xref: /third_party/skia/gm/lcdblendmodes.cpp (revision cb93a386) 
1/*
2 * Copyright 2015 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/SkBlendMode.h"
10#include "include/core/SkCanvas.h"
11#include "include/core/SkColor.h"
12#include "include/core/SkFont.h"
13#include "include/core/SkImageInfo.h"
14#include "include/core/SkPaint.h"
15#include "include/core/SkPoint.h"
16#include "include/core/SkRect.h"
17#include "include/core/SkRefCnt.h"
18#include "include/core/SkScalar.h"
19#include "include/core/SkShader.h"
20#include "include/core/SkSize.h"
21#include "include/core/SkString.h"
22#include "include/core/SkSurface.h"
23#include "include/core/SkTileMode.h"
24#include "include/core/SkTypeface.h"
25#include "include/core/SkTypes.h"
26#include "include/effects/SkGradientShader.h"
27#include "tools/ToolUtils.h"
28
29namespace skiagm {
30
31constexpr int kColWidth = 180;
32constexpr int kNumCols = 4;
33constexpr int kWidth = kColWidth * kNumCols;
34constexpr int kHeight = 750;
35
36static sk_sp<SkShader> make_shader(const SkRect& bounds) {
37    const SkPoint pts[] = {
38        { bounds.left(), bounds.top() },
39        { bounds.right(), bounds.bottom() },
40    };
41    const SkColor colors[] = {
42        SK_ColorRED, SK_ColorGREEN,
43    };
44    return SkGradientShader::MakeLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
45                                        SkTileMode::kRepeat);
46}
47
48class LcdBlendGM : public skiagm::GM {
49public:
50    LcdBlendGM() {
51        const int kPointSize = 25;
52        fTextHeight = SkIntToScalar(kPointSize);
53    }
54
55protected:
56    SkString onShortName() override {
57        return SkString("lcdblendmodes");
58    }
59
60    void onOnceBeforeDraw() override {
61        fCheckerboard = ToolUtils::create_checkerboard_shader(SK_ColorBLACK, SK_ColorWHITE, 4);
62    }
63
64    SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
65
66    void onDraw(SkCanvas* canvas) override {
67        SkPaint p;
68        p.setAntiAlias(false);
69        p.setStyle(SkPaint::kFill_Style);
70        p.setShader(fCheckerboard);
71        SkRect r = SkRect::MakeWH(SkIntToScalar(kWidth), SkIntToScalar(kHeight));
72        canvas->drawRect(r, p);
73
74        SkImageInfo info = SkImageInfo::MakeN32Premul(kWidth, kHeight);
75        SkSurfaceProps props = SkSurfaceProps(0, kRGB_H_SkPixelGeometry);
76        auto surface(ToolUtils::makeSurface(canvas, info, &props));
77
78        SkCanvas* surfCanvas = surface->getCanvas();
79        this->drawColumn(surfCanvas, SK_ColorBLACK, SK_ColorWHITE, false);
80        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
81        this->drawColumn(surfCanvas, SK_ColorWHITE, SK_ColorBLACK, false);
82        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
83        this->drawColumn(surfCanvas, SK_ColorGREEN, SK_ColorMAGENTA, false);
84        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
85        this->drawColumn(surfCanvas, SK_ColorCYAN, SK_ColorMAGENTA, true);
86
87        SkPaint surfPaint;
88        surfPaint.setBlendMode(SkBlendMode::kSrcOver);
89        surface->draw(canvas, 0, 0, SkSamplingOptions(), &surfPaint);
90    }
91
92    void drawColumn(SkCanvas* canvas, SkColor backgroundColor, SkColor textColor, bool useGrad) {
93        const SkBlendMode gModes[] = {
94            SkBlendMode::kClear,
95            SkBlendMode::kSrc,
96            SkBlendMode::kDst,
97            SkBlendMode::kSrcOver,
98            SkBlendMode::kDstOver,
99            SkBlendMode::kSrcIn,
100            SkBlendMode::kDstIn,
101            SkBlendMode::kSrcOut,
102            SkBlendMode::kDstOut,
103            SkBlendMode::kSrcATop,
104            SkBlendMode::kDstATop,
105            SkBlendMode::kXor,
106            SkBlendMode::kPlus,
107            SkBlendMode::kModulate,
108            SkBlendMode::kScreen,
109            SkBlendMode::kOverlay,
110            SkBlendMode::kDarken,
111            SkBlendMode::kLighten,
112            SkBlendMode::kColorDodge,
113            SkBlendMode::kColorBurn,
114            SkBlendMode::kHardLight,
115            SkBlendMode::kSoftLight,
116            SkBlendMode::kDifference,
117            SkBlendMode::kExclusion,
118            SkBlendMode::kMultiply,
119            SkBlendMode::kHue,
120            SkBlendMode::kSaturation,
121            SkBlendMode::kColor,
122            SkBlendMode::kLuminosity,
123        };
124        // Draw background rect
125        SkPaint backgroundPaint;
126        backgroundPaint.setColor(backgroundColor);
127        canvas->drawRect(SkRect::MakeIWH(kColWidth, kHeight), backgroundPaint);
128        SkScalar y = fTextHeight;
129        for (size_t m = 0; m < SK_ARRAY_COUNT(gModes); m++) {
130            SkPaint paint;
131            paint.setColor(textColor);
132            paint.setBlendMode(gModes[m]);
133            SkFont font(ToolUtils::create_portable_typeface(), fTextHeight);
134            font.setSubpixel(true);
135            font.setEdging(SkFont::Edging::kSubpixelAntiAlias);
136            if (useGrad) {
137                SkRect r;
138                r.setXYWH(0, y - fTextHeight, SkIntToScalar(kColWidth), fTextHeight);
139                paint.setShader(make_shader(r));
140            }
141            SkString string(SkBlendMode_Name(gModes[m]));
142            canvas->drawString(string, 0, y, font, paint);
143            y+=fTextHeight;
144        }
145    }
146
147private:
148    SkScalar fTextHeight;
149    sk_sp<SkShader> fCheckerboard;
150    using INHERITED = skiagm::GM;
151};
152
153//////////////////////////////////////////////////////////////////////////////
154
155DEF_GM( return new LcdBlendGM; )
156}  // namespace skiagm
157