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 "SkAnimTimer.h"
10 #include "SkView.h"
11 #include "SkCanvas.h"
12 #include "SkDrawable.h"
13 #include "SkPath.h"
14 #include "SkRandom.h"
15 #include "SkRSXform.h"
16 #include "SkSurface.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, SkXfermode::kModulate_Mode, 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 SkImage* make_atlas(int atlasSize, int cellSize) {
43     SkImageInfo info = SkImageInfo::MakeN32Premul(atlasSize, atlasSize);
44     SkAutoTUnref<SkSurface> surface(SkSurface::NewRaster(info));
45     SkCanvas* canvas = surface->getCanvas();
46 
47     SkPaint paint;
48     paint.setAntiAlias(true);
49     SkRandom rand;
50 
51     const SkScalar half = cellSize * SK_ScalarHalf;
52     const char* s = "01234567890!@#$%^&*=+<>?abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
53     paint.setTextSize(28);
54     paint.setTextAlign(SkPaint::kCenter_Align);
55     int i = 0;
56     for (int y = 0; y < atlasSize; y += cellSize) {
57         for (int x = 0; x < atlasSize; x += cellSize) {
58             paint.setColor(rand.nextU());
59             paint.setAlpha(0xFF);
60             int index = i % strlen(s);
61             canvas->drawText(&s[index], 1, x + half, y + half + half/2, paint);
62             i += 1;
63         }
64     }
65     return surface->newImageSnapshot();
66 }
67 
68 class DrawAtlasDrawable : public SkDrawable {
69     enum {
70         kMaxScale = 2,
71         kCellSize = 32,
72         kAtlasSize = 512,
73     };
74 
75     struct Rec {
76         SkPoint     fCenter;
77         SkVector    fVelocity;
78         SkScalar    fScale;
79         SkScalar    fDScale;
80         SkScalar    fRadian;
81         SkScalar    fDRadian;
82         SkScalar    fAlpha;
83         SkScalar    fDAlpha;
84 
advanceDrawAtlasDrawable::Rec85         void advance(const SkRect& bounds) {
86             fCenter += fVelocity;
87             if (fCenter.fX > bounds.right()) {
88                 SkASSERT(fVelocity.fX > 0);
89                 fVelocity.fX = -fVelocity.fX;
90             } else if (fCenter.fX < bounds.left()) {
91                 SkASSERT(fVelocity.fX < 0);
92                 fVelocity.fX = -fVelocity.fX;
93             }
94             if (fCenter.fY > bounds.bottom()) {
95                 if (fVelocity.fY > 0) {
96                     fVelocity.fY = -fVelocity.fY;
97                 }
98             } else if (fCenter.fY < bounds.top()) {
99                 if (fVelocity.fY < 0) {
100                     fVelocity.fY = -fVelocity.fY;
101                 }
102             }
103 
104             fScale += fDScale;
105             if (fScale > 2 || fScale < SK_Scalar1/2) {
106                 fDScale = -fDScale;
107             }
108 
109             fRadian += fDRadian;
110             fRadian = SkScalarMod(fRadian, 2 * SK_ScalarPI);
111 
112             fAlpha += fDAlpha;
113             if (fAlpha > 1) {
114                 fAlpha = 1;
115                 fDAlpha = -fDAlpha;
116             } else if (fAlpha < 0) {
117                 fAlpha = 0;
118                 fDAlpha = -fDAlpha;
119             }
120         }
121 
asRSXformDrawAtlasDrawable::Rec122         SkRSXform asRSXform() const {
123             return SkRSXform::MakeFromRadians(fScale, fRadian, fCenter.x(), fCenter.y(),
124                                               SkScalarHalf(kCellSize), SkScalarHalf(kCellSize));
125         }
126     };
127 
128     DrawAtlasProc fProc;
129 
130     enum {
131         N = 256,
132     };
133 
134     SkAutoTUnref<SkImage> fAtlas;
135     Rec         fRec[N];
136     SkRect      fTex[N];
137     SkRect      fBounds;
138     bool        fUseColors;
139 
140 public:
DrawAtlasDrawable(DrawAtlasProc proc,const SkRect & r)141     DrawAtlasDrawable(DrawAtlasProc proc, const SkRect& r)
142         : fProc(proc), fBounds(r), fUseColors(false)
143     {
144         SkRandom rand;
145         fAtlas.reset(make_atlas(kAtlasSize, kCellSize));
146         const SkScalar kMaxSpeed = 5;
147         const SkScalar cell = SkIntToScalar(kCellSize);
148         int i = 0;
149         for (int y = 0; y < kAtlasSize; y += kCellSize) {
150             for (int x = 0; x < kAtlasSize; x += kCellSize) {
151                 const SkScalar sx = SkIntToScalar(x);
152                 const SkScalar sy = SkIntToScalar(y);
153                 fTex[i].setXYWH(sx, sy, cell, cell);
154 
155                 fRec[i].fCenter.set(sx + cell/2, sy + 3*cell/4);
156                 fRec[i].fVelocity.fX = rand.nextSScalar1() * kMaxSpeed;
157                 fRec[i].fVelocity.fY = rand.nextSScalar1() * kMaxSpeed;
158                 fRec[i].fScale = 1;
159                 fRec[i].fDScale = rand.nextSScalar1() / 16;
160                 fRec[i].fRadian = 0;
161                 fRec[i].fDRadian = rand.nextSScalar1() / 8;
162                 fRec[i].fAlpha = rand.nextUScalar1();
163                 fRec[i].fDAlpha = rand.nextSScalar1() / 10;
164                 i += 1;
165             }
166         }
167     }
168 
toggleUseColors()169     void toggleUseColors() {
170         fUseColors = !fUseColors;
171     }
172 
173 protected:
onDraw(SkCanvas * canvas)174     void onDraw(SkCanvas* canvas) override {
175         SkRSXform xform[N];
176         SkColor colors[N];
177 
178         for (int i = 0; i < N; ++i) {
179             fRec[i].advance(fBounds);
180             xform[i] = fRec[i].asRSXform();
181             if (fUseColors) {
182                 colors[i] = SkColorSetARGB((int)(fRec[i].fAlpha * 0xFF), 0xFF, 0xFF, 0xFF);
183             }
184         }
185         SkPaint paint;
186         paint.setFilterQuality(kLow_SkFilterQuality);
187 
188         const SkRect cull = this->getBounds();
189         const SkColor* colorsPtr = fUseColors ? colors : nullptr;
190         fProc(canvas, fAtlas, xform, fTex, colorsPtr, N, &cull, &paint);
191     }
192 
onGetBounds()193     SkRect onGetBounds() override {
194         const SkScalar border = kMaxScale * kCellSize;
195         SkRect r = fBounds;
196         r.outset(border, border);
197         return r;
198     }
199 
200 private:
201     typedef SkDrawable INHERITED;
202 };
203 
204 class DrawAtlasView : public SampleView {
205     const char*         fName;
206     DrawAtlasDrawable*  fDrawable;
207 
208 public:
DrawAtlasView(const char name[],DrawAtlasProc proc)209     DrawAtlasView(const char name[], DrawAtlasProc proc) : fName(name) {
210         fDrawable = new DrawAtlasDrawable(proc, SkRect::MakeWH(640, 480));
211     }
212 
~DrawAtlasView()213     ~DrawAtlasView() override {
214         fDrawable->unref();
215     }
216 
217 protected:
onQuery(SkEvent * evt)218     bool onQuery(SkEvent* evt) override {
219         if (SampleCode::TitleQ(*evt)) {
220             SampleCode::TitleR(evt, fName);
221             return true;
222         }
223         SkUnichar uni;
224         if (SampleCode::CharQ(*evt, &uni)) {
225             switch (uni) {
226                 case 'C': fDrawable->toggleUseColors(); this->inval(nullptr); return true;
227                 default: break;
228             }
229         }
230         return this->INHERITED::onQuery(evt);
231     }
232 
onDrawContent(SkCanvas * canvas)233     void onDrawContent(SkCanvas* canvas) override {
234         canvas->drawDrawable(fDrawable);
235         this->inval(nullptr);
236     }
237 
238 #if 0
239     // TODO: switch over to use this for our animation
240     bool onAnimate(const SkAnimTimer& timer) override {
241         SkScalar angle = SkDoubleToScalar(fmod(timer.secs() * 360 / 24, 360));
242         fAnimatingDrawable->setSweep(angle);
243         return true;
244     }
245 #endif
246 
247 private:
248     typedef SampleView INHERITED;
249 };
250 
251 //////////////////////////////////////////////////////////////////////////////
252 
253 DEF_SAMPLE( return new DrawAtlasView("DrawAtlas", draw_atlas); )
254 DEF_SAMPLE( return new DrawAtlasView("DrawAtlasSim", draw_atlas_sim); )
255