private PointF[] CalculateFaceTextureCoordinates(TmxTile tmxTile, bool flipDiagonal, bool flipHorizontal, bool flipVertical)
{
Point imageLocation = tmxTile.LocationOnSource;
Size tileSize = tmxTile.TileSize;
Size imageSize = tmxTile.TmxImage.Size;
PointF[] points = new PointF[4];
points[0] = imageLocation;
points[1] = PointF.Add(imageLocation, new Size(tileSize.Width, 0));
points[2] = PointF.Add(imageLocation, tileSize);
points[3] = PointF.Add(imageLocation, new Size(0, tileSize.Height));
PointF center = new PointF(tileSize.Width * 0.5f, tileSize.Height * 0.5f);
center.X += imageLocation.X;
center.Y += imageLocation.Y;
TmxMath.TransformPoints_DiagFirst(points, center, flipDiagonal, flipHorizontal, flipVertical);
//TmxMath.TransformPoints(points, center, flipDiagonal, flipHorizontal, flipVertical);
PointF[] coordinates = new PointF[4];
coordinates[3] = PointToTextureCoordinate(points[0], imageSize);
coordinates[2] = PointToTextureCoordinate(points[1], imageSize);
coordinates[1] = PointToTextureCoordinate(points[2], imageSize);
coordinates[0] = PointToTextureCoordinate(points[3], imageSize);
// Apply a small bias to the "inner" edges of the texels
// This keeps us from seeing seams
//const float bias = 1.0f / 8192.0f;
//const float bias = 1.0f / 4096.0f;
//const float bias = 1.0f / 2048.0f;
if (Program.TexelBias > 0)
{
float bias = 1.0f / Program.TexelBias;
PointF[] multiply = new PointF[4];
multiply[0] = new PointF(1, 1);
multiply[1] = new PointF(-1, 1);
multiply[2] = new PointF(-1, -1);
multiply[3] = new PointF(1, -1);
// This nudge has to be transformed too
TmxMath.TransformPoints_DiagFirst(multiply, Point.Empty, flipDiagonal, flipHorizontal, flipVertical);
coordinates[0] = TmxMath.AddPoints(coordinates[0], TmxMath.ScalePoints(multiply[0], bias));
coordinates[1] = TmxMath.AddPoints(coordinates[1], TmxMath.ScalePoints(multiply[1], bias));
coordinates[2] = TmxMath.AddPoints(coordinates[2], TmxMath.ScalePoints(multiply[2], bias));
coordinates[3] = TmxMath.AddPoints(coordinates[3], TmxMath.ScalePoints(multiply[3], bias));
}
return(coordinates);
}