trisurf-ng.git - Gitblit

Samo Penic

2010-12-27 3131dcbf73ff8a0699a688119d57eaf386f49590

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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);
	60	tlist->tria[tlist->n-1]->data=(ts_triangle_data *)calloc(1,sizeof(ts_triangle_data));
	61
d7639a	62	//NOW insert vertices!
a2a676	63	tlist->tria[tlist->n - 1]->idx=tlist->n-1;
SP	64	tlist->tria[tlist->n - 1]->data->vertex[0]=vtx1;
	65	tlist->tria[tlist->n - 1]->data->vertex[1]=vtx2;
	66	tlist->tria[tlist->n - 1]->data->vertex[2]=vtx3;
	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
	75	* ts_triangle type. It then adds eachother to eachother's list. Upon
	76	* success it returns TS_SUCCESS, upon detecting NULL pointers
	77	* returns TS_FAIL and it FATALY ends when the data structure
	78	* cannot be resized.
	79	*
	80	*
	81	* WARNING: Function can be accelerated a bit by removing the NULL checks.
	82	* However the time gained by removal doesn't justify the time spent by
	83	* debugging stupid NULL pointers.
	84	*
	85	* Example of usage:
	86	* triangle_remove_neighbour(tlist->tria[3], tlist->tria[4]);
	87	*
	88	* Triangles 3 and 4 are not neighbours anymore.
	89	*
	90	*/
d7639a	91
SP	92	ts_bool triangle_add_neighbour(ts_triangle tria, ts_triangle ntria){
a2a676	93	if(tria==NULL \|\| ntria==NULL) return TS_FAIL;
SP	94	/*TODO: check if the neighbour already exists! Now there is no such check
	95	* because of the performance issue. */
	96	tria->data->neigh_no++;
	97	tria->data->neigh=realloc(tria->data->neigh,tria->data->neigh_nosizeof(ts_triangle ));
	98	if(tria->data->neigh == NULL)
d7639a	99	fatal("Reallocation of memory failed during insertion of triangle neighbour in triangle_add_neighbour",3);
a2a676	100	tria->data->neigh[tria->data->neigh_no-1]=ntria;
3131dc	101
SP	102
a2a676	103	/* we repeat the procedure for the neighbour */
3131dc	104	/* ntria->data->neigh_no++;
a2a676	105	ntria->data->neigh=realloc(ntria->data->neigh,ntria->data->neigh_nosizeof(ts_triangle ));
SP	106	if(ntria->data->neigh == NULL)
	107	fatal("Reallocation of memory failed during insertion of triangle neighbour in triangle_add_neighbour",3);
	108	ntria->data->neigh[ntria->data->neigh_no-1]=tria;
3131dc	109	*/
d7639a	110	return TS_SUCCESS;
SP	111	}
	112
bb77ca	113	/** @brief Remove the neigbours from triangle.
SP	114	*
	115	* Removes the neigbour from the list of neighbouring triangles. The
	116	* neighbouring triangles are those, who share two vertices. Function resizes
	117	* the list and deletes the pointer to neighbour. It receives two arguments of
	118	* ts_triangle type. It then removes eachother form eachother's list. Upon
	119	* success it returns TS_SUCCESS, upon failure to find the triangle in the
	120	* neighbour list returns TS_FAIL and it FATALY ends when the datastructure
	121	* cannot be resized.
	122	*
	123	* WARNING: The function doesn't check whether the pointer is NULL or invalid. It is the
	124	* job of programmer to make sure the pointer is valid.
	125	*
	126	* WARNING: Function is slow. Do not use it often!
	127	*
	128	* Example of usage:
	129	* triangle_remove_neighbour(tlist->tria[3], tlist->tria[4]);
	130	*
	131	* Triangles 3 and 4 are not neighbours anymore.
	132	*
	133	*/
d7639a	134	ts_bool triangle_remove_neighbour(ts_triangle tria, ts_triangle ntria){
a2a676	135	ts_uint i,j=0;
SP	136	if(tria==NULL \|\| ntria==NULL) return TS_FAIL;
	137
	138	for(i=0;i<tria->data->neigh_no;i++){
	139	if(tria->data->neigh[i]!=ntria){
	140	tria->data->neigh[j]=tria->data->neigh[i];
d7639a	141	j++;
SP	142	}
	143	}
a2a676	144	if(j==i) {
SP	145	return TS_FAIL;
	146	//fatal("In triangle_remove_neighbour: Specified neighbour does not exist for given triangle",3);
	147	}
	148	tria->data->neigh_no--;
	149	tria->data->neigh=(ts_triangle *)realloc(tria->data->neigh,tria->data->neigh_nosizeof(ts_triangle *));
	150	if(tria->data->neigh == NULL){
	151	fatal("Reallocation of memory failed during removal of vertex neighbour in triangle_remove_neighbour",100);
	152	}
	153	/* we repeat the procedure for neighbour */
	154	for(i=0;i<ntria->data->neigh_no;i++){
	155	if(ntria->data->neigh[i]!=tria){
	156	ntria->data->neigh[j]=ntria->data->neigh[i];
	157	j++;
	158	}
	159	}
	160	if(j==i) {
	161	return TS_FAIL;
	162	//fatal("In triangle_remove_neighbour: Specified neighbour does not exist for given triangle",3);
	163	}
	164	ntria->data->neigh_no--;
	165	ntria->data->neigh=(ts_triangle *)realloc(ntria->data->neigh,ntria->data->neigh_nosizeof(ts_triangle *));
	166	if(ntria->data->neigh == NULL){
	167	fatal("Reallocation of memory failed during removal of vertex neighbour in triangle_remove_neighbour",100);
	168	}
d7639a	169	return TS_SUCCESS;
SP	170	}
	171
bb77ca	172
SP	173	/** @brief Calculates normal vector of the triangle.
	174
	175	*
	176	* Calculate normal vector of the triangle (xnorm, ynorm and znorm) and stores
	177	* information in underlying ts_triangle_data data_structure.
	178	*
	179	* Function receives one argument of type ts_triangle. It should be corectly
	180	* initialized with underlying data structure of type ts_triangle_data. the
	181	* result is stored in triangle->data->xnorm, triangle->data->ynorm,
	182	* triangle->data->znorm. Returns TS_SUCCESS on completion.
	183	*
	184	* NOTE: Function uses math.h library. pow function implementation is selected
	185	* accordind to the setting in genreal.h
	186	*
	187	* Example of usage:
	188	* triangle_normal_vector(tlist->tria[3]);
	189	*
	190	* Computes normals and stores information into tlist->tria[3]->xnorm,
	191	* tlist->tria[3]->ynorm, tlist->tria[3]->znorm.
	192	*
	193	*/
d7639a	194	ts_bool triangle_normal_vector(ts_triangle *tria){
SP	195	ts_double x21,x31,y21,y31,z21,z31,xden;
a2a676	196	x21=tria->data->vertex[1]->data->x - tria->data->vertex[0]->data->x;
SP	197	x31=tria->data->vertex[2]->data->x - tria->data->vertex[0]->data->x;
	198	y21=tria->data->vertex[1]->data->y - tria->data->vertex[0]->data->y;
	199	y31=tria->data->vertex[2]->data->y - tria->data->vertex[0]->data->y;
	200	z21=tria->data->vertex[1]->data->z - tria->data->vertex[0]->data->z;
	201	z31=tria->data->vertex[2]->data->z - tria->data->vertex[0]->data->z;
d7639a	202
a2a676	203	tria->data->xnorm=y21z31 - z21y31;
SP	204	tria->data->ynorm=z21x31 - x21z31;
	205	tria->data->znorm=x21y31 - y21x31;
	206	xden=tria->data->xnorm*tria->data->xnorm +
	207	tria->data->ynorm*tria->data->ynorm +
	208	tria->data->znorm*tria->data->znorm;
d7639a	209	#ifdef TS_DOUBLE_DOUBLE
SP	210	xden=sqrt(xden);
	211	#endif
	212	#ifdef TS_DOUBLE_FLOAT
	213	xden=sqrtf(xden);
	214	#endif
	215	#ifdef TS_DOUBLE_LONGDOUBLE
	216	xden=sqrtl(xden);
	217	#endif
a2a676	218	tria->data->xnorm=tria->data->xnorm/xden;
SP	219	tria->data->ynorm=tria->data->ynorm/xden;
	220	tria->data->znorm=tria->data->znorm/xden;
d7639a	221	return TS_SUCCESS;
SP	222	}
	223
	224
bb77ca	225
SP	226
	227
	228	/** @brief Frees the memory allocated for data structure of triangle data
	229	* (ts_triangle_data)
	230	*
	231	* Function frees the memory of ts_triangle_data previously allocated. It
	232	* accepts one argument, the address of data structure. It destroys all
	233	* pointers the structure might have (currently only neigh -- the pointer to
	234	* list of neighbouring triangles) and data structure itself. The return value
	235	* is always TS_SUCCESS.
	236	*
	237	* WARNING: The function doesn't check whether the pointer is NULL or invalid. It is the
	238	* job of programmer to make sure the pointer is valid.
	239	*
	240	* Example of usage:
	241	* triangle_data_free(tlist->tria[3]->data);
	242	*
	243	* Clears the data structure with all pointers.
	244	*
	245	*/
a2a676	246	ts_bool triangle_data_free(ts_triangle_data *data){
SP	247	if(data->neigh!=NULL) free(data->neigh);
	248	free(data);
d7639a	249	return TS_SUCCESS;
SP	250	}
	251
bb77ca	252	/** @brief Frees the memory allocated for data structure of triangle list
SP	253	* (ts_triangle_list)
	254	*
	255	* Function frees the memory of ts_triangle_list previously allocated. It
	256	* accepts one argument, the address of data structure. It destroys all
	257	* ts_triangle's in the list with underlying data (by calling
	258	* triangle_data_free()), and the list itself.
	259	*
	260	* Should be used eveytime the deletion of triangle list (created by
	261	* init_triangle_list() and altered by add_triangle() or remove_triangle()) is desired.
	262	*
	263	* WARNING: The function doesn't check whether the pointer is NULL or invalid. It is the
	264	* job of programmer to make sure the pointer is valid.
	265	*
	266	* WARNING: Careful when destroying triangle lists. There could be pointers to
	267	* that information remaining in structures like vertex_data. This pointers
	268	* will be rendered invalid by this operation and should not be used anymore.
	269	*
	270	* Example of usage:
	271	* triangle_list_free(tlist);
	272	*
	273	* Clears all the information on triangles.
	274	*
	275	*/
d7639a	276	ts_bool triangle_list_free(ts_triangle_list *tlist){
a2a676	277	ts_uint i;
d7639a	278	for(i=0;i<tlist->n;i++){
a2a676	279	triangle_data_free(tlist->tria[i]->data);
SP	280	free(tlist->tria[i]);
d7639a	281	}
a2a676	282	free(tlist->tria);
SP	283	free(tlist);
d7639a	284	return TS_SUCCESS;
SP	285	}
	286