/*
* /// <summary>
* /// Performs a terrain passability check betwee two points by doing pixel validity checks at interval delta.
* /// </summary>
* public List<Creature> RayTracerPassabilityCheckRough(Creature client, Vector v1, Vector v2, double delta)
* {
* Vector difference = v2 - v1;
* Vector deltaV = difference;
* deltaV.ScaleToLength(delta);
*
* Vector currentPosition = v1;
*
* for (int i = 0; i < difference.Length() / deltaV.Length(); ++i)
* {
* Coords pixel = new Coords(CoordsType.Pixel, currentPosition);
* List<Creature> collision = _myCollider.CreatureClippingCheck(client, pixel, false);
* if (collision == null || collision.Count > 0)
* {
* return collision;
* }
* currentPosition += deltaV;
* }
*
* return new List<Creature>();
* }
*/
/*
* /// <summary>
* /// Returns the Bresenham line between p0 and p1; Borrowed the code
* /// from some dude whose name I don't have, who in turn borrowed from Wikipedia.
* /// </summary>
* private List<Coords> BresenhamLine(Coords p0, Coords p1)
* {
* List<Coords> returnList = new List<Coords>();
*
* Boolean steep = Math.Abs(p1.Y - p0.Y) > Math.Abs(p1.X - p0.X);
*
* if (steep == true)
* {
* Coords tmpPoint = new Coords(CoordsType.Tile, p0.X, p0.Y);
* p0 = new Coords(CoordsType.Tile, tmpPoint.Y, tmpPoint.X);
*
* tmpPoint = p1;
* p1 = new Coords(CoordsType.Tile, tmpPoint.Y, tmpPoint.X);
* }
*
* Int32 deltaX = Math.Abs(p1.X - p0.X);
* Int32 deltaY = Math.Abs(p1.Y - p0.Y);
* Int32 error = 0;
* Int32 deltaError = deltaY;
* Int32 yStep = 0;
* Int32 xStep = 0;
* Int32 y = p0.Y;
* Int32 x = p0.X;
*
* if (p0.Y < p1.Y)
* {
* yStep = 1;
* }
* else
* {
* yStep = -1;
* }
*
* if (p0.X < p1.X)
* {
* xStep = 1;
* }
* else
* {
* xStep = -1;
* }
*
* Int32 tmpX = 0;
* Int32 tmpY = 0;
*
* while (x != p1.X)
* {
*
* x += xStep;
* error += deltaError;
*
* //if the error exceeds the X delta then
* //move one along on the Y axis
* if ((2 * error) > deltaX)
* {
* y += yStep;
* error -= deltaX;
* }
*
* //flip the coords if they're steep
* if (steep)
* {
* tmpX = y;
* tmpY = x;
* }
* else
* {
* tmpX = x;
* tmpY = y;
* }
*
* //check the point generated is legal
* //and if it is add it to the list
* if (_myCollider.CheckInBounds(new Coords(CoordsType.Tile, tmpX, tmpY)) == true)
* {
* returnList.Add(new Coords(CoordsType.Tile, tmpX, tmpY));
* }
* else
* { //a bad point has been found, so return the list thus far
* return returnList;
* }
*
* }
*
* return returnList;
* }
*/
/// <summary>
/// Checks if the Bresenham line between p0 and p1 goes only through visible tiles
/// !!! Code repetition, should redo.
/// </summary>
public bool BresenhamLineCheckVisible(Coords p0, Coords p1)
{
if (p0.Equals(p1))
{
return(true);
}
Boolean steep = Math.Abs(p1.Y - p0.Y) > Math.Abs(p1.X - p0.X);
// fix this stupidity
Coords p0original = new Coords(CoordsType.Tile, p0.X, p0.Y);
Coords p1original = new Coords(CoordsType.Tile, p1.X, p1.Y);
if (steep == true)
{
Coords tmpPoint = new Coords(CoordsType.Tile, p0.X, p0.Y);
p0 = new Coords(CoordsType.Tile, tmpPoint.Y, tmpPoint.X);
tmpPoint = p1;
p1 = new Coords(CoordsType.Tile, tmpPoint.Y, tmpPoint.X);
}
Int32 deltaX = Math.Abs(p1.X - p0.X);
Int32 deltaY = Math.Abs(p1.Y - p0.Y);
Int32 error = 0;
Int32 deltaError = deltaY;
Int32 yStep = 0;
Int32 xStep = 0;
Int32 y = p0.Y;
Int32 x = p0.X;
if (p0.Y < p1.Y)
{
yStep = 1;
}
else
{
yStep = -1;
}
if (p0.X < p1.X)
{
xStep = 1;
}
else
{
xStep = -1;
}
Int32 tmpX = 0;
Int32 tmpY = 0;
float visibilityTotal = 1f;
while (x != p1.X)
{
x += xStep;
error += deltaError;
//if the error exceeds the X delta then
//move one along on the Y axis
if ((2 * error) > deltaX)
{
y += yStep;
error -= deltaX;
}
//flip the coords if they're steep
if (steep)
{
tmpX = y;
tmpY = x;
}
else
{
tmpX = x;
tmpY = y;
}
// check the point generated is legal
// using passability check. creatures will leave shadows. should write a visibility
// check later
Coords currentCoords = new Coords(CoordsType.Tile, tmpX, tmpY);
// for this to look good you must make sure it takes account of the eucledean distances over which the coeffcients hold
// otherwise you get square FOVs.
visibilityTotal *= this._visibilityMap[currentCoords.X, currentCoords.Y];
if (
(visibilityTotal < Constants.VisibilityTreshold)
&
(!(currentCoords.Equals(p0original) | currentCoords.Equals(p1original)))
)
{
return(false);
}
}
return(true);
}
