samplecode/SamplePathEffects.cpp

   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 "SkPath.h"
  14 #include "SkRegion.h"
  15 #include "SkShader.h"
  16 #include "SkUtils.h"
  17 #include "Sk1DPathEffect.h"
  18 #include "SkCornerPathEffect.h"
  19 #include "SkPathMeasure.h"
  20 #include "SkRandom.h"
  21 #include "SkColorPriv.h"
  22 #include "SkPixelXorXfermode.h"
  23
  24 #define CORNER_RADIUS   12
  25
  26 static const int gXY[] = {
  27     4, 0, 0, -4, 8, -4, 12, 0, 8, 4, 0, 4
  28 };
  29
  30 static SkPathEffect* make_pe(int flags, SkScalar phase) {
  31     if (flags == 1)
  32         return SkCornerPathEffect::Create(SkIntToScalar(CORNER_RADIUS));
  33
  34     SkPath  path;
  35     path.moveTo(SkIntToScalar(gXY[0]), SkIntToScalar(gXY[1]));
  36     for (unsigned i = 2; i < SK_ARRAY_COUNT(gXY); i += 2)
  37         path.lineTo(SkIntToScalar(gXY[i]), SkIntToScalar(gXY[i+1]));
  38     path.close();
  39     path.offset(SkIntToScalar(-6), 0);
  40
  41     SkPathEffect* outer = SkPath1DPathEffect::Create(path, 12, phase,
  42                                                      SkPath1DPathEffect::kRotate_Style);
  43
  44     if (flags == 2)
  45         return outer;
  46
  47     SkPathEffect* inner = SkCornerPathEffect::Create(SkIntToScalar(CORNER_RADIUS));
  48
  49     SkPathEffect* pe = SkComposePathEffect::Create(outer, inner);
  50     outer->unref();
  51     inner->unref();
  52     return pe;
  53 }
  54
  55 static SkPathEffect* make_warp_pe(SkScalar phase) {
  56     SkPath  path;
  57     path.moveTo(SkIntToScalar(gXY[0]), SkIntToScalar(gXY[1]));
  58     for (unsigned i = 2; i < SK_ARRAY_COUNT(gXY); i += 2)
  59         path.lineTo(SkIntToScalar(gXY[i]), SkIntToScalar(gXY[i+1]));
  60     path.close();
  61     path.offset(SkIntToScalar(-6), 0);
  62
  63     SkPathEffect* outer = SkPath1DPathEffect::Create(
  64         path, 12, phase, SkPath1DPathEffect::kMorph_Style);
  65     SkPathEffect* inner = SkCornerPathEffect::Create(SkIntToScalar(CORNER_RADIUS));
  66
  67     SkPathEffect* pe = SkComposePathEffect::Create(outer, inner);
  68     outer->unref();
  69     inner->unref();
  70     return pe;
  71 }
  72
  73 ///////////////////////////////////////////////////////////
  74
  75 #include "SkColorFilter.h"
  76 #include "SkLayerRasterizer.h"
  77
  78 class TestRastBuilder : public SkLayerRasterizer::Builder {
  79 public:
  80     TestRastBuilder() {
  81         SkPaint paint;
  82         paint.setAntiAlias(true);
  83
  84         paint.setAlpha(0x66);
  85         this->addLayer(paint, SkIntToScalar(4), SkIntToScalar(4));
  86
  87         paint.setAlpha(0xFF);
  88         this->addLayer(paint);
  89     }
  90 };
  91
  92 class PathEffectView : public SampleView {
  93     SkPath  fPath;
  94     SkPoint fClickPt;
  95     SkScalar fPhase;
  96
  97 public:
  98     PathEffectView() : fPhase(0) {
  99         }
 100
 101 protected:
 102     void onOnceBeforeDraw() SK_OVERRIDE {
 103         SkRandom    rand;
 104         int         steps = 20;
 105         SkScalar    dist = SkIntToScalar(400);
 106         SkScalar    x = SkIntToScalar(20);
 107         SkScalar    y = SkIntToScalar(50);
 108
 109         fPath.moveTo(x, y);
 110         for (int i = 0; i < steps; i++) {
 111             x += dist/steps;
 112             SkScalar tmpY = y + SkIntToScalar(rand.nextS() % 25);
 113             if (i == steps/2) {
 114                 fPath.moveTo(x, tmpY);
 115             } else {
 116                 fPath.lineTo(x, tmpY);
 117             }
 118         }
 119
 120         {
 121             SkRect  oval;
 122             oval.set(SkIntToScalar(20), SkIntToScalar(30),
 123                      SkIntToScalar(100), SkIntToScalar(60));
 124             oval.offset(x, 0);
 125             fPath.addRoundRect(oval, SkIntToScalar(8), SkIntToScalar(8));
 126         }
 127
 128         fClickPt.set(SkIntToScalar(200), SkIntToScalar(200));
 129
 130         this->setBGColor(0xFFDDDDDD);
 131     }
 132
 133     bool onQuery(SkEvent* evt) SK_OVERRIDE {
 134         if (SampleCode::TitleQ(*evt)) {
 135             SampleCode::TitleR(evt, "PathEffects");
 136             return true;
 137         }
 138         return this->INHERITED::onQuery(evt);
 139     }
 140
 141     void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
 142         SkPaint paint;
 143
 144         canvas->translate(0, 50);
 145
 146         paint.setColor(SK_ColorBLUE);
 147         paint.setPathEffect(make_pe(2, fPhase))->unref();
 148         canvas->drawPath(fPath, paint);
 149
 150         canvas->translate(0, 50);
 151
 152         paint.setARGB(0xFF, 0, 0xBB, 0);
 153         paint.setPathEffect(make_pe(3, fPhase))->unref();
 154         canvas->drawPath(fPath, paint);
 155
 156         canvas->translate(0, 50);
 157
 158         paint.setARGB(0xFF, 0, 0, 0);
 159         paint.setPathEffect(make_warp_pe(fPhase))->unref();
 160         TestRastBuilder testRastBuilder;
 161         paint.setRasterizer(testRastBuilder.detachRasterizer())->unref();
 162         canvas->drawPath(fPath, paint);
 163     }
 164
 165     bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
 166         fPhase = timer.scaled(40);
 167         return true;
 168     }
 169
 170 private:
 171     typedef SampleView INHERITED;
 172 };
 173
 174 //////////////////////////////////////////////////////////////////////////////
 175
 176 static SkView* MyFactory() { return new PathEffectView; }
 177 static SkViewRegister reg(MyFactory);