math.c File Reference

#include "shared/shared.h"
#include "common/math.h"

Go to the source code of this file.

Macros
#define	P(i, j, k)

Functions
int	DirToByte (const vec3_t dir)
void	SetPlaneType (cplane_t *plane)
void	SetPlaneSignbits (cplane_t *plane)
int	BoxOnPlaneSide (vec3_t emins, vec3_t emaxs, cplane_t *p)
void	RotatePointAroundVector (vec3_t dst, const vec3_t dir, const vec3_t point, float degrees)
void	SetupRotationMatrix (vec3_t matrix[3], const vec3_t dir, float degrees)

Variables
const vec3_t	bytedirs [NUMVERTEXNORMALS]

Macro Definition Documentation

P

#define P	(		i,
			j,
			k
	)

Value:

    p->normal[0] * bounds[i][0] + \
    p->normal[1] * bounds[j][1] + \
    p->normal[2] * bounds[k][2]

Function Documentation

BoxOnPlaneSide()

int BoxOnPlaneSide	(	vec3_t	emins,
		vec3_t	emaxs,
		cplane_t *	p
	)

Definition at line 322 of file math.c.

{
    vec_t   *bounds[2] = { emins, emaxs };
    int     i = p->signbits & 1;
    int     j = (p->signbits >> 1) & 1;
    int     k = (p->signbits >> 2) & 1;
 
#define P(i, j, k) \
    p->normal[0] * bounds[i][0] + \
    p->normal[1] * bounds[j][1] + \
    p->normal[2] * bounds[k][2]
 
    vec_t   dist1 = P(i ^ 1, j ^ 1, k ^ 1);
    vec_t   dist2 = P(i, j, k);
    int     sides = 0;
 
#undef P
 
    if (dist1 >= p->dist)
        sides = BOX_INFRONT;
    if (dist2 < p->dist)
        sides |= BOX_BEHIND;
 
    return sides;
}

Referenced by GL_ClipNode(), and GL_CullBox().

DirToByte()

int DirToByte

(

const vec3_t

dir

)

Definition at line 245 of file math.c.

{
    int     i, best;
    float   d, bestd;
 
    if (!dir) {
        return 0;
    }
 
    bestd = 0;
    best = 0;
    for (i = 0; i < NUMVERTEXNORMALS; i++) {
        d = DotProduct(dir, bytedirs[i]);
        if (d > bestd) {
            bestd = d;
            best = i;
        }
    }
 
    return best;
}

Referenced by MSG_WriteDir().

RotatePointAroundVector()

void RotatePointAroundVector	(	vec3_t	dst,
		const vec3_t	dir,
		const vec3_t	point,
		float	degrees
	)

Definition at line 348 of file math.c.

{
    vec3_t  matrix[3];
 
    SetupRotationMatrix(matrix, dir, degrees);
 
    dst[0] = DotProduct(matrix[0], point);
    dst[1] = DotProduct(matrix[1], point);
    dst[2] = DotProduct(matrix[2], point);
}

Referenced by R_DrawBeam().

SetPlaneSignbits()

void SetPlaneSignbits

(

cplane_t *

plane

)

Definition at line 298 of file math.c.

{
    int bits = 0;
 
    if (plane->normal[0] < 0) {
        bits |= 1;
    }
    if (plane->normal[1] < 0) {
        bits |= 2;
    }
    if (plane->normal[2] < 0) {
        bits |= 4;
    }
 
    plane->signbits = bits;
}

Referenced by GL_SetupFrustum(), and LOAD().

SetPlaneType()

void SetPlaneType

(

cplane_t *

plane

)

Definition at line 278 of file math.c.

{
    vec_t *normal = plane->normal;
 
    if (normal[0] == 1) {
        plane->type = PLANE_X;
        return;
    }
    if (normal[1] == 1) {
        plane->type = PLANE_Y;
        return;
    }
    if (normal[2] == 1) {
        plane->type = PLANE_Z;
        return;
    }
 
    plane->type = PLANE_NON_AXIAL;
}

Referenced by LOAD().

SetupRotationMatrix()

void SetupRotationMatrix	(	vec3_t	matrix[3],
		const vec3_t	dir,
		float	degrees
	)

Definition at line 367 of file math.c.

{
    vec_t   angle, s, c, one_c, xx, yy, zz, xy, yz, zx, xs, ys, zs;
 
    angle = DEG2RAD(degrees);
    s = sin(angle);
    c = cos(angle);
    one_c = 1.0F - c;
 
    xx = dir[0] * dir[0];
    yy = dir[1] * dir[1];
    zz = dir[2] * dir[2];
    xy = dir[0] * dir[1];
    yz = dir[1] * dir[2];
    zx = dir[2] * dir[0];
    xs = dir[0] * s;
    ys = dir[1] * s;
    zs = dir[2] * s;
 
    matrix[0][0] = (one_c * xx) + c;
    matrix[0][1] = (one_c * xy) - zs;
    matrix[0][2] = (one_c * zx) + ys;
 
    matrix[1][0] = (one_c * xy) + zs;
    matrix[1][1] = (one_c * yy) + c;
    matrix[1][2] = (one_c * yz) - xs;
 
    matrix[2][0] = (one_c * zx) - ys;
    matrix[2][1] = (one_c * yz) + xs;
    matrix[2][2] = (one_c * zz) + c;
}

Referenced by prepare_sky_matrix(), R_AddSkySurface(), and RotatePointAroundVector().

Variable Documentation

bytedirs

const vec3_t bytedirs[NUMVERTEXNORMALS]

Definition at line 80 of file math.c.

Referenced by CL_BfgParticles(), CL_FlyParticles(), DirToByte(), GL_InitTables(), MOD_LoadMD2_RTX(), MSG_ReadDir(), and R_AliasTransformFinalVerts().