SampleSubpixelTranslate.cpp revision 1803f4eb341dd0209dde8cc7ee0fa4b409fb2704 
1
2/*
3 * Copyright 2014 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9#include "gm.h"
10#include "SampleCode.h"
11#include "SkBlurMaskFilter.h"
12#include "SkColorPriv.h"
13#include "SkCanvas.h"
14#include "SkImageDecoder.h"
15#include "SkRandom.h"
16#include "SkStream.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
21class SubpixelTranslateView : public SampleView {
22public:
23    SubpixelTranslateView(const char imageFilename[],
24                          float horizontalVelocity,
25                          float verticalVelocity)
26      : fFilename(imageFilename),
27        fHorizontalVelocity(horizontalVelocity),
28        fVerticalVelocity(verticalVelocity) {
29      SkString path(skiagm::GM::GetResourcePath());
30      path.append("/");
31      path.append(fFilename);
32
33      SkImageDecoder *codec = NULL;
34      SkFILEStream stream(path.c_str());
35      if (stream.isValid()) {
36          codec = SkImageDecoder::Factory(&stream);
37      }
38      if (codec) {
39          stream.rewind();
40          codec->decode(&stream, &fBM, SkBitmap::kARGB_8888_Config,
41                        SkImageDecoder::kDecodePixels_Mode);
42          SkDELETE(codec);
43      } else {
44          fBM.allocN32Pixels(1, 1);
45          *(fBM.getAddr32(0,0)) = 0xFF0000FF; // red == bad
46      }
47      fCurPos = SkPoint::Make(0,0);
48      fSize = 200;
49    }
50
51protected:
52    SkBitmap fBM;
53    SkString fFilename;
54    int fSize;
55    float fHorizontalVelocity, fVerticalVelocity;
56
57    SkPoint fCurPos;
58
59    // overrides from SkEventSink
60    virtual bool onQuery(SkEvent* evt) SK_OVERRIDE {
61        if (SampleCode::TitleQ(*evt)) {
62            SampleCode::TitleR(evt, "SubpixelTranslate");
63            return true;
64        }
65        return this->INHERITED::onQuery(evt);
66    }
67
68    virtual void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
69
70        static const SkPaint::FilterLevel gLevels[] = {
71            SkPaint::kNone_FilterLevel,
72            SkPaint::kLow_FilterLevel,
73            SkPaint::kMedium_FilterLevel,
74            SkPaint::kHigh_FilterLevel
75        };
76
77        SkPaint paint;
78        paint.setTextSize(48);
79
80        paint.setAntiAlias(true);
81        for (size_t i = 0; i < SK_ARRAY_COUNT(gLevels); ++i) {
82            paint.setFilterLevel(gLevels[i]);
83            SkRect r = SkRect::MakeXYWH( fCurPos.fX + i * (fSize + 10), fCurPos.fY, fSize, fSize );
84            canvas->drawBitmapRect( fBM, r, &paint );
85        }
86
87        canvas->drawText( "AA Scaled", strlen("AA Scaled"), fCurPos.fX + SK_ARRAY_COUNT(gLevels) * (fSize + 10), fCurPos.fY + fSize/2, paint );
88
89        paint.setAntiAlias(false);
90        for (size_t i = 0; i < SK_ARRAY_COUNT(gLevels); ++i) {
91            paint.setFilterLevel(gLevels[i]);
92            SkRect r = SkRect::MakeXYWH( fCurPos.fX + i * (fSize + 10), fCurPos.fY + fSize + 10, fSize, fSize );
93            canvas->drawBitmapRect( fBM, r, &paint );
94        }
95        canvas->drawText( "Scaled", strlen("Scaled"), fCurPos.fX + SK_ARRAY_COUNT(gLevels) * (fSize + 10), fCurPos.fY + fSize + 10 + fSize/2, paint );
96
97        paint.setAntiAlias(true);
98        for (size_t i = 0; i < SK_ARRAY_COUNT(gLevels); ++i) {
99            paint.setFilterLevel(gLevels[i]);
100            canvas->drawBitmap( fBM, fCurPos.fX + i * (fBM.width() + 10), fCurPos.fY + 2*(fSize + 10), &paint );
101        }
102
103        canvas->drawText( "AA No Scale", strlen("AA No Scale"), fCurPos.fX + SK_ARRAY_COUNT(gLevels) * (fBM.width() + 10), fCurPos.fY + 2*(fSize + 10) + fSize/2, paint );
104
105        paint.setAntiAlias(false);
106        for (size_t i = 0; i < SK_ARRAY_COUNT(gLevels); ++i) {
107            paint.setFilterLevel(gLevels[i]);
108            canvas->drawBitmap( fBM, fCurPos.fX + i * (fBM.width() + 10), fCurPos.fY + 2*(fSize + 10) + fBM.height() + 10, &paint );
109        }
110
111        canvas->drawText( "No Scale", strlen("No Scale"), fCurPos.fX + SK_ARRAY_COUNT(gLevels) * (fBM.width() + 10), fCurPos.fY + 2*(fSize + 10) + fBM.height() + 10 + fSize/2, paint );
112
113
114        fCurPos.fX += fHorizontalVelocity;
115        fCurPos.fY += fVerticalVelocity;
116        this->inval(NULL);
117    }
118
119private:
120    typedef SampleView INHERITED;
121};
122
123//////////////////////////////////////////////////////////////////////////////
124
125static SkView* MyFactory() { return new SubpixelTranslateView("mandrill_256.png", .05, .05); }
126static SkViewRegister reg(MyFactory);
127