1/* 2 * Copyright 2017 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8enum class Mode { 9 kGaussian = 0, 10 kSmoothStep = 1 11}; 12 13layout(key) in Mode mode; 14 15void main() { 16 half factor = 1.0 - sk_InColor.a; 17 @switch (mode) { 18 case Mode::kGaussian: 19 factor = exp(-factor * factor * 4.0) - 0.018; 20 break; 21 case Mode::kSmoothStep: 22 factor = smoothstep(1.0, 0.0, factor); 23 break; 24 } 25 sk_OutColor = half4(factor); 26} 27