you had an error in calculation of n_b, and parallel worked but your demo patch didn’t display it properly.

i simplified code and patch a little, seems to work fine now.

Line Intersections_1.zip (7.5 kB)

you had an error in calculation of n_b, and parallel worked but your demo patch didn’t display it properly.

i simplified code and patch a little, seems to work fine now.

Line Intersections_1.zip (7.5 kB)

nice one… no text …

Sweet as a nut. Cheers Elias.

wow,

i was missing only one day and look at this ;)

Thanks Hadasi and Elias

Taking advance of the situation…

I´m cleaning up the Multiple circle intersection plugin and, it shows variables even when there isn´t any solution.

Anyone knows how to return false (nil) when there isn´t any intersection?

It seems that the behaviour is different than the multiple lines intersect.

Thanks

```
- region usings
using System;
using System.ComponentModel.Composition;
using VVVV.PluginInterfaces.V1;
using VVVV.PluginInterfaces.V2;
using VVVV.Utils.VColor;
using VVVV.Utils.VMath;
using VVVV.Core.Logging;
- endregion usings
namespace VVVV.Nodes
{
#region PluginInfo
[PluginInfo(Name = "IntersectCircles", Category = "2d", Help = "Basic template with one value in/out", Tags = "")](PluginInfo(Name = "IntersectCircles", Category = "2d", Help = "Basic template with one value in/out", Tags = ""))
#endregion PluginInfo
public class C2dIntersectCirclesNode : IPluginEvaluate
{
#region fields & pins
[Input("Centers")](Input("Centers"))
ISpread<Vector2D> FCenters;
[Input("Radius", DefaultValue = 1.0)](Input("Radius", DefaultValue = 1.0))
ISpread<double> FRadii;
[Output("Intersection")](Output("Intersection"))
ISpread<Vector2D> FIntersections;
[Output("Number of Solutions")](Output("Number of Solutions"))
ISpread<int> FSolutionCount;
// [Import()](Import())
// ILogger FLogger;
#endregion fields & pins
//called when data for any output pin is requested
public void Evaluate(int SpreadMax)
{
FIntersections.SliceCount = SpreadMax;
FSolutionCount.SliceCount = SpreadMax;
for(int i = 0; i < FSolutionCount.SliceCount; i++)
{
FIntersections.SliceCount = 0;
}
for (int i = 0; i < SpreadMax; i++)
{
for (int j = i + 1; j < SpreadMax; j++)
{
Vector2D s1;
Vector2D s2;
if ( CircleIntersection(FCenters[i](i), FRadii[i](i), FCenters[j](j), FRadii[j](j), out s1, out s2))
FIntersections.Add(s1);
FIntersections.Add(s2);
}
}
}
private bool CircleIntersection (Vector2D c1, double c1r, Vector2D c2, double c2r, out Vector2D p1, out Vector2D p2)
{
p1 = new Vector2D();
p2 = new Vector2D();
//Calculate distance between centres of circle
double d = !(c1 - c2);
double m = c1r + c2r;
double n = c1r - c2r;
if (n < 0)
n = n * -1;
//Solve for a
double a = ( c1r * c1r - c2r * c2r + d * d ) / (2 * d);
//Solve for h
double h = Math.Sqrt( c1r * c1r - a * a );
//Calculate point p, where the line through the circle intersection points crosses the line between the circle centers.
Vector2D p;
p.x = c1.x + ( a / d ) * ( c2.x -c1.x );
p.y = c1.y + ( a / d ) * ( c2.y -c1.y );
//No solns //Circle are contained within each other //Circles are the same
if ( d > m || d < n || d == 0 && c1r == c2r)
{
return false;
}
//1 soln , circles are touching
if ( d == c1r + c2r )
{
p1 = p;
{
return true;
}
}
//2solns
p1.x = p.x + ( h / d ) * ( c2.y - c1.y );
p1.y = p.y - ( h / d ) * ( c2.x - c1.x );
p2.x = p.x - ( h / d ) * ( c2.y - c1.y );
p2.y = p.y + ( h / d ) * ( c2.x - c1.x );
return true;
{
return false;
}
}
}
}
```