/* 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 edge0 = 0.25; const float edge1 = 0.75; gl_FragColor = vec4(smoothstep(edge0, edge1, color.r), 0.0, 0.0, 1.0); }