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 "Sample.h"
9 #include "SkAnimTimer.h"
10 #include "SkCanvas.h"
11 #include "SkDrawable.h"
12 #include "SkPath.h"
13 #include "SkRandom.h"
14 #include "SkRSXform.h"
15 #include "SkSurface.h"
16 #include "SkTextUtils.h"
17 
18 typedef void (*DrawAtlasProc)(SkCanvas*, SkImage*, const SkRSXform[], const SkRect[],
19                               const SkColor[], int, const SkRect*, const SkPaint*);
20 
draw_atlas(SkCanvas * canvas,SkImage * atlas,const SkRSXform xform[],const SkRect tex[],const SkColor colors[],int count,const SkRect * cull,const SkPaint * paint)21 static void draw_atlas(SkCanvas* canvas, SkImage* atlas, const SkRSXform xform[],
22                        const SkRect tex[], const SkColor colors[], int count, const SkRect* cull,
23                        const SkPaint* paint) {
24     canvas->drawAtlas(atlas, xform, tex, colors, count, SkBlendMode::kModulate, cull, paint);
25 }
26 
draw_atlas_sim(SkCanvas * canvas,SkImage * atlas,const SkRSXform xform[],const SkRect tex[],const SkColor colors[],int count,const SkRect * cull,const SkPaint * paint)27 static void draw_atlas_sim(SkCanvas* canvas, SkImage* atlas, const SkRSXform xform[],
28                            const SkRect tex[], const SkColor colors[], int count, const SkRect* cull,
29                            const SkPaint* paint) {
30     for (int i = 0; i < count; ++i) {
31         SkMatrix matrix;
32         matrix.setRSXform(xform[i]);
33 
34         canvas->save();
35         canvas->concat(matrix);
36         canvas->drawImageRect(atlas, tex[i], tex[i].makeOffset(-tex[i].x(), -tex[i].y()), paint,
37                               SkCanvas::kFast_SrcRectConstraint);
38         canvas->restore();
39     }
40 }
41 
make_atlas(int atlasSize,int cellSize)42 static sk_sp<SkImage> make_atlas(int atlasSize, int cellSize) {
43     SkImageInfo info = SkImageInfo::MakeN32Premul(atlasSize, atlasSize);
44     auto surface(SkSurface::MakeRaster(info));
45     SkCanvas* canvas = surface->getCanvas();
46 
47     SkPaint paint;
48     SkRandom rand;
49 
50     const SkScalar half = cellSize * SK_ScalarHalf;
51     const char* s = "01234567890!@#$%^&*=+<>?abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
52     SkFont font(nullptr, 28);
53 
54     int i = 0;
55     for (int y = 0; y < atlasSize; y += cellSize) {
56         for (int x = 0; x < atlasSize; x += cellSize) {
57             paint.setColor(rand.nextU());
58             paint.setAlpha(0xFF);
59             int index = i % strlen(s);
60             SkTextUtils::Draw(canvas, &s[index], 1, kUTF8_SkTextEncoding,
61                               x + half, y + half + half/2, font, paint,
62                               SkTextUtils::kCenter_Align);
63             i += 1;
64         }
65     }
66     return surface->makeImageSnapshot();
67 }
68 
69 class DrawAtlasDrawable : public SkDrawable {
70     enum {
71         kMaxScale = 2,
72         kCellSize = 32,
73         kAtlasSize = 512,
74     };
75 
76     struct Rec {
77         SkPoint     fCenter;
78         SkVector    fVelocity;
79         SkScalar    fScale;
80         SkScalar    fDScale;
81         SkScalar    fRadian;
82         SkScalar    fDRadian;
83         SkScalar    fAlpha;
84         SkScalar    fDAlpha;
85 
advanceDrawAtlasDrawable::Rec86         void advance(const SkRect& bounds) {
87             fCenter += fVelocity;
88             if (fCenter.fX > bounds.right()) {
89                 SkASSERT(fVelocity.fX > 0);
90                 fVelocity.fX = -fVelocity.fX;
91             } else if (fCenter.fX < bounds.left()) {
92                 SkASSERT(fVelocity.fX < 0);
93                 fVelocity.fX = -fVelocity.fX;
94             }
95             if (fCenter.fY > bounds.bottom()) {
96                 if (fVelocity.fY > 0) {
97                     fVelocity.fY = -fVelocity.fY;
98                 }
99             } else if (fCenter.fY < bounds.top()) {
100                 if (fVelocity.fY < 0) {
101                     fVelocity.fY = -fVelocity.fY;
102                 }
103             }
104 
105             fScale += fDScale;
106             if (fScale > 2 || fScale < SK_Scalar1/2) {
107                 fDScale = -fDScale;
108             }
109 
110             fRadian += fDRadian;
111             fRadian = SkScalarMod(fRadian, 2 * SK_ScalarPI);
112 
113             fAlpha += fDAlpha;
114             if (fAlpha > 1) {
115                 fAlpha = 1;
116                 fDAlpha = -fDAlpha;
117             } else if (fAlpha < 0) {
118                 fAlpha = 0;
119                 fDAlpha = -fDAlpha;
120             }
121         }
122 
asRSXformDrawAtlasDrawable::Rec123         SkRSXform asRSXform() const {
124             return SkRSXform::MakeFromRadians(fScale, fRadian, fCenter.x(), fCenter.y(),
125                                               SkScalarHalf(kCellSize), SkScalarHalf(kCellSize));
126         }
127     };
128 
129     DrawAtlasProc fProc;
130 
131     enum {
132         N = 256,
133     };
134 
135     sk_sp<SkImage> fAtlas;
136     Rec         fRec[N];
137     SkRect      fTex[N];
138     SkRect      fBounds;
139     bool        fUseColors;
140 
141 public:
DrawAtlasDrawable(DrawAtlasProc proc,const SkRect & r)142     DrawAtlasDrawable(DrawAtlasProc proc, const SkRect& r)
143         : fProc(proc), fBounds(r), fUseColors(false)
144     {
145         SkRandom rand;
146         fAtlas = make_atlas(kAtlasSize, kCellSize);
147         const SkScalar kMaxSpeed = 5;
148         const SkScalar cell = SkIntToScalar(kCellSize);
149         int i = 0;
150         for (int y = 0; y < kAtlasSize; y += kCellSize) {
151             for (int x = 0; x < kAtlasSize; x += kCellSize) {
152                 const SkScalar sx = SkIntToScalar(x);
153                 const SkScalar sy = SkIntToScalar(y);
154                 fTex[i].setXYWH(sx, sy, cell, cell);
155 
156                 fRec[i].fCenter.set(sx + cell/2, sy + 3*cell/4);
157                 fRec[i].fVelocity.fX = rand.nextSScalar1() * kMaxSpeed;
158                 fRec[i].fVelocity.fY = rand.nextSScalar1() * kMaxSpeed;
159                 fRec[i].fScale = 1;
160                 fRec[i].fDScale = rand.nextSScalar1() / 16;
161                 fRec[i].fRadian = 0;
162                 fRec[i].fDRadian = rand.nextSScalar1() / 8;
163                 fRec[i].fAlpha = rand.nextUScalar1();
164                 fRec[i].fDAlpha = rand.nextSScalar1() / 10;
165                 i += 1;
166             }
167         }
168     }
169 
toggleUseColors()170     void toggleUseColors() {
171         fUseColors = !fUseColors;
172     }
173 
174 protected:
onDraw(SkCanvas * canvas)175     void onDraw(SkCanvas* canvas) override {
176         SkRSXform xform[N];
177         SkColor colors[N];
178 
179         for (int i = 0; i < N; ++i) {
180             fRec[i].advance(fBounds);
181             xform[i] = fRec[i].asRSXform();
182             if (fUseColors) {
183                 colors[i] = SkColorSetARGB((int)(fRec[i].fAlpha * 0xFF), 0xFF, 0xFF, 0xFF);
184             }
185         }
186         SkPaint paint;
187         paint.setFilterQuality(kLow_SkFilterQuality);
188 
189         const SkRect cull = this->getBounds();
190         const SkColor* colorsPtr = fUseColors ? colors : nullptr;
191         fProc(canvas, fAtlas.get(), xform, fTex, colorsPtr, N, &cull, &paint);
192     }
193 
onGetBounds()194     SkRect onGetBounds() override {
195         const SkScalar border = kMaxScale * kCellSize;
196         SkRect r = fBounds;
197         r.outset(border, border);
198         return r;
199     }
200 
201 private:
202     typedef SkDrawable INHERITED;
203 };
204 
205 class DrawAtlasView : public Sample {
206     const char* fName;
207     DrawAtlasProc fProc;
208     sk_sp<DrawAtlasDrawable> fDrawable;
209 
210 public:
DrawAtlasView(const char name[],DrawAtlasProc proc)211     DrawAtlasView(const char name[], DrawAtlasProc proc) : fName(name), fProc(proc) { }
212 
213 protected:
onQuery(Sample::Event * evt)214     bool onQuery(Sample::Event* evt) override {
215         if (Sample::TitleQ(*evt)) {
216             Sample::TitleR(evt, fName);
217             return true;
218         }
219         SkUnichar uni;
220         if (Sample::CharQ(*evt, &uni)) {
221             switch (uni) {
222                 case 'C': fDrawable->toggleUseColors(); return true;
223                 default: break;
224             }
225         }
226         return this->INHERITED::onQuery(evt);
227     }
228 
onOnceBeforeDraw()229     void onOnceBeforeDraw() override {
230         fDrawable = sk_make_sp<DrawAtlasDrawable>(fProc, SkRect::MakeWH(640, 480));
231     }
232 
onDrawContent(SkCanvas * canvas)233     void onDrawContent(SkCanvas* canvas) override {
234         canvas->drawDrawable(fDrawable.get());
235     }
236 
onAnimate(const SkAnimTimer &)237     bool onAnimate(const SkAnimTimer&) override {
238         return true;
239     }
240 #if 0
241     // TODO: switch over to use this for our animation
242     bool onAnimate(const SkAnimTimer& timer) override {
243         SkScalar angle = SkDoubleToScalar(fmod(timer.secs() * 360 / 24, 360));
244         fAnimatingDrawable->setSweep(angle);
245         return true;
246     }
247 #endif
248 
249 private:
250     typedef Sample INHERITED;
251 };
252 
253 //////////////////////////////////////////////////////////////////////////////
254 
255 DEF_SAMPLE( return new DrawAtlasView("DrawAtlas", draw_atlas); )
256 DEF_SAMPLE( return new DrawAtlasView("DrawAtlasSim", draw_atlas_sim); )
257