gzdoom/src/vectors.cpp

#include "vectors.h"
#include "actor.h"
#include "tables.h"

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


// [RH] Convert a thing's position into a vec3_t
void VectorPosition (const AActor *thing, vec3_t out)
{
	out[0] = (float)thing->x / 65536.0f;
	out[1] = (float)thing->y / 65536.0f;
	out[2] = (float)thing->z / 65536.0f;
}

void FixedAngleToVector (angle_t an, int pitch, vec3_t v)
{
	an >>= ANGLETOFINESHIFT;
	v[0] = ((float)finecosine[an]) / 65536.0f;
	v[1] = ((float)finesine[an]) / 65536.0f;
	v[2] = ((float)finetangent[FINEANGLES/4-(pitch>>ANGLETOFINESHIFT)]) / 65536.0f;
	VectorNormalize (v);
}

// Taken from Q2
vec_t VectorLength (const vec3_t v)
{
	float	length;
	
	length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
	length = sqrtf (length);

	return length;
}

void VectorMA (const vec3_t a, float scale, const vec3_t b, vec3_t out)
{
	out[0] = a[0] + scale * b[0];
	out[1] = a[1] + scale * b[1];
	out[2] = a[2] + scale * b[2];
}

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

void VectorScale2 (vec3_t v, float scale)
{
	v[0] = v[0] * scale;
	v[1] = v[1] * scale;
	v[2] = v[2] * scale;
}

int VectorCompare (const vec3_t v1, const vec3_t v2)
{
	if (v1[0] != v2[0] || v1[1] != v2[1] || v1[2] != v2[2])
		return 0;
			
	return 1;
}

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

	length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
	length = sqrtf (length);

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

}

vec_t VectorNormalize2 (const vec3_t v, vec3_t out)
{
	float length, ilength;

	length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
	length = sqrtf (length);

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

}

void CrossProduct (const vec3_t v1, const 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];
}

#ifdef _MSC_VER
#pragma optimize( "", off )
#endif

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

#ifdef _MSC_VER
#pragma optimize( "", on )
#endif

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 = (float)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 );
}

/*
================
R_ConcatRotations
================
*/
void R_ConcatRotations (const float in1[3][3], const 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];
}