Added background to refinement shader

opengl-test-two/refinement.fragmentshader

@@ -9,6 +9,7 @@ out vec3 color;
 // Values that stay constant for the whole mesh.
 uniform sampler2D trimap;
 uniform sampler2D foreground;
+uniform sampler2D background;
 
 
 int IS_BACKGROUND = 0;
@@ -24,6 +25,10 @@ vec3 getForeColor(vec2 uvCoord) {
     return texture(foreground, uvCoord).rgb;
 }
 
+vec3 getBackColor(vec2 uvCoord) {
+    return texture(background, uvCoord).rgb;
+}
+
 int getState(vec3 c) {
     if (all(lessThanEqual(c, vec3(0.2f)))) {
         return IS_BACKGROUND;
@@ -42,5 +47,9 @@ void main(){
 
     if (status==IS_FOREGROUND) {
         color = getForeColor(UV).rgb;
+    } else if (status==IS_BACKGROUND) {
+        color = getBackColor(UV).rgb;
+    } else {
+        // render undefined area
     }
 }