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      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 
     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 
     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, nullptr,
     46                     SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode);
     47 }
     48 
     49 ///////////////////////////////////////////////////////////////////////////////
     50 
     51 class Patch {
     52 public:
     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 
     65 private:
     66     SkPoint fPts[13];
     67     int     fW, fH;
     68 };
     69 
     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], nullptr, nullptr);
     78     }
     79 }
     80 
     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 
    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 
    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 
    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 : nullptr,
    203                              doColors ? colors : nullptr, nullptr,
    204                              nullptr, 0, paint);
    205     }
    206 }
    207 
    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:
    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 
    263 protected:
    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 
    354 private:
    355     typedef SampleView INHERITED;
    356 };
    357 
    358 //////////////////////////////////////////////////////////////////////////////
    359 
    360 static SkView* MyFactory() { return new PatchView; }
    361 static SkViewRegister reg(MyFactory);
    362