jkxr/Projects/Android/jni/JKVR/mathlib.c
2022-09-19 22:46:47 +01:00

525 lines
10 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 "mathlib.h"
unsigned short FloatToHalf( float v )
{
unsigned int i = *((unsigned int *)&v);
unsigned int e = (i >> 23) & 0x00ff;
unsigned int m = i & 0x007fffff;
unsigned short h;
if( e <= 127 - 15 )
h = ((m | 0x00800000) >> (127 - 14 - e)) >> 13;
else h = (i >> 13) & 0x3fff;
h |= (i >> 16) & 0xc000;
return h;
}
float HalfToFloat( unsigned short h )
{
unsigned int f = (h << 16) & 0x80000000;
unsigned int em = h & 0x7fff;
if( em > 0x03ff )
{
f |= (em << 13) + ((127 - 15) << 23);
}
else
{
unsigned int m = em & 0x03ff;
if( m != 0 )
{
unsigned int e = (em >> 10) & 0x1f;
while(( m & 0x0400 ) == 0 )
{
m <<= 1;
e--;
}
m &= 0x3ff;
f |= ((e + (127 - 14)) << 23) | (m << 13);
}
}
return *((float *)&f);
}
/*
=================
NearestPOW
=================
*/
int NearestPOW( int value, bool 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 )
{
#if _MSC_VER == 1200
_asm
{
fld dword ptr [radians]
fsincos
mov edx, dword ptr [cosine]
mov eax, dword ptr [sine]
fstp dword ptr [edx]
fstp dword ptr [eax]
}
#else
// I think, better use math.h function, instead of ^
#if defined (__linux__) && !defined (__ANDROID__)
sincosf(radians, sine, cosine);
#else
*sine = sinf(radians);
*cosine = cosf(radians);
#endif
#endif
}
#ifdef XASH_VECTORIZE_SINCOS
void SinCosFastVector4(float r1, float r2, float r3, float r4,
float *s0, float *s1, float *s2, float *s3,
float *c0, float *c1, float *c2, float *c3)
{
v4sf rad_vector = {r1, r2, r3, r4};
v4sf sin_vector, cos_vector;
sincos_ps(rad_vector, &sin_vector, &cos_vector);
*s0 = s4f_x(sin_vector);
*s1 = s4f_y(sin_vector);
*s2 = s4f_z(sin_vector);
*s3 = s4f_w(sin_vector);
*c0 = s4f_x(cos_vector);
*c1 = s4f_y(cos_vector);
*c2 = s4f_z(cos_vector);
*c3 = s4f_w(cos_vector);
}
void SinCosFastVector3(float r1, float r2, float r3,
float *s0, float *s1, float *s2,
float *c0, float *c1, float *c2)
{
v4sf rad_vector = {r1, r2, r3, 0};
v4sf sin_vector, cos_vector;
sincos_ps(rad_vector, &sin_vector, &cos_vector);
*s0 = s4f_x(sin_vector);
*s1 = s4f_y(sin_vector);
*s2 = s4f_z(sin_vector);
*c0 = s4f_x(cos_vector);
*c1 = s4f_y(cos_vector);
*c2 = s4f_z(cos_vector);
}
void SinCosFastVector2(float r1, float r2,
float *s0, float *s1,
float *c0, float *c1)
{
v4sf rad_vector = {r1, r2, 0, 0};
v4sf sin_vector, cos_vector;
sincos_ps(rad_vector, &sin_vector, &cos_vector);
*s0 = s4f_x(sin_vector);
*s1 = s4f_y(sin_vector);
*c0 = s4f_x(cos_vector);
*c1 = s4f_y(cos_vector);
}
void SinFastVector3(float r1, float r2, float r3,
float *s0, float *s1, float *s2)
{
v4sf rad_vector = {r1, r2, r3, 0};
v4sf sin_vector;
sin_vector = sin_ps(rad_vector);
*s0 = s4f_x(sin_vector);
*s1 = s4f_y(sin_vector);
*s2 = s4f_z(sin_vector);
}
#endif
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 GAME_EXPORT AngleVectors( const vec3_t angles, vec3_t forward, vec3_t right, vec3_t up )
{
static float sr, sp, sy, cr, cp, cy;
#ifdef XASH_VECTORIZE_SINCOS
SinCosFastVector3( DEG2RAD(angles[YAW]), DEG2RAD(angles[PITCH]), DEG2RAD(angles[ROLL]),
&sy, &sp, &sr,
&cy, &cp, &cr);
#else
SinCos( DEG2RAD( angles[YAW] ), &sy, &cy );
SinCos( DEG2RAD( angles[PITCH] ), &sp, &cp );
SinCos( DEG2RAD( angles[ROLL] ), &sr, &cr );
#endif
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;
}
/*
=================
InterpolateAngles
=================
*/
void InterpolateAngles( vec3_t start, vec3_t end, vec3_t out, float frac )
{
float d, ang1, ang2;
int i;
for( i = 0; i < 3; i++ )
{
ang1 = start[i];
ang2 = end[i];
d = ang1 - ang2;
if( d > 180.0f ) d -= 360.0f;
else if( d < -180.0f ) d += 360.0f;
out[i] = ang2 + d * frac;
}
}
/*
=================
BoundsIntersect
=================
*/
bool 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 qfalse;
if( maxs1[0] < mins2[0] || maxs1[1] < mins2[1] || maxs1[2] < mins2[2] )
return qfalse;
return qtrue;
}
/*
=================
BoundsAndSphereIntersect
=================
*/
bool 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 qfalse;
if( maxs[0] < origin[0] - radius || maxs[1] < origin[1] - radius || maxs[2] < origin[2] - radius )
return qfalse;
return qtrue;
}
//
// studio utils
//
/*
====================
AngleQuaternion
====================
*/
void AngleQuaternion( const vec3_t angles, vec4_t q )
{
float sr, sp, sy, cr, cp, cy;
#ifdef XASH_VECTORIZE_SINCOS
SinCosFastVector3( angles[2] * 0.5f, angles[1] * 0.5f, angles[0] * 0.5f,
&sy, &sp, &sr,
&cy, &cp, &cr);
#else
float angle;
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 );
#endif
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, sclp, sclq;
float cosom, sinom;
float a = 0.0f;
float b = 0.0f;
int i;
// decide if one of the quaternions is backwards
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(( 1.0f - cosom ) > 0.000001f )
{
omega = acos( cosom );
#ifdef XASH_VECTORIZE_SINCOS
SinFastVector3( omega, ( 1.0f - t ) * omega, t * omega,
&sinom, &sclp, &sclq );
sclp /= sinom;
sclq /= sinom;
#else
sinom = sin( omega );
sclp = sin(( 1.0f - t ) * omega ) / sinom;
sclq = sin( t * omega ) / sinom;
#endif
}
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];
}
}