math_matrix.cpp

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/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
#include "q_shared.h"

mat3_t mat3_default( idVec3_t( 1, 0, 0 ), idVec3_t( 0, 1, 0 ), idVec3_t( 0, 0, 1 ) );

void toMatrix( quat_t const &src, mat3_t &dst ) {
    float   wx, wy, wz;
    float   xx, yy, yz;
    float   xy, xz, zz;
    float   x2, y2, z2;

    x2 = src.x + src.x;
    y2 = src.y + src.y;
    z2 = src.z + src.z;

    xx = src.x * x2;
    xy = src.x * y2;
    xz = src.x * z2;

    yy = src.y * y2;
    yz = src.y * z2;
    zz = src.z * z2;

    wx = src.w * x2;
    wy = src.w * y2;
    wz = src.w * z2;

    dst[ 0 ][ 0 ] = 1.0f - ( yy + zz );
    dst[ 0 ][ 1 ] = xy - wz;
    dst[ 0 ][ 2 ] = xz + wy;

    dst[ 1 ][ 0 ] = xy + wz;
    dst[ 1 ][ 1 ] = 1.0f - ( xx + zz );
    dst[ 1 ][ 2 ] = yz - wx;

    dst[ 2 ][ 0 ] = xz - wy;
    dst[ 2 ][ 1 ] = yz + wx;
    dst[ 2 ][ 2 ] = 1.0f - ( xx + yy );
}

void toMatrix( angles_t const &src, mat3_t &dst ) {
    float           angle;
    static float    sr, sp, sy, cr, cp, cy; // static to help MS compiler fp bugs
        
    angle = src.yaw * ( M_PI * 2.0f / 360.0f );
    sy = sin( angle );
    cy = cos( angle );

    angle = src.pitch * ( M_PI * 2.0f / 360.0f );
    sp = sin( angle );
    cp = cos( angle );

    angle = src.roll * ( M_PI * 2.0f / 360.0f );
    sr = sin( angle );
    cr = cos( angle );

    dst[ 0 ].set( cp * cy, cp * sy, -sp );
    dst[ 1 ].set( sr * sp * cy + cr * -sy, sr * sp * sy + cr * cy, sr * cp );
    dst[ 2 ].set( cr * sp * cy + -sr * -sy, cr * sp * sy + -sr * cy, cr * cp );
}

void toMatrix( idVec3_t const &src, mat3_t &dst ) {
        angles_t sup = src;
        toMatrix(sup, dst);
}

void mat3_t::ProjectVector( const idVec3_t &src, idVec3_t &dst ) const {
    dst.x = src * mat[ 0 ];
    dst.y = src * mat[ 1 ];
    dst.z = src * mat[ 2 ];
}

void mat3_t::UnprojectVector( const idVec3_t &src, idVec3_t &dst ) const {
    dst = mat[ 0 ] * src.x + mat[ 1 ] * src.y + mat[ 2 ] * src.z;
}

void mat3_t::Transpose( mat3_t &matrix ) {
    int i;
    int j;
   
    for( i = 0; i < 3; i++ ) {
        for( j = 0; j < 3; j++ ) {
            matrix[ i ][ j ] = mat[ j ][ i ];
        }
    }
}

void mat3_t::Transpose( void ) {
    float   temp;
    int     i;
    int     j;
   
    for( i = 0; i < 3; i++ ) {
        for( j = i + 1; j < 3; j++ ) {
            temp = mat[ i ][ j ];
            mat[ i ][ j ] = mat[ j ][ i ];
            mat[ j ][ i ] = temp;
        }
    }
}

mat3_t mat3_t::Inverse( void ) const {
    mat3_t inv( *this );

    inv.Transpose();

    return inv;
}

void mat3_t::Clear( void ) {
    mat[0].set( 1, 0, 0 );
    mat[1].set( 0, 1, 0 );
    mat[2].set( 0, 0, 1 );
}

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