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      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 
     30 static 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 
     40 static 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 
     50 class Patch {
     51 public:
     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 
     64 private:
     65     SkPoint fPts[13];
     66     int     fW, fH;
     67 };
     68 
     69 static 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 
     80 static 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 
    111 static 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 
    121 static 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 
    127 void 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 
    207 static void drawpatches(SkCanvas* canvas, const SkPaint& paint, int nu, int nv,
    208                         Patch* patch) {
    209     SkAutoCanvasRestore ar(canvas, true);
    210 
    211     patch->draw(canvas, paint, nu, nv, false, false);
    212     canvas->translate(SkIntToScalar(180), 0);
    213     patch->draw(canvas, paint, nu, nv, true, false);
    214     canvas->translate(SkIntToScalar(180), 0);
    215     patch->draw(canvas, paint, nu, nv, false, true);
    216     canvas->translate(SkIntToScalar(180), 0);
    217     patch->draw(canvas, paint, nu, nv, true, true);
    218 }
    219 
    220 const SkScalar DX = 20;
    221 const SkScalar DY = 0;
    222 
    223 class PatchView : public SampleView {
    224     SkShader*   fShader0;
    225     SkShader*   fShader1;
    226     SkIPoint    fSize0, fSize1;
    227     SkPoint     fPts[12];
    228 
    229 public:
    230     PatchView() {
    231         fShader0 = make_shader0(&fSize0);
    232         fSize1 = fSize0;
    233         if (fSize0.fX == 0 || fSize0.fY == 0) {
    234             fSize1.set(2, 2);
    235         }
    236         fShader1 = make_shader1(fSize1);
    237 
    238         const SkScalar S = SkIntToScalar(50);
    239         const SkScalar T = SkIntToScalar(40);
    240         fPts[0].set(S*0, T);
    241         fPts[1].set(S*1, T);
    242         fPts[2].set(S*2, T);
    243         fPts[3].set(S*3, T);
    244         fPts[4].set(S*3, T*2);
    245         fPts[5].set(S*3, T*3);
    246         fPts[6].set(S*3, T*4);
    247         fPts[7].set(S*2, T*4);
    248         fPts[8].set(S*1, T*4);
    249         fPts[9].set(S*0, T*4);
    250         fPts[10].set(S*0, T*3);
    251         fPts[11].set(S*0, T*2);
    252 
    253         this->setBGColor(SK_ColorGRAY);
    254     }
    255 
    256     virtual ~PatchView() {
    257         SkSafeUnref(fShader0);
    258         SkSafeUnref(fShader1);
    259     }
    260 
    261 protected:
    262     // overrides from SkEventSink
    263     virtual bool onQuery(SkEvent* evt)  {
    264         if (SampleCode::TitleQ(*evt)) {
    265             SampleCode::TitleR(evt, "Patch");
    266             return true;
    267         }
    268         return this->INHERITED::onQuery(evt);
    269     }
    270 
    271     virtual void onDrawContent(SkCanvas* canvas) {
    272         const int nu = 10;
    273         const int nv = 10;
    274 
    275         SkPaint paint;
    276         paint.setDither(true);
    277         paint.setFilterLevel(SkPaint::kLow_FilterLevel);
    278 
    279         canvas->translate(DX, DY);
    280 
    281         Patch   patch;
    282 
    283         paint.setShader(fShader0);
    284         if (fSize0.fX == 0) {
    285             fSize0.fX = 1;
    286         }
    287         if (fSize0.fY == 0) {
    288             fSize0.fY = 1;
    289         }
    290         patch.setBounds(fSize0.fX, fSize0.fY);
    291 
    292         patch.setPatch(fPts);
    293         drawpatches(canvas, paint, nu, nv, &patch);
    294 
    295         paint.setShader(NULL);
    296         paint.setAntiAlias(true);
    297         paint.setStrokeWidth(SkIntToScalar(5));
    298         canvas->drawPoints(SkCanvas::kPoints_PointMode, SK_ARRAY_COUNT(fPts), fPts, paint);
    299 
    300         canvas->translate(0, SkIntToScalar(300));
    301 
    302         paint.setAntiAlias(false);
    303         paint.setShader(fShader1);
    304         if (true) {
    305             SkMatrix m;
    306             m.setSkew(1, 0);
    307             SkShader* s = SkShader::CreateLocalMatrixShader(paint.getShader(), m);
    308             paint.setShader(s)->unref();
    309         }
    310         if (true) {
    311             static int gAngle;
    312             SkMatrix m;
    313             m.setRotate(SkIntToScalar(gAngle++));
    314             SkShader* s = SkShader::CreateLocalMatrixShader(paint.getShader(), m);
    315             paint.setShader(s)->unref();
    316         }
    317         patch.setBounds(fSize1.fX, fSize1.fY);
    318         drawpatches(canvas, paint, nu, nv, &patch);
    319 
    320         this->inval(NULL);
    321     }
    322 
    323     class PtClick : public Click {
    324     public:
    325         int fIndex;
    326         PtClick(SkView* view, int index) : Click(view), fIndex(index) {}
    327     };
    328 
    329     static bool hittest(const SkPoint& pt, SkScalar x, SkScalar y) {
    330         return SkPoint::Length(pt.fX - x, pt.fY - y) < SkIntToScalar(5);
    331     }
    332 
    333     virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
    334                                               unsigned modi) SK_OVERRIDE {
    335         x -= DX;
    336         y -= DY;
    337         for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); i++) {
    338             if (hittest(fPts[i], x, y)) {
    339                 return new PtClick(this, (int)i);
    340             }
    341         }
    342         return this->INHERITED::onFindClickHandler(x, y, modi);
    343     }
    344 
    345     virtual bool onClick(Click* click) {
    346         fPts[((PtClick*)click)->fIndex].set(click->fCurr.fX - DX, click->fCurr.fY - DY);
    347         this->inval(NULL);
    348         return true;
    349     }
    350 
    351 private:
    352     typedef SampleView INHERITED;
    353 };
    354 
    355 //////////////////////////////////////////////////////////////////////////////
    356 
    357 static SkView* MyFactory() { return new PatchView; }
    358 static SkViewRegister reg(MyFactory);
    359