private void PlaceTileMapping(int x, int y, int tileSetId, int tileId)
{
var tileCoordinate = new TileCoordinate(x, y, tileSetId, tileId);
if (CoordinateMap.Contains(tileCoordinate))
{
var index = CoordinateMap.IndexOf(tileCoordinate);
CoordinateMap[index] = tileCoordinate;
}
else
{
CoordinateMap.Add(tileCoordinate);
}
}
private bool PointIsVisible(Point origin, Point target)
{
Fraction slope;
bool slopeIsUndefined = false;
int deltaX = target.X - origin.X;
int deltaY = target.Y - origin.Y;
// Test for purely vertical slope
if (deltaX == 0)
{
slopeIsUndefined = true;
// This slope value will be ignored, but needs assigned so the program compiles
slope = new Fraction();
}
// Test for purely horizontal slope
else if (deltaY == 0)
{
// This slope value will be ignored, but needs assigned so the program compiles
slope = new Fraction();
}
// Any other slope
else
{
slope = new Fraction(deltaY, deltaX);
}
bool negativeDirection = false;
// Check UP-DOWN direction when deniminator is 0
if (slopeIsUndefined)
{
if (target.Y < origin.Y)
{
negativeDirection = true;
}
}
// Check LEFT-RIGHT direction when numerator is 0
if (slope.Numerator == 0 && target.X < origin.X)
{
negativeDirection = true;
}
//Console.WriteLine($"origin: {origin} | target: {target} | deltaX={deltaX} deltaY={deltaY} | slope: {slope.ToString()} neg: {negativeDirection}");
// Handling for straight vertical slope
if (slopeIsUndefined)
{
// Note: Negative Y direction visually goes UP on the input grid, since the top-left corner is (0,0)
if (negativeDirection)
{
for (int y = origin.Y - 1; y >= target.Y; y--)
{
Point currentPoint = new Point(origin.X, y);
if (CoordinateMap.Contains(currentPoint))
{
if (currentPoint.Equals(target))
{
return(true);
}
else
{
return(false);
}
}
}
throw new InvalidProgramException($"Failed to process with origin: {origin} | target: {target}");
}
// Note: Negative Y direction visually goes DOWN on the input grid, since the top-left corner is (0,0)
else
{
for (int y = origin.Y + 1; y <= target.Y; y++)
{
Point currentPoint = new Point(origin.X, y);
if (CoordinateMap.Contains(currentPoint))
{
if (currentPoint.Equals(target))
{
return(true);
}
else
{
return(false);
}
}
}
}
}
// Handling for straight horizontal slope
if (slope.Numerator == 0)
{
if (negativeDirection)
{
for (int x = origin.X - 1; x >= target.X; x--)
{
Point currentPoint = new Point(x, origin.Y);
if (CoordinateMap.Contains(currentPoint))
{
if (currentPoint.Equals(target))
{
return(true);
}
else
{
return(false);
}
}
}
}
else
{
for (int x = origin.X + 1; x <= target.X; x++)
{
Point currentPoint = new Point(x, origin.Y);
if (CoordinateMap.Contains(currentPoint))
{
if (currentPoint.Equals(target))
{
return(true);
}
else
{
return(false);
}
}
}
}
}
// Handling for all other slope values
bool endLoop = false;
long runningX = origin.X;
long runningY = origin.Y;
while (!endLoop)
{
runningX += slope.Denominator;
runningY += slope.Numerator;
Point currentPoint = new Point((int)runningX, (int)runningY);
if (CoordinateMap.Contains(currentPoint))
{
if (currentPoint.Equals(target))
{
endLoop = true;
return(true);
}
else
{
endLoop = true;
return(false);
}
}
}
throw new InvalidProgramException($"Failed to find visible point with origin: {origin} | target: {target}");
}