1 /*
2  * Copyright 2011 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 "SkGradientShader.h"
13 #include "SkGraphics.h"
14 #include "SkImageDecoder.h"
15 #include "SkPath.h"
16 #include "SkRandom.h"
17 #include "SkRegion.h"
18 #include "SkShader.h"
19 #include "SkUtils.h"
20 #include "SkXfermode.h"
21 #include "SkColorPriv.h"
22 #include "SkColorFilter.h"
23 #include "SkTime.h"
24 #include "SkTypeface.h"
25 
26 #include "SkOSFile.h"
27 #include "SkStream.h"
28 
29 #include "SkGeometry.h" // private include :(
30 
make_shader0(SkIPoint * size)31 static SkShader* make_shader0(SkIPoint* size) {
32     SkBitmap    bm;
33 
34 //    SkImageDecoder::DecodeFile("/skimages/progressivejpg.jpg", &bm);
35     SkImageDecoder::DecodeFile("/skimages/logo.png", &bm);
36     size->set(bm.width(), bm.height());
37     return SkShader::CreateBitmapShader(bm, SkShader::kClamp_TileMode,
38                                         SkShader::kClamp_TileMode);
39 }
40 
make_shader1(const SkIPoint & size)41 static SkShader* make_shader1(const SkIPoint& size) {
42     SkPoint pts[] = { { 0, 0, },
43                       { SkIntToScalar(size.fX), SkIntToScalar(size.fY) } };
44     SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorRED };
45     return SkGradientShader::CreateLinear(pts, colors, NULL,
46                     SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode);
47 }
48 
49 ///////////////////////////////////////////////////////////////////////////////
50 
51 class Patch {
52 public:
Patch()53     Patch() { sk_bzero(fPts, sizeof(fPts)); }
~Patch()54     ~Patch() {}
55 
setPatch(const SkPoint pts[12])56     void setPatch(const SkPoint pts[12]) {
57         memcpy(fPts, pts, 12 * sizeof(SkPoint));
58         fPts[12] = pts[0];  // the last shall be first
59     }
setBounds(int w,int h)60     void setBounds(int w, int h) { fW = w; fH = h; }
61 
62     void draw(SkCanvas*, const SkPaint&, int segsU, int segsV,
63               bool doTextures, bool doColors);
64 
65 private:
66     SkPoint fPts[13];
67     int     fW, fH;
68 };
69 
eval_patch_edge(const SkPoint cubic[],SkPoint samples[],int segs)70 static void eval_patch_edge(const SkPoint cubic[], SkPoint samples[], int segs) {
71     SkScalar t = 0;
72     SkScalar dt = SK_Scalar1 / segs;
73 
74     samples[0] = cubic[0];
75     for (int i = 1; i < segs; i++) {
76         t += dt;
77         SkEvalCubicAt(cubic, t, &samples[i], NULL, NULL);
78     }
79 }
80 
eval_sheet(const SkPoint edge[],int nu,int nv,int iu,int iv,SkPoint * pt)81 static void eval_sheet(const SkPoint edge[], int nu, int nv, int iu, int iv,
82                        SkPoint* pt) {
83     const int TL = 0;
84     const int TR = nu;
85     const int BR = TR + nv;
86     const int BL = BR + nu;
87 
88     SkScalar u = SkIntToScalar(iu) / nu;
89     SkScalar v = SkIntToScalar(iv) / nv;
90 
91     SkScalar uv = SkScalarMul(u, v);
92     SkScalar Uv = SkScalarMul(SK_Scalar1 - u, v);
93     SkScalar uV = SkScalarMul(u, SK_Scalar1 - v);
94     SkScalar UV = SkScalarMul(SK_Scalar1 - u, SK_Scalar1 - v);
95 
96     SkScalar x0 = SkScalarMul(UV, edge[TL].fX) + SkScalarMul(uV, edge[TR].fX) +
97                   SkScalarMul(Uv, edge[BL].fX) + SkScalarMul(uv, edge[BR].fX);
98     SkScalar y0 = SkScalarMul(UV, edge[TL].fY) + SkScalarMul(uV, edge[TR].fY) +
99                   SkScalarMul(Uv, edge[BL].fY) + SkScalarMul(uv, edge[BR].fY);
100 
101     SkScalar x =    SkScalarMul(SK_Scalar1 - v, edge[TL+iu].fX) +
102                     SkScalarMul(u, edge[TR+iv].fX) +
103                     SkScalarMul(v, edge[BR+nu-iu].fX) +
104                     SkScalarMul(SK_Scalar1 - u, edge[BL+nv-iv].fX) - x0;
105     SkScalar y =    SkScalarMul(SK_Scalar1 - v, edge[TL+iu].fY) +
106                     SkScalarMul(u, edge[TR+iv].fY) +
107                     SkScalarMul(v, edge[BR+nu-iu].fY) +
108                     SkScalarMul(SK_Scalar1 - u, edge[BL+nv-iv].fY) - y0;
109     pt->set(x, y);
110 }
111 
ScalarTo255(SkScalar v)112 static int ScalarTo255(SkScalar v) {
113     int scale = SkScalarToFixed(v) >> 8;
114     if (scale < 0) {
115         scale = 0;
116     } else if (scale > 255) {
117         scale = 255;
118     }
119     return scale;
120 }
121 
make_color(SkScalar s,SkScalar t)122 static SkColor make_color(SkScalar s, SkScalar t) {
123     int cs = ScalarTo255(s);
124     int ct = ScalarTo255(t);
125     return SkColorSetARGB(0xFF, cs, 0, 0) + SkColorSetARGB(0, 0, ct, 0);
126 }
127 
draw(SkCanvas * canvas,const SkPaint & paint,int nu,int nv,bool doTextures,bool doColors)128 void Patch::draw(SkCanvas* canvas, const SkPaint& paint, int nu, int nv,
129                  bool doTextures, bool doColors) {
130     if (nu < 1 || nv < 1) {
131         return;
132     }
133 
134     int i, npts = (nu + nv) * 2;
135     SkAutoSTMalloc<16, SkPoint> storage(npts + 1);
136     SkPoint* edge0 = storage.get();
137     SkPoint* edge1 = edge0 + nu;
138     SkPoint* edge2 = edge1 + nv;
139     SkPoint* edge3 = edge2 + nu;
140 
141     // evaluate the edge points
142     eval_patch_edge(fPts + 0, edge0, nu);
143     eval_patch_edge(fPts + 3, edge1, nv);
144     eval_patch_edge(fPts + 6, edge2, nu);
145     eval_patch_edge(fPts + 9, edge3, nv);
146     edge3[nv] = edge0[0];   // the last shall be first
147 
148     for (i = 0; i < npts; i++) {
149 //        canvas->drawLine(edge0[i].fX, edge0[i].fY, edge0[i+1].fX, edge0[i+1].fY, paint);
150     }
151 
152     int row, vertCount = (nu + 1) * (nv + 1);
153     SkAutoTMalloc<SkPoint>  vertStorage(vertCount);
154     SkPoint* verts = vertStorage.get();
155 
156     // first row
157     memcpy(verts, edge0, (nu + 1) * sizeof(SkPoint));
158     // rows
159     SkPoint* r = verts;
160     for (row = 1; row < nv; row++) {
161         r += nu + 1;
162         r[0] = edge3[nv - row];
163         for (int col = 1; col < nu; col++) {
164             eval_sheet(edge0, nu, nv, col, row, &r[col]);
165         }
166         r[nu] = edge1[row];
167     }
168     // last row
169     SkPoint* last = verts + nv * (nu + 1);
170     for (i = 0; i <= nu; i++) {
171         last[i] = edge2[nu - i];
172     }
173 
174 //    canvas->drawPoints(verts, vertCount, paint);
175 
176     int stripCount = (nu + 1) * 2;
177     SkAutoTMalloc<SkPoint>  stripStorage(stripCount * 2);
178     SkAutoTMalloc<SkColor>  colorStorage(stripCount);
179     SkPoint* strip = stripStorage.get();
180     SkPoint* tex = strip + stripCount;
181     SkColor* colors = colorStorage.get();
182     SkScalar t = 0;
183     const SkScalar ds = SK_Scalar1 * fW / nu;
184     const SkScalar dt = SK_Scalar1 * fH / nv;
185     r = verts;
186     for (row = 0; row < nv; row++) {
187         SkPoint* upper = r;
188         SkPoint* lower = r + nu + 1;
189         r = lower;
190         SkScalar s = 0;
191         for (i = 0; i <= nu; i++)  {
192             strip[i*2 + 0] = *upper++;
193             strip[i*2 + 1] = *lower++;
194             tex[i*2 + 0].set(s, t);
195             tex[i*2 + 1].set(s, t + dt);
196             colors[i*2 + 0] = make_color(s/fW, t/fH);
197             colors[i*2 + 1] = make_color(s/fW, (t + dt)/fH);
198             s += ds;
199         }
200         t += dt;
201         canvas->drawVertices(SkCanvas::kTriangleStrip_VertexMode, stripCount,
202                              strip, doTextures ? tex : NULL,
203                              doColors ? colors : NULL, NULL,
204                              NULL, 0, paint);
205     }
206 }
207 
drawpatches(SkCanvas * canvas,const SkPaint & paint,int nu,int nv,Patch * patch)208 static void drawpatches(SkCanvas* canvas, const SkPaint& paint, int nu, int nv,
209                         Patch* patch) {
210     SkAutoCanvasRestore ar(canvas, true);
211 
212     patch->draw(canvas, paint, nu, nv, false, false);
213     canvas->translate(SkIntToScalar(180), 0);
214     patch->draw(canvas, paint, nu, nv, true, false);
215     canvas->translate(SkIntToScalar(180), 0);
216     patch->draw(canvas, paint, nu, nv, false, true);
217     canvas->translate(SkIntToScalar(180), 0);
218     patch->draw(canvas, paint, nu, nv, true, true);
219 }
220 
221 const SkScalar DX = 20;
222 const SkScalar DY = 0;
223 
224 class PatchView : public SampleView {
225     SkScalar    fAngle;
226     SkShader*   fShader0;
227     SkShader*   fShader1;
228     SkIPoint    fSize0, fSize1;
229     SkPoint     fPts[12];
230 
231 public:
PatchView()232     PatchView() : fAngle(0) {
233         fShader0 = make_shader0(&fSize0);
234         fSize1 = fSize0;
235         if (fSize0.fX == 0 || fSize0.fY == 0) {
236             fSize1.set(2, 2);
237         }
238         fShader1 = make_shader1(fSize1);
239 
240         const SkScalar S = SkIntToScalar(50);
241         const SkScalar T = SkIntToScalar(40);
242         fPts[0].set(S*0, T);
243         fPts[1].set(S*1, T);
244         fPts[2].set(S*2, T);
245         fPts[3].set(S*3, T);
246         fPts[4].set(S*3, T*2);
247         fPts[5].set(S*3, T*3);
248         fPts[6].set(S*3, T*4);
249         fPts[7].set(S*2, T*4);
250         fPts[8].set(S*1, T*4);
251         fPts[9].set(S*0, T*4);
252         fPts[10].set(S*0, T*3);
253         fPts[11].set(S*0, T*2);
254 
255         this->setBGColor(SK_ColorGRAY);
256     }
257 
~PatchView()258     virtual ~PatchView() {
259         SkSafeUnref(fShader0);
260         SkSafeUnref(fShader1);
261     }
262 
263 protected:
264     // overrides from SkEventSink
onQuery(SkEvent * evt)265     virtual bool onQuery(SkEvent* evt)  {
266         if (SampleCode::TitleQ(*evt)) {
267             SampleCode::TitleR(evt, "Patch");
268             return true;
269         }
270         return this->INHERITED::onQuery(evt);
271     }
272 
onDrawContent(SkCanvas * canvas)273     virtual void onDrawContent(SkCanvas* canvas) {
274         const int nu = 10;
275         const int nv = 10;
276 
277         SkPaint paint;
278         paint.setDither(true);
279         paint.setFilterQuality(kLow_SkFilterQuality);
280 
281         canvas->translate(DX, DY);
282 
283         Patch   patch;
284 
285         paint.setShader(fShader0);
286         if (fSize0.fX == 0) {
287             fSize0.fX = 1;
288         }
289         if (fSize0.fY == 0) {
290             fSize0.fY = 1;
291         }
292         patch.setBounds(fSize0.fX, fSize0.fY);
293 
294         patch.setPatch(fPts);
295         drawpatches(canvas, paint, nu, nv, &patch);
296 
297         paint.setShader(NULL);
298         paint.setAntiAlias(true);
299         paint.setStrokeWidth(SkIntToScalar(5));
300         canvas->drawPoints(SkCanvas::kPoints_PointMode, SK_ARRAY_COUNT(fPts), fPts, paint);
301 
302         canvas->translate(0, SkIntToScalar(300));
303 
304         paint.setAntiAlias(false);
305         paint.setShader(fShader1);
306         if (true) {
307             SkMatrix m;
308             m.setSkew(1, 0);
309             SkShader* s = SkShader::CreateLocalMatrixShader(paint.getShader(), m);
310             paint.setShader(s)->unref();
311         }
312         if (true) {
313             SkMatrix m;
314             m.setRotate(fAngle);
315             SkShader* s = SkShader::CreateLocalMatrixShader(paint.getShader(), m);
316             paint.setShader(s)->unref();
317         }
318         patch.setBounds(fSize1.fX, fSize1.fY);
319         drawpatches(canvas, paint, nu, nv, &patch);
320     }
321 
onAnimate(const SkAnimTimer & timer)322     bool onAnimate(const SkAnimTimer& timer) override {
323         fAngle = timer.scaled(60, 360);
324         return true;
325     }
326 
327     class PtClick : public Click {
328     public:
329         int fIndex;
PtClick(SkView * view,int index)330         PtClick(SkView* view, int index) : Click(view), fIndex(index) {}
331     };
332 
hittest(const SkPoint & pt,SkScalar x,SkScalar y)333     static bool hittest(const SkPoint& pt, SkScalar x, SkScalar y) {
334         return SkPoint::Length(pt.fX - x, pt.fY - y) < SkIntToScalar(5);
335     }
336 
onFindClickHandler(SkScalar x,SkScalar y,unsigned modi)337     virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
338                                               unsigned modi) override {
339         x -= DX;
340         y -= DY;
341         for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); i++) {
342             if (hittest(fPts[i], x, y)) {
343                 return new PtClick(this, (int)i);
344             }
345         }
346         return this->INHERITED::onFindClickHandler(x, y, modi);
347     }
348 
onClick(Click * click)349     virtual bool onClick(Click* click) {
350         fPts[((PtClick*)click)->fIndex].set(click->fCurr.fX - DX, click->fCurr.fY - DY);
351         this->inval(NULL);
352         return true;
353     }
354 
355 private:
356     typedef SampleView INHERITED;
357 };
358 
359 //////////////////////////////////////////////////////////////////////////////
360 
MyFactory()361 static SkView* MyFactory() { return new PatchView; }
362 static SkViewRegister reg(MyFactory);
363