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Xash3DArchive/engine/common/mathlib.c
2022-06-27 01:15:21 +03:00

464 lines
9.4 KiB
C

/*
mathlib.c - internal mathlib
Copyright (C) 2010 Uncle Mike
This program 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 3 of the License, or
(at your option) any later version.
This program 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.
*/
#include "common.h"
#include "mathlib.h"
vec3_t vec3_origin = { 0, 0, 0 };
/*
=================
anglemod
=================
*/
float anglemod( const float a )
{
return (360.0f/65536) * ((int)(a*(65536/360.0f)) & 65535);
}
/*
=================
SignbitsForPlane
fast box on planeside test
=================
*/
int SignbitsForPlane( const vec3_t normal )
{
int bits, i;
for( bits = i = 0; i < 3; i++ )
if( normal[i] < 0.0f ) bits |= 1<<i;
return bits;
}
/*
=================
NearestPOW
=================
*/
int NearestPOW( int value, qboolean roundDown )
{
int n = 1;
if( value <= 0 ) return 1;
while( n < value ) n <<= 1;
if( roundDown )
{
if( n > value ) n >>= 1;
}
return n;
}
// remap a value in the range [A,B] to [C,D].
float RemapVal( float val, float A, float B, float C, float D )
{
return C + (D - C) * (val - A) / (B - A);
}
float ApproachVal( float target, float value, float speed )
{
float delta = target - value;
if( delta > speed )
value += speed;
else if( delta < -speed )
value -= speed;
else value = target;
return value;
}
/*
=================
rsqrt
=================
*/
float rsqrt( float number )
{
int i;
float x, y;
if( number == 0.0f )
return 0.0f;
x = number * 0.5f;
i = *(int *)&number; // evil floating point bit level hacking
i = 0x5f3759df - (i >> 1); // what the fuck?
y = *(float *)&i;
y = y * (1.5f - (x * y * y)); // first iteration
return y;
}
/*
=================
SinCos
=================
*/
void SinCos( float radians, float *sine, float *cosine )
{
_asm
{
fld dword ptr [radians]
fsincos
mov edx, dword ptr [cosine]
mov eax, dword ptr [sine]
fstp dword ptr [edx]
fstp dword ptr [eax]
}
}
float VectorNormalizeLength2( const vec3_t v, vec3_t out )
{
float length, ilength;
length = v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
length = sqrt( length );
if( length )
{
ilength = 1.0f / length;
out[0] = v[0] * ilength;
out[1] = v[1] * ilength;
out[2] = v[2] * ilength;
}
return length;
}
void VectorVectors( const vec3_t forward, vec3_t right, vec3_t up )
{
float d;
right[0] = forward[2];
right[1] = -forward[0];
right[2] = forward[1];
d = DotProduct( forward, right );
VectorMA( right, -d, forward, right );
VectorNormalize( right );
CrossProduct( right, forward, up );
}
/*
=================
AngleVectors
=================
*/
void AngleVectors( const vec3_t angles, vec3_t forward, vec3_t right, vec3_t up )
{
float sr, sp, sy, cr, cp, cy;
SinCos( DEG2RAD( angles[YAW] ), &sy, &cy );
SinCos( DEG2RAD( angles[PITCH] ), &sp, &cp );
SinCos( DEG2RAD( angles[ROLL] ), &sr, &cr );
if( forward )
{
forward[0] = cp * cy;
forward[1] = cp * sy;
forward[2] = -sp;
}
if( right )
{
right[0] = (-1.0f * sr * sp * cy + -1.0f * cr * -sy );
right[1] = (-1.0f * sr * sp * sy + -1.0f * cr * cy );
right[2] = (-1.0f * sr * cp);
}
if( up )
{
up[0] = (cr * sp * cy + -sr * -sy );
up[1] = (cr * sp * sy + -sr * cy );
up[2] = (cr * cp);
}
}
/*
=================
VectorAngles
=================
*/
void VectorAngles( const float *forward, float *angles )
{
float tmp, yaw, pitch;
if( !forward || !angles )
{
if( angles ) VectorClear( angles );
return;
}
if( forward[1] == 0 && forward[0] == 0 )
{
// fast case
yaw = 0;
if( forward[2] > 0 )
pitch = 90.0f;
else pitch = 270.0f;
}
else
{
yaw = ( atan2( forward[1], forward[0] ) * 180 / M_PI );
if( yaw < 0 ) yaw += 360;
tmp = sqrt( forward[0] * forward[0] + forward[1] * forward[1] );
pitch = ( atan2( forward[2], tmp ) * 180 / M_PI );
if( pitch < 0 ) pitch += 360;
}
VectorSet( angles, pitch, yaw, 0 );
}
/*
=================
VectorsAngles
=================
*/
void VectorsAngles( const vec3_t forward, const vec3_t right, const vec3_t up, vec3_t angles )
{
float pitch, cpitch, yaw, roll;
pitch = -asin( forward[2] );
cpitch = cos( pitch );
if( fabs( cpitch ) > EQUAL_EPSILON ) // gimball lock?
{
cpitch = 1.0f / cpitch;
pitch = RAD2DEG( pitch );
yaw = RAD2DEG( atan2( forward[1] * cpitch, forward[0] * cpitch ));
roll = RAD2DEG( atan2( -right[2] * cpitch, up[2] * cpitch ));
}
else
{
pitch = forward[2] > 0 ? -90.0f : 90.0f;
yaw = RAD2DEG( atan2( right[0], -right[1] ));
roll = 180.0f;
}
angles[PITCH] = pitch;
angles[YAW] = yaw;
angles[ROLL] = roll;
}
//
// bounds operations
//
/*
=================
ClearBounds
=================
*/
void ClearBounds( vec3_t mins, vec3_t maxs )
{
// make bogus range
mins[0] = mins[1] = mins[2] = 999999;
maxs[0] = maxs[1] = maxs[2] = -999999;
}
/*
=================
AddPointToBounds
=================
*/
void AddPointToBounds( const vec3_t v, vec3_t mins, vec3_t maxs )
{
float val;
int i;
for( i = 0; i < 3; i++ )
{
val = v[i];
if( val < mins[i] ) mins[i] = val;
if( val > maxs[i] ) maxs[i] = val;
}
}
/*
=================
BoundsIntersect
=================
*/
qboolean BoundsIntersect( const vec3_t mins1, const vec3_t maxs1, const vec3_t mins2, const vec3_t maxs2 )
{
if( mins1[0] > maxs2[0] || mins1[1] > maxs2[1] || mins1[2] > maxs2[2] )
return false;
if( maxs1[0] < mins2[0] || maxs1[1] < mins2[1] || maxs1[2] < mins2[2] )
return false;
return true;
}
/*
=================
BoundsAndSphereIntersect
=================
*/
qboolean BoundsAndSphereIntersect( const vec3_t mins, const vec3_t maxs, const vec3_t origin, float radius )
{
if( mins[0] > origin[0] + radius || mins[1] > origin[1] + radius || mins[2] > origin[2] + radius )
return false;
if( maxs[0] < origin[0] - radius || maxs[1] < origin[1] - radius || maxs[2] < origin[2] - radius )
return false;
return true;
}
/*
=================
RadiusFromBounds
=================
*/
float RadiusFromBounds( const vec3_t mins, const vec3_t maxs )
{
vec3_t corner;
int i;
for( i = 0; i < 3; i++ )
{
corner[i] = fabs( mins[i] ) > fabs( maxs[i] ) ? fabs( mins[i] ) : fabs( maxs[i] );
}
return VectorLength( corner );
}
/*
====================
RotatePointAroundVector
====================
*/
void RotatePointAroundVector( vec3_t dst, const vec3_t dir, const vec3_t point, float degrees )
{
float t0, t1;
float angle, c, s;
vec3_t vr, vu, vf;
angle = DEG2RAD( degrees );
SinCos( angle, &s, &c );
VectorCopy( dir, vf );
VectorVectors( vf, vr, vu );
t0 = vr[0] * c + vu[0] * -s;
t1 = vr[0] * s + vu[0] * c;
dst[0] = (t0 * vr[0] + t1 * vu[0] + vf[0] * vf[0]) * point[0]
+ (t0 * vr[1] + t1 * vu[1] + vf[0] * vf[1]) * point[1]
+ (t0 * vr[2] + t1 * vu[2] + vf[0] * vf[2]) * point[2];
t0 = vr[1] * c + vu[1] * -s;
t1 = vr[1] * s + vu[1] * c;
dst[1] = (t0 * vr[0] + t1 * vu[0] + vf[1] * vf[0]) * point[0]
+ (t0 * vr[1] + t1 * vu[1] + vf[1] * vf[1]) * point[1]
+ (t0 * vr[2] + t1 * vu[2] + vf[1] * vf[2]) * point[2];
t0 = vr[2] * c + vu[2] * -s;
t1 = vr[2] * s + vu[2] * c;
dst[2] = (t0 * vr[0] + t1 * vu[0] + vf[2] * vf[0]) * point[0]
+ (t0 * vr[1] + t1 * vu[1] + vf[2] * vf[1]) * point[1]
+ (t0 * vr[2] + t1 * vu[2] + vf[2] * vf[2]) * point[2];
}
//
// studio utils
//
/*
====================
AngleQuaternion
====================
*/
void AngleQuaternion( const vec3_t angles, vec4_t q )
{
float angle;
float sr, sp, sy, cr, cp, cy;
angle = angles[2] * 0.5f;
SinCos( angle, &sy, &cy );
angle = angles[1] * 0.5f;
SinCos( angle, &sp, &cp );
angle = angles[0] * 0.5f;
SinCos( angle, &sr, &cr );
q[0] = sr * cp * cy - cr * sp * sy; // X
q[1] = cr * sp * cy + sr * cp * sy; // Y
q[2] = cr * cp * sy - sr * sp * cy; // Z
q[3] = cr * cp * cy + sr * sp * sy; // W
}
/*
====================
QuaternionSlerp
====================
*/
void QuaternionSlerp( const vec4_t p, vec4_t q, float t, vec4_t qt )
{
float omega, cosom, sinom, sclp, sclq;
int i;
// decide if one of the quaternions is backwards
float a = 0;
float b = 0;
for( i = 0; i < 4; i++ )
{
a += (p[i] - q[i]) * (p[i] - q[i]);
b += (p[i] + q[i]) * (p[i] + q[i]);
}
if( a > b )
{
for( i = 0; i < 4; i++ )
{
q[i] = -q[i];
}
}
cosom = p[0] * q[0] + p[1] * q[1] + p[2] * q[2] + p[3] * q[3];
if(( 1.0 + cosom ) > 0.000001f )
{
if(( 1.0 - cosom ) > 0.000001f )
{
omega = acos( cosom );
sinom = sin( omega );
sclp = sin(( 1.0f - t ) * omega ) / sinom;
sclq = sin( t * omega ) / sinom;
}
else
{
sclp = 1.0f - t;
sclq = t;
}
for( i = 0; i < 4; i++ )
qt[i] = sclp * p[i] + sclq * q[i];
}
else
{
qt[0] = -q[1];
qt[1] = q[0];
qt[2] = -q[3];
qt[3] = q[2];
sclp = sin(( 1.0f - t ) * ( 0.5f * M_PI ));
sclq = sin( t * ( 0.5f * M_PI ));
for( i = 0; i < 3; i++ )
qt[i] = sclp * p[i] + sclq * qt[i];
}
}