public RectangleF (PointF origin, SizeF size)
{
X = origin.X;
Y = origin.Y;
Width = size.Width;
Height = size.Height;
}
public IntersectionInfo (PointF loc)
{
Location = loc;
}
public static PointF Subtract (this PointF a, PointF b)
{
return new PointF (a.X - b.X, a.Y - b.Y);
}
public static PointF Add (this PointF a, PointF b)
{
return new PointF (a.X + b.X, a.Y + b.Y);
}
public float DistanceTo (PointF p3)
{
var x21 = EndX - X;
var y21 = EndY - Y;
var x31 = p3.X - X;
var y31 = p3.Y - Y;
var d = x21*x21 + y21*y21;
if (d <= 0) return (float)Math.Sqrt (x31*x31 + y31*y31);
var n = x31*x21 + y31*y21;
var u = n / d;
if (u <= 0) {
return (float)Math.Sqrt (x31*x31 + y31*y31);
}
else if (u >= 1) {
var x32 = p3.X - EndX;
var y32 = p3.Y - EndY;
return (float)Math.Sqrt (x32*x32 + y32*y32);
}
else {
var dx = X + u*x21 - p3.X;
var dy = Y + u*y21 - p3.Y;
return (float)Math.Sqrt (dx*dx + dy*dy);
}
}
public void AddPoint(PointF rawPoint)
{
_points.Add(rawPoint);
_apoints = null;
_bbvalid = false;
}
public static float Dot (this PointF a, PointF b)
{
return a.X * b.X + a.Y * b.Y;
}
public void AddPoint (PointF rawPoint)
{
_points.Add (rawPoint);
_apoints = null;
_bbvalid = false;
}
public static void DrawLine(this IGraphics g, PointF s, PointF e, float w)
{
g.DrawLine (s.X, s.Y, e.X, e.Y, w);
}
public static float DistanceTo (this PointF a, PointF b)
{
var dx = a.X - b.X;
var dy = a.Y - b.Y;
return (float)Math.Sqrt (dx*dx + dy*dy);
}
public static void DrawString(this IGraphics g, string s, PointF p, Font f)
{
g.SetFont (f);
g.DrawString (s, p.X, p.Y);
}
public static void DrawString (this IGraphics g, string s, PointF p)
{
g.DrawString(s, p.X, p.Y);
}
public static void AddPoint(this Polygon poly, PointF p)
{
poly.AddPoint (p.X, p.Y);
}
public IntersectionInfo GetIntersectionWith (Stroke other)
{
for (var i = 0; i < _points.Count - 1; i++) {
var x1 = _points [i].X;
var y1 = _points [i].Y;
var x21 = _points [i + 1].X - x1;
var y21 = _points [i + 1].Y - y1;
for (var j = 0; j < other._points.Count - 1; j++) {
var x3 = other._points [j].X;
var y3 = other._points [j].Y;
var x43 = other._points [j + 1].X - x3;
var y43 = other._points [j + 1].Y - y3;
var x13 = x1 - x3;
var y13 = y1 - y3;
var d = y43*x21 - x43*y21;
if (d == 0.0f) continue;
var na = x43*y13 - y43*x13;
var ua = na / d;
if (ua < 0 || ua > 1) continue;
var nb = x21*y13 - y21*x13;
var ub = nb / d;
if (ub >= 0 && ub <= 1) {
var loc = new PointF (x1 + ua * x21, y1 + ua * y21);
return new IntersectionInfo (loc);
}
}
}
return null;
}
public static PointF Lerp (this PointF s, PointF d, float t)
{
var dx = d.X - s.X;
var dy = d.Y - s.Y;
return new PointF (s.X + t * dx, s.Y + t * dy);
}
int RemoveInitialFlourish ()
{
var stroke = this;
var points = stroke.Points;
var totalLength = 0.0f;
for (var i = 0; i < points.Length - 1; i++) {
totalLength += points [i].DistanceTo (points [i+1]);
}
//
// Look for a sharp bend within the first bit of the shape
//
var len = 0.0f;
var lastDir = new PointF ();
for (var i = 0; i < points.Length - 1; i++) {
var dir = points [i+1].Subtract (points [i]).Normalized ();
if (i > 0) {
var dot = lastDir.Dot (dir);
if (dot < 0) {
//
// Big turn
//
//stroke.WriteSvg ("/Users/fak/Desktop/turn.svg");
return i;
}
}
lastDir = dir;
//
// Only look at the first 5%
//
len += points [i].DistanceTo (points [i+1]);
if (len > totalLength * 0.05f) {
return 0;
}
}
return 0;
}
public static float DistanceToLine (this PointF p3, PointF p1, PointF p2)
{
return new LineSegmentF (p1, p2).DistanceTo (p3);
}
public int GetClosestPoint (PointF p/*, out float dist*/)
{
var minIndex = -1;
var minDist = 0.0f;
for (var i = StartIndex; i <= EndIndex; i++) {
var d = _points [i].DistanceTo (p);
if (minIndex == -1 || (d < minDist)) {
minIndex = i;
minDist = d;
}
}
//dist = minDist;
return minIndex;
}
public LineSegmentF (PointF begin, PointF end)
{
X = begin.X;
Y = begin.Y;
EndX = end.X;
EndY = end.Y;
}
public bool Contains(PointF loc)
{
return (X <= loc.X && loc.X < (X + Width) && Y <= loc.Y && loc.Y < (Y + Height));
}
public IntersectionInfo(PointF loc)
{
Location = loc;
}