From: jpbruyere <jp.bruyere@hotmail.com>
Date: Tue, 16 Aug 2016 02:27:25 +0000 (+0200)
Subject: 	arrows
X-Git-Tag: v0.9.5-beta~259^2~37
X-Git-Url: https://git.osiis.dedyn.io/?a=commitdiff_plain;h=12c134e150cb580ab6353638c1d45fec5444a8c2;p=jp%2Fcrow.git

	arrows
---

diff --git a/src/ExtensionsMethods.cs b/src/ExtensionsMethods.cs
index d1b951b9..2bfc36ea 100644
--- a/src/ExtensionsMethods.cs
+++ b/src/ExtensionsMethods.cs
@@ -26,6 +26,7 @@ namespace Crow
 	public static class ExtensionsMethods
 	{
 		#region Cairo extensions
+
 		public static void Rectangle(this Cairo.Context ctx, Rectangle r, double stroke = 0.0)
 		{
 			if (stroke > 0.0) {
@@ -36,6 +37,59 @@ namespace Crow
 			}else
 				ctx.Rectangle (r.X, r.Y, r.Width, r.Height);
 		}
+		public static double GetLength(this Cairo.PointD p){
+			return Math.Sqrt (Math.Pow (p.X, 2) + Math.Pow (p.Y, 2));
+		}
+		public static Cairo.PointD GetPerp(this Cairo.PointD p){
+			return new Cairo.PointD(-p.Y, p.X);
+		}
+		public static Cairo.PointD GetNormalized(this Cairo.PointD p){
+			double length = p.GetLength();
+			p.X /= length;
+			p.Y /= length;
+			return p;
+		}
+		public static Cairo.PointD Substract(this Cairo.PointD p1, Cairo.PointD p2){
+			return new Cairo.PointD(p1.X - p2.X, p1.Y - p2.Y);
+		}
+		public static Cairo.PointD Add(this Cairo.PointD p1, Cairo.PointD p2){
+			return new Cairo.PointD(p1.X + p2.X, p1.Y + p2.Y);
+		}
+		public static Cairo.PointD Multiply(this Cairo.PointD p1, double v){
+			return new Cairo.PointD(p1.X * v, p1.Y * v);
+		}
+		public static void DrawCote(this Cairo.Context ctx, Cairo.PointD p1, Cairo.PointD p2, double stroke = 1.0)
+		{
+			const double arrowWidth = 4.0;
+			const double arrowLength = 10.0;
+
+			Cairo.PointD vDir = p2.Substract(p1);
+			vDir = vDir.GetNormalized ();
+			Cairo.PointD vPerp = vDir.GetPerp ();
+
+			Cairo.PointD pA0 = p1.Add(vDir.Multiply(arrowLength));
+			Cairo.PointD pA1 = p2.Substract(vDir.Multiply(arrowLength));
+
+			Cairo.PointD vA = vPerp.Multiply (arrowWidth);
+
+			ctx.MoveTo (p1);
+			ctx.LineTo (pA0.Add (vA));
+			ctx.LineTo (pA0.Substract (vA));
+			ctx.LineTo (p1);
+
+			ctx.MoveTo (p2);
+			ctx.LineTo (pA1.Add (vA));
+			ctx.LineTo (pA1.Substract (vA));
+			ctx.LineTo (p2);
+
+			ctx.Fill ();
+
+			ctx.MoveTo (p1);
+			ctx.LineTo (p2);
+			ctx.LineWidth = stroke;
+			ctx.Stroke ();
+
+		}
 		public static void SetSourceColor(this Cairo.Context ctx, Color c)
 		{
 			ctx.SetSourceRGBA(c.R,c.G,c.B,c.A);
@@ -45,6 +99,7 @@ namespace Crow
 			grad.AddColorStop (offset, new Cairo.Color (c.R, c.G, c.B, c.A));
 		}
 		#endregion
+
 		public static void Raise(this EventHandler handler, object sender, EventArgs e)
 		{
 			if(handler != null)
diff --git a/src/Point.cs b/src/Point.cs
index ba0103e3..2e196133 100644
--- a/src/Point.cs
+++ b/src/Point.cs
@@ -29,6 +29,9 @@ namespace Crow
 		public int Length {
 			get { return (int)Math.Sqrt (Math.Pow (_x, 2) + Math.Pow (_y, 2)); }
 		}
+		public double LengthD {
+			get { return Math.Sqrt (Math.Pow (_x, 2) + Math.Pow (_y, 2)); }
+		}
         public static implicit operator Cairo.Point(Point p)
         {
             return new Cairo.Point(p.X, p.Y);