silverlight 碰撞检测

1:  private bool CheckCollision(FrameworkElement control1, FrameworkElement controlElem1, FrameworkElement control2, FrameworkElement controlElem2)

2:  {

3:      // first see if sprite rectangles collide

4:      Rect rect1 = UserControlBounds(control1);

5:      Rect rect2 = UserControlBounds(control2);

6: 

7:      rect1.Intersect(rect2);

8:      if (rect1 == Rect.Empty)

9:      {

10:          // no collision - GET OUT!

11:          return false;

12:      }

13:      else

14:      {

15:          bool bCollision = false;

16:          Point ptCheck = new Point();

17: 

18:          // NOTE that creating the writeablebitmap is a bit intense

19:          // so we will do this once and store results in Tag property

20:          // in a real game, you might abstract this into a Sprite class.

21:          if (controlElem1 is Image)

22:              controlElem1.Tag = GetWriteableBitmap(control1);

23: 

24:          if (controlElem2 is Image)

25:              controlElem2.Tag = GetWriteableBitmap(control2);

26: 

27:          // now we do a more accurate pixel hit test

28:          for (int x = Convert.ToInt32(rect1.X); x < Convert.ToInt32(rect1.X + rect1.Width); x++)

29:          {

30:              for (int y = Convert.ToInt32(rect1.Y); y < Convert.ToInt32(rect1.Y + rect1.Height); y++)

31:              {

32:                  ptCheck.X = x;

33:                  ptCheck.Y = y;

34: 

35: 

36:                  if (CheckCollisionPoint(ptCheck, control1, controlElem1))

37:                      if (CheckCollisionPoint(ptCheck, control2, controlElem2))

38:                      {

39:                          bCollision = true;

40:                          break;

41:                      }

42: 

43:              }

44:              if (bCollision) break;

45:          }

46:          return bCollision;

47:      }

48:  }

49: 

50:  public bool CheckCollisionPoint(Point pt, FrameworkElement control, FrameworkElement controlElem)

51:  {

52:      if (controlElem is Image)

53:      {

54:          // NOTE that we saved the WB in the Tag object for performance.

55:          // in a real app, you might abstract this in your sprite class.

56:          WriteableBitmap wb = controlElem.Tag as WriteableBitmap;

57: 

58:          int width = wb.PixelWidth;

59:          int height = wb.PixelHeight;

60: 

61:          double offSetX = Convert.ToDouble(control.GetValue(Canvas.LeftProperty));

62:          double offSetY = Convert.ToDouble(control.GetValue(Canvas.TopProperty));

63: 

64:          pt.X = pt.X - offSetX;

65:          pt.Y = pt.Y - offSetY;

66: 

67:          int offset = Convert.ToInt32((width * pt.Y) + pt.X);

68: 

69:          return (wb.Pixels[offset] != 0);

70:      }

71:      else

72:      {

73:          List<UIElement> hits = System.Windows.Media.VisualTreeHelper.FindElementsInHostCoordinates(pt, controlElem) as List<UIElement>;

74:          return (hits.Contains(controlElem));

75:      }

76:  }

77: 

78:  private WriteableBitmap GetWriteableBitmap(FrameworkElement control)

79:  {

80:      WriteableBitmap wb = new WriteableBitmap((int)control.Width, (int)control.Height); ;

81:      wb.Render(control, new TranslateTransform());

82:      wb.Invalidate();

83: 

84:      return wb;

85:  }

86: 

87:  public Rect UserControlBounds(FrameworkElement control)

88:  {

89:      Point ptTopLeft = new Point(Convert.ToDouble(control.GetValue(Canvas.LeftProperty)), Convert.ToDouble(control.GetValue(Canvas.TopProperty)));

90:      Point ptBottomRight = new Point(Convert.ToDouble(control.GetValue(Canvas.LeftProperty)) + control.Width, Convert.ToDouble(control.GetValue(Canvas.TopProperty)) + control.Height);

91: 

92:      return new Rect(ptTopLeft, ptBottomRight);

93:  }

94: 

1:  if (CheckCollision(sp1, sp1.ShipShell, sp2, sp2.ShipShell))

2:  {

3:      tb.Text = "true";

4:  }

5:  else

6:  {

7:      tb.Text = "false";

8:  }