Fix in Colorband: the "B-Spline" interpolation didn't extend well, when a

marker wasn't on the first or last possible position. Caused by clipping.
As bonus; added Cardinal interpolation option too, which is just that
little bit different! (Cardinal goes through the controlpoints, bspline not)

1 files changed, 21 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/texture.c b/source/blender/blenkernel/intern/texture.c
index 9fba11fd625..8988b301f7e 100644
--- a/source/blender/blenkernel/intern/texture.c
+++ b/source/blender/blenkernel/intern/texture.c
@@ -248,20 +248,32 @@ int do_colorband(ColorBand *coba, float in, float out[4])
 		out[3]= cbd1->a;
 	}
 	else {
-		if(in < cbd1->pos) {
+		if(in < cbd1->pos && coba->ipotype<2) {
 			out[0]= cbd1->r;
 			out[1]= cbd1->g;
 			out[2]= cbd1->b;
 			out[3]= cbd1->a;
 		}
 		else {
-
+			CBData left, right;
+			
 			/* we're looking for first pos > in */
 			for(a=0; a<coba->tot; a++, cbd1++) if(cbd1->pos > in) break;
 				
-			if(a==coba->tot) cbd1--;
+			if(a==coba->tot) {
+				cbd2= cbd1-1;
+				right= *cbd2;
+				right.pos= 1.0f;
+				cbd1= &right;
+			}
+			else if(a==0) {
+				left= *cbd1;
+				left.pos= 0.0f;
+				cbd2= &left;
+			}
+			else cbd2= cbd1-1;
 			
-			if(in > cbd1->pos) {
+			if(in > cbd1->pos && coba->ipotype<2) {
 				out[0]= cbd1->r;
 				out[1]= cbd1->g;
 				out[2]= cbd1->b;
@@ -269,10 +281,9 @@ int do_colorband(ColorBand *coba, float in, float out[4])
 			}
 			else {
 		
-				cbd2= cbd1-1;
 				fac= (in-cbd1->pos)/(cbd2->pos-cbd1->pos);
 				
-				if(coba->ipotype==2) {
+				if(coba->ipotype>=2) {
 					/* ipo from right to left: 3 2 1 0 */
 					
 					if(a>=coba->tot-1) cbd0= cbd1;
@@ -280,7 +291,10 @@ int do_colorband(ColorBand *coba, float in, float out[4])
 					if(a<2) cbd3= cbd2;
 					else cbd3= cbd2-1;
 					
-					set_four_ipo(fac, t, KEY_BSPLINE);
+					if(coba->ipotype==3)
+						set_four_ipo(fac, t, KEY_CARDINAL);
+					else
+						set_four_ipo(fac, t, KEY_BSPLINE);
 
 					out[0]= t[3]*cbd3->r +t[2]*cbd2->r +t[1]*cbd1->r +t[0]*cbd0->r;
 					out[1]= t[3]*cbd3->g +t[2]*cbd2->g +t[1]*cbd1->g +t[0]*cbd0->g;