50e5e9acd9
-Auras now take additional parameters from XML, containing a tag for r, g, b, and a. No line thickness parameter yet. -For territories, added function to frustum for determining if line segment passes through the frustum. This was SVN commit r4242.
141 lines
2.9 KiB
C++
141 lines
2.9 KiB
C++
//***********************************************************
|
|
//
|
|
// Name: Plane.Cpp
|
|
// Last Update: 17/2/02
|
|
// Author: Poya Manouchehri
|
|
//
|
|
// Description: A Plane in R3 and several utility methods.
|
|
// Note that the format used for the plane
|
|
// equation is Ax + By + Cz + D = 0, where
|
|
// <A,B,C> is the normal vector.
|
|
//
|
|
//***********************************************************
|
|
|
|
#include "precompiled.h"
|
|
|
|
#include "Plane.h"
|
|
|
|
CPlane::CPlane ()
|
|
{
|
|
m_Norm.Clear ();
|
|
m_Dist = 0.0f;
|
|
}
|
|
|
|
//sets the plane equation from 3 points on that plane
|
|
void CPlane::Set (const CVector3D &p1, const CVector3D &p2, const CVector3D &p3)
|
|
{
|
|
CVector3D D1, D2;
|
|
CVector3D Norm;
|
|
|
|
//calculate two vectors on the surface of the plane
|
|
D1 = p2-p1;
|
|
D2 = p3-p1;
|
|
|
|
//cross multiply gives normal
|
|
Norm = D2.Cross(D1);
|
|
|
|
Set (Norm, p1);
|
|
}
|
|
|
|
//sets the plane equation from a normal and a point on
|
|
//that plane
|
|
void CPlane::Set (const CVector3D &norm, const CVector3D &point)
|
|
{
|
|
m_Norm = norm;
|
|
|
|
m_Dist = - (norm.X * point.X +
|
|
norm.Y * point.Y +
|
|
norm.Z * point.Z);
|
|
|
|
// Normalize ();
|
|
}
|
|
|
|
//normalizes the plane equation
|
|
void CPlane::Normalize ()
|
|
{
|
|
float Scale;
|
|
|
|
Scale = 1.0f/m_Norm.GetLength ();
|
|
|
|
m_Norm.X *= Scale;
|
|
m_Norm.Y *= Scale;
|
|
m_Norm.Z *= Scale;
|
|
m_Dist *= Scale;
|
|
}
|
|
|
|
//returns the side of the plane on which this point
|
|
//lies.
|
|
PLANESIDE CPlane::ClassifyPoint (const CVector3D &point) const
|
|
{
|
|
float Dist;
|
|
|
|
Dist = m_Norm.X * point.X +
|
|
m_Norm.Y * point.Y +
|
|
m_Norm.Z * point.Z +
|
|
m_Dist;
|
|
|
|
if (Dist > 0.0f)
|
|
return PS_FRONT;
|
|
else if (Dist < 0.0f)
|
|
return PS_BACK;
|
|
|
|
return PS_ON;
|
|
}
|
|
|
|
//solves the plane equation for a particular point
|
|
float CPlane::DistanceToPlane (const CVector3D &point) const
|
|
{
|
|
float Dist;
|
|
|
|
Dist = m_Norm.X * point.X +
|
|
m_Norm.Y * point.Y +
|
|
m_Norm.Z * point.Z +
|
|
m_Dist;
|
|
|
|
return Dist;
|
|
}
|
|
|
|
//calculates the intersection point of a line with this
|
|
//plane. Returns false if there is no intersection
|
|
bool CPlane::FindLineSegIntersection (const CVector3D &start, const CVector3D &end, CVector3D *intsect)
|
|
{
|
|
PLANESIDE StartS, EndS;
|
|
CVector3D Dir;
|
|
float Length;
|
|
|
|
//work out where each point is
|
|
StartS = ClassifyPoint (start);
|
|
EndS = ClassifyPoint (end);
|
|
|
|
//if they are not on opposite sides of the plane return false
|
|
if (StartS == EndS)
|
|
return false;
|
|
|
|
//work out a normalized vector in the direction start to end
|
|
Dir = end - start;
|
|
Dir.Normalize ();
|
|
|
|
//a bit of algebra to work out how much we need to scale
|
|
//this direction vector to get to the plane
|
|
Length = -m_Norm.Dot(start)/m_Norm.Dot(Dir);
|
|
|
|
//scale it by this amount
|
|
Dir *= Length;
|
|
|
|
//workout actual position vector of impact
|
|
*intsect = start + Dir;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool CPlane::FindRayIntersection (CVector3D &start, CVector3D &direction, CVector3D *intsect)
|
|
{
|
|
float dot = m_Norm.Dot (direction);
|
|
if (dot == 0.0f)
|
|
return false;
|
|
|
|
//CVector3D a; // EDIT: John M. Mena - Not sure why this is here
|
|
*intsect = start - (direction * (DistanceToPlane (start)/dot));
|
|
return true;
|
|
}
|