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
8in uniform sampler2D mask;
9in uniform half innerThreshold;
10in uniform half outerThreshold;
11
12@class {
13    inline OptimizationFlags optFlags(float outerThreshold);
14}
15
16@constructorParams {
17    const SkIRect& bounds
18}
19
20@make {
21    static std::unique_ptr<GrFragmentProcessor> Make(sk_sp<GrTextureProxy> mask,
22                                                     float innerThreshold,
23                                                     float outerThreshold,
24                                                     const SkIRect& bounds) {
25        return std::unique_ptr<GrFragmentProcessor>(new GrAlphaThresholdFragmentProcessor(
26                mask, innerThreshold, outerThreshold, bounds));
27    }
28}
29
30@coordTransform(mask) {
31    SkMatrix::MakeTrans(SkIntToScalar(-bounds.x()), SkIntToScalar(-bounds.y()))
32}
33
34@cpp {
35    inline GrFragmentProcessor::OptimizationFlags GrAlphaThresholdFragmentProcessor::optFlags(
36                                                                             float outerThreshold) {
37        if (outerThreshold >= 1.0) {
38            return kPreservesOpaqueInput_OptimizationFlag |
39                   kCompatibleWithCoverageAsAlpha_OptimizationFlag;
40        } else {
41            return kCompatibleWithCoverageAsAlpha_OptimizationFlag;
42        }
43    }
44}
45
46void main() {
47    half4 color = sk_InColor;
48    half4 mask_color = texture(mask, sk_TransformedCoords2D[0]);
49    if (mask_color.a < 0.5) {
50        if (color.a > outerThreshold) {
51            half scale = outerThreshold / color.a;
52            color.rgb *= scale;
53            color.a = outerThreshold;
54        }
55    } else if (color.a < innerThreshold) {
56        half scale = innerThreshold / max(0.001, color.a);
57        color.rgb *= scale;
58        color.a = innerThreshold;
59    }
60    sk_OutColor = color;
61}
62
63@test(testData) {
64    sk_sp<GrTextureProxy> maskProxy = testData->textureProxy(GrProcessorUnitTest::kAlphaTextureIdx);
65    // Make the inner and outer thresholds be in (0, 1) exclusive and be sorted correctly.
66    float innerThresh = testData->fRandom->nextUScalar1() * .99f + 0.005f;
67    float outerThresh = testData->fRandom->nextUScalar1() * .99f + 0.005f;
68    const int kMaxWidth = 1000;
69    const int kMaxHeight = 1000;
70    uint32_t width = testData->fRandom->nextULessThan(kMaxWidth);
71    uint32_t height = testData->fRandom->nextULessThan(kMaxHeight);
72    uint32_t x = testData->fRandom->nextULessThan(kMaxWidth - width);
73    uint32_t y = testData->fRandom->nextULessThan(kMaxHeight - height);
74    SkIRect bounds = SkIRect::MakeXYWH(x, y, width, height);
75    return GrAlphaThresholdFragmentProcessor::Make(std::move(maskProxy), innerThresh, outerThresh,
76                                                   bounds);
77}
78