/*
  Copyright (C) 2010-2011  Charles Pence <charles@charlespence.net>
  Copyright (C) 1996-1997  Id Software, Inc.

  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.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "pch.h"
#include "quakedef.h"

void Sys_Error (char *error, ...);

vec3_t vec3_origin = {0,0,0};
int nanmask = 255<<23;

/*-----------------------------------------------------------------*/

#define DEG2RAD( a ) ( a * M_PI ) / 180.0F

void ProjectPointOnPlane( vec3_t dst, const vec3_t p, const vec3_t normal )
{
    float d;
    vec3_t n;
    float inv_denom;

    inv_denom = 1.0F / DotProduct( normal, normal );

    d = DotProduct( normal, p ) * inv_denom;

    n[0] = normal[0] * inv_denom;
    n[1] = normal[1] * inv_denom;
    n[2] = normal[2] * inv_denom;

    dst[0] = p[0] - d * n[0];
    dst[1] = p[1] - d * n[1];
    dst[2] = p[2] - d * n[2];
}

/*
** assumes "src" is normalized
*/
void PerpendicularVector( vec3_t dst, const vec3_t src )
{
    int    pos;
    int i;
    float minelem = 1.0F;
    vec3_t tempvec;

    /*
    ** find the smallest magnitude axially aligned vector
    */
    for ( pos = 0, i = 0; i < 3; i++ )
    {
        if ( fabs( src[i] ) < minelem )
        {
            pos = i;
            minelem = fabs( src[i] );
        }
    }
    tempvec[0] = tempvec[1] = tempvec[2] = 0.0F;
    tempvec[pos] = 1.0F;

    /*
    ** project the point onto the plane defined by src
    */
    ProjectPointOnPlane( dst, tempvec, src );

    /*
    ** normalize the result
    */
    VectorNormalize( dst );
}


void RotatePointAroundVector( vec3_t dst, const vec3_t dir, const vec3_t point, float degrees )
{
    float    m[3][3];
    float    im[3][3];
    float    zrot[3][3];
    float    tmpmat[3][3];
    float    rot[3][3];
    int    i;
    vec3_t vr, vup, vf;

    vf[0] = dir[0];
    vf[1] = dir[1];
    vf[2] = dir[2];

    PerpendicularVector( vr, dir );
    CrossProduct( vr, vf, vup );

    m[0][0] = vr[0];
    m[1][0] = vr[1];
    m[2][0] = vr[2];

    m[0][1] = vup[0];
    m[1][1] = vup[1];
    m[2][1] = vup[2];

    m[0][2] = vf[0];
    m[1][2] = vf[1];
    m[2][2] = vf[2];

    memcpy( im, m, sizeof( im ) );

    im[0][1] = m[1][0];
    im[0][2] = m[2][0];
    im[1][0] = m[0][1];
    im[1][2] = m[2][1];
    im[2][0] = m[0][2];
    im[2][1] = m[1][2];

    memset( zrot, 0, sizeof( zrot ) );
    zrot[0][0] = zrot[1][1] = zrot[2][2] = 1.0F;

    zrot[0][0] = cos( DEG2RAD( degrees ) );
    zrot[0][1] = sin( DEG2RAD( degrees ) );
    zrot[1][0] = -sin( DEG2RAD( degrees ) );
    zrot[1][1] = cos( DEG2RAD( degrees ) );

    R_ConcatRotations( m, zrot, tmpmat );
    R_ConcatRotations( tmpmat, im, rot );

    for ( i = 0; i < 3; i++ )
    {
        dst[i] = rot[i][0] * point[0] + rot[i][1] * point[1] + rot[i][2] * point[2];
    }
}

/*-----------------------------------------------------------------*/


float    anglemod(float a)
{
#if 0
    if (a >= 0)
        a -= 360*(int)(a/360);
    else
        a += 360*( 1 + (int)(-a/360) );
#endif
    a = (360.0/65536) * ((int)(a*(65536/360.0)) & 65535);
    return a;
}

/*
==================
BOPS_Error

Split out like this for ASM to call.
==================
*/
void BOPS_Error (void)
{
    Sys_Error ("BoxOnPlaneSide:  Bad signbits");
}

/*
==================
BoxOnPlaneSide

Returns 1, 2, or 1 + 2
==================
*/
int BoxOnPlaneSide (vec3_t emins, vec3_t emaxs, mplane_t *p)
{
    float    dist1, dist2;
    int        sides;

#if 0    // this is done by the BOX_ON_PLANE_SIDE macro before calling this
        // function
// fast axial cases
    if (p->type < 3)
    {
        if (p->dist <= emins[p->type])
            return 1;
        if (p->dist >= emaxs[p->type])
            return 2;
        return 3;
    }
#endif

// general case
    switch (p->signbits)
    {
    case 0:
dist1 = p->normal[0]*emaxs[0] + p->normal[1]*emaxs[1] + p->normal[2]*emaxs[2];
dist2 = p->normal[0]*emins[0] + p->normal[1]*emins[1] + p->normal[2]*emins[2];
        break;
    case 1:
dist1 = p->normal[0]*emins[0] + p->normal[1]*emaxs[1] + p->normal[2]*emaxs[2];
dist2 = p->normal[0]*emaxs[0] + p->normal[1]*emins[1] + p->normal[2]*emins[2];
        break;
    case 2:
dist1 = p->normal[0]*emaxs[0] + p->normal[1]*emins[1] + p->normal[2]*emaxs[2];
dist2 = p->normal[0]*emins[0] + p->normal[1]*emaxs[1] + p->normal[2]*emins[2];
        break;
    case 3:
dist1 = p->normal[0]*emins[0] + p->normal[1]*emins[1] + p->normal[2]*emaxs[2];
dist2 = p->normal[0]*emaxs[0] + p->normal[1]*emaxs[1] + p->normal[2]*emins[2];
        break;
    case 4:
dist1 = p->normal[0]*emaxs[0] + p->normal[1]*emaxs[1] + p->normal[2]*emins[2];
dist2 = p->normal[0]*emins[0] + p->normal[1]*emins[1] + p->normal[2]*emaxs[2];
        break;
    case 5:
dist1 = p->normal[0]*emins[0] + p->normal[1]*emaxs[1] + p->normal[2]*emins[2];
dist2 = p->normal[0]*emaxs[0] + p->normal[1]*emins[1] + p->normal[2]*emaxs[2];
        break;
    case 6:
dist1 = p->normal[0]*emaxs[0] + p->normal[1]*emins[1] + p->normal[2]*emins[2];
dist2 = p->normal[0]*emins[0] + p->normal[1]*emaxs[1] + p->normal[2]*emaxs[2];
        break;
    case 7:
dist1 = p->normal[0]*emins[0] + p->normal[1]*emins[1] + p->normal[2]*emins[2];
dist2 = p->normal[0]*emaxs[0] + p->normal[1]*emaxs[1] + p->normal[2]*emaxs[2];
        break;
    default:
        dist1 = dist2 = 0;        // shut up compiler
        BOPS_Error ();
        break;
    }

#if 0
    int        i;
    vec3_t    corners[2];

    for (i=0 ; i<3 ; i++)
    {
        if (plane->normal[i] < 0)
        {
            corners[0][i] = emins[i];
            corners[1][i] = emaxs[i];
        }
        else
        {
            corners[1][i] = emins[i];
            corners[0][i] = emaxs[i];
        }
    }
    dist = DotProduct (plane->normal, corners[0]) - plane->dist;
    dist2 = DotProduct (plane->normal, corners[1]) - plane->dist;
    sides = 0;
    if (dist1 >= 0)
        sides = 1;
    if (dist2 < 0)
        sides |= 2;

#endif

    sides = 0;
    if (dist1 >= p->dist)
        sides = 1;
    if (dist2 < p->dist)
        sides |= 2;

    return sides;
}


void AngleVectors (vec3_t angles, vec3_t forward, vec3_t right, vec3_t up)
{
    float        angle;
    float        sr, sp, sy, cr, cp, cy;

    angle = angles[YAW] * (M_PI*2 / 360);
    sy = sin(angle);
    cy = cos(angle);
    angle = angles[PITCH] * (M_PI*2 / 360);
    sp = sin(angle);
    cp = cos(angle);
    angle = angles[ROLL] * (M_PI*2 / 360);
    sr = sin(angle);
    cr = cos(angle);

    forward[0] = cp*cy;
    forward[1] = cp*sy;
    forward[2] = -sp;
    right[0] = (-1*sr*sp*cy+-1*cr*-sy);
    right[1] = (-1*sr*sp*sy+-1*cr*cy);
    right[2] = -1*sr*cp;
    up[0] = (cr*sp*cy+-sr*-sy);
    up[1] = (cr*sp*sy+-sr*cy);
    up[2] = cr*cp;
}

int VectorCompare (vec3_t v1, vec3_t v2)
{
    int        i;

    for (i=0 ; i<3 ; i++)
        if (v1[i] != v2[i])
            return 0;

    return 1;
}

void VectorMA (vec3_t veca, float scale, vec3_t vecb, vec3_t vecc)
{
    vecc[0] = veca[0] + scale*vecb[0];
    vecc[1] = veca[1] + scale*vecb[1];
    vecc[2] = veca[2] + scale*vecb[2];
}


float _DotProduct (vec3_t v1, vec3_t v2)
{
    return v1[0]*v2[0] + v1[1]*v2[1] + v1[2]*v2[2];
}

void _VectorSubtract (vec3_t veca, vec3_t vecb, vec3_t out)
{
    out[0] = veca[0]-vecb[0];
    out[1] = veca[1]-vecb[1];
    out[2] = veca[2]-vecb[2];
}

void _VectorAdd (vec3_t veca, vec3_t vecb, vec3_t out)
{
    out[0] = veca[0]+vecb[0];
    out[1] = veca[1]+vecb[1];
    out[2] = veca[2]+vecb[2];
}

void _VectorCopy (vec3_t in, vec3_t out)
{
    out[0] = in[0];
    out[1] = in[1];
    out[2] = in[2];
}

void CrossProduct (vec3_t v1, vec3_t v2, vec3_t cross)
{
    cross[0] = v1[1]*v2[2] - v1[2]*v2[1];
    cross[1] = v1[2]*v2[0] - v1[0]*v2[2];
    cross[2] = v1[0]*v2[1] - v1[1]*v2[0];
}

float Length(vec3_t v)
{
    int        i;
    float    length;

    length = 0;
    for (i=0 ; i< 3 ; i++)
        length += v[i]*v[i];
    length = sqrt (length);        // FIXME

    return length;
}

float VectorNormalize (vec3_t v)
{
    float    length, ilength;

    length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
    length = sqrt (length);        // FIXME

    if (length)
    {
        ilength = 1/length;
        v[0] *= ilength;
        v[1] *= ilength;
        v[2] *= ilength;
    }

    return length;

}

void VectorInverse (vec3_t v)
{
    v[0] = -v[0];
    v[1] = -v[1];
    v[2] = -v[2];
}

void VectorScale (vec3_t in, float scale, vec3_t out)
{
    out[0] = in[0]*scale;
    out[1] = in[1]*scale;
    out[2] = in[2]*scale;
}


int Q_log2(int val)
{
    int answer=0;
    while (val>>=1)
        answer++;
    return answer;
}


/*
================
R_ConcatRotations
================
*/
void R_ConcatRotations (float in1[3][3], float in2[3][3], float out[3][3])
{
    out[0][0] = in1[0][0] * in2[0][0] + in1[0][1] * in2[1][0] +
                in1[0][2] * in2[2][0];
    out[0][1] = in1[0][0] * in2[0][1] + in1[0][1] * in2[1][1] +
                in1[0][2] * in2[2][1];
    out[0][2] = in1[0][0] * in2[0][2] + in1[0][1] * in2[1][2] +
                in1[0][2] * in2[2][2];
    out[1][0] = in1[1][0] * in2[0][0] + in1[1][1] * in2[1][0] +
                in1[1][2] * in2[2][0];
    out[1][1] = in1[1][0] * in2[0][1] + in1[1][1] * in2[1][1] +
                in1[1][2] * in2[2][1];
    out[1][2] = in1[1][0] * in2[0][2] + in1[1][1] * in2[1][2] +
                in1[1][2] * in2[2][2];
    out[2][0] = in1[2][0] * in2[0][0] + in1[2][1] * in2[1][0] +
                in1[2][2] * in2[2][0];
    out[2][1] = in1[2][0] * in2[0][1] + in1[2][1] * in2[1][1] +
                in1[2][2] * in2[2][1];
    out[2][2] = in1[2][0] * in2[0][2] + in1[2][1] * in2[1][2] +
                in1[2][2] * in2[2][2];
}


/*
================
R_ConcatTransforms
================
*/
void R_ConcatTransforms (float in1[3][4], float in2[3][4], float out[3][4])
{
    out[0][0] = in1[0][0] * in2[0][0] + in1[0][1] * in2[1][0] +
                in1[0][2] * in2[2][0];
    out[0][1] = in1[0][0] * in2[0][1] + in1[0][1] * in2[1][1] +
                in1[0][2] * in2[2][1];
    out[0][2] = in1[0][0] * in2[0][2] + in1[0][1] * in2[1][2] +
                in1[0][2] * in2[2][2];
    out[0][3] = in1[0][0] * in2[0][3] + in1[0][1] * in2[1][3] +
                in1[0][2] * in2[2][3] + in1[0][3];
    out[1][0] = in1[1][0] * in2[0][0] + in1[1][1] * in2[1][0] +
                in1[1][2] * in2[2][0];
    out[1][1] = in1[1][0] * in2[0][1] + in1[1][1] * in2[1][1] +
                in1[1][2] * in2[2][1];
    out[1][2] = in1[1][0] * in2[0][2] + in1[1][1] * in2[1][2] +
                in1[1][2] * in2[2][2];
    out[1][3] = in1[1][0] * in2[0][3] + in1[1][1] * in2[1][3] +
                in1[1][2] * in2[2][3] + in1[1][3];
    out[2][0] = in1[2][0] * in2[0][0] + in1[2][1] * in2[1][0] +
                in1[2][2] * in2[2][0];
    out[2][1] = in1[2][0] * in2[0][1] + in1[2][1] * in2[1][1] +
                in1[2][2] * in2[2][1];
    out[2][2] = in1[2][0] * in2[0][2] + in1[2][1] * in2[1][2] +
                in1[2][2] * in2[2][2];
    out[2][3] = in1[2][0] * in2[0][3] + in1[2][1] * in2[1][3] +
                in1[2][2] * in2[2][3] + in1[2][3];
}

