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 "SkRandom.h"
15#include "SkSystemEventTypes.h"
16#include "SkTime.h"
17#include "SkTypeface.h"
18#include "SkXfermode.h"
19#include "Timer.h"
20
21#if SK_SUPPORT_GPU
22#include "GrContext.h"
23#include "SkGpuDevice.h"
24#endif
25
26SkRandom gRand;
27
28static void DrawTheText(SkCanvas* canvas, const char text[], size_t length, SkScalar x, SkScalar y,
29                        const SkPaint& paint) {
30    SkPaint p(paint);
31
32    p.setSubpixelText(true);
33    canvas->drawText(text, length, x, y, p);
34}
35
36// This sample demonstrates the cache behavior of bitmap vs. distance field text
37// It renders variously sized text with an animated scale and rotation.
38// Specifically one should:
39//   use 'D' to toggle between bitmap and distance field fonts
40//   use '2' to toggle between scaling the image by 2x
41//            -- this feature boosts the rendering out of the small point-size
42//               SDF-text special case (which falls back to bitmap fonts for small points)
43
44class AnimatedTextView : public SampleView {
45public:
46    AnimatedTextView() : fScale(1.0f), fScaleInc(0.1f), fRotation(0.0f), fSizeScale(1) {
47        fCurrentTime = 0;
48        fTimer.start();
49        memset(fTimes, 0, sizeof(fTimes));
50    }
51
52protected:
53    // overrides from SkEventSink
54    bool onQuery(SkEvent* evt) override {
55        if (SampleCode::TitleQ(*evt)) {
56            SampleCode::TitleR(evt, "AnimatedText");
57            return true;
58        }
59
60        SkUnichar uni;
61        if (SampleCode::CharQ(*evt, &uni)) {
62            if ('2' == uni) {
63                if (fSizeScale == 2) {
64                    fSizeScale = 1;
65                } else {
66                    fSizeScale = 2;
67                }
68                return true;
69            }
70        }
71        return this->INHERITED::onQuery(evt);
72    }
73
74    void onDrawContent(SkCanvas* canvas) override {
75        SkPaint paint;
76        SkSafeUnref(paint.setTypeface(SkTypeface::CreateFromFile("/skimages/samplefont.ttf")));
77        paint.setAntiAlias(true);
78        paint.setFilterQuality(kMedium_SkFilterQuality);
79
80        SkString outString("fps: ");
81        fTimer.end();
82
83        // TODO: generalize this timing code in utils
84        fTimes[fCurrentTime] = (float)(fTimer.fWall);
85        fCurrentTime = (fCurrentTime + 1) & 0x1f;
86
87        float meanTime = 0.0f;
88        for (int i = 0; i < 32; ++i) {
89            meanTime += fTimes[i];
90        }
91        meanTime /= 32.f;
92        SkScalar fps = 1000.f / meanTime;
93        outString.appendScalar(fps);
94        outString.append(" ms: ");
95        outString.appendScalar(meanTime);
96
97        SkString modeString("Text scale: ");
98        modeString.appendU32(fSizeScale);
99        modeString.append("x");
100
101        fTimer.start();
102
103        canvas->save();
104
105#if SK_SUPPORT_GPU
106        SkBaseDevice* device = canvas->getDevice_just_for_deprecated_compatibility_testing();
107        GrContext* grContext = canvas->getGrContext();
108        if (grContext) {
109            GrTexture* tex = grContext->getFontAtlasTexture(GrMaskFormat::kA8_GrMaskFormat);
110            reinterpret_cast<SkGpuDevice*>(device)->drawTexture(tex,
111                                                       SkRect::MakeXYWH(512, 10, 512, 512), paint);
112        }
113#endif
114        canvas->translate(180, 180);
115        canvas->rotate(fRotation);
116        canvas->scale(fScale, fScale);
117        canvas->translate(-180, -180);
118
119        const char* text = "Hamburgefons";
120        size_t length = strlen(text);
121
122        SkScalar y = SkIntToScalar(0);
123        for (int i = 12; i <= 26; i++) {
124            paint.setTextSize(SkIntToScalar(i*fSizeScale));
125            y += paint.getFontSpacing();
126            DrawTheText(canvas, text, length, SkIntToScalar(110), y, paint);
127        }
128        canvas->restore();
129
130        paint.setTextSize(16);
131//        canvas->drawText(outString.c_str(), outString.size(), 512.f, 540.f, paint);
132        canvas->drawText(modeString.c_str(), modeString.size(), 768.f, 540.f, paint);
133    }
134
135    bool onAnimate(const SkAnimTimer& timer) override {
136        // We add noise to the scale and rotation animations to
137        // keep the font atlas from falling into a steady state
138        fRotation += (1.0f + gRand.nextRangeF(-0.1f, 0.1f));
139        fScale += (fScaleInc + gRand.nextRangeF(-0.025f, 0.025f));
140        if (fScale >= 2.0f) {
141            fScaleInc = -0.1f;
142        } else if (fScale <= 1.0f) {
143            fScaleInc = 0.1f;
144        }
145        return true;
146    }
147
148private:
149    float fScale;
150    float fScaleInc;
151    float fRotation;
152    int   fSizeScale;
153
154    WallTimer   fTimer;
155    float       fTimes[32];
156    int         fCurrentTime;
157
158
159    typedef SampleView INHERITED;
160};
161
162//////////////////////////////////////////////////////////////////////////////
163
164static SkView* MyFactory() { return new AnimatedTextView; }
165static SkViewRegister reg(MyFactory);
166