gm/stringart.cpp

   1 /*
   2  * Copyright 2013 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 "gm.h"
   9 #include "SkCanvas.h"
  10 #include "SkPath.h"
  11
  12 // Reproduces https://code.google.com/p/chromium/issues/detail?id=279014
  13
  14 static const int kWidth = 640;
  15 static const int kHeight = 480;
  16 static const SkScalar kAngle = 0.305f;
  17
  18 // Renders a string art shape.
  19 // The particular shape rendered can be controlled by adjusting kAngle, from 0 to 1
  20
  21 class StringArtGM : public skiagm::GM {
  22 public:
  23     StringArtGM() {}
  24
  25 protected:
  26
  27     SkString onShortName() SK_OVERRIDE {
  28         return SkString("stringart");
  29     }
  30
  31     SkISize onISize() SK_OVERRIDE {
  32         return SkISize::Make(kWidth, kHeight);
  33     }
  34
  35     void onDraw(SkCanvas* canvas) SK_OVERRIDE {
  36         SkScalar angle = kAngle*SK_ScalarPI + SkScalarHalf(SK_ScalarPI);
  37         SkScalar size = SkIntToScalar(SkMin32(kWidth, kHeight));
  38         SkPoint center = SkPoint::Make(SkScalarHalf(kWidth), SkScalarHalf(kHeight));
  39         SkScalar length = 5;
  40         SkScalar step = angle;
  41
  42         SkPath path;
  43         path.moveTo(center);
  44
  45         while (length < (SkScalarHalf(size) - 10.f))
  46         {
  47             SkPoint rp = SkPoint::Make(length*SkScalarCos(step) + center.fX,
  48                                        length*SkScalarSin(step) + center.fY);
  49             path.lineTo(rp);
  50             length += SkScalarDiv(angle, SkScalarHalf(SK_ScalarPI));
  51             step += angle;
  52         }
  53         path.close();
  54
  55         SkPaint paint;
  56         paint.setAntiAlias(true);
  57         paint.setStyle(SkPaint::kStroke_Style);
  58         paint.setColor(0xFF007700);
  59
  60         canvas->drawPath(path, paint);
  61     }
  62
  63 private:
  64     typedef GM INHERITED;
  65 };
  66
  67 DEF_GM( return new StringArtGM; )