1 /* 2 * Copyright 2018 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 8 // Provides tiling for the repeat or mirror modes. 9 10 in fragmentProcessor colorizer; 11 in fragmentProcessor gradLayout; 12 13 layout(key) in bool mirror; 14 layout(key) in bool makePremul; 15 // Trust the creator that this matches the color spec of the gradient 16 in bool colorsAreOpaque; 17 18 void main() { 19 half4 t = process(gradLayout); 20 21 if (!gradLayout.preservesOpaqueInput && t.y < 0) { 22 // layout has rejected this fragment (rely on sksl to remove this branch if the layout FP 23 // preserves opacity is false) 24 sk_OutColor = half4(0); 25 } else { 26 @if(mirror) { 27 half t_1 = t.x - 1; 28 half tiled_t = t_1 - 2 * floor(t_1 * 0.5) - 1; 29 if (sk_Caps.mustDoOpBetweenFloorAndAbs) { 30 // At this point the expected value of tiled_t should between -1 and 1, so this 31 // clamp has no effect other than to break up the floor and abs calls and make sure 32 // the compiler doesn't merge them back together. 33 tiled_t = clamp(tiled_t, -1, 1); 34 } 35 t.x = abs(tiled_t); 36 } else { 37 // Simple repeat mode 38 t.x = fract(t.x); 39 } 40 41 // t.x has been tiled (repeat or mirrored), but pass through remaining 3 components 42 // unmodified. 43 sk_OutColor = process(colorizer, t); 44 } 45 46 @if (makePremul) { 47 sk_OutColor.xyz *= sk_OutColor.w; 48 } 49 } 50 51 ////////////////////////////////////////////////////////////////////////////// 52 53 // If the layout does not preserve opacity, remove the opaque optimization, 54 // but otherwise respect the provided color opacity state. 55 @optimizationFlags { 56 kCompatibleWithCoverageAsAlpha_OptimizationFlag | 57 (colorsAreOpaque && gradLayout->preservesOpaqueInput() ? kPreservesOpaqueInput_OptimizationFlag 58 : kNone_OptimizationFlags) 59 } 60
