xref: /aosp_15_r20/external/skia/gm/gammatext.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/SkCanvas.h"
10 #include "include/core/SkColor.h"
11 #include "include/core/SkFont.h"
12 #include "include/core/SkFontStyle.h"
13 #include "include/core/SkPaint.h"
14 #include "include/core/SkPoint.h"
15 #include "include/core/SkRect.h"
16 #include "include/core/SkRefCnt.h"
17 #include "include/core/SkScalar.h"
18 #include "include/core/SkShader.h"
19 #include "include/core/SkSize.h"
20 #include "include/core/SkString.h"
21 #include "include/core/SkTileMode.h"
22 #include "include/core/SkTypeface.h"
23 #include "include/core/SkTypes.h"
24 #include "include/effects/SkGradientShader.h"
25 #include "tools/fonts/FontToolUtils.h"
26 
make_heatGradient(const SkPoint pts[2])27 static sk_sp<SkShader> make_heatGradient(const SkPoint pts[2]) {
28     const SkColor bw[] = { SK_ColorBLACK, SK_ColorWHITE };
29 
30     return SkGradientShader::MakeLinear(pts, bw, nullptr, std::size(bw), SkTileMode::kClamp);
31 }
32 
33 /**
34    Test a set of clipping problems discovered while writing blitAntiRect,
35    and test all the code paths through the clipping blitters.
36    Each region should show as a blue center surrounded by a 2px green
37    border, with no red.
38 */
39 
40 #define HEIGHT 480
41 
42 class GammaTextGM : public skiagm::GM {
43 protected:
getName() const44     SkString getName() const override { return SkString("gammatext"); }
45 
getISize()46     SkISize getISize() override { return SkISize::Make(1024, HEIGHT); }
47 
drawGrad(SkCanvas * canvas)48     static void drawGrad(SkCanvas* canvas) {
49         const SkPoint pts[] = { { 0, 0 }, { 0, SkIntToScalar(HEIGHT) } };
50 
51         canvas->clear(SK_ColorRED);
52         SkPaint paint;
53         paint.setShader(make_heatGradient(pts));
54         SkRect r = { 0, 0, SkIntToScalar(1024), SkIntToScalar(HEIGHT) };
55         canvas->drawRect(r, paint);
56     }
57 
onDraw(SkCanvas * canvas)58     void onDraw(SkCanvas* canvas) override {
59         drawGrad(canvas);
60 
61         const SkColor fg[] = {
62             0xFFFFFFFF,
63             0xFFFFFF00, 0xFFFF00FF, 0xFF00FFFF,
64             0xFFFF0000, 0xFF00FF00, 0xFF0000FF,
65             0xFF000000,
66         };
67 
68         const char* text = "Hamburgefons";
69 
70         SkPaint paint;
71         SkFont font = ToolUtils::DefaultPortableFont();
72         font.setSize(16);
73         font.setEdging(SkFont::Edging::kSubpixelAntiAlias);
74 
75         SkScalar x = SkIntToScalar(10);
76         for (size_t i = 0; i < std::size(fg); ++i) {
77             paint.setColor(fg[i]);
78 
79             SkScalar y = SkIntToScalar(40);
80             SkScalar stopy = SkIntToScalar(HEIGHT);
81             while (y < stopy) {
82                 canvas->drawString(text, x, y, font, paint);
83                 y += font.getSize() * 2;
84             }
85             x += SkIntToScalar(1024) / std::size(fg);
86         }
87     }
88 
89 private:
90     using INHERITED = skiagm::GM;
91 };
92 
DEF_GM(return new GammaTextGM;)93 DEF_GM( return new GammaTextGM; )
94 
95 //////////////////////////////////////////////////////////////////////////////
96 
97 static sk_sp<SkShader> make_gradient(SkColor c) {
98     const SkPoint pts[] = { { 0, 0 }, { 240, 0 } };
99     SkColor colors[2];
100     colors[0] = c;
101     colors[1] = SkColorSetA(c, 0);
102     return SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkTileMode::kClamp);
103 }
104 
draw_pair(SkCanvas * canvas,const SkFont & font,SkColor color,const sk_sp<SkShader> & shader)105 static void draw_pair(SkCanvas* canvas, const SkFont& font, SkColor color,
106                       const sk_sp<SkShader>& shader) {
107     static const char text[] = "Now is the time for all good";
108     SkPaint paint;
109     paint.setColor(color);
110     canvas->drawString(text, 10, 20, font, paint);
111     paint.setShader(SkShaders::Color(paint.getColor()));
112     canvas->drawString(text, 10, 40, font, paint);
113     paint.setShader(shader);
114     canvas->drawString(text, 10, 60, font, paint);
115 }
116 
117 class GammaShaderTextGM : public skiagm::GM {
118     sk_sp<SkShader> fShaders[3];
119     SkColor fColors[3];
120 
121 public:
GammaShaderTextGM()122     GammaShaderTextGM() {
123         const SkColor colors[] = { SK_ColorBLACK, SK_ColorRED, SK_ColorBLUE };
124         for (size_t i = 0; i < std::size(fShaders); ++i) {
125             fColors[i] = colors[i];
126         }
127     }
128 
129 protected:
getName() const130     SkString getName() const override { return SkString("gammagradienttext"); }
131 
getISize()132     SkISize getISize() override { return SkISize::Make(300, 300); }
133 
onOnceBeforeDraw()134     void onOnceBeforeDraw() override {
135         for (size_t i = 0; i < std::size(fShaders); ++i) {
136             fShaders[i] = make_gradient(fColors[i]);
137         }
138     }
139 
onDraw(SkCanvas * canvas)140     void onDraw(SkCanvas* canvas) override {
141         SkPaint paint;
142         paint.setAntiAlias(true);
143         sk_sp<SkTypeface> tf = ToolUtils::CreatePortableTypeface("serif", SkFontStyle::Italic());
144         SkASSERT(tf);
145         SkFont font(tf, 18);
146         font.setEdging(SkFont::Edging::kSubpixelAntiAlias);
147 
148         for (size_t i = 0; i < std::size(fShaders); ++i) {
149             draw_pair(canvas, font, fColors[i], fShaders[i]);
150             canvas->translate(0, 80);
151         }
152     }
153 
154 private:
155     using INHERITED = skiagm::GM;
156 };
157 
158 DEF_GM( return new GammaShaderTextGM; )
159 
160 DEF_SIMPLE_GM_BG(gammatext_color_shader, canvas, 300, 275, SK_ColorGRAY) {
161     const char* kText = "ABCDEFG";
162     sk_sp<SkTypeface> tf = ToolUtils::CreatePortableTypeface("serif", SkFontStyle());
163     SkASSERT(tf);
164     SkFont font(tf, 18);
165     font.setEdging(SkFont::Edging::kSubpixelAntiAlias);
166 
167     canvas->translate(10, 30);
168     for (int i = 0; i < 256; i += 20) {
169         SkColor color = SkColorSetRGB(i, i, i);
170         SkPaint paint;
171         paint.setColor(color);
172         canvas->drawString(kText, 0, 0, font, paint);
173         paint.setShader(SkShaders::Color(color));
174         canvas->drawString(kText, 100, 0, font, paint);
175         paint.setShader(SkShaders::Color(SkColor4f::FromColor(color), SkColorSpace::MakeSRGB()));
176         canvas->drawString(kText, 200, 0, font, paint);
177         canvas->translate(0, 20);
178     }
179 }
180