// NOTE THAT cDirection MUST BE NORMALIZED.
public static float FindIntersectionOnBitmap(FastBitmap cBitmap, PointF pntStartPoint, Vector cDirection)
{
float MAXIMAL_SEARCH_AREA = Math.Max(cBitmap.Width, cBitmap.Height);
int nSearchMultiplier = 0;
PointF pntCurrSearchPoint = pntStartPoint;
float dSearchAreaEnd = MAXIMAL_SEARCH_AREA;
PointF pntSearchAreaStart = pntStartPoint;
PointF pntSearchAreaEnd = Vector.GetEndPointFromStartPoint(pntStartPoint, cDirection.Multiply(dSearchAreaEnd));
float dApproximatedDistnace = MAXIMAL_SEARCH_AREA;
float dCurrentDistanceToBlackPoint;
while ((pntCurrSearchPoint.X >= 0) &&
(pntCurrSearchPoint.X < cBitmap.Width) &&
(pntCurrSearchPoint.Y >= 0) &&
(pntCurrSearchPoint.Y < cBitmap.Height))
{
Color clrColor = cBitmap.GetPixel((int)pntCurrSearchPoint.X, (int)pntCurrSearchPoint.Y);
if ((clrColor.R == 0) && (clrColor.G == 0) && (clrColor.B == 0))
{
dCurrentDistanceToBlackPoint = new Vector(pntStartPoint, pntCurrSearchPoint).Distance();
if (dCurrentDistanceToBlackPoint < dApproximatedDistnace)
{
dApproximatedDistnace = dCurrentDistanceToBlackPoint;
}
}
nSearchMultiplier += 10;
pntCurrSearchPoint = Vector.GetEndPointFromStartPoint(pntSearchAreaStart, cDirection.Multiply(nSearchMultiplier));
}
dCurrentDistanceToBlackPoint = new Vector(pntStartPoint, pntCurrSearchPoint).Distance();
if (dCurrentDistanceToBlackPoint < dApproximatedDistnace)
{
dApproximatedDistnace = dCurrentDistanceToBlackPoint;
}
return(dApproximatedDistnace);
}
public static float FindIntersectionOnBitmapOld(FastBitmap cBitmap, PointF pntStartPoint, Vector cDirection)
{
float MAXIMAL_SEARCH_AREA = Math.Max(cBitmap.Width, cBitmap.Height);
Point pntResult;
int nSearchMultiplier = 1;
PointF pntCurrSearchPoint = pntStartPoint;
float dSearchAreaStart = 0;
float dSearchAreaEnd = MAXIMAL_SEARCH_AREA;
PointF pntSearchAreaStart = pntStartPoint;
PointF pntSearchAreaEnd = Vector.GetEndPointFromStartPoint(pntStartPoint, cDirection.Multiply(dSearchAreaEnd));
float dApproximatedDistnace = MAXIMAL_SEARCH_AREA;
bool fSearchingBottomBlock = false;
while ((pntCurrSearchPoint.X >= 0) &&
(pntCurrSearchPoint.X < cBitmap.Width) &&
(pntCurrSearchPoint.Y >= 0) &&
(pntCurrSearchPoint.Y < cBitmap.Height) &&
(nSearchMultiplier < (dSearchAreaEnd - dSearchAreaStart)))
{
Color clrColor = cBitmap.GetPixel((int)pntCurrSearchPoint.X, (int)pntCurrSearchPoint.Y);
if ((clrColor.R == 0) && (clrColor.G == 0) && (clrColor.B == 0))
{
float dCurrentDistanceToBlackPoint = new Vector(pntStartPoint, pntCurrSearchPoint).Distance();
if (dCurrentDistanceToBlackPoint < dApproximatedDistnace)
{
dApproximatedDistnace = dCurrentDistanceToBlackPoint;
}
if ((dSearchAreaEnd - dSearchAreaStart) == 1)
{
return((new Vector(pntStartPoint, pntCurrSearchPoint)).Distance());
}
else
{
float dTotalSearchAreaDistnaceHalfed = (dSearchAreaEnd - dSearchAreaStart) / 2;
dSearchAreaStart = Math.Max(0, nSearchMultiplier - dTotalSearchAreaDistnaceHalfed);
dSearchAreaEnd = dSearchAreaStart + dTotalSearchAreaDistnaceHalfed;
pntSearchAreaStart = Vector.GetEndPointFromStartPoint(pntStartPoint, cDirection.Multiply(dSearchAreaStart));
nSearchMultiplier = 1;
fSearchingBottomBlock = true;
}
}
nSearchMultiplier *= 2;
pntCurrSearchPoint = Vector.GetEndPointFromStartPoint(pntSearchAreaStart, cDirection.Multiply(nSearchMultiplier));
if (!(((pntCurrSearchPoint.X >= 0) &&
(pntCurrSearchPoint.X < cBitmap.Width) &&
(pntCurrSearchPoint.Y >= 0) &&
(pntCurrSearchPoint.Y < cBitmap.Height) &&
(nSearchMultiplier < (dSearchAreaEnd - dSearchAreaStart)))))
{
if (fSearchingBottomBlock == true)
{
fSearchingBottomBlock = false;
float dTotalSearchArea = dSearchAreaEnd - dSearchAreaStart;
dSearchAreaStart += dTotalSearchArea;
dSearchAreaEnd += dTotalSearchArea;
pntSearchAreaStart = Vector.GetEndPointFromStartPoint(pntStartPoint, cDirection.Multiply(dSearchAreaStart));
nSearchMultiplier = 1;
}
}
}
return(dApproximatedDistnace);
}
public World(Bitmap cBackgroundImage)
{
m_cBackgroundImage = cBackgroundImage;
m_cBackgroundImageFast = new FastBitmap(m_cBackgroundImage);
}
