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 "SampleCode.h"
9#include "SkView.h"
10#include "SkCanvas.h"
11#include "SkUtils.h"
12#include "SkColorPriv.h"
13#include "SkColorFilter.h"
14#include "SkImage.h"
15#include "SkRandom.h"
16#include "SkTime.h"
17#include "SkTypeface.h"
18#include "Timer.h"
19
20#if SK_SUPPORT_GPU
21#include "GrContext.h"
22#endif
23
24SkRandom gRand;
25
26static void DrawTheText(SkCanvas* canvas, const char text[], size_t length, SkScalar x, SkScalar y,
27                        const SkPaint& paint) {
28    SkPaint p(paint);
29
30    p.setSubpixelText(true);
31    canvas->drawText(text, length, x, y, p);
32}
33
34// This sample demonstrates the cache behavior of bitmap vs. distance field text
35// It renders variously sized text with an animated scale and rotation.
36// Specifically one should:
37//   use 'D' to toggle between bitmap and distance field fonts
38//   use '2' to toggle between scaling the image by 2x
39//            -- this feature boosts the rendering out of the small point-size
40//               SDF-text special case (which falls back to bitmap fonts for small points)
41
42class AnimatedTextView : public SampleView {
43public:
44    AnimatedTextView() : fScale(1.0f), fScaleInc(0.1f), fRotation(0.0f), fSizeScale(1) {
45        fCurrentTime = 0;
46        fTimer.start();
47        memset(fTimes, 0, sizeof(fTimes));
48    }
49
50protected:
51    // overrides from SkEventSink
52    bool onQuery(SkEvent* evt) override {
53        if (SampleCode::TitleQ(*evt)) {
54            SampleCode::TitleR(evt, "AnimatedText");
55            return true;
56        }
57
58        SkUnichar uni;
59        if (SampleCode::CharQ(*evt, &uni)) {
60            if ('2' == uni) {
61                if (fSizeScale == 2) {
62                    fSizeScale = 1;
63                } else {
64                    fSizeScale = 2;
65                }
66                return true;
67            }
68        }
69        return this->INHERITED::onQuery(evt);
70    }
71
72    void onDrawContent(SkCanvas* canvas) override {
73        SkPaint paint;
74        paint.setTypeface(SkTypeface::MakeFromFile("/skimages/samplefont.ttf"));
75        paint.setAntiAlias(true);
76        paint.setFilterQuality(kMedium_SkFilterQuality);
77
78        SkString outString("fps: ");
79        fTimer.end();
80
81        // TODO: generalize this timing code in utils
82        fTimes[fCurrentTime] = (float)(fTimer.fWall);
83        fCurrentTime = (fCurrentTime + 1) & 0x1f;
84
85        float meanTime = 0.0f;
86        for (int i = 0; i < 32; ++i) {
87            meanTime += fTimes[i];
88        }
89        meanTime /= 32.f;
90        SkScalar fps = 1000.f / meanTime;
91        outString.appendScalar(fps);
92        outString.append(" ms: ");
93        outString.appendScalar(meanTime);
94
95        SkString modeString("Text scale: ");
96        modeString.appendU32(fSizeScale);
97        modeString.append("x");
98
99        fTimer.start();
100
101        canvas->save();
102
103#if SK_SUPPORT_GPU
104        GrContext* grContext = canvas->getGrContext();
105        if (grContext) {
106            sk_sp<SkImage> image =
107                        grContext->getFontAtlasImage_ForTesting(GrMaskFormat::kA8_GrMaskFormat);
108            canvas->drawImageRect(image,
109                                  SkRect::MakeXYWH(512.0f, 10.0f, 512.0f, 512.0f), &paint);
110        }
111#endif
112        canvas->translate(180, 180);
113        canvas->rotate(fRotation);
114        canvas->scale(fScale, fScale);
115        canvas->translate(-180, -180);
116
117        const char* text = "Hamburgefons";
118        size_t length = strlen(text);
119
120        SkScalar y = SkIntToScalar(0);
121        for (int i = 12; i <= 26; i++) {
122            paint.setTextSize(SkIntToScalar(i*fSizeScale));
123            y += paint.getFontSpacing();
124            DrawTheText(canvas, text, length, SkIntToScalar(110), y, paint);
125        }
126        canvas->restore();
127
128        paint.setTextSize(16);
129//        canvas->drawString(outString, 512.f, 540.f, paint);
130        canvas->drawString(modeString, 768.f, 540.f, paint);
131    }
132
133    bool onAnimate(const SkAnimTimer& timer) override {
134        // We add noise to the scale and rotation animations to
135        // keep the font atlas from falling into a steady state
136        fRotation += (1.0f + gRand.nextRangeF(-0.1f, 0.1f));
137        fScale += (fScaleInc + gRand.nextRangeF(-0.025f, 0.025f));
138        if (fScale >= 2.0f) {
139            fScaleInc = -0.1f;
140        } else if (fScale <= 1.0f) {
141            fScaleInc = 0.1f;
142        }
143        return true;
144    }
145
146private:
147    float fScale;
148    float fScaleInc;
149    float fRotation;
150    int   fSizeScale;
151
152    WallTimer   fTimer;
153    float       fTimes[32];
154    int         fCurrentTime;
155
156
157    typedef SampleView INHERITED;
158};
159
160//////////////////////////////////////////////////////////////////////////////
161
162static SkView* MyFactory() { return new AnimatedTextView; }
163static SkViewRegister reg(MyFactory);
164