Quake-III-Arena

Quake III Arena GPL Source Release
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math_angles.cpp (3594B)


      1 /*
      2 ===========================================================================
      3 Copyright (C) 1999-2005 Id Software, Inc.
      4 
      5 This file is part of Quake III Arena source code.
      6 
      7 Quake III Arena source code is free software; you can redistribute it
      8 and/or modify it under the terms of the GNU General Public License as
      9 published by the Free Software Foundation; either version 2 of the License,
     10 or (at your option) any later version.
     11 
     12 Quake III Arena source code is distributed in the hope that it will be
     13 useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
     14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15 GNU General Public License for more details.
     16 
     17 You should have received a copy of the GNU General Public License
     18 along with Foobar; if not, write to the Free Software
     19 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
     20 ===========================================================================
     21 */
     22 #include "q_shared.h"
     23 #include <float.h>
     24 
     25 angles_t ang_zero( 0.0f, 0.0f, 0.0f );
     26 
     27 void toAngles( mat3_t &src, angles_t &dst ) {
     28 	double		theta;
     29 	double		cp;
     30 	double		sp;
     31 
     32 	sp = src[ 0 ][ 2 ];
     33 
     34 	// cap off our sin value so that we don't get any NANs
     35 	if ( sp > 1.0 ) {
     36 		sp = 1.0;
     37 	} else if ( sp < -1.0 ) {
     38 		sp = -1.0;
     39 	}
     40 
     41 	theta = -asin( sp );
     42 	cp = cos( theta );
     43 
     44 	if ( cp > 8192 * FLT_EPSILON ) {
     45 		dst.pitch	= theta * 180 / M_PI;
     46 		dst.yaw		= atan2( src[ 0 ][ 1 ], src[ 0 ][ 0 ] ) * 180 / M_PI;
     47 		dst.roll	= atan2( src[ 1 ][ 2 ], src[ 2 ][ 2 ] ) * 180 / M_PI;
     48 	} else {
     49 		dst.pitch	= theta * 180 / M_PI;
     50 		dst.yaw		= -atan2( src[ 1 ][ 0 ], src[ 1 ][ 1 ] ) * 180 / M_PI;
     51 		dst.roll	= 0;
     52 	}
     53 }
     54 
     55 void toAngles( quat_t &src, angles_t &dst ) {
     56 	mat3_t temp;
     57 
     58 	toMatrix( src, temp );
     59 	toAngles( temp, dst );
     60 }
     61 
     62 void toAngles( idVec3_t &src, angles_t &dst ) {
     63 	dst.pitch	= src[ 0 ];
     64 	dst.yaw		= src[ 1 ];
     65 	dst.roll	= src[ 2 ];
     66 }
     67 
     68 void angles_t::toVectors( idVec3_t *forward, idVec3_t *right, idVec3_t *up ) {
     69 	float			angle;
     70 	static float	sr, sp, sy, cr, cp, cy; // static to help MS compiler fp bugs
     71 	
     72 	angle = yaw * ( M_PI * 2 / 360 );
     73 	sy = sin( angle );
     74 	cy = cos( angle );
     75 
     76 	angle = pitch * ( M_PI * 2 / 360 );
     77 	sp = sin( angle );
     78 	cp = cos( angle );
     79 
     80 	angle = roll * ( M_PI * 2 / 360 );
     81 	sr = sin( angle );
     82 	cr = cos( angle );
     83 
     84 	if ( forward ) {
     85 		forward->set( cp * cy, cp * sy, -sp );
     86 	}
     87 
     88 	if ( right ) {
     89 		right->set( -sr * sp * cy + cr * sy, -sr * sp * sy + -cr * cy, -sr * cp );
     90 	}
     91 
     92 	if ( up ) {
     93 		up->set( cr * sp * cy + -sr * -sy, cr * sp * sy + -sr * cy, cr * cp );
     94 	}
     95 }
     96 
     97 idVec3_t angles_t::toForward( void ) {
     98 	float			angle;
     99 	static float	sp, sy, cp, cy; // static to help MS compiler fp bugs
    100 	
    101 	angle = yaw * ( M_PI * 2 / 360 );
    102 	sy = sin( angle );
    103 	cy = cos( angle );
    104 
    105 	angle = pitch * ( M_PI * 2 / 360 );
    106 	sp = sin( angle );
    107 	cp = cos( angle );
    108 
    109 	return idVec3_t( cp * cy, cp * sy, -sp );
    110 }
    111 
    112 /*
    113 =================
    114 Normalize360
    115 
    116 returns angles normalized to the range [0 <= angle < 360]
    117 =================
    118 */
    119 angles_t& angles_t::Normalize360( void ) {
    120 	pitch	= (360.0 / 65536) * ( ( int )( pitch	* ( 65536 / 360.0 ) ) & 65535 );
    121 	yaw		= (360.0 / 65536) * ( ( int )( yaw		* ( 65536 / 360.0 ) ) & 65535 );
    122 	roll	= (360.0 / 65536) * ( ( int )( roll		* ( 65536 / 360.0 ) ) & 65535 );
    123 
    124 	return *this;
    125 }
    126 
    127 
    128 /*
    129 =================
    130 Normalize180
    131 
    132 returns angles normalized to the range [-180 < angle <= 180]
    133 =================
    134 */
    135 angles_t& angles_t::Normalize180( void ) {
    136 	Normalize360();
    137 
    138 	if ( pitch > 180.0 ) {
    139 		pitch -= 360.0;
    140 	}
    141 	
    142 	if ( yaw > 180.0 ) {
    143 		yaw  -= 360.0;
    144 	}
    145 
    146 	if ( roll > 180.0 ) {
    147 		roll -= 360.0;
    148 	}
    149 	return *this;
    150 }