL(row2, 2);
-					EXTEND_PIXEL(row3, 1);
-					EXTEND_PIXEL(row1+4, 2);
-					EXTEND_PIXEL(row3+4, 2);
-					if(x!=rowlen-1) {
-						EXTEND_PIXEL(row1+8, 1);
-						EXTEND_PIXEL(row2+8, 2);
-						EXTEND_PIXEL(row3+8, 1);
-					}					
-					if(tot) {
-						cp[0]= r/tot;
-						cp[1]= g/tot;
-						cp[2]= b/tot;
-						cp[3]= a/tot;
-					}
-				}
-				cp+=4;
-				
-				if(x!=0) {
-					row1+=4; row2+=4; row3+=4;
-				}
-			}
-		}
-		
-		MEM_freeN(temprect);
+		/* keep the original buffer up to date. */
+		memcpy(srcbuf, dstbuf, bsize);
+		if(dstmask!=NULL) memcpy(srcmask, dstmask, width*height);
 	}
+
+	/* free memory */
+	MEM_freeN(dstbuf);
+	if(dstmask!=NULL) MEM_freeN(dstmask);
 }
 
 /* threadsafe version, only recreates existing maps */
-- 
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