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 "samplecode/Sample.h"
9 
10 #include "include/core/SkCanvas.h"
11 #include "include/core/SkColorPriv.h"
12 #include "include/core/SkFont.h"
13 #include "include/core/SkStream.h"
14 #include "include/utils/SkRandom.h"
15 #include "samplecode/DecodeFile.h"
16 #include "tools/Resources.h"
17 
18 // Intended to exercise pixel snapping observed with scaled images (and
19 // with non-scaled images, but for a different reason):  Bug 1145
20 
21 class SubpixelTranslateView : public Sample {
22 public:
SubpixelTranslateView(const char imageFilename[],float horizontalVelocity,float verticalVelocity)23     SubpixelTranslateView(const char imageFilename[],
24                           float horizontalVelocity,
25                           float verticalVelocity)
26         : fHorizontalVelocity(horizontalVelocity)
27         , fVerticalVelocity(verticalVelocity)
28     {
29         if (!DecodeDataToBitmap(GetResourceAsData(imageFilename), &fBM)) {
30             fBM.allocN32Pixels(1, 1);
31             *(fBM.getAddr32(0,0)) = 0xFF0000FF; // red == bad
32         }
33         fCurPos = SkPoint::Make(0,0);
34         fSize = 200;
35     }
36 
37 protected:
38     SkBitmap fBM;
39     SkScalar fSize;
40     float fHorizontalVelocity, fVerticalVelocity;
41 
42     SkPoint fCurPos;
43 
name()44     SkString name() override { return SkString("SubpixelTranslate"); }
45 
onDrawContent(SkCanvas * canvas)46     void onDrawContent(SkCanvas* canvas) override {
47 
48         static const SkFilterQuality gQualitys[] = {
49             kNone_SkFilterQuality,
50             kLow_SkFilterQuality,
51             kMedium_SkFilterQuality,
52             kHigh_SkFilterQuality
53         };
54 
55         SkPaint paint;
56         SkFont font(nullptr, 48);
57         font.setSubpixel(true);
58 
59         paint.setAntiAlias(true);
60         for (size_t i = 0; i < SK_ARRAY_COUNT(gQualitys); ++i) {
61             paint.setFilterQuality(gQualitys[i]);
62             SkRect r = SkRect::MakeXYWH( fCurPos.fX + i * (fSize + 10), fCurPos.fY, fSize, fSize );
63             canvas->drawBitmapRect( fBM, r, &paint );
64         }
65 
66         canvas->drawString("AA Scaled", fCurPos.fX + SK_ARRAY_COUNT(gQualitys) * (fSize + 10),
67                            fCurPos.fY + fSize/2, font, paint);
68 
69         paint.setAntiAlias(false);
70         font.setEdging(SkFont::Edging::kAlias);
71         for (size_t i = 0; i < SK_ARRAY_COUNT(gQualitys); ++i) {
72             paint.setFilterQuality(gQualitys[i]);
73             SkRect r = SkRect::MakeXYWH( fCurPos.fX + i * (fSize + 10), fCurPos.fY + fSize + 10, fSize, fSize );
74             canvas->drawBitmapRect( fBM, r, &paint );
75         }
76         canvas->drawString("Scaled", fCurPos.fX + SK_ARRAY_COUNT(gQualitys) * (fSize + 10),
77                            fCurPos.fY + fSize + 10 + fSize/2, font, paint);
78 
79         paint.setAntiAlias(true);
80         font.setEdging(SkFont::Edging::kAntiAlias);
81         for (size_t i = 0; i < SK_ARRAY_COUNT(gQualitys); ++i) {
82             paint.setFilterQuality(gQualitys[i]);
83             canvas->drawBitmap( fBM, fCurPos.fX + i * (fBM.width() + 10), fCurPos.fY + 2*(fSize + 10), &paint );
84         }
85 
86         canvas->drawString("AA No Scale",
87                            fCurPos.fX + SK_ARRAY_COUNT(gQualitys) * (fBM.width() + 10),
88                            fCurPos.fY + 2*(fSize + 10) + fSize/2, font, paint);
89 
90         paint.setAntiAlias(false);
91         font.setEdging(SkFont::Edging::kAlias);
92         for (size_t i = 0; i < SK_ARRAY_COUNT(gQualitys); ++i) {
93             paint.setFilterQuality(gQualitys[i]);
94             canvas->drawBitmap( fBM, fCurPos.fX + i * (fBM.width() + 10), fCurPos.fY + 2*(fSize + 10) + fBM.height() + 10, &paint );
95         }
96 
97         canvas->drawString("No Scale", fCurPos.fX + SK_ARRAY_COUNT(gQualitys) * (fBM.width() + 10),
98                            fCurPos.fY + 2*(fSize + 10) + fBM.height() + 10 + fSize/2, font, paint);
99 
100 
101         fCurPos.fX += fHorizontalVelocity;
102         fCurPos.fY += fVerticalVelocity;
103     }
104 
105 private:
106     typedef Sample INHERITED;
107 };
108 
109 //////////////////////////////////////////////////////////////////////////////
110 
111 DEF_SAMPLE( return new SubpixelTranslateView("images/mandrill_256.png", .05f, .05f); )
112