public bool Intersects(Rectangle rectangle)
{
Vector2 targetorigin = new Vector2(rectangle.X + rectangle.Width / 2, rectangle.Y + rectangle.Height / 2);
Vector2 size = new Vector2(rectangle.Width, rectangle.Height);
OBB2D o = new OBB2D(targetorigin, 0, size);
return(Intersects(o));
}
public bool Intersects(BoundingBox box)
{
Vector3 origin3 = box.Min + (box.Max - box.Min) / 2;
Vector2 targetorigin = new Vector2(origin3.X, origin3.Y);
Vector2 size = new Vector2(box.Max.X - box.Min.X, box.Max.Y - box.Min.Y);
OBB2D o = new OBB2D(targetorigin, 0, size);
return(Intersects(o));
}
public override void Start()
{
base.Start();
p1box = new OBB2D(Pos1, rot1, new Vector2(testImage.Width, testImage.Height));
p2box = new OBB2D(Pos2, rot2, new Vector2(testImage.Width, testImage.Height));
}
public bool Intersects(OBB2D targetBox)
{
float projectedSource, projectedTarget; // source and target projection radii onto selected axes
float[,] Rot = new float[2, 2]; // scalar values representing rotation onto local axes
float[,] AbsRot = new float[2, 2]; // absolute values of those scalars
// get the distance between the two box origins
Vector2 distanceOnLocalAxes = targetBox.origin - origin;
// then rotate it so that it's expressed in the local box axes
distanceOnLocalAxes = new Vector2(Vector2.Dot(distanceOnLocalAxes, LocalXAxis),
Vector2.Dot(distanceOnLocalAxes, LocalYAxis));
// calculate rotated proportions that will place boxes in correct frame of reference
Rot[0, 0] = Vector2.Dot(LocalXAxis, targetBox.LocalXAxis);
Rot[0, 1] = Vector2.Dot(LocalXAxis, targetBox.LocalYAxis);
Rot[1, 0] = Vector2.Dot(LocalYAxis, targetBox.LocalXAxis);
Rot[1, 1] = Vector2.Dot(LocalYAxis, targetBox.LocalYAxis);
// add a tiny bit on to correct for potential rounding errors
// in floating point calculations
AbsRot[0, 0] = Math.Abs(Rot[0, 0]) + 0.00001f;
AbsRot[0, 1] = Math.Abs(Rot[0, 1]) + 0.00001f;
AbsRot[1, 0] = Math.Abs(Rot[1, 0]) + 0.00001f;
AbsRot[1, 1] = Math.Abs(Rot[1, 1]) + 0.00001f;
// Check if the local X axis is a separating axis.
// First, get the size of one half of the source box on its own axis.
projectedSource = size.X / 2;
// Then, get the size of one half of the target box on that axis,
// using its own size and those rotated proportions we worked out earlier
projectedTarget = (targetBox.size.X / 2) * AbsRot[0, 0]
+ (targetBox.size.Y / 2) * AbsRot[0, 1];
// Then, if the size of the two projected half-lengths is less than the distance
// between the origins then we have found an axis that separates them so there
// is no intersection.
if (Math.Abs(distanceOnLocalAxes.X) > (projectedSource + projectedTarget))
{
return(false);
}
// Next, check the local Y axis for a separating axis
projectedSource = size.Y / 2;
projectedTarget = (targetBox.size.X / 2) * AbsRot[1, 0] +
(targetBox.size.Y / 2) * AbsRot[1, 1];
if (Math.Abs(distanceOnLocalAxes.Y) > (projectedSource + projectedTarget))
{
return(false);
}
// Now check the target's X axis
projectedSource = (size.X / 2) * AbsRot[0, 0] + (size.Y / 2) * AbsRot[1, 0];
projectedTarget = targetBox.size.X / 2;
if (Math.Abs(distanceOnLocalAxes.X * Rot[0, 0] + distanceOnLocalAxes.Y * Rot[1, 0]) > (projectedSource + projectedTarget))
{
return(false);
}
// Now check the target's Y axis
projectedSource = (size.X / 2) * AbsRot[0, 1] + (size.Y / 2) * AbsRot[1, 1];
projectedTarget = targetBox.size.Y / 2;
if (Math.Abs(distanceOnLocalAxes.X * Rot[0, 1] + distanceOnLocalAxes.Y * Rot[1, 1]) > (projectedSource + projectedTarget))
{
return(false);
}
// no separating axis found - therefore the two boxes intersect.
return(true);
}
