#version 110 const float EPSILON = 0.0001; void main() { gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0); // Values inside depth buffer for fragments of the contour of a selected area are offset // by small epsilon to solve z-fighting between painted triangles and contour lines. gl_FragDepth = gl_FragCoord.z - EPSILON; }