struct mesh *mesh_duplicate(struct mesh *original)
{
struct mesh *copy;
copy = allocate_mesh_for_copy(original->ntriangles, original->nvertices,
original->nlines, original->tex != NULL);
if (!copy)
return copy;
copy_mesh_contents(copy, original);
return copy;
}
static struct mesh *mesh_subdivide_icosphere(struct mesh *m, int subdivisions)
{
struct mesh *m2;
int i, ntris = m->ntriangles;
if (subdivisions == 0)
return m;
/* Allocate space for the new, bigger mesh */
m2 = allocate_mesh_for_copy(m->ntriangles * 4, m->nvertices + m->ntriangles * 3, 0, 0);
if (!m2)
return NULL;
copy_mesh_contents(m2, m);
mesh_free(m);
for (i = 0; i < ntris; i++)
subdivide_triangle(m2, i);
normalize_sphere(m2);
mesh_set_spherical_vertex_normals(m2);
return mesh_subdivide_icosphere(m2, subdivisions - 1);
}
/* fabricate a tube of length h, radius r, with nfaces, parallel to x axis */
struct mesh *mesh_tube(float h, float r, float nfaces)
{
struct mesh *m;
int ntris = nfaces * 2;
int nvertices = nfaces * 2;
int i, j;
float angle, da;
float l = h / 2.0;
m = allocate_mesh_for_copy(ntris, nvertices, 0, 1);
if (!m)
return m;
m->geometry_mode = MESH_GEOMETRY_TRIANGLES;
da = 2 * M_PI / (float) nfaces;
angle = 0.0;
for (i = 0; i < nvertices; i += 2) {
m->v[i].x = -l;
m->v[i].y = r * cos(angle);
m->v[i].z = r * -sin(angle);
m->v[i + 1].x = l;
m->v[i + 1].y = m->v[i].y;
m->v[i + 1].z = m->v[i].z;
angle += da;
}
m->nvertices = nvertices;
for (i = 0; i < ntris; i += 2) {
m->t[i].v[2] = &m->v[i % nvertices];
m->t[i].v[1] = &m->v[(i + 1) % nvertices];
m->t[i].v[0] = &m->v[(i + 2) % nvertices];
m->t[i + 1].v[2] = &m->v[(i + 2) % nvertices];
m->t[i + 1].v[1] = &m->v[(i + 1) % nvertices];
m->t[i + 1].v[0] = &m->v[(i + 3) % nvertices];
}
m->ntriangles = ntris;
for (i = 0; i < ntris; i++) {
union vec3 normal;
normal = compute_triangle_normal(&m->t[i]);
m->t[i].n.x = normal.v.x;
m->t[i].n.y = normal.v.y;
m->t[i].n.z = normal.v.z;
for (j = 0; j < 3; j++) {
union vec3 normal = { { 0, -m->t[i].v[j]->y, -m->t[i].v[j]->z } };
vec3_normalize_self(&normal);
m->t[i].vnormal[j].x = normal.v.x;
m->t[i].vnormal[j].y = normal.v.y;
m->t[i].vnormal[j].z = normal.v.z;
}
}
mesh_set_flat_shading_vertex_normals(m);
for (i = 0; i < ntris; i += 2) {
mesh_set_triangle_texture_coords(m, i,
0.0, (float) ((int) ((i + 2) / 2)) * 1.0 / (float) nfaces,
1.0, (float) ((int) (i / 2)) / (float) nfaces,
0.0, (float) ((int) (i / 2)) / (float) nfaces);
mesh_set_triangle_texture_coords(m, i + 1,
1.0, (float) ((int) ((i + 2) / 2)) / (float) nfaces,
1.0, (float) ((int) (i / 2)) / (float) nfaces,
0.0, (float) ((int) ((i + 2) / 2)) / (float) nfaces);
}
m->nlines = 0;
m->radius = mesh_compute_radius(m);
mesh_graph_dev_init(m);
return m;
}
