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