raymaths.h

用于2维的射线追踪

#ifndef __RAYMATHS_H__
#define __RAYMATHS_H__

#include <mesh/cellinfo.h>
/*
 * Stephane Genaud. 
 *
 * temporary basic maths used for ray. Should move to
 * raydescartes maths file if it gets used a bit more.
 *
 */

/**
 * --------------------------------------------------------------------
 * cart_distance : given points c1 and c2 expressed as cartesian      
 * coordinates, return the distance between c1 and c2                
 *--------------------------------------------------------------------
 **/
double cart_distance(struct coord_cart_t *c1, struct coord_cart_t *c2);
/**
 * --------------------------------------------------------------------
 * geo_distance : given points c1 and c2 expressed as geographic      
 * coordinates (angles in radians, depth=0 at surface), return the    
 * distance between c1 and c2 (units identical as the one used for    
 * depth)                                                             
 *--------------------------------------------------------------------
 **/
double geo_distance(struct coord_geo_t *g1, struct coord_geo_t *g2);
/**
 *--------------------------------------------------------------------
 * geo_middle : given points g1 and g2 expressed as geographic        
 * coordinates (angles are in radians), return the middle point of    
 * the segment [g1,g2] (units identical as the one used for depth)    
 *---------------------------------------------------------------------
 **/
struct coord_geo_t *geo_middle(struct coord_geo_t *g1, struct coord_geo_t *g2);
struct coord_geo_t *geo_middleb(struct coord_geo_t *g1, struct coord_geo_t *g2);

/**
 * cart2lin3D : given cartesian coordinates x,y,z, return a unique id 
 **/
blocknum_t cart2lin3D(blocknum_t x,
		   blocknum_t y,
		   blocknum_t z,
		   blocknum_t max_x,
		   blocknum_t max_y) ;
/**
 * lin2cart3d : given a unique id dest, updates the coordinates x,y,z 
 **/
void lin2cart3D(blocknum_t dest,
                blocknum_t *x,blocknum_t *y,blocknum_t *z,
                blocknum_t max_x,blocknum_t max_y) ;


int equal_z3(struct coord_z3_t p1, struct coord_z3_t p2);
struct coord_cart_t * vector_minus_vector( struct coord_cart_t *v0, struct coord_cart_t *v1);
struct coord_cart_t * vector_plus_vector( struct coord_cart_t *v0, struct coord_cart_t *v1);
struct coord_cart_t * scal_prod(float k, struct coord_cart_t *v);
struct coord_cart_t * vect_prod(struct coord_cart_t *c1, struct coord_cart_t* c2);
/**
   face_segment_intersect : computes the intersection point in Z^3 
   of a segment and a plane.
 **/

int face_segment_intersect( struct coord_cart_t *s0,
	                      struct coord_cart_t *s1,
	                      struct coord_cart_t *p0,
	                      struct coord_cart_t *n,
   	                      struct coord_cart_t **i);

int face_segment_intersect2(
     struct coord_cart_t *p1,
     struct coord_cart_t *p2,
     struct coord_cart_t *pa,
     struct coord_cart_t *pb, 
     struct coord_cart_t *pc, 
     struct coord_cart_t **i); 
     
int face_segment_intersect3(
     struct coord_cart_t *p1,
     struct coord_cart_t *p2,  
     double r,
     struct coord_cart_t **i);
     
int face_segment_intersect4(
     struct coord_cart_t *p1,
     struct coord_cart_t *p2,  
     double Beta,
     struct coord_cart_t **i);
     
int face_segment_intersect5(
     struct coord_cart_t *p1,
     struct coord_cart_t *p2,  
     struct coord_cart_t **i);  

#endif