/* Copyright (c) 2019 The Khronos Group Inc. Use of this source code is governed by an MIT-style license that can be found in the LICENSE.txt file. */ #ifdef GL_ES precision mediump float; #endif varying vec4 color; void main (void) { const float M_PI = 3.14159265358979323846; // Both are unit vectors float v1 = (color.g * 2.0) - 1.0; float v2 = (color.b * 2.0) - 1.0; gl_FragColor = vec4((faceforward(v1, v2, v1) + 1.0) / 2.0, 0.0, 0.0, 1.0); }