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
9/*
10 * Tests text rendering with LCD and the various blend modes.
11 */
12
13#include "gm.h"
14#include "sk_tool_utils.h"
15#include "SkCanvas.h"
16#include "SkGradientShader.h"
17#include "SkSurface.h"
18
19namespace skiagm {
20
21constexpr int kColWidth = 180;
22constexpr int kNumCols = 4;
23constexpr int kWidth = kColWidth * kNumCols;
24constexpr int kHeight = 750;
25
26static sk_sp<SkShader> make_shader(const SkRect& bounds) {
27    const SkPoint pts[] = {
28        { bounds.left(), bounds.top() },
29        { bounds.right(), bounds.bottom() },
30    };
31    const SkColor colors[] = {
32        SK_ColorRED, SK_ColorGREEN,
33    };
34    return SkGradientShader::MakeLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
35                                        SkShader::kRepeat_TileMode);
36}
37
38class LcdBlendGM : public skiagm::GM {
39public:
40    LcdBlendGM() {
41        const int kPointSize = 25;
42        fTextHeight = SkIntToScalar(kPointSize);
43    }
44
45protected:
46    SkString onShortName() override {
47        return SkString("lcdblendmodes");
48    }
49
50    void onOnceBeforeDraw() override {
51        fCheckerboard = sk_tool_utils::create_checkerboard_shader(SK_ColorBLACK, SK_ColorWHITE, 4);
52    }
53
54    SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
55
56    void onDraw(SkCanvas* canvas) override {
57        SkPaint p;
58        p.setAntiAlias(false);
59        p.setStyle(SkPaint::kFill_Style);
60        p.setShader(fCheckerboard);
61        SkRect r = SkRect::MakeWH(SkIntToScalar(kWidth), SkIntToScalar(kHeight));
62        canvas->drawRect(r, p);
63
64        SkImageInfo info = SkImageInfo::MakeN32Premul(kWidth, kHeight);
65        auto surface(sk_tool_utils::makeSurface(canvas, info));
66
67        SkCanvas* surfCanvas = surface->getCanvas();
68        this->drawColumn(surfCanvas, SK_ColorBLACK, SK_ColorWHITE, false);
69        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
70        this->drawColumn(surfCanvas, SK_ColorWHITE, SK_ColorBLACK, false);
71        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
72        this->drawColumn(surfCanvas, SK_ColorGREEN, SK_ColorMAGENTA, false);
73        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
74        this->drawColumn(surfCanvas, SK_ColorCYAN, SK_ColorMAGENTA, true);
75
76        SkPaint surfPaint;
77        surfPaint.setBlendMode(SkBlendMode::kSrcOver);
78        surface->draw(canvas, 0, 0, &surfPaint);
79    }
80
81    void drawColumn(SkCanvas* canvas, SkColor backgroundColor, SkColor textColor, bool useGrad) {
82        const SkBlendMode gModes[] = {
83            SkBlendMode::kClear,
84            SkBlendMode::kSrc,
85            SkBlendMode::kDst,
86            SkBlendMode::kSrcOver,
87            SkBlendMode::kDstOver,
88            SkBlendMode::kSrcIn,
89            SkBlendMode::kDstIn,
90            SkBlendMode::kSrcOut,
91            SkBlendMode::kDstOut,
92            SkBlendMode::kSrcATop,
93            SkBlendMode::kDstATop,
94            SkBlendMode::kXor,
95            SkBlendMode::kPlus,
96            SkBlendMode::kModulate,
97            SkBlendMode::kScreen,
98            SkBlendMode::kOverlay,
99            SkBlendMode::kDarken,
100            SkBlendMode::kLighten,
101            SkBlendMode::kColorDodge,
102            SkBlendMode::kColorBurn,
103            SkBlendMode::kHardLight,
104            SkBlendMode::kSoftLight,
105            SkBlendMode::kDifference,
106            SkBlendMode::kExclusion,
107            SkBlendMode::kMultiply,
108            SkBlendMode::kHue,
109            SkBlendMode::kSaturation,
110            SkBlendMode::kColor,
111            SkBlendMode::kLuminosity,
112        };
113        // Draw background rect
114        SkPaint backgroundPaint;
115        backgroundPaint.setColor(backgroundColor);
116        canvas->drawRect(SkRect::MakeIWH(kColWidth, kHeight), backgroundPaint);
117        SkScalar y = fTextHeight;
118        for (size_t m = 0; m < SK_ARRAY_COUNT(gModes); m++) {
119            SkPaint paint;
120            paint.setColor(textColor);
121            paint.setAntiAlias(true);
122            paint.setSubpixelText(true);
123            paint.setLCDRenderText(true);
124            paint.setTextSize(fTextHeight);
125            paint.setBlendMode(gModes[m]);
126            sk_tool_utils::set_portable_typeface(&paint);
127            if (useGrad) {
128                SkRect r;
129                r.setXYWH(0, y - fTextHeight, SkIntToScalar(kColWidth), fTextHeight);
130                paint.setShader(make_shader(r));
131            }
132            SkString string(SkBlendMode_Name(gModes[m]));
133            canvas->drawString(string, 0, y, paint);
134            y+=fTextHeight;
135        }
136    }
137
138private:
139    SkScalar fTextHeight;
140    sk_sp<SkShader> fCheckerboard;
141    typedef skiagm::GM INHERITED;
142};
143
144//////////////////////////////////////////////////////////////////////////////
145
146DEF_GM( return new LcdBlendGM; )
147}
148