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.h"
9 #include "sk_tool_utils.h"
10 #include "SkBitmap.h"
11 #include "SkCanvas.h"
12 #include "SkFontPriv.h"
13 #include "SkGradientShader.h"
14 #include "SkImageGenerator.h"
15 #include "SkPaint.h"
16 #include "SkPath.h"
17 #include "SkPathOps.h"
18 #include "SkPicture.h"
19 #include "SkPictureRecorder.h"
20 #include "SkTextUtils.h"
21 
draw_vector_logo(SkCanvas * canvas,const SkRect & viewBox)22 static void draw_vector_logo(SkCanvas* canvas, const SkRect& viewBox) {
23     constexpr char kSkiaStr[] = "SKIA";
24     constexpr SkScalar kGradientPad = .1f;
25     constexpr SkScalar kVerticalSpacing = 0.25f;
26     constexpr SkScalar kAccentScale = 1.20f;
27 
28     SkPaint paint;
29     paint.setAntiAlias(true);
30 
31     SkFont font(sk_tool_utils::create_portable_typeface());
32     font.setSubpixel(true);
33     font.setEmbolden(true);
34 
35     SkPath path;
36     SkRect iBox, skiBox, skiaBox;
37     SkTextUtils::GetPath("SKI", 3, kUTF8_SkTextEncoding, 0, 0, font, &path);
38     TightBounds(path, &skiBox);
39     SkTextUtils::GetPath("I", 1, kUTF8_SkTextEncoding, 0, 0, font, &path);
40     TightBounds(path, &iBox);
41     iBox.offsetTo(skiBox.fRight - iBox.width(), iBox.fTop);
42 
43     const size_t textLen = strlen(kSkiaStr);
44     SkTextUtils::GetPath(kSkiaStr, textLen, kUTF8_SkTextEncoding, 0, 0, font, &path);
45     TightBounds(path, &skiaBox);
46     skiaBox.outset(0, 2 * iBox.width() * (kVerticalSpacing + 1));
47 
48     const SkScalar accentSize = iBox.width() * kAccentScale;
49     const SkScalar underlineY = iBox.bottom() +
50         (kVerticalSpacing + SkScalarSqrt(3) / 2) * accentSize;
51     SkMatrix m;
52     m.setRectToRect(skiaBox, viewBox, SkMatrix::kFill_ScaleToFit);
53     SkAutoCanvasRestore acr(canvas, true);
54     canvas->concat(m);
55 
56     canvas->drawCircle(iBox.centerX(),
57                        iBox.y() - (0.5f + kVerticalSpacing) * accentSize,
58                        accentSize / 2,
59                        paint);
60 
61     path.reset();
62     path.moveTo(iBox.centerX() - accentSize / 2, iBox.bottom() + kVerticalSpacing * accentSize);
63     path.rLineTo(accentSize, 0);
64     path.lineTo(iBox.centerX(), underlineY);
65     canvas->drawPath(path, paint);
66 
67     SkRect underlineRect = SkRect::MakeLTRB(iBox.centerX() - iBox.width() * accentSize * 3,
68                                             underlineY,
69                                             iBox.centerX(),
70                                             underlineY + accentSize / 10);
71     const SkPoint pts1[] = { SkPoint::Make(underlineRect.x(), 0),
72                              SkPoint::Make(iBox.centerX(), 0) };
73     const SkScalar pos1[] = { 0, 0.75f };
74     const SkColor colors1[] = { SK_ColorTRANSPARENT, SK_ColorBLACK };
75     SkASSERT(SK_ARRAY_COUNT(pos1) == SK_ARRAY_COUNT(colors1));
76     paint.setShader(SkGradientShader::MakeLinear(pts1, colors1, pos1, SK_ARRAY_COUNT(pos1),
77                                                  SkShader::kClamp_TileMode));
78     canvas->drawRect(underlineRect, paint);
79 
80     const SkPoint pts2[] = { SkPoint::Make(iBox.x() - iBox.width() * kGradientPad, 0),
81                              SkPoint::Make(iBox.right() + iBox.width() * kGradientPad, 0) };
82     const SkScalar pos2[] = { 0, .01f, 1.0f/3, 1.0f/3, 2.0f/3, 2.0f/3, .99f, 1 };
83     const SkColor colors2[] = {
84         SK_ColorBLACK,
85         0xffca5139,
86         0xffca5139,
87         0xff8dbd53,
88         0xff8dbd53,
89         0xff5460a5,
90         0xff5460a5,
91         SK_ColorBLACK
92     };
93     SkASSERT(SK_ARRAY_COUNT(pos2) == SK_ARRAY_COUNT(colors2));
94     paint.setShader(SkGradientShader::MakeLinear(pts2, colors2, pos2, SK_ARRAY_COUNT(pos2),
95                                                  SkShader::kClamp_TileMode));
96     canvas->drawSimpleText(kSkiaStr, textLen, kUTF8_SkTextEncoding, 0, 0, font, paint);
97 }
98 
99 // This GM exercises SkPictureImageGenerator features
100 // (in particular its matrix vs. bounds semantics).
101 class PictureGeneratorGM : public skiagm::GM {
102 protected:
onShortName()103     SkString onShortName() override {
104         return SkString("pictureimagegenerator");
105     }
106 
onISize()107     SkISize onISize() override {
108         return SkISize::Make(1160, 860);
109     }
110 
onOnceBeforeDraw()111     void onOnceBeforeDraw() override {
112         const SkRect rect = SkRect::MakeWH(kPictureWidth, kPictureHeight);
113         SkPictureRecorder recorder;
114         SkCanvas* canvas = recorder.beginRecording(rect);
115         draw_vector_logo(canvas, rect);
116         fPicture = recorder.finishRecordingAsPicture();
117     }
118 
onDraw(SkCanvas * canvas)119     void onDraw(SkCanvas* canvas) override {
120         const struct {
121             SkISize  size;
122             SkScalar scaleX, scaleY;
123             SkScalar opacity;
124         } configs[] = {
125             { SkISize::Make(200, 100), 1, 1, 1 },
126             { SkISize::Make(200, 200), 1, 1, 1 },
127             { SkISize::Make(200, 200), 1, 2, 1 },
128             { SkISize::Make(400, 200), 2, 2, 1 },
129 
130             { SkISize::Make(200, 100), 1, 1, 0.9f  },
131             { SkISize::Make(200, 200), 1, 1, 0.75f },
132             { SkISize::Make(200, 200), 1, 2, 0.5f  },
133             { SkISize::Make(400, 200), 2, 2, 0.25f },
134 
135             { SkISize::Make(200, 200), 0.5f, 1,    1 },
136             { SkISize::Make(200, 200), 1,    0.5f, 1 },
137             { SkISize::Make(200, 200), 0.5f, 0.5f, 1 },
138             { SkISize::Make(200, 200), 2,    2,    1 },
139 
140             { SkISize::Make(200, 100), -1,  1, 1    },
141             { SkISize::Make(200, 100),  1, -1, 1    },
142             { SkISize::Make(200, 100), -1, -1, 1    },
143             { SkISize::Make(200, 100), -1, -1, 0.5f },
144         };
145 
146         auto srgbColorSpace = SkColorSpace::MakeSRGB();
147         const unsigned kDrawsPerRow = 4;
148         const SkScalar kDrawSize = 250;
149 
150         for (size_t i = 0; i < SK_ARRAY_COUNT(configs); ++i) {
151             SkPaint p;
152             p.setAlpha(SkScalarRoundToInt(255 * configs[i].opacity));
153 
154             SkMatrix m = SkMatrix::MakeScale(configs[i].scaleX, configs[i].scaleY);
155             if (configs[i].scaleX < 0) {
156                 m.postTranslate(SkIntToScalar(configs[i].size.width()), 0);
157             }
158             if (configs[i].scaleY < 0) {
159                 m.postTranslate(0, SkIntToScalar(configs[i].size.height()));
160             }
161             std::unique_ptr<SkImageGenerator> gen =
162                 SkImageGenerator::MakeFromPicture(configs[i].size, fPicture, &m,
163                                                  p.getAlpha() != 255 ? &p : nullptr,
164                                                  SkImage::BitDepth::kU8, srgbColorSpace);
165 
166             SkImageInfo bmInfo = gen->getInfo().makeColorSpace(canvas->imageInfo().refColorSpace());
167 
168             SkBitmap bm;
169             bm.allocPixels(bmInfo);
170             SkAssertResult(gen->getPixels(bm.info(), bm.getPixels(), bm.rowBytes()));
171 
172             const SkScalar x = kDrawSize * (i % kDrawsPerRow);
173             const SkScalar y = kDrawSize * (i / kDrawsPerRow);
174 
175             p.setColor(0xfff0f0f0);
176             p.setAlpha(255);
177             canvas->drawRect(SkRect::MakeXYWH(x, y,
178                                               SkIntToScalar(bm.width()),
179                                               SkIntToScalar(bm.height())), p);
180             canvas->drawBitmap(bm, x, y);
181         }
182     }
183 
184 private:
185     sk_sp<SkPicture> fPicture;
186 
187     const SkScalar kPictureWidth = 200;
188     const SkScalar kPictureHeight = 100;
189 
190     typedef skiagm::GM INHERITED;
191 };
192 
193 DEF_GM(return new PictureGeneratorGM;)
194