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 "include/core/SkCanvas.h"
9 #include "include/core/SkColorFilter.h"
10 #include "include/core/SkColorPriv.h"
11 #include "include/core/SkFont.h"
12 #include "include/core/SkFontMgr.h"
13 #include "include/core/SkImage.h"
14 #include "include/core/SkTypeface.h"
15 #include "src/base/SkRandom.h"
16 #include "src/base/SkTime.h"
17 #include "src/base/SkUTF.h"
18 #include "tools/fonts/FontToolUtils.h"
19 #include "tools/viewer/Slide.h"
20
21 #if defined(SK_GANESH)
22 #include "include/gpu/ganesh/GrDirectContext.h"
23 #include "src/gpu/ganesh/GrDirectContextPriv.h"
24
25 using MaskFormat = skgpu::MaskFormat;
26 #endif
27
28 SkRandom gRand;
29
DrawTheText(SkCanvas * canvas,const char text[],size_t length,SkScalar x,SkScalar y,const SkFont & font,const SkPaint & paint)30 static void DrawTheText(SkCanvas* canvas, const char text[], size_t length, SkScalar x, SkScalar y,
31 const SkFont& font, const SkPaint& paint) {
32 SkFont f(font);
33 f.setSubpixel(true);
34 canvas->drawSimpleText(text, length, SkTextEncoding::kUTF8, x, y, f, paint);
35 }
36
37 // This sample demonstrates the cache behavior of bitmap vs. distance field text
38 // It renders variously sized text with an animated scale and rotation.
39 // Specifically one should:
40 // use 'D' to toggle between bitmap and distance field fonts
41 // use '2' to toggle between scaling the image by 2x
42 // -- this feature boosts the rendering out of the small point-size
43 // SDF-text special case (which falls back to bitmap fonts for small points)
44
45 class AnimatedTextSlide : public Slide {
46 float fScale = 1;
47 float fScaleInc = 0.1f;
48 float fRotation = 0;
49 int fSizeScale = 1;
50
51 public:
AnimatedTextSlide()52 AnimatedTextSlide() { fName = "AnimatedText"; }
53
onChar(SkUnichar uni)54 bool onChar(SkUnichar uni) override {
55 if ('2' == uni) {
56 if (fSizeScale == 2) {
57 fSizeScale = 1;
58 } else {
59 fSizeScale = 2;
60 }
61 return true;
62 }
63 return false;
64 }
65
draw(SkCanvas * canvas)66 void draw(SkCanvas* canvas) override {
67 SkFont font(ToolUtils::TestFontMgr()->makeFromFile("/skimages/samplefont.ttf"));
68
69 SkPaint paint;
70 paint.setAntiAlias(true);
71
72 canvas->save();
73
74 #if defined(SK_GANESH)
75 auto direct = GrAsDirectContext(canvas->recordingContext());
76 if (direct) {
77 SkSamplingOptions sampling(SkFilterMode::kLinear, SkMipmapMode::kNearest);
78 sk_sp<SkImage> image = direct->priv().testingOnly_getFontAtlasImage(MaskFormat::kA8);
79 const SkRect rect = SkRect::MakeXYWH(512.0f, 10.0f, 512.0f, 512.0f);
80 canvas->drawImageRect(image.get(), rect, rect, sampling, &paint,
81 SkCanvas::kFast_SrcRectConstraint);
82 }
83 #endif
84 canvas->translate(180, 180);
85 canvas->rotate(fRotation);
86 canvas->scale(fScale, fScale);
87 canvas->translate(-180, -180);
88
89 const char* text = "Hamburgefons";
90 size_t length = strlen(text);
91
92 SkScalar y = SkIntToScalar(0);
93 for (int i = 12; i <= 26; i++) {
94 font.setSize(SkIntToScalar(i*fSizeScale));
95 y += font.getSpacing();
96 DrawTheText(canvas, text, length, SkIntToScalar(110), y, font, paint);
97 }
98 canvas->restore();
99
100 font.setSize(16);
101 }
102
animate(double nanos)103 bool animate(double nanos) override {
104 // TODO: use nanos
105 // We add noise to the scale and rotation animations to
106 // keep the font atlas from falling into a steady state
107 fRotation += (1.0f + gRand.nextRangeF(-0.1f, 0.1f));
108 fScale += (fScaleInc + gRand.nextRangeF(-0.025f, 0.025f));
109 if (fScale >= 2.0f) {
110 fScaleInc = -0.1f;
111 } else if (fScale <= 1.0f) {
112 fScaleInc = 0.1f;
113 }
114 return true;
115 }
116 };
117
118 DEF_SLIDE( return new AnimatedTextSlide(); )
119