added a few missing lines

opengl-test-two/trimap.fragmentshader

@@ -4,7 +4,8 @@
 in vec2 UV;
 
 // Ouput data
-out vec3 color;
+//out vec3 color;
+layout(location = 0) out vec3 color;
 
 // Values that stay constant for the whole mesh.
 uniform sampler2D myTextureSampler;