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
8 #include "gm.h"
9 #include "SkColorSpaceXform.h"
10 #include "SkColorSpaceXformPriv.h"
11 #include "SkOpts.h"
12 #include "SkUtils.h"
13
clamp_to_alpha(uint32_t * pixels,int count)14 static void clamp_to_alpha(uint32_t* pixels, int count) {
15 for (int i = 0; i < count; i++) {
16 uint8_t a = SkGetPackedA32(pixels[i]);
17 uint8_t r = SkGetPackedR32(pixels[i]);
18 uint8_t g = SkGetPackedG32(pixels[i]);
19 uint8_t b = SkGetPackedB32(pixels[i]);
20 pixels[i] = SkPackARGB32(a,
21 SkTMin(a, r),
22 SkTMin(a, g),
23 SkTMin(a, b));
24 }
25 }
26
27 class GammaEncodedPremulGM : public skiagm::GM {
28 public:
GammaEncodedPremulGM(sk_sp<SkColorSpace> dst,sk_sp<SkColorSpace> src,const char * desc)29 GammaEncodedPremulGM(sk_sp<SkColorSpace> dst, sk_sp<SkColorSpace> src, const char* desc)
30 : fDstSpace(dst)
31 , fSrcSpace(src)
32 , fXform(SkColorSpaceXform::New(src.get(), dst.get()))
33 , fName(SkStringPrintf("gamma_encoded_premul_dst-v-src_%s", desc))
34 {
35 int i = 0;
36 for (int r = 0; r < kColorSteps; r++) {
37 for (int g = 0; g < kColorSteps; g++) {
38 for (int b = 0; b < kColorSteps; b++) {
39 fColors[i++] = SkColorSetARGBInline(0xFF,
40 r * kColorScale,
41 g * kColorScale,
42 b * kColorScale);
43 }
44 }
45 }
46
47 }
48
49 protected:
onISize()50 virtual SkISize onISize() override {
51 return SkISize::Make(kAlphaMax, kNumColors * 2 * kStripeHeight);
52 }
53
onShortName()54 SkString onShortName() override {
55 return fName;
56 }
57
onDraw(SkCanvas * canvas)58 void onDraw(SkCanvas* canvas) override {
59 if (canvas->imageInfo().isOpaque()) {
60 return;
61 }
62
63 SkBitmap bitmap;
64 SkImageInfo bitmapInfo = SkImageInfo::MakeN32Premul(kAlphaMax, 1,
65 canvas->imageInfo().refColorSpace());
66 bitmap.allocPixels(bitmapInfo);
67 uint32_t* pixels = bitmap.getAddr32(0, 0);
68
69 for (int i = 0; i < kNumColors; i++) {
70 // Create an entire row of the same color, with the alpha from 0 to kAlphaMax.
71 uint32_t row[kAlphaMax];
72 sk_memset32(row, fColors[i], kAlphaMax);
73 for (int a = 0; a < kAlphaMax; a++) {
74 row[a] = (row[a] & 0x00FFFFFF) | (a << 24);
75 }
76
77 // Tranform row to dst, then premultiply.
78 fXform->apply(select_xform_format(kN32_SkColorType), pixels,
79 SkColorSpaceXform::kBGRA_8888_ColorFormat, row, kAlphaMax,
80 kUnpremul_SkAlphaType);
81 SkOpts::RGBA_to_rgbA(pixels, pixels, kAlphaMax);
82
83 // Write the dst space premultiplied row to the canvas.
84 for (int j = 0; j < kStripeHeight; j++) {
85 canvas->drawBitmap(bitmap, 0, 2 * i * kStripeHeight + j);
86 }
87
88 // Premultiply, then transform the row to dst.
89 SkOpts::RGBA_to_rgbA(pixels, row, kAlphaMax);
90 fXform->apply(select_xform_format(kN32_SkColorType), pixels,
91 SkColorSpaceXform::kBGRA_8888_ColorFormat, pixels, kAlphaMax,
92 kUnpremul_SkAlphaType);
93 clamp_to_alpha(pixels, kAlphaMax);
94
95 // Write the src space premultiplied row to the canvas.
96 for (int j = 0; j < kStripeHeight; j++) {
97 canvas->drawBitmap(bitmap, 0, (2 * i + 1) * kStripeHeight + j);
98 }
99 }
100 }
101
102 private:
103 static constexpr int kColorSteps = 4;
104 static constexpr int kNumColors = kColorSteps * kColorSteps * kColorSteps;
105 static constexpr int kColorScale = 255 / (kColorSteps - 1);
106 static constexpr int kStripeHeight = 10;
107 static constexpr int kAlphaMax = 255;
108
109 sk_sp<SkColorSpace> fDstSpace;
110 sk_sp<SkColorSpace> fSrcSpace;
111 std::unique_ptr<SkColorSpaceXform> fXform;
112 SkString fName;
113 SkColor fColors[kNumColors];
114
115 typedef GM INHERITED;
116 };
117
118 DEF_GM(return new GammaEncodedPremulGM(SkColorSpace::MakeSRGB(),
119 SkColorSpace::MakeRGB(SkColorSpace::kSRGB_RenderTargetGamma, SkColorSpace::kRec2020_Gamut),
120 "toWideGamut");)
121 DEF_GM(return new GammaEncodedPremulGM(SkColorSpace::MakeRGB(SkColorSpace::kSRGB_RenderTargetGamma,
122 SkColorSpace::kRec2020_Gamut), SkColorSpace::MakeSRGB(), "fromWideGamut");)
123 DEF_GM(return new GammaEncodedPremulGM(SkColorSpace::MakeSRGB(),
124 SkColorSpace::MakeRGB(SkColorSpace::kLinear_RenderTargetGamma, SkColorSpace::kSRGB_Gamut),
125 "toLinear");)
126 DEF_GM(return new GammaEncodedPremulGM(
127 SkColorSpace::MakeRGB(SkColorSpace::kLinear_RenderTargetGamma, SkColorSpace::kSRGB_Gamut),
128 SkColorSpace::MakeSRGB(), "fromLinear");)
129 DEF_GM(return new GammaEncodedPremulGM(
130 SkColorSpace::MakeRGB({ 1.8f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f },
131 SkColorSpace::kSRGB_Gamut), SkColorSpace::MakeSRGB(), "from1.8");)
132