private void CurveTo(bool isRelative)
{
var point1 = NewPoint(NextValue, NextValue, isRelative, false);
float x = NextValue;
float y = NextValue;
bool isQuad = char.IsLetter(_commandStack.Peek()[0]);
var point2 = NewPoint(x, y, isRelative, isQuad);
if (isQuad)
{
_path.QuadTo(point1, point2);
_lastCurveControlPoint = point1;
}
else
{
var point3 = NewPoint(NextValue, NextValue, isRelative, true);
_path.CurveTo(point1, point2, point3);
_lastCurveControlPoint = point2;
//Logger.Debug($"CurveTo({point1.X},{point1.Y},{point2.X},{point2.Y},{point3.X},{point3.Y})");
}
}
/**
* Draws an arc of type "open" only. Accepts an optional x axis rotation value
**/
public static void DrawArc(float x, float y, float startAngle, float arc, float radius, float yRadius, float xAxisRotation, PathF aPath)
{
// Circumvent drawing more than is needed
if (Math.Abs(arc) > 360)
{
arc = 360;
}
// Draw in a maximum of 45 degree segments. First we calculate how many
// segments are needed for our arc.
float segs = (float)Math.Ceiling(Math.Abs(arc) / 45);
// Now calculate the sweep of each segment
float segAngle = arc / segs;
float theta = Geometry.DegreesToRadians(segAngle);
float angle = Geometry.DegreesToRadians(startAngle);
// Draw as 45 degree segments
if (segs > 0)
{
float beta = Geometry.DegreesToRadians(xAxisRotation);
float sinbeta = (float)Math.Sin(beta);
float cosbeta = (float)Math.Cos(beta);
// Loop for drawing arc segments
for (int i = 0; i < segs; i++)
{
angle += theta;
float sinangle = (float)Math.Sin(angle - theta / 2);
float cosangle = (float)Math.Cos(angle - theta / 2);
float div = (float)Math.Cos(theta / 2);
float cx = x + (radius * cosangle * cosbeta - yRadius * sinangle * sinbeta) / div;
//Why divide by Math.cos(theta/2)? - FIX THIS
float cy = y + (radius * cosangle * sinbeta + yRadius * sinangle * cosbeta) / div;
//Why divide by Math.cos(theta/2)? - FIX THIS
sinangle = (float)Math.Sin(angle);
cosangle = (float)Math.Cos(angle);
float x1 = x + (radius * cosangle * cosbeta - yRadius * sinangle * sinbeta);
float y1 = y + (radius * cosangle * sinbeta + yRadius * sinangle * cosbeta);
aPath.QuadTo(cx, cy, x1, y1);
}
}
}