/// <summary>
/// Checks for collision between two figures/shapes with the use of SAT (Seperating Axis Theorem), and returns the pushvector, which is zero if there is no collision.
/// </summary>
/// <param name="edgesFigure1"></param>
/// <param name="posFigure1"></param>
/// <param name="edgesFigure2"></param>
/// <param name="posFigure2"></param>
/// <returns></returns>
static public Vector2 CheckV2(Vector2[,] edgesFigure1, Vector2 posFigure1, Vector2[,] edgesFigure2, Vector2 posFigure2)
{
//Gets the axes for both figures.
Vector2[] axes1 = Normals(edgesFigure1);
Vector2[] axes2 = Normals(edgesFigure2);
//The push vectors
List <Vector2> axisNorms = new List <Vector2>();
// loop over the axes1
for (int i = 0; i < axes1.GetLength(0); i++)
{
Vector2 axis = axes1[i];
// project both shapes onto the axis
Projection p1 = FigureProjection(edgesFigure1, axis, posFigure1);
Projection p2 = FigureProjection(edgesFigure2, axis, posFigure2);
// do the projections overlap?
if (!p1.Overlapping(p2))
{
// then we can guarantee that the shapes do not overlap, so return a vector with 0 in length
return(Vector2.Zero);
}
else
{
double pushScalar = p1.OverlappingV2(p2);
Vector2 norm = Vector2.Normalize(axis);
axisNorms.Add((float)pushScalar * norm);
}
}
// loop over the axes2
for (int i = 0; i < axes2.GetLength(0); i++)
{
Vector2 axis = axes2[i];
// project both shapes onto the axis
Projection p1 = FigureProjection(edgesFigure1, axis, posFigure1);
Projection p2 = FigureProjection(edgesFigure2, axis, posFigure2);
// do the projections overlap?
if (!p1.Overlapping(p2))
{
// then we can guarantee that the shapes do not overlap, so return a vector with 0 in length
return(Vector2.Zero);
}
else
{
double pushScalar = p1.OverlappingV2(p2);
Vector2 norm = Vector2.Normalize(axis);
axisNorms.Add((float)pushScalar * norm);
}
}
// if we get here then we know that every axis had overlap on it
// so we can guarantee an intersection
//Finds the smallest push vector
Vector2 pushVector = new Vector2(1000000, 0);
for (int i = 0; i < axisNorms.Count; i++)
{
if (axisNorms[i].Length() < pushVector.Length())
{
pushVector = -axisNorms[i];
}
}
//Returns the push vector
return(pushVector);
}
/// <summary>
/// Returns a push scalar.
/// </summary>
/// <param name="other"></param>
/// <returns></returns>
public double OverlappingV2(Projection other)
{
return(this.Max - other.Min);
//return (this.Min < other.Min) ? (this.Max - other.Min) : (this.Min - other.Max);
}
