gtkradiant/libs/splines/math_angles.cpp

/*
   Copyright (C) 1999-2007 id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "q_shared.h"
#include <float.h>

angles_t ang_zero( 0.0f, 0.0f, 0.0f );

void toAngles( mat3_t &src, angles_t &dst ) {
	double theta;
	double cp;
	double sp;

	sp = src[ 0 ][ 2 ];

	// cap off our sin value so that we don't get any NANs
	if ( sp > 1.0 ) {
		sp = 1.0;
	}
	else if ( sp < -1.0 ) {
		sp = -1.0;
	}

	theta = -asin( sp );
	cp = cos( theta );

	if ( cp > 8192 * FLT_EPSILON ) {
		dst.pitch   = theta * 180 / M_PI;
		dst.yaw     = atan2( src[ 0 ][ 1 ], src[ 0 ][ 0 ] ) * 180 / M_PI;
		dst.roll    = atan2( src[ 1 ][ 2 ], src[ 2 ][ 2 ] ) * 180 / M_PI;
	}
	else {
		dst.pitch   = theta * 180 / M_PI;
		dst.yaw     = -atan2( src[ 1 ][ 0 ], src[ 1 ][ 1 ] ) * 180 / M_PI;
		dst.roll    = 0;
	}
}

void toAngles( quat_t &src, angles_t &dst ) {
	mat3_t temp;

	toMatrix( src, temp );
	toAngles( temp, dst );
}

void toAngles( idVec3 &src, angles_t &dst ) {
	dst.pitch   = src[ 0 ];
	dst.yaw     = src[ 1 ];
	dst.roll    = src[ 2 ];
}

void angles_t::toVectors( idVec3 *forward, idVec3 *right, idVec3 *up ) {
	float angle;
	static float sr, sp, sy, cr, cp, cy;    // static to help MS compiler fp bugs

	angle = yaw * ( M_PI * 2 / 360 );
	sy = sin( angle );
	cy = cos( angle );

	angle = pitch * ( M_PI * 2 / 360 );
	sp = sin( angle );
	cp = cos( angle );

	angle = roll * ( M_PI * 2 / 360 );
	sr = sin( angle );
	cr = cos( angle );

	if ( forward ) {
		forward->set( cp * cy, cp * sy, -sp );
	}

	if ( right ) {
		right->set( -sr * sp * cy + cr * sy, -sr * sp * sy + -cr * cy, -sr * cp );
	}

	if ( up ) {
		up->set( cr * sp * cy + -sr * -sy, cr * sp * sy + -sr * cy, cr * cp );
	}
}

idVec3 angles_t::toForward( void ) {
	float angle;
	static float sp, sy, cp, cy;    // static to help MS compiler fp bugs

	angle = yaw * ( M_PI * 2 / 360 );
	sy = sin( angle );
	cy = cos( angle );

	angle = pitch * ( M_PI * 2 / 360 );
	sp = sin( angle );
	cp = cos( angle );

	return idVec3( cp * cy, cp * sy, -sp );
}

/*
   =================
   Normalize360

   returns angles normalized to the range [0 <= angle < 360]
   =================
 */
angles_t& angles_t::Normalize360( void ) {
	pitch   = ( 360.0 / 65536 ) * ( ( int )( pitch    * ( 65536 / 360.0 ) ) & 65535 );
	yaw     = ( 360.0 / 65536 ) * ( ( int )( yaw      * ( 65536 / 360.0 ) ) & 65535 );
	roll    = ( 360.0 / 65536 ) * ( ( int )( roll     * ( 65536 / 360.0 ) ) & 65535 );

	return *this;
}


/*
   =================
   Normalize180

   returns angles normalized to the range [-180 < angle <= 180]
   =================
 */
angles_t& angles_t::Normalize180( void ) {
	Normalize360();

	if ( pitch > 180.0 ) {
		pitch -= 360.0;
	}

	if ( yaw > 180.0 ) {
		yaw  -= 360.0;
	}

	if ( roll > 180.0 ) {
		roll -= 360.0;
	}
	return *this;
}