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