#version 140 const float EPSILON = 0.0001; out vec4 frag_color; void main() { frag_color = 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; }