/// <summary>
/// Draws a line between two points using Bresenham's algorithm with a supplied color and thickness
/// </summary>
/// <param name="image"></param>
/// <param name="x1"></param>
/// <param name="y1"></param>
/// <param name="x2"></param>
/// <param name="y2"></param>
/// <param name="color"></param>
/// <param name="thickness"></param>
public static void SetImageBytes(Span <Rgba32> span, int x1, int y1, int x2, int y2, Rgba32 color, int thickness, int width, int height)
{
if (thickness == 1)
{
XiaolinWuAlgoriithm.DrawLine(span, x1, y1, x2, y2, color, width, height);
}
else
{
IList <Point> normalPoints = GetLineStartingPoints(x1, y1, x2, y2, thickness);
for (var i = 0; i < normalPoints.Count(); i++)
{
var point = normalPoints[i];
float targetX = x2 + (point.X - x1);
float targetY = y2 + (point.Y - y1);
//if these are the outer lines, use Xiaolin to anti-aliase them
if (i == 0 || i == normalPoints.Count() - 1)
{
//XiaolinWuAlgoriithm.DrawLine(span, point.X, point.Y, targetX, targetY, color, width, height);
}
BresenhamLineAlgorithm.DrawLine(span, point.X, point.Y, targetX, targetY, color, width, height);
}
}
}
/// <summary>
/// Obtains the points of the normals of a line, up to a certain distance from the original line (and starting on x1,y1)
/// </summary>
/// <param name="x1"></param>
/// <param name="y1"></param>
/// <param name="x2"></param>
/// <param name="y2"></param>
/// <param name="thickness"></param>
/// <returns></returns>
public static IList <Point> GetLineStartingPoints(int x1, int y1, int x2, int y2, int thickness)
{
Vector2 unitVector = Vector2.Normalize(new Vector2(x2 - x1, y2 - y1));
Vector2 normalVectorRight = new Vector2(-unitVector.Y, unitVector.X);
Vector2 normalVectorLeft = new Vector2(unitVector.Y, -unitVector.X);
float normalSize = (thickness - 1) / 2f;
var normalPoints = new List <Point>();
//Obtain the points of the normals
Point startingPoint = BresenhamLineAlgorithm.GetNonDiagonalPointsOfLine(x1, y1, normalVectorRight, normalSize).Last();
normalPoints.Add(startingPoint);
foreach (Point point in BresenhamLineAlgorithm.GetNonDiagonalPointsOfLine(startingPoint.X, startingPoint.Y, normalVectorLeft, thickness - 1))
{
normalPoints.Add(point);
}
return(normalPoints);
}
