simgear/Math/mat3.h
1998-01-19 18:40:33 +00:00

148 lines
5.2 KiB
C

/* Copyright 1988, Brown Computer Graphics Group. All Rights Reserved. */
/* -------------------------------------------------------------------------
Public MAT3 include file
------------------------------------------------------------------------- */
#ifndef MAT3_HAS_BEEN_INCLUDED
#define MAT3_HAS_BEEN_INCLUDED
/* ----------------------------- Constants ------------------------------ */
/*
* Make sure the math library .h file is included, in case it wasn't.
*/
#ifndef HUGE
#include <math.h>
#endif
#include <stdio.h>
#define MAT3_DET0 -1 /* Indicates singular mat */
#define MAT3_EPSILON 1e-12 /* Close enough to zero */
#define MAT3_PI 3.141592653589793 /* Pi */
/* ------------------------------ Types --------------------------------- */
typedef double MAT3mat[4][4]; /* 4x4 matrix */
typedef double MAT3vec[3]; /* Vector */
typedef double MAT3hvec[4]; /* Vector with homogeneous coord */
/* ------------------------------ Macros -------------------------------- */
/* Tests if a number is within EPSILON of zero */
#define MAT3_IS_ZERO(N) ((N) < MAT3_EPSILON && (N) > -MAT3_EPSILON)
/* Sets a vector to the three given values */
#define MAT3_SET_VEC(V,X,Y,Z) ((V)[0]=(X), (V)[1]=(Y), (V)[2]=(Z))
/* Tests a vector for all components close to zero */
#define MAT3_IS_ZERO_VEC(V) (MAT3_IS_ZERO((V)[0]) && \
MAT3_IS_ZERO((V)[1]) && \
MAT3_IS_ZERO((V)[2]))
/* Dot product of two vectors */
#define MAT3_DOT_PRODUCT(V1,V2) \
((V1)[0]*(V2)[0] + (V1)[1]*(V2)[1] + (V1)[2]*(V2)[2])
/* Copy one vector to other */
#define MAT3_COPY_VEC(TO,FROM) ((TO)[0] = (FROM)[0], \
(TO)[1] = (FROM)[1], \
(TO)[2] = (FROM)[2])
/* Normalize vector to unit length, using TEMP as temporary variable.
* TEMP will be zero if vector has zero length */
#define MAT3_NORMALIZE_VEC(V,TEMP) \
if ((TEMP = sqrt(MAT3_DOT_PRODUCT(V,V))) > MAT3_EPSILON) { \
TEMP = 1.0 / TEMP; \
MAT3_SCALE_VEC(V,V,TEMP); \
} else TEMP = 0.0
/* Scale vector by given factor, storing result vector in RESULT_V */
#define MAT3_SCALE_VEC(RESULT_V,V,SCALE) \
MAT3_SET_VEC(RESULT_V, (V)[0]*(SCALE), (V)[1]*(SCALE), (V)[2]*(SCALE))
/* Adds vectors V1 and V2, storing result in RESULT_V */
#define MAT3_ADD_VEC(RESULT_V,V1,V2) \
MAT3_SET_VEC(RESULT_V, (V1)[0]+(V2)[0], (V1)[1]+(V2)[1], \
(V1)[2]+(V2)[2])
/* Subtracts vector V2 from V1, storing result in RESULT_V */
#define MAT3_SUB_VEC(RESULT_V,V1,V2) \
MAT3_SET_VEC(RESULT_V, (V1)[0]-(V2)[0], (V1)[1]-(V2)[1], \
(V1)[2]-(V2)[2])
/* Multiplies vectors V1 and V2, storing result in RESULT_V */
#define MAT3_MULT_VEC(RESULT_V,V1,V2) \
MAT3_SET_VEC(RESULT_V, (V1)[0]*(V2)[0], (V1)[1]*(V2)[1], \
(V1)[2]*(V2)[2])
/* Sets RESULT_V to the linear combination of V1 and V2, scaled by
* SCALE1 and SCALE2, respectively */
#define MAT3_LINEAR_COMB(RESULT_V,SCALE1,V1,SCALE2,V2) \
MAT3_SET_VEC(RESULT_V, (SCALE1)*(V1)[0] + (SCALE2)*(V2)[0], \
(SCALE1)*(V1)[1] + (SCALE2)*(V2)[1], \
(SCALE1)*(V1)[2] + (SCALE2)*(V2)[2])
/* Several of the vector macros are useful for homogeneous-coord vectors */
#define MAT3_SET_HVEC(V,X,Y,Z,W) ((V)[0]=(X), (V)[1]=(Y), \
(V)[2]=(Z), (V)[3]=(W))
#define MAT3_COPY_HVEC(TO,FROM) ((TO)[0] = (FROM)[0], \
(TO)[1] = (FROM)[1], \
(TO)[2] = (FROM)[2], \
(TO)[3] = (FROM)[3])
#define MAT3_SCALE_HVEC(RESULT_V,V,SCALE) \
MAT3_SET_HVEC(RESULT_V, (V)[0]*(SCALE), (V)[1]*(SCALE), \
(V)[2]*(SCALE), (V)[3]*(SCALE))
#define MAT3_ADD_HVEC(RESULT_V,V1,V2) \
MAT3_SET_HVEC(RESULT_V, (V1)[0]+(V2)[0], (V1)[1]+(V2)[1], \
(V1)[2]+(V2)[2], (V1)[3]+(V2)[3])
#define MAT3_SUB_HVEC(RESULT_V,V1,V2) \
MAT3_SET_HVEC(RESULT_V, (V1)[0]-(V2)[0], (V1)[1]-(V2)[1], \
(V1)[2]-(V2)[2], (V1)[3]-(V2)[3])
#define MAT3_MULT_HVEC(RESULT_V,V1,V2) \
MAT3_SET_HVEC(RESULT_V, (V1)[0]*(V2)[0], (V1)[1]*(V2)[1], \
(V1)[2]*(V2)[2], (V1)[3]*(V2)[3])
/* ------------------------------ Entries ------------------------------- */
/* In MAT3geom.c */
void MAT3direction_matrix (MAT3mat result_mat, MAT3mat mat);
int MAT3normal_matrix (MAT3mat result_mat, MAT3mat mat);
void MAT3rotate (MAT3mat result_mat, MAT3vec axis, double angle_in_radians);
void MAT3translate (MAT3mat result_mat, MAT3vec trans);
void MAT3scale (MAT3mat result_mat, MAT3vec scale);
void MAT3shear(MAT3mat result_mat, double xshear, double yshear);
/* In MAT3mat.c */
void MAT3identity(MAT3mat);
void MAT3zero(MAT3mat);
void MAT3copy (MAT3mat to, MAT3mat from);
void MAT3mult (MAT3mat result, MAT3mat, MAT3mat);
void MAT3transpose (MAT3mat result, MAT3mat);
int MAT3invert (MAT3mat result, MAT3mat);
void MAT3print (MAT3mat, FILE *fp);
void MAT3print_formatted (MAT3mat, FILE *fp,
char *title, char *head, char *format, char *tail);
extern int MAT3equal( void );
extern double MAT3trace( void );
extern int MAT3power( void );
extern int MAT3column_reduce( void );
extern int MAT3kernel_basis( void );
/* In MAT3vec.c */
void MAT3mult_vec(MAT3vec result_vec, MAT3vec vec, MAT3mat mat);
int MAT3mult_hvec (MAT3hvec result_vec, MAT3hvec vec, MAT3mat mat, int normalize);
void MAT3cross_product(MAT3vec result,MAT3vec,MAT3vec);
void MAT3perp_vec(MAT3vec result_vec, MAT3vec vec, int is_unit);
#endif /* MAT3_HAS_BEEN_INCLUDED */