-> Fix for bug #5472

Vertex snapping now works with backbuffered selection modes. Previously
backbuffer sampling had no way to check whether or not the indices that
it retrieved were selected or not. To resolve this I added two optional
arguments to sample_backbuf_rect in drawview.c. The first argument tells
the function that some additional testing  of the retrieved index values
needs to be done and the second argument is a pointer to a function to
do the testing. findnearestvert() in editmesh_mods.c now makes use of this
and passes sample_backbuf_rect() the appropriate argument when being used
for vertex snapping.

1 files changed, 17 insertions, 6 deletions

diff --git a/source/blender/src/drawview.c b/source/blender/src/drawview.c
index b8e00bbc14b..bfbbcee66fa 100644
--- a/source/blender/src/drawview.c
+++ b/source/blender/src/drawview.c
@@ -1198,7 +1198,7 @@ ImBuf *read_backbuf(short xmin, short ymin, short xmax, short ymax)
 }
 
 /* smart function to sample a rect spiralling outside, nice for backbuf selection */
-unsigned int sample_backbuf_rect(short mval[2], int size, unsigned int min, unsigned int max, int *dist)
+unsigned int sample_backbuf_rect(short mval[2], int size, unsigned int min, unsigned int max, int *dist, short strict, unsigned int (*indextest)(unsigned int index))
 {
 	struct ImBuf *buf;
 	unsigned int *bufmin, *bufmax, *tbuf;
@@ -1206,7 +1206,8 @@ unsigned int sample_backbuf_rect(short mval[2], int size, unsigned int min, unsi
 	int a, b, rc, nr, amount, dirvec[4][2];
 	int distance=0;
 	unsigned int index = 0;
-	
+	short indexok = 0;	
+
 	amount= (size-1)/2;
 
 	minx = mval[0]-(amount+1);
@@ -1230,10 +1231,20 @@ unsigned int sample_backbuf_rect(short mval[2], int size, unsigned int min, unsi
 		
 		for(a=0; a<2; a++) {
 			for(b=0; b<nr; b++, distance++) {
-				if (*tbuf && *tbuf>=min && *tbuf<max) {
-					*dist= (short) sqrt( (float)distance ); // XXX, this distance is wrong - zr
-					index = *tbuf - min+1; // messy yah, but indices start at 1
-					goto exit;
+				if (*tbuf && *tbuf>=min && *tbuf<max) { //we got a hit
+					if(strict){
+						indexok =  indextest(*tbuf - min+1);
+						if(indexok){
+							*dist= (short) sqrt( (float)distance   );
+							index = *tbuf - min+1;
+							goto exit; 
+						}						
+					}
+					else{
+						*dist= (short) sqrt( (float)distance ); // XXX, this distance is wrong - 
+						index = *tbuf - min+1; // messy yah, but indices start at 1
+						goto exit;
+					}			
 				}
 				
 				tbuf+= (dirvec[rc][0]+dirvec[rc][1]);