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2013-12-03 8db569a42c280be13ea9edbe4c528e0041b6fd3f

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d7639a	1	#include<stdlib.h>
SP	2	#include<stdio.h>
	3	#include "general.h"
	4	#include "triangle.h"
	5	#include<math.h>
	6
bb77ca	7	/** @brief Prepares the list for triangles.
SP	8	*
	9	* Create empty list for holding the information on triangles. Triangles are
	10	* added later on with triangle_add().
	11	* Returns pointer to the tlist datastructure it has created. This pointer must
	12	* be assigned to some variable or it will be lost.
	13	*
	14	*
	15	* Example of usage:
	16	* ts_triangle_list *tlist;
	17	* tlist=triangle_data_free();
	18	*
	19	* Initalized data structure for holding the information on triangles.
	20	*
	21	*/
a2a676	22	ts_triangle_list *init_triangle_list(){
SP	23	ts_triangle_list tlist=(ts_triangle_list )malloc(sizeof(ts_triangle_list));
d7639a	24	tlist->n = 0;
a2a676	25	tlist->tria=NULL;
SP	26	return tlist;
d7639a	27	}
SP	28
bb77ca	29	/** @brief Add the triangle to the triangle list and create necessary data
SP	30	* structures.
	31	*
	32	* Add the triangle ts_triangle with ts_triangle_data to the ts_triangle_list.
	33	* The triangle list is resized, the ts_triangle is allocated and
	34	* ts_triangle_data is allocated and zeroed. The function receives 4 arguments:
	35	* ts_triangle_list tlist as list of triangles and 3 ts_vertex vtx as
	36	* vertices that are used to form a triangle. Returns a pointer to newly
	37	* created triangle. This pointer doesn't need assigning, since it is
	38	* referenced by triangle list.
	39	*
	40	* WARNING: Function can be accelerated a bit by removing the NULL checks.
	41	* However the time gained by removal doesn't justify the time spent by
	42	* debugging stupid NULL pointers.
	43	*
	44	* Example of usage:
	45	* triangle_add(tlist, vlist->vtx[1], vlist->vtx[2], vlist->vtx[3]);
	46	*
	47	* Creates a triangle with given vertices and puts it into the list.
	48	*
	49	*/
a2a676	50	ts_triangle triangle_add(ts_triangle_list tlist, ts_vertex vtx1, ts_vertex vtx2, ts_vertex *vtx3){
SP	51	if(vtx1==NULL \|\| vtx2==NULL \|\| vtx3==NULL){
	52	return NULL;
	53	}
d7639a	54	tlist->n++;
a2a676	55	tlist->tria=(ts_triangle *)realloc(tlist->tria,tlist->nsizeof(ts_triangle *));
SP	56	if(tlist->tria==NULL) fatal("Cannot reallocate memory for additional ts_triangle.",5);
	57
	58	tlist->tria[tlist->n-1]=(ts_triangle *)calloc(1,sizeof(ts_triangle));
	59	if(tlist->tria[tlist->n-1]==NULL) fatal("Cannot reallocate memory for additional ts_triangle.",5);
41a035	60	// tlist->tria[tlist->n-1]->data=(ts_triangle_data *)calloc(1,sizeof(ts_triangle_data));
a2a676	61
d7639a	62	//NOW insert vertices!
a2a676	63	tlist->tria[tlist->n - 1]->idx=tlist->n-1;
41a035	64	tlist->tria[tlist->n - 1]->vertex[0]=vtx1;
SP	65	tlist->tria[tlist->n - 1]->vertex[1]=vtx2;
	66	tlist->tria[tlist->n - 1]->vertex[2]=vtx3;
a2a676	67	return tlist->tria[tlist->n-1];
d7639a	68	}
SP	69
bb77ca	70	/** @brief Add the neigbour to triangles.
SP	71	*
	72	* Add the neigbour to the list of neighbouring triangles. The
	73	* neighbouring triangles are those, who share two vertices. Function resizes
	74	* the list and adds the pointer to neighbour. It receives two arguments of
dac2e5	75	* ts_triangle type. It then adds second triangle to the list of first
SP	76	* triangle, but not the opposite. Upon
bb77ca	77	* success it returns TS_SUCCESS, upon detecting NULL pointers
SP	78	* returns TS_FAIL and it FATALY ends when the data structure
	79	* cannot be resized.
	80	*
	81	*
	82	* WARNING: Function can be accelerated a bit by removing the NULL checks.
	83	* However the time gained by removal doesn't justify the time spent by
	84	* debugging stupid NULL pointers.
	85	*
	86	* Example of usage:
	87	* triangle_remove_neighbour(tlist->tria[3], tlist->tria[4]);
	88	*
	89	* Triangles 3 and 4 are not neighbours anymore.
	90	*
	91	*/
d7639a	92
SP	93	ts_bool triangle_add_neighbour(ts_triangle tria, ts_triangle ntria){
a2a676	94	if(tria==NULL \|\| ntria==NULL) return TS_FAIL;
SP	95	/*TODO: check if the neighbour already exists! Now there is no such check
	96	* because of the performance issue. */
41a035	97	tria->neigh_no++;
SP	98	tria->neigh=realloc(tria->neigh,tria->neigh_nosizeof(ts_triangle ));
	99	if(tria->neigh == NULL)
d7639a	100	fatal("Reallocation of memory failed during insertion of triangle neighbour in triangle_add_neighbour",3);
41a035	101	tria->neigh[tria->neigh_no-1]=ntria;
3131dc	102
SP	103
a2a676	104	/* we repeat the procedure for the neighbour */
3131dc	105	/* ntria->data->neigh_no++;
a2a676	106	ntria->data->neigh=realloc(ntria->data->neigh,ntria->data->neigh_nosizeof(ts_triangle ));
SP	107	if(ntria->data->neigh == NULL)
	108	fatal("Reallocation of memory failed during insertion of triangle neighbour in triangle_add_neighbour",3);
	109	ntria->data->neigh[ntria->data->neigh_no-1]=tria;
3131dc	110	*/
d7639a	111	return TS_SUCCESS;
SP	112	}
	113
bb77ca	114	/** @brief Remove the neigbours from triangle.
SP	115	*
	116	* Removes the neigbour from the list of neighbouring triangles. The
	117	* neighbouring triangles are those, who share two vertices. Function resizes
	118	* the list and deletes the pointer to neighbour. It receives two arguments of
	119	* ts_triangle type. It then removes eachother form eachother's list. Upon
	120	* success it returns TS_SUCCESS, upon failure to find the triangle in the
	121	* neighbour list returns TS_FAIL and it FATALY ends when the datastructure
	122	* cannot be resized.
	123	*
	124	* WARNING: The function doesn't check whether the pointer is NULL or invalid. It is the
	125	* job of programmer to make sure the pointer is valid.
	126	*
	127	* WARNING: Function is slow. Do not use it often!
	128	*
	129	* Example of usage:
	130	* triangle_remove_neighbour(tlist->tria[3], tlist->tria[4]);
	131	*
	132	* Triangles 3 and 4 are not neighbours anymore.
	133	*
	134	*/
d7639a	135	ts_bool triangle_remove_neighbour(ts_triangle tria, ts_triangle ntria){
a2a676	136	ts_uint i,j=0;
SP	137	if(tria==NULL \|\| ntria==NULL) return TS_FAIL;
	138
41a035	139	for(i=0;i<tria->neigh_no;i++){
SP	140	if(tria->neigh[i]!=ntria){
	141	tria->neigh[j]=tria->neigh[i];
d7639a	142	j++;
SP	143	}
	144	}
a2a676	145	if(j==i) {
SP	146	return TS_FAIL;
	147	//fatal("In triangle_remove_neighbour: Specified neighbour does not exist for given triangle",3);
	148	}
41a035	149	tria->neigh_no--;
e19e79	150	// fprintf(stderr,"*** tria_number=%d\n",tria->neigh_no);
41a035	151	tria->neigh=(ts_triangle *)realloc(tria->neigh,tria->neigh_nosizeof(ts_triangle *));
SP	152	if(tria->neigh == NULL){
a2a676	153	fatal("Reallocation of memory failed during removal of vertex neighbour in triangle_remove_neighbour",100);
SP	154	}
	155	/* we repeat the procedure for neighbour */
e19e79	156	j=0;
41a035	157	for(i=0;i<ntria->neigh_no;i++){
SP	158	if(ntria->neigh[i]!=tria){
	159	ntria->neigh[j]=ntria->neigh[i];
a2a676	160	j++;
SP	161	}
	162	}
	163	if(j==i) {
	164	return TS_FAIL;
	165	//fatal("In triangle_remove_neighbour: Specified neighbour does not exist for given triangle",3);
	166	}
41a035	167	ntria->neigh_no--;
e19e79	168	// fprintf(stderr,"*** ntria_number=%d\n",ntria->neigh_no);
41a035	169	ntria->neigh=(ts_triangle *)realloc(ntria->neigh,ntria->neigh_nosizeof(ts_triangle *));
SP	170	if(ntria->neigh == NULL){
a2a676	171	fatal("Reallocation of memory failed during removal of vertex neighbour in triangle_remove_neighbour",100);
SP	172	}
d7639a	173	return TS_SUCCESS;
SP	174	}
	175
bb77ca	176
SP	177	/** @brief Calculates normal vector of the triangle.
	178
	179	*
	180	* Calculate normal vector of the triangle (xnorm, ynorm and znorm) and stores
	181	* information in underlying ts_triangle_data data_structure.
	182	*
	183	* Function receives one argument of type ts_triangle. It should be corectly
	184	* initialized with underlying data structure of type ts_triangle_data. the
	185	* result is stored in triangle->data->xnorm, triangle->data->ynorm,
	186	* triangle->data->znorm. Returns TS_SUCCESS on completion.
	187	*
	188	* NOTE: Function uses math.h library. pow function implementation is selected
	189	* accordind to the setting in genreal.h
	190	*
	191	* Example of usage:
	192	* triangle_normal_vector(tlist->tria[3]);
	193	*
	194	* Computes normals and stores information into tlist->tria[3]->xnorm,
	195	* tlist->tria[3]->ynorm, tlist->tria[3]->znorm.
	196	*
	197	*/
d7639a	198	ts_bool triangle_normal_vector(ts_triangle *tria){
SP	199	ts_double x21,x31,y21,y31,z21,z31,xden;
8f6a69	200	x21=tria->vertex[1]->x - tria->vertex[0]->x;
SP	201	x31=tria->vertex[2]->x - tria->vertex[0]->x;
	202	y21=tria->vertex[1]->y - tria->vertex[0]->y;
	203	y31=tria->vertex[2]->y - tria->vertex[0]->y;
	204	z21=tria->vertex[1]->z - tria->vertex[0]->z;
	205	z31=tria->vertex[2]->z - tria->vertex[0]->z;
d7639a	206
41a035	207	tria->xnorm=y21z31 - z21y31;
SP	208	tria->ynorm=z21x31 - x21z31;
	209	tria->znorm=x21y31 - y21x31;
	210	xden=tria->xnorm*tria->xnorm +
	211	tria->ynorm*tria->ynorm +
	212	tria->znorm*tria->znorm;
d7639a	213	#ifdef TS_DOUBLE_DOUBLE
SP	214	xden=sqrt(xden);
	215	#endif
	216	#ifdef TS_DOUBLE_FLOAT
	217	xden=sqrtf(xden);
	218	#endif
	219	#ifdef TS_DOUBLE_LONGDOUBLE
	220	xden=sqrtl(xden);
	221	#endif
41a035	222	tria->xnorm=tria->xnorm/xden;
SP	223	tria->ynorm=tria->ynorm/xden;
	224	tria->znorm=tria->znorm/xden;
c9d07c	225
SP	226	/* Here it is an excellent point to recalculate volume of the triangle and
	227	* store it into datastructure. Volume is required at least by constant volume
	228	* calculation of vertex move and bondflip and spherical harmonics. */
	229	tria->volume=(tria->vertex[0]->x+ tria->vertex[1]->x + tria->vertex[2]->x) * tria->xnorm +
	230	(tria->vertex[0]->y+ tria->vertex[1]->y + tria->vertex[2]->y) * tria->ynorm +
	231	(tria->vertex[0]->z+ tria->vertex[1]->z + tria->vertex[2]->z) * tria->znorm;
	232	tria->volume=-xden*tria->volume/18.0;
	233	/* Also, area can be calculated in each triangle */
	234	tria->area=xden/2;
	235
	236
d7639a	237	return TS_SUCCESS;
SP	238	}
	239
	240
bb77ca	241
SP	242
	243
d7639a	244
bb77ca	245	/** @brief Frees the memory allocated for data structure of triangle list
SP	246	* (ts_triangle_list)
	247	*
	248	* Function frees the memory of ts_triangle_list previously allocated. It
	249	* accepts one argument, the address of data structure. It destroys all
	250	* ts_triangle's in the list with underlying data (by calling
	251	* triangle_data_free()), and the list itself.
	252	*
	253	* Should be used eveytime the deletion of triangle list (created by
	254	* init_triangle_list() and altered by add_triangle() or remove_triangle()) is desired.
	255	*
	256	* WARNING: The function doesn't check whether the pointer is NULL or invalid. It is the
	257	* job of programmer to make sure the pointer is valid.
	258	*
	259	* WARNING: Careful when destroying triangle lists. There could be pointers to
	260	* that information remaining in structures like vertex_data. This pointers
	261	* will be rendered invalid by this operation and should not be used anymore.
	262	*
	263	* Example of usage:
	264	* triangle_list_free(tlist);
	265	*
	266	* Clears all the information on triangles.
	267	*
	268	*/
d7639a	269	ts_bool triangle_list_free(ts_triangle_list *tlist){
a2a676	270	ts_uint i;
d7639a	271	for(i=0;i<tlist->n;i++){
41a035	272	if(tlist->tria[i]->neigh!=NULL) free(tlist->tria[i]->neigh);
a2a676	273	free(tlist->tria[i]);
d7639a	274	}
a2a676	275	free(tlist->tria);
SP	276	free(tlist);
d7639a	277	return TS_SUCCESS;
SP	278	}
	279