polygon.cpp

Symbian s60 游戏编程示例

#include "Polygon.h"
#include "mathutils.h"

TBool MPolygon::InsidePolygon(const TPoint p) const
	{
	TInt counter = 0;
	TInt i;
	TReal xinters;
	TPoint p1,p2;

	p1 = PolyPoint(0);
	for (i=1;i<=PolyCount();i++) 
		{
		p2 = PolyPoint(i % PolyCount());
		if (p.iY > Min(p1.iY,p2.iY)) 
		{
		if (p.iY <= Max(p1.iY,p2.iY)) 
			{
			if (p.iX <= Max(p1.iX,p2.iX)) 
				{
				if (p1.iY != p2.iY) 
					{
					xinters = (p.iY-p1.iY)*(p2.iX-p1.iX)/(p2.iY-p1.iY)+p1.iX;
					if (p1.iX == p2.iX || p.iX <= xinters)
						 counter++;
					}
				}
			}
		}
	p1 = p2;
	}

		if (counter % 2 == 0)
			return(EFalse);
		else
			return(ETrue);
		}


TBool MPolygon::Intersects(TPoint aPoint1, TPoint aPoint2) const
	{
	for(TInt i=0; i<PolyLineCount(); i++)
		{
		TPoint poly1, poly2;
		GetPolyLine(i, poly1, poly2);
		if(MathUtils::Intersect(poly1,poly2, aPoint1, aPoint2))
			return ETrue;
		}
		
	if(InsidePolygon(aPoint1) || InsidePolygon(aPoint2))
		return ETrue;
	return EFalse;		
	}

TBool MPolygon::Intersects(const MPolygon& aOther) const
	{
	for(TInt i=0; i<aOther.PolyLineCount(); i++)
		{
		TPoint a, b;
		aOther.GetPolyLine(i, a, b);
		if(Intersects(a, b))
			return ETrue;
		}
	return EFalse;
	}
	
TInt RPolygon::PolyCount() const
	{
	return iPointArray.Count();
	}

void RPolygon::RemovePoint(TInt aIndex)
	{
	iPointArray.Remove(aIndex);
	}

TPoint RPolygon::PolyPoint(TInt aPointNumber) const 
	{
	return iPointArray[aPointNumber];
	}

void RPolygon::SetPolyPoint(TInt aPointNumber, TPoint aPoint)
	{
	iPointArray[aPointNumber] = aPoint;
	}

inline const TPoint& RPolygon::operator[](TInt aNum) const
	{
	return iPointArray[aNum];
	}
 
inline TPoint& RPolygon::operator[](TInt aNum)
	{
	return iPointArray[aNum];
	}
 
void RPolygon::Close()
	{
	iPointArray.Close();
	}

TBool MPolygon::PointInterSects(const TPoint& aPoint) const
	{
	TInt x=aPoint.iX;
	TInt y=aPoint.iY;
	TInt i, j, c = 0;
	for (i = 0, j = PolyCount()-1; i < PolyCount(); j = i++) 
		{
		if
			(
				(
				( (PolyPoint(i).iY <= y) && (y < PolyPoint(j).iY) ) ||
				( (PolyPoint(j).iY <= y) && (y < PolyPoint(i).iY) )
				) &&
			
			(x < (PolyPoint(j).iX - PolyPoint(i).iX) * 
			(y - PolyPoint(i).iY) / (PolyPoint(j).iY - PolyPoint(i).iY) + PolyPoint(i).iX))
			{	
			c = !c;
			}
		}
	  return c;
	}

TBool MPolygon::RectInterSects(const TRect& /*aRect*/) const
	{
	return EFalse;
	}


void MPolygon::GetPolyLine(TInt aLineNumber, TPoint& aStartLine, TPoint& aEndLine) const
		{
		aStartLine = PolyPoint(aLineNumber);
		if(aLineNumber == PolyLineCount()-1)
			aEndLine = PolyPoint(0);
		else
			aEndLine = PolyPoint(aLineNumber+1);
		}

void MPolygon::Rotate(TInt aAngle, MPolygon &aDestination) const
		{
		TPoint origin(0,0);

		for(TInt i=0; i<PolyCount(); i++)
			{
			TPoint point(PolyPoint(i));
			
			TReal a = MathUtils::Sin(aAngle); 
			TReal b = MathUtils::Cos(aAngle); 

			TReal newX = (point.iX * a + point.iY * b);
			TReal newY = (point.iY * a - point.iX * b);
			Math::Round(newX, newX,0);
			Math::Round(newY, newY,0);
			aDestination.SetPolyPoint(i,TPoint(MathUtils::Round(newX), MathUtils::Round(newY)));			
			}
		}

void MPolygon::Scale(TReal iDx, TReal iDy)
		{		
		TPoint origin(0,0);
		for(TInt i=0; i<PolyCount(); i++)
			{
			TPoint point(PolyPoint(i));
			TReal newX = (TReal)point.iX * iDx;
			TReal newY = (TReal)point.iY * iDy;
			SetPolyPoint(i,TPoint(MathUtils::Round(newX), MathUtils::Round(newY)));			
			}
		}

void MPolygon::GetBoundingRect(TRect& aRect) const
	{
	aRect= TRect(KMaxTInt,KMaxTInt, KMinTInt,KMinTInt);
	for(TInt i=0; i<PolyCount(); i++)			
		{
		TPoint point(PolyPoint(i));
		if(point.iX < aRect.iTl.iX)
			aRect.iTl.iX = point.iX;
		
		if(point.iX > aRect.iBr.iX)
			aRect.iBr.iX = point.iX+1;

		if(point.iY > aRect.iBr.iY)
				aRect.iBr.iY = point.iY+1;
			
		if(point.iY < aRect.iTl.iY)
				aRect.iTl.iY = point.iY;
		}
	}

void MPolygon::RotateAndOffset(TInt aAngle,TPoint aOffset, MPolygon& aDestination) const
	{
	aAngle = aAngle%360;
	TPoint origin(0,0);
	
	for(TInt i=0; i<PolyCount(); i++)
		{
		TPoint point = PolyPoint(i);
		TReal a = MathUtils::Sin(aAngle); 
		TReal b = MathUtils::Cos(aAngle);
		
		TReal newX = (point.iX * a + point.iY * b);
		TReal newY = (point.iY * a - point.iX * b);			
		aDestination.SetPolyPoint(i,TPoint(MathUtils::Round(newX)+aOffset.iX, MathUtils::Round(newY)+aOffset.iY));			
		}
	}


void MPolygon::Offset(TPoint aOffset,  MPolygon& aDestination) const
	{
	for(TInt i=0; i<PolyCount(); i++)
		{
		aDestination.SetPolyPoint(i, PolyPoint(i) + aOffset);
		}
	}

void MPolygon::RotateOffsetAndScale(TInt aAngle,TPoint aOffset,TReal iXScale, TReal iYScale,  MPolygon& aDestination) const
	{
	aAngle = aAngle%360;
	TPoint origin(0,0);

	for(TInt i=0; i<PolyCount(); i++)
		{
		TPoint point = PolyPoint(i);
		const TReal a = MathUtils::Sin(aAngle); 
		const TReal b = MathUtils::Cos(aAngle) ;
		
		TReal newX = (point.iX * a + point.iY * b) * iXScale;
		TReal newY = (point.iY * a - point.iX * b) * iYScale;			

		aDestination.SetPolyPoint(i,TPoint(MathUtils::Round(newX)+aOffset.iX, MathUtils::Round(newY)+aOffset.iY));			
		}
	}