xref: /aosp_15_r20/external/skia/gm/colormatrix.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2011 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/gm.h"
9 #include "include/core/SkBitmap.h"
10 #include "include/core/SkBlendMode.h"
11 #include "include/core/SkCanvas.h"
12 #include "include/core/SkColor.h"
13 #include "include/core/SkColorFilter.h"
14 #include "include/core/SkImage.h"
15 #include "include/core/SkPaint.h"
16 #include "include/core/SkPoint.h"
17 #include "include/core/SkRect.h"
18 #include "include/core/SkRefCnt.h"
19 #include "include/core/SkScalar.h"
20 #include "include/core/SkShader.h"
21 #include "include/core/SkSize.h"
22 #include "include/core/SkString.h"
23 #include "include/core/SkTileMode.h"
24 #include "include/core/SkTypes.h"
25 #include "include/effects/SkColorMatrix.h"
26 #include "include/effects/SkGradientShader.h"
27 
28 #define WIDTH 500
29 #define HEIGHT 160
30 
set_color_matrix(SkPaint * paint,const SkColorMatrix & matrix)31 static void set_color_matrix(SkPaint* paint, const SkColorMatrix& matrix) {
32     paint->setColorFilter(SkColorFilters::Matrix(matrix));
33 }
34 
set_array(SkPaint * paint,const float array[])35 static void set_array(SkPaint* paint, const float array[]) {
36     paint->setColorFilter(SkColorFilters::Matrix(array));
37 }
38 
39 class ColorMatrixGM : public skiagm::GM {
40 public:
ColorMatrixGM()41     ColorMatrixGM() {
42         this->setBGColor(0xFF808080);
43     }
44 
45 protected:
getName() const46     SkString getName() const override { return SkString("colormatrix"); }
47 
getISize()48     SkISize getISize() override { return SkISize::Make(WIDTH, HEIGHT); }
49 
onOnceBeforeDraw()50     void onOnceBeforeDraw() override {
51         fSolidImg = CreateSolidBitmap(64, 64);
52         fTransparentImg = CreateTransparentBitmap(64, 64);
53     }
54 
CreateSolidBitmap(int width,int height)55     static sk_sp<SkImage> CreateSolidBitmap(int width, int height) {
56         SkBitmap bm;
57         bm.allocN32Pixels(width, height);
58         SkCanvas canvas(bm);
59         canvas.clear(0x0);
60         for (int y = 0; y < height; ++y) {
61             for (int x = 0; x < width; ++x) {
62                 SkPaint paint;
63                 paint.setColor(SkColorSetARGB(255, x * 255 / width, y * 255 / height, 0));
64                 canvas.drawRect(SkRect::MakeXYWH(SkIntToScalar(x),
65                     SkIntToScalar(y), SK_Scalar1, SK_Scalar1), paint);
66             }
67         }
68         return bm.asImage();
69     }
70 
71     // creates a bitmap with shades of transparent gray.
CreateTransparentBitmap(int width,int height)72     static sk_sp<SkImage> CreateTransparentBitmap(int width, int height) {
73         SkBitmap bm;
74         bm.allocN32Pixels(width, height);
75         SkCanvas canvas(bm);
76         canvas.clear(0x0);
77 
78         SkPoint pts[] = {{0, 0}, {SkIntToScalar(width), SkIntToScalar(height)}};
79         SkColor colors[] = {0x00000000, 0xFFFFFFFF};
80         SkPaint paint;
81         paint.setShader(SkGradientShader::MakeLinear(pts, colors, nullptr, 2,
82                                                      SkTileMode::kClamp));
83         canvas.drawRect(SkRect::MakeWH(SkIntToScalar(width), SkIntToScalar(height)), paint);
84         return bm.asImage();
85     }
86 
onDraw(SkCanvas * canvas)87     void onDraw(SkCanvas* canvas) override {
88         SkPaint paint;
89         SkColorMatrix matrix;
90 
91         paint.setBlendMode(SkBlendMode::kSrc);
92         const SkImage* bmps[] = { fSolidImg.get(), fTransparentImg.get() };
93 
94         for (size_t i = 0; i < std::size(bmps); ++i) {
95             matrix.setIdentity();
96             set_color_matrix(&paint, matrix);
97             canvas->drawImage(bmps[i], 0, 0, SkSamplingOptions(), &paint);
98 
99             ///////////////////////////////////////////////
100 
101             matrix.setSaturation(0.0f);
102             set_color_matrix(&paint, matrix);
103             canvas->drawImage(bmps[i], 80, 0, SkSamplingOptions(), &paint);
104 
105             matrix.setSaturation(0.5f);
106             set_color_matrix(&paint, matrix);
107             canvas->drawImage(bmps[i], 160, 0, SkSamplingOptions(), &paint);
108 
109             matrix.setSaturation(1.0f);
110             set_color_matrix(&paint, matrix);
111             canvas->drawImage(bmps[i], 240, 0, SkSamplingOptions(), &paint);
112 
113             matrix.setSaturation(2.0f);
114             set_color_matrix(&paint, matrix);
115             canvas->drawImage(bmps[i], 320, 0, SkSamplingOptions(), &paint);
116 
117             ///////////////////////////////////////////////
118 
119             // Move red into alpha, set color to white
120             float data[20] = {
121                 0,  0, 0, 0, 1,
122                 0,  0, 0, 0, 1,
123                 0,  0, 0, 0, 1,
124                 1, 0, 0, 0, 0,
125             };
126 
127             set_array(&paint, data);
128             canvas->drawImage(bmps[i], 400, 0, SkSamplingOptions(), &paint);
129             ///////////////////////////////////////////////
130             canvas->translate(0, 80);
131         }
132     }
133 
134 private:
135     sk_sp<SkImage>   fSolidImg;
136     sk_sp<SkImage>   fTransparentImg;
137 
138     using INHERITED = skiagm::GM;
139 };
140 DEF_GM( return new ColorMatrixGM; )
141