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 "SkCanvas.h"
15#include "SkGradientShader.h"
16#include "SkSurface.h"
17
18namespace skiagm {
19
20static const int kColWidth = 180;
21static const int kNumCols = 4;
22static const int kWidth = kColWidth * kNumCols;
23static const int kHeight = 750;
24
25static SkShader* make_shader(const SkRect& bounds) {
26    const SkPoint pts[] = {
27        { bounds.left(), bounds.top() },
28        { bounds.right(), bounds.bottom() },
29    };
30    const SkColor colors[] = {
31        SK_ColorRED, SK_ColorGREEN,
32    };
33    return SkGradientShader::CreateLinear(pts,
34                                          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.reset(sk_tool_utils::create_checkerboard_shader(SK_ColorBLACK,
52                                                                      SK_ColorWHITE,
53                                                                      4));
54    }
55
56    SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
57
58    void onDraw(SkCanvas* canvas) override {
59        SkPaint p;
60        p.setAntiAlias(false);
61        p.setStyle(SkPaint::kFill_Style);
62        p.setShader(fCheckerboard);
63        SkRect r = SkRect::MakeWH(SkIntToScalar(kWidth), SkIntToScalar(kHeight));
64        canvas->drawRect(r, p);
65
66        SkImageInfo info = SkImageInfo::MakeN32Premul(kWidth, kHeight);
67        SkAutoTUnref<SkSurface> surface(canvas->newSurface(info));
68        if (nullptr == surface) {
69            surface.reset(SkSurface::NewRaster(info));
70        }
71
72        SkCanvas* surfCanvas = surface->getCanvas();
73        this->drawColumn(surfCanvas, SK_ColorBLACK, SK_ColorWHITE, false);
74        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
75        this->drawColumn(surfCanvas, SK_ColorWHITE, SK_ColorBLACK, false);
76        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
77        this->drawColumn(surfCanvas, SK_ColorGREEN, SK_ColorMAGENTA, false);
78        surfCanvas->translate(SkIntToScalar(kColWidth), 0);
79        this->drawColumn(surfCanvas, SK_ColorCYAN, SK_ColorMAGENTA, true);
80
81        SkPaint surfPaint;
82        SkAutoTUnref<SkXfermode> xfermode(SkXfermode::Create(SkXfermode::kSrcOver_Mode));
83        surfPaint.setXfermode(xfermode);
84        surface->draw(canvas, 0, 0, &surfPaint);
85    }
86
87    void drawColumn(SkCanvas* canvas, SkColor backgroundColor, SkColor textColor, bool useGrad) {
88        const struct {
89            SkXfermode::Mode  fMode;
90            const char*       fLabel;
91        } gModes[] = {
92            { SkXfermode::kClear_Mode,        "Clear"       },
93            { SkXfermode::kSrc_Mode,          "Src"         },
94            { SkXfermode::kDst_Mode,          "Dst"         },
95            { SkXfermode::kSrcOver_Mode,      "SrcOver"     },
96            { SkXfermode::kDstOver_Mode,      "DstOver"     },
97            { SkXfermode::kSrcIn_Mode,        "SrcIn"       },
98            { SkXfermode::kDstIn_Mode,        "DstIn"       },
99            { SkXfermode::kSrcOut_Mode,       "SrcOut"      },
100            { SkXfermode::kDstOut_Mode,       "DstOut"      },
101            { SkXfermode::kSrcATop_Mode,      "SrcATop"     },
102            { SkXfermode::kDstATop_Mode,      "DstATop"     },
103            { SkXfermode::kXor_Mode,          "Xor"         },
104            { SkXfermode::kPlus_Mode,         "Plus"        },
105            { SkXfermode::kModulate_Mode,     "Modulate"    },
106            { SkXfermode::kScreen_Mode,       "Screen"      },
107            { SkXfermode::kOverlay_Mode,      "Overlay"     },
108            { SkXfermode::kDarken_Mode,       "Darken"      },
109            { SkXfermode::kLighten_Mode,      "Lighten"     },
110            { SkXfermode::kColorDodge_Mode,   "ColorDodge"  },
111            { SkXfermode::kColorBurn_Mode,    "ColorBurn"   },
112            { SkXfermode::kHardLight_Mode,    "HardLight"   },
113            { SkXfermode::kSoftLight_Mode,    "SoftLight"   },
114            { SkXfermode::kDifference_Mode,   "Difference"  },
115            { SkXfermode::kExclusion_Mode,    "Exclusion"   },
116            { SkXfermode::kMultiply_Mode,     "Multiply"    },
117            { SkXfermode::kHue_Mode,          "Hue"         },
118            { SkXfermode::kSaturation_Mode,   "Saturation"  },
119            { SkXfermode::kColor_Mode,        "Color"       },
120            { SkXfermode::kLuminosity_Mode,   "Luminosity"  },
121        };
122        // Draw background rect
123        SkPaint backgroundPaint;
124        backgroundPaint.setColor(backgroundColor);
125        canvas->drawRectCoords(0, 0, SkIntToScalar(kColWidth), SkIntToScalar(kHeight),
126                               backgroundPaint);
127        SkScalar y = fTextHeight;
128        for (size_t m = 0; m < SK_ARRAY_COUNT(gModes); m++) {
129            SkAutoTUnref<SkXfermode> xfermode(SkXfermode::Create(gModes[m].fMode));
130            SkPaint paint;
131            paint.setColor(textColor);
132            paint.setAntiAlias(true);
133            paint.setSubpixelText(true);
134            paint.setLCDRenderText(true);
135            paint.setTextSize(fTextHeight);
136            paint.setXfermode(xfermode);
137            sk_tool_utils::set_portable_typeface(&paint);
138            if (useGrad) {
139                SkRect r;
140                r.setXYWH(0, y - fTextHeight, SkIntToScalar(kColWidth), fTextHeight);
141                paint.setShader(make_shader(r))->unref();
142            }
143            SkString string(gModes[m].fLabel);
144            canvas->drawText(gModes[m].fLabel, string.size(), 0, y, paint);
145            y+=fTextHeight;
146        }
147    }
148
149private:
150    SkScalar fTextHeight;
151    SkAutoTUnref<SkShader> fCheckerboard;
152    typedef skiagm::GM INHERITED;
153};
154
155//////////////////////////////////////////////////////////////////////////////
156
157DEF_GM( return new LcdBlendGM; )
158}
159