/// <summary>
/// From Real-time Collision Detection, p179.
/// </summary>
/// <param name="output"></param>
/// <param name="input"></param>
/// <param name="argPool"></param>
public bool Raycast(RayCastOutput output, RayCastInput input, IWorldPool argPool)
{
//UPGRADE_TODO: The equivalent in .NET for field 'java.lang.Float.MIN_VALUE' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'"
float tmin = Single.Epsilon;
float tmax = Single.MaxValue;
Vec2 p = argPool.PopVec2();
Vec2 d = argPool.PopVec2();
Vec2 absD = argPool.PopVec2();
Vec2 normal = argPool.PopVec2();
p.Set(input.P1);
d.Set(input.P2).SubLocal(input.P1);
Vec2.AbsToOut(d, absD);
// x then y
if (absD.X < Settings.EPSILON)
{
// Parallel.
if (p.X < LowerBound.X || UpperBound.X < p.X)
{
argPool.PushVec2(4);
return(false);
}
}
else
{
float inv_d = 1.0f / d.X;
float t1 = (LowerBound.X - p.X) * inv_d;
float t2 = (UpperBound.X - p.X) * inv_d;
// Sign of the normal vector.
float s = -1.0f;
if (t1 > t2)
{
float temp = t1;
t1 = t2;
t2 = temp;
s = 1.0f;
}
// Push the min up
if (t1 > tmin)
{
normal.SetZero();
normal.X = s;
tmin = t1;
}
// Pull the max down
tmax = MathUtils.Min(tmax, t2);
if (tmin > tmax)
{
argPool.PushVec2(4);
return(false);
}
}
if (absD.Y < Settings.EPSILON)
{
// Parallel.
if (p.Y < LowerBound.Y || UpperBound.Y < p.Y)
{
argPool.PushVec2(4);
return(false);
}
}
else
{
float inv_d = 1.0f / d.Y;
float t1 = (LowerBound.Y - p.Y) * inv_d;
float t2 = (UpperBound.Y - p.Y) * inv_d;
// Sign of the normal vector.
float s = -1.0f;
if (t1 > t2)
{
float temp = t1;
t1 = t2;
t2 = temp;
s = 1.0f;
}
// Push the min up
if (t1 > tmin)
{
normal.SetZero();
normal.Y = s;
tmin = t1;
}
// Pull the max down
tmax = MathUtils.Min(tmax, t2);
if (tmin > tmax)
{
argPool.PushVec2(4);
return(false);
}
}
// Does the ray start inside the box?
// Does the ray intersect beyond the max fraction?
if (tmin < 0.0f || input.MaxFraction < tmin)
{
argPool.PushVec2(4);
return(false);
}
// Intersection.
output.Fraction = tmin;
output.Normal.X = normal.X;
output.Normal.Y = normal.Y;
argPool.PushVec2(4);
return(true);
}
