Trimap implemented; need bugfixes

opengl-test-two/trimap.fragmentshader

@@ -8,10 +8,70 @@ out vec3 color;
 
 // Values that stay constant for the whole mesh.
 uniform sampler2D myTextureSampler;
+uniform float pixWidth;
+uniform float pixHeight;
 
-void main(){
 
-    // Output color = color of the texture at the specified UV
-    color = texture( myTextureSampler, UV ).rgb;
+
+
+
+int IS_BACKGROUND = 0;
+int IS_UNDEFINED = 1;
+int IS_FOREGROUND = 2;
+int UNSET = -1;
+
+
+vec3 getColor(vec2 uvCoord) {
+    return texture(myTextureSampler, UV).rgb;
 }
 
+bool isBackground(vec3 c) {
+    if (all(   lessThanEqual(c, vec3(51.0f/255.0f, 208.0f/255.0f, 13.0f/255.0f))) &&
+        all(greaterThanEqual(c, vec3(47.0f/255.0f, 204.0f/255.0f, 9.0f/255.0f)))
+        ) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+void main(){
+    int status = UNSET;
+    float pw = pixWidth;
+    float ph = pixHeight;
+
+    // 49,206, 11
+    // Output color = color of the texture at the specified UV
+    color = getColor(UV);
+    for(int w=-5;w<=5;w++){
+        for(int h=-5;h<=5;h++){
+            if (w+h==-10) { // first pixel
+                if (isBackground(getColor(UV+vec2(pixWidth*w,pixHeight*h)))) {
+                    status = IS_BACKGROUND;
+                } else {
+                    status = IS_FOREGROUND;
+                }
+            } else { // other pixels
+                if (isBackground(getColor(UV+vec2(pixWidth*w,pixHeight*h)))) {
+                    if (status != IS_BACKGROUND) {
+                        status = IS_UNDEFINED;
+                        break;
+                    }
+                } else {
+                    if (status != IS_FOREGROUND) {
+                        status = IS_UNDEFINED;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    if (status == IS_BACKGROUND) {
+        color = vec3(1.0f, 0.0f, 0.0f);
+    } else if (status == IS_FOREGROUND) {
+        color = vec3(0.0f, 1.0f, 0.0f);
+    } else {
+        color = vec3(0.0f, 0.0f, 1.0f);
+    }
+}