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/*
* Pure Data Packet module. mesh object specification
* Copyright (c) by Tom Schouten <pdp@zzz.kotnet.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
/* a very naive approach to triangular meshes */
#ifndef PDP_MESH_H
#define PDP_MESH_H
#include "pdp_list.h"
/* VERTEX type
a vertex has a coordinate and normal vector
a list of triangles it is connected to
and a list of vertexes it is connected to (these count as links) */
typedef struct _vertex
{
float c[3]; // coordinates
float n[3]; // normal (or force vector)
t_pdp_list *trilist;
t_pdp_list *vertlist;
} t_vertex;
/* TRIANGLE type:
a triangle consist of
- 3 vertices
- 3 optional median vertices (subdivision intermediates) */
typedef struct _triangle
{
t_vertex *v[3]; // vertices
t_vertex *m[3]; // median vertices
float n[3]; //triangle normal
} t_triangle;
/* MESH type:
a mesh is a list of vertices
and a list of triangles (connections) */
typedef struct _mesh
{
t_pdp_list *triangles;
t_pdp_list *vertices;
int normal_type;
int refine_type;
} t_mesh;
/* object configuratie */
#define MESH_NORMAL_SPHERE 1 // normal = origin -> vertex
#define MESH_NORMAL_PRISM 2 // normal = center of gravity of prism base -> vertex
#define MESH_NORMAL_RANDOM 3 // normal = random vector
#define MESH_NORMAL_AVERAGE 4 // normal = average of surrounding triangles
/* refinement method */
#define MESH_REFINE_THREE 1 // triangle -> 3 triangles connecting center of gravity
#define MESH_REFINE_FOUR 2 // triangle -> 4 triangles connecting link medians
// vector utility stuff
// fixed size iterators for the lazy
#define I3(i) for(i=0; i<3; i++)
#define I4(i) for(i=0; i<4; i++)
static inline float _vector3_dot(float *v0, float *v1)
{
float d;
d = v0[0] * v1[0];
d += v0[1] * v1[1];
d += v0[2] * v1[2];
return d;
}
static inline void _vector3_scale(float *v, float s)
{
int k;
I3(k) v[k] *= s;
}
static inline float _vector3_normalize(float *v)
{
float length = 0;
float scale = 0;
int k;
length = sqrt(_vector3_dot(v,v));
scale = 1.0f / length;
_vector3_scale(v, scale);
return length;
}
static inline void _vector3_cross(float *a, float *b, float *r)
{
r[0] = a[1]*b[2] - a[2]*b[1];
r[1] = a[2]*b[0] - a[0]*b[2];
r[2] = a[0]*b[1] - a[1]*b[0];
}
static inline float _rand(void)
{
long int r = random();
float f;
r -= (RAND_MAX >> 1);
f = (float)r;
f *= (2.0f / (float)RAND_MAX);
return f;
}
/* VERTEX methods */
void vertex_add_triangle(t_vertex *v, t_triangle *t);
void vertex_remove_triangle(t_vertex *v, t_triangle *t);
void vertex_add_neighbour(t_vertex *v, t_vertex *neighbour);
/* constructor/destructors are "private"
they may only be called by the mesh object to ensure
the vector list stays sound (i.e. without duplicates) */
void _vertex_free(t_vertex *v);
t_vertex *_vertex_new(float *c, float *n);
void vertex_compute_normal_random(t_vertex *v);
void vertex_compute_normal_sphere(t_vertex *v);
void vertex_compute_normal_prism(t_vertex *v);
float vertex_normalize(t_vertex *v);
/* TRIANGLE methods */
/* create triangle (a connection between 3 vertices):
counterclockwize with facing front
this method is "private"
you can only create triangles as part of a mesh */
t_triangle *_triangle_new(t_vertex *v0, t_vertex *v1, t_vertex *v2);
/* delete a triangle, disconnecting the vertices */
void _triangle_free(t_triangle *t);
/* get triangle that shares the link between v0 and v1 */
t_triangle *triangle_neighbour(t_triangle *t, t_vertex *v0, t_vertex *v1);
/* add a median vector to a link in a triangle
note: vertices must be in triangle, or behaviour is undefined */
void triangle_add_median(t_triangle *t, t_vertex *v0, t_vertex *v1, t_vertex *median);
/* MESH methods */
/* add and remove methods for vertices and triangles */
t_vertex *mesh_vertex_add(t_mesh *m, float *c, float *n);
void mesh_vertex_remove(t_mesh *m, t_vertex *v);
t_triangle *mesh_triangle_add(t_mesh *m, t_vertex *v0, t_vertex *v1, t_vertex *v2);
void mesh_triangle_remove(t_mesh *m, t_triangle *t);
/* calculate normals */
void mesh_calculate_normals(t_mesh *m);
/* split a triangle in 4, using the intermedia median vertex storage */
void mesh_split_four(t_mesh *m, t_triangle *old_t);
/* split a triangle in 3 */
void mesh_split_three(t_mesh *m, t_triangle *old_t);
void mesh_split_all_four(t_mesh *m);
void mesh_split_all_three(t_mesh *m);
void mesh_split_random_three(t_mesh *m);
void mesh_free(t_mesh *m);
t_mesh *_mesh_new(void);
/* new tetra */
t_mesh *mesh_new_tetra(void);
void _mesh_relax_compute_resultant_spring(t_mesh *m, float *center, float d0, float r0);
void _mesh_relax_apply_force(t_mesh *m, float k);
void mesh_compute_center(t_mesh *m, float *c);
void mesh_translate(t_mesh *m, float *c);
/* relax a mesh (move toward equal link length) */
void mesh_relax(t_mesh *m, float step, float d0, float r0);
/* print some debug information */
void mesh_debug(t_mesh *m);
#endif
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