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
31static 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
41static 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, nullptr,
46                    SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode);
47}
48
49///////////////////////////////////////////////////////////////////////////////
50
51class Patch {
52public:
53    Patch() { sk_bzero(fPts, sizeof(fPts)); }
54    ~Patch() {}
55
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    }
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
65private:
66    SkPoint fPts[13];
67    int     fW, fH;
68};
69
70static 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], nullptr, nullptr);
78    }
79}
80
81static 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
112static 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
122static 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
128void 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 : nullptr,
203                             doColors ? colors : nullptr, nullptr,
204                             nullptr, 0, paint);
205    }
206}
207
208static 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
221const SkScalar DX = 20;
222const SkScalar DY = 0;
223
224class PatchView : public SampleView {
225    SkScalar    fAngle;
226    SkShader*   fShader0;
227    SkShader*   fShader1;
228    SkIPoint    fSize0, fSize1;
229    SkPoint     fPts[12];
230
231public:
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
258    virtual ~PatchView() {
259        SkSafeUnref(fShader0);
260        SkSafeUnref(fShader1);
261    }
262
263protected:
264    // overrides from SkEventSink
265    bool onQuery(SkEvent* evt)  override {
266        if (SampleCode::TitleQ(*evt)) {
267            SampleCode::TitleR(evt, "Patch");
268            return true;
269        }
270        return this->INHERITED::onQuery(evt);
271    }
272
273    void onDrawContent(SkCanvas* canvas) override {
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(nullptr);
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 = paint.getShader()->newWithLocalMatrix(m);
310            paint.setShader(s)->unref();
311        }
312        if (true) {
313            SkMatrix m;
314            m.setRotate(fAngle);
315            SkShader* s = paint.getShader()->newWithLocalMatrix(m);
316            paint.setShader(s)->unref();
317        }
318        patch.setBounds(fSize1.fX, fSize1.fY);
319        drawpatches(canvas, paint, nu, nv, &patch);
320    }
321
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;
330        PtClick(SkView* view, int index) : Click(view), fIndex(index) {}
331    };
332
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
337    SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override {
338        x -= DX;
339        y -= DY;
340        for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); i++) {
341            if (hittest(fPts[i], x, y)) {
342                return new PtClick(this, (int)i);
343            }
344        }
345        return this->INHERITED::onFindClickHandler(x, y, modi);
346    }
347
348    bool onClick(Click* click) override {
349        fPts[((PtClick*)click)->fIndex].set(click->fCurr.fX - DX, click->fCurr.fY - DY);
350        this->inval(nullptr);
351        return true;
352    }
353
354private:
355    typedef SampleView INHERITED;
356};
357
358//////////////////////////////////////////////////////////////////////////////
359
360static SkView* MyFactory() { return new PatchView; }
361static SkViewRegister reg(MyFactory);
362