etqw-sdk/source/idlib/math/Plane.cpp
2008-05-29 00:00:00 +00:00

133 lines
2.8 KiB
C++

// Copyright (C) 2007 Id Software, Inc.
//
#include "../precompiled.h"
#pragma hdrstop
idPlane plane_origin( 0.0f, 0.0f, 0.0f, 0.0f );
/*
================
idPlane::Type
================
*/
int idPlane::Type( void ) const {
if ( Normal()[0] == 0.0f ) {
if ( Normal()[1] == 0.0f ) {
return Normal()[2] > 0.0f ? PLANETYPE_Z : PLANETYPE_NEGZ;
}
else if ( Normal()[2] == 0.0f ) {
return Normal()[1] > 0.0f ? PLANETYPE_Y : PLANETYPE_NEGY;
}
else {
return PLANETYPE_ZEROX;
}
}
else if ( Normal()[1] == 0.0f ) {
if ( Normal()[2] == 0.0f ) {
return Normal()[0] > 0.0f ? PLANETYPE_X : PLANETYPE_NEGX;
}
else {
return PLANETYPE_ZEROY;
}
}
else if ( Normal()[2] == 0.0f ) {
return PLANETYPE_ZEROZ;
}
else {
return PLANETYPE_NONAXIAL;
}
}
/*
================
idPlane::HeightFit
================
*/
bool idPlane::HeightFit( const idVec3 *points, const int numPoints ) {
int i;
float sumXX = 0.0f, sumXY = 0.0f, sumXZ = 0.0f;
float sumYY = 0.0f, sumYZ = 0.0f;
idVec3 sum, average, dir;
if ( numPoints == 1 ) {
a = 0.0f;
b = 0.0f;
c = 1.0f;
d = -points[0].z;
return true;
}
if ( numPoints == 2 ) {
dir = points[1] - points[0];
Normal() = dir.Cross( idVec3( 0, 0, 1 ) ).Cross( dir );
Normalize();
d = -( Normal() * points[0] );
return true;
}
sum.Zero();
for ( i = 0; i < numPoints; i++) {
sum += points[i];
}
average = sum / numPoints;
for ( i = 0; i < numPoints; i++ ) {
dir = points[i] - average;
sumXX += dir.x * dir.x;
sumXY += dir.x * dir.y;
sumXZ += dir.x * dir.z;
sumYY += dir.y * dir.y;
sumYZ += dir.y * dir.z;
}
idMat2 m( sumXX, sumXY, sumXY, sumYY );
if ( !m.InverseSelf() ) {
a = 0.0f;
b = 0.0f;
c = 1.0f;
d = -points[0].z;
return false;
}
a = - sumXZ * m[0][0] - sumYZ * m[0][1];
b = - sumXZ * m[1][0] - sumYZ * m[1][1];
c = 1.0f;
Normalize();
d = -( a * average.x + b * average.y + c * average.z );
return true;
}
/*
================
idPlane::PlaneIntersection
================
*/
bool idPlane::PlaneIntersection( const idPlane &plane, idVec3 &start, idVec3 &dir ) const {
double n00, n01, n11, det, invDet, f0, f1;
n00 = Normal().LengthSqr();
n01 = Normal() * plane.Normal();
n11 = plane.Normal().LengthSqr();
det = n00 * n11 - n01 * n01;
if ( idMath::Fabs(det) < 1e-6f ) {
return false;
}
invDet = 1.0f / det;
f0 = ( n01 * plane.d - n11 * d ) * invDet;
f1 = ( n01 * d - n00 * plane.d ) * invDet;
dir = Normal().Cross( plane.Normal() );
start = f0 * Normal() + f1 * plane.Normal();
return true;
}
/*
=============
idPlane::ToString
=============
*/
const char *idPlane::ToString( int precision ) const {
return idStr::FloatArrayToString( ToFloatPtr(), GetDimension(), precision );
}