xref: /aosp_15_r20/external/skia/gm/tallstretchedbitmaps.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2014 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/SkBitmap.h"
10 #include "include/core/SkCanvas.h"
11 #include "include/core/SkImage.h"
12 #include "include/core/SkPaint.h"
13 #include "include/core/SkRect.h"
14 #include "include/core/SkScalar.h"
15 #include "include/core/SkSize.h"
16 #include "include/core/SkString.h"
17 #include "include/core/SkTiledImageUtils.h"
18 #include "include/core/SkTypes.h"
19 #include "include/private/base/SkTo.h"
20 #include "src/base/SkRandom.h"
21 
make_bm(SkBitmap * bm,int height)22 int make_bm(SkBitmap* bm, int height) {
23     constexpr int kRadius = 22;
24     constexpr int kMargin = 8;
25     constexpr SkScalar kStartAngle = 0;
26     constexpr SkScalar kDAngle = 25;
27     constexpr SkScalar kSweep = 320;
28     constexpr SkScalar kThickness = 8;
29 
30     int count = (height / (2 * kRadius + kMargin));
31     height = count * (2 * kRadius + kMargin);
32 
33     bm->allocN32Pixels(2 * (kRadius + kMargin), height);
34     SkRandom random;
35 
36     SkCanvas wholeCanvas(*bm);
37     wholeCanvas.clear(0x00000000);
38 
39     SkScalar angle = kStartAngle;
40     for (int i = 0; i < count; ++i) {
41         SkPaint paint;
42         // The sw rasterizer disables AA for large canvii. So we make a small canvas for each draw.
43         SkBitmap smallBM;
44         SkIRect subRect = SkIRect::MakeXYWH(0, i * (kMargin + 2 * kRadius),
45                                             2 * kRadius + kMargin, 2 * kRadius + kMargin);
46         bm->extractSubset(&smallBM, subRect);
47         SkCanvas canvas(smallBM);
48         canvas.translate(kMargin + kRadius, kMargin + kRadius);
49 
50         paint.setAntiAlias(true);
51         paint.setColor(random.nextU() | 0xFF000000);
52         paint.setStyle(SkPaint::kStroke_Style);
53         paint.setStrokeWidth(kThickness);
54         paint.setStrokeCap(SkPaint::kRound_Cap);
55         SkScalar radius = kRadius - kThickness / 2;
56         SkRect bounds = SkRect::MakeLTRB(-radius, -radius, radius, radius);
57 
58         canvas.drawArc(bounds, angle, kSweep, false, paint);
59         angle += kDAngle;
60     }
61     bm->setImmutable();
62     return count;
63 }
64 
65 class TallStretchedBitmapsGM : public skiagm::GM {
66 public:
TallStretchedBitmapsGM()67     TallStretchedBitmapsGM() {}
68 
69 protected:
getName() const70     SkString getName() const override { return SkString("tall_stretched_bitmaps"); }
71 
getISize()72     SkISize getISize() override { return SkISize::Make(730, 690); }
73 
onOnceBeforeDraw()74     void onOnceBeforeDraw() override {
75         for (size_t i = 0; i < std::size(fTallBmps); ++i) {
76             int h = SkToInt((4 + i) * 1024);
77 
78             fTallBmps[i].fItemCnt = make_bm(&fTallBmps[i].fBmp, h);
79         }
80     }
81 
onDraw(SkCanvas * canvas)82     void onDraw(SkCanvas* canvas) override {
83         canvas->scale(1.3f, 1.3f);
84         for (size_t i = 0; i < std::size(fTallBmps); ++i) {
85             SkASSERT(fTallBmps[i].fItemCnt > 10);
86             SkBitmap bmp = fTallBmps[i].fBmp;
87             // Draw the last 10 elements of the bitmap.
88             int startItem = fTallBmps[i].fItemCnt - 10;
89             int itemHeight = bmp.height() / fTallBmps[i].fItemCnt;
90             SkIRect subRect = SkIRect::MakeLTRB(0, startItem * itemHeight,
91                                                bmp.width(), bmp.height());
92             SkRect dstRect = SkRect::MakeWH(SkIntToScalar(bmp.width()), 10.f * itemHeight);
93             SkTiledImageUtils::DrawImageRect(canvas, bmp.asImage(),
94                                              SkRect::Make(subRect), dstRect,
95                                              SkSamplingOptions(SkFilterMode::kLinear), nullptr,
96                                              SkCanvas::kStrict_SrcRectConstraint);
97             canvas->translate(SkIntToScalar(bmp.width() + 10), 0);
98         }
99     }
100 
101 private:
102     struct {
103         SkBitmap fBmp;
104         int      fItemCnt;
105     } fTallBmps[8];
106     using INHERITED = skiagm::GM;
107 };
108 
109 //////////////////////////////////////////////////////////////////////////////
110 
111 DEF_GM(return new TallStretchedBitmapsGM;)
112