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
24 SkRandom gRand;
25
DrawTheText(SkCanvas * canvas,const char text[],size_t length,SkScalar x,SkScalar y,const SkPaint & paint)26 static 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
42 class AnimatedTextView : public SampleView {
43 public:
AnimatedTextView()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
50 protected:
51 // overrides from SkEventSink
onQuery(SkEvent * evt)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
onDrawContent(SkCanvas * canvas)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
onAnimate(const SkAnimTimer & timer)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
146 private:
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
MyFactory()162 static SkView* MyFactory() { return new AnimatedTextView; }
163 static SkViewRegister reg(MyFactory);
164