text: /*
   * Copyright 2011 Google Inc.
   *
   * Use of this source code is governed by a BSD-style license that can be
   * found in the LICENSE file.
   */
  #include "include/core/SkBitmap.h"
  #include "include/core/SkCanvas.h"
  #include "include/core/SkColorFilter.h"
  #include "include/core/SkColorPriv.h"
  #include "include/core/SkGraphics.h"
  #include "include/core/SkPath.h"
  #include "include/core/SkRegion.h"
  #include "include/core/SkShader.h"
  #include "include/core/SkTime.h"
  #include "include/core/SkTypeface.h"
  #include "include/core/SkVertices.h"
  #include "include/effects/SkGradientShader.h"
  #include "include/utils/SkRandom.h"
  #include "samplecode/Sample.h"
  #include "src/utils/SkUTF.h"
  
  #include "include/core/SkStream.h"
  #include "src/core/SkOSFile.h"
  
  static sk_sp<SkShader> make_shader0(SkIPoint* size) {
      SkBitmap    bm;
      size->set(2, 2);
      SkPMColor color0 = SkPreMultiplyARGB(0x80, 0x80, 0xff, 0x80);
      SkPMColor color1 = SkPreMultiplyARGB(0x40, 0xff, 0x00, 0xff);
      bm.allocN32Pixels(size->fX, size->fY);
      bm.eraseColor(color0);
      uint32_t* pixels = (uint32_t*) bm.getPixels();
      pixels[0] = pixels[2] = color0;
      pixels[1] = pixels[3] = color1;
  
      return bm.makeShader(SkTileMode::kRepeat, SkTileMode::kRepeat,
                           SkSamplingOptions(SkFilterMode::kLinear));
  }
  
  static sk_sp<SkShader> make_shader1(const SkIPoint& size) {
      SkPoint pts[] = { { 0, 0 },
                        { SkIntToScalar(size.fX), SkIntToScalar(size.fY) } };
      SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorRED };
      return SkGradientShader::MakeLinear(pts, colors, nullptr,
                      SK_ARRAY_COUNT(colors), SkTileMode::kMirror);
  }
  
  class VerticesView : public Sample {
      sk_sp<SkShader> fShader0;
      sk_sp<SkShader> fShader1;
  
  public:
      VerticesView() {
          SkIPoint    size;
  
          fShader0 = make_shader0(&size);
          fShader1 = make_shader1(size);
  
          make_strip(&fRecs[0], size.fX, size.fY);
          make_fan(&fRecs[1], size.fX, size.fY);
          make_tris(&fRecs[2]);
  
          fScale = SK_Scalar1;
  
          this->setBGColor(SK_ColorGRAY);
      }
  
  protected:
      SkString name() override { return SkString("Vertices"); }
  
      SkScalar fScale;
  
      void onDrawContent(SkCanvas* canvas) override {
          SkPaint paint;
          paint.setDither(true);
  
          for (size_t i = 0; i < SK_ARRAY_COUNT(fRecs); i++) {
              auto verts = SkVertices::MakeCopy(fRecs[i].fMode, fRecs[i].fCount,
                                                fRecs[i].fVerts, fRecs[i].fTexs,
                                                nullptr);
              canvas->save();
  
              paint.setShader(nullptr);
              canvas->drawVertices(verts, SkBlendMode::kModulate, paint);
  
              canvas->translate(SkIntToScalar(250), 0);
  
              paint.setShader(fShader0);
              canvas->drawVertices(verts, SkBlendMode::kModulate, paint);
  
              canvas->translate(SkIntToScalar(250), 0);
  
              paint.setShader(fShader1);
              canvas->drawVertices(verts, SkBlendMode::kModulate, paint);
              canvas->restore();
  
              canvas->translate(0, SkIntToScalar(250));
          }
      }
  
      Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey) override {
          return new Click();
      }
  
      bool onClick(Click* click) override {
      //    fCurrX = click->fICurr.fX;
      //    fCurrY = click->fICurr.fY;
          return true;
      }
  
  private:
      struct Rec {
          SkVertices::VertexMode  fMode;
          int                     fCount;
          SkPoint*                fVerts;
          SkPoint*                fTexs;
  
          Rec() : fCount(0), fVerts(nullptr), fTexs(nullptr) {}
          ~Rec() { delete[] fVerts; delete[] fTexs; }
      };
  
      void make_tris(Rec* rec) {
          int n = 10;
          SkRandom    rand;
  
          rec->fMode = SkVertices::kTriangles_VertexMode;
          rec->fCount = n * 3;
          rec->fVerts = new SkPoint[rec->fCount];
  
          for (int i = 0; i < n; i++) {
              SkPoint* v = &rec->fVerts[i*3];
              for (int j = 0; j < 3; j++) {
                  v[j].set(rand.nextUScalar1() * 250, rand.nextUScalar1() * 250);
              }
          }
      }
  
      void make_fan(Rec* rec, int texWidth, int texHeight) {
          const SkScalar tx = SkIntToScalar(texWidth);
          const SkScalar ty = SkIntToScalar(texHeight);
          const int n = 24;
  
          rec->fMode = SkVertices::kTriangleFan_VertexMode;
          rec->fCount = n + 2;
          rec->fVerts = new SkPoint[rec->fCount];
          rec->fTexs  = new SkPoint[rec->fCount];
  
          SkPoint* v = rec->fVerts;
          SkPoint* t = rec->fTexs;
  
          v[0].set(0, 0);
          t[0].set(0, 0);
          for (int i = 0; i < n; i++) {
              SkScalar r   = SK_ScalarPI * 2 * i / n,
                       sin = SkScalarSin(r),
                       cos = SkScalarCos(r);
              v[i+1].set(cos, sin);
              t[i+1].set(i*tx/n, ty);
          }
          v[n+1] = v[1];
          t[n+1].set(tx, ty);
  
          SkMatrix m;
          m.setScale(SkIntToScalar(100), SkIntToScalar(100));
          m.postTranslate(SkIntToScalar(110), SkIntToScalar(110));
          m.mapPoints(v, rec->fCount);
      }
  
      void make_strip(Rec* rec, int texWidth, int texHeight) {
          const SkScalar tx = SkIntToScalar(texWidth);
          const SkScalar ty = SkIntToScalar(texHeight);
          const int n = 24;
  
          rec->fMode = SkVertices::kTriangleStrip_VertexMode;
          rec->fCount = 2 * (n + 1);
          rec->fVerts = new SkPoint[rec->fCount];
          rec->fTexs  = new SkPoint[rec->fCount];
  
          SkPoint* v = rec->fVerts;
          SkPoint* t = rec->fTexs;
  
          for (int i = 0; i < n; i++) {
              SkScalar r   = SK_ScalarPI * 2 * i / n,
                       sin = SkScalarSin(r),
                       cos = SkScalarCos(r);
              v[i*2 + 0].set(cos/2, sin/2);
              v[i*2 + 1].set(cos, sin);
  
              t[i*2 + 0].set(tx * i / n, ty);
              t[i*2 + 1].set(tx * i / n, 0);
          }
          v[2*n + 0] = v[0];
          v[2*n + 1] = v[1];
  
          t[2*n + 0].set(tx, ty);
          t[2*n + 1].set(tx, 0);
  
          SkMatrix m;
          m.setScale(SkIntToScalar(100), SkIntToScalar(100));
          m.postTranslate(SkIntToScalar(110), SkIntToScalar(110));
          m.mapPoints(v, rec->fCount);
      }
  
      Rec fRecs[3];
  
      using INHERITED = Sample;
  };
  
  //////////////////////////////////////////////////////////////////////////////
  
  DEF_SAMPLE( return new VerticesView(); )
  