/*!
* Calculates the vertex normals corresponding to the smoothing group
* settings for each face of a mesh.
*
* \param mesh A pointer to the mesh to calculate the normals for.
* \param normals A pointer to a buffer to store the calculated
* normals. The buffer must have the size:
* 3*3*sizeof(float)*mesh->nfaces.
*
* To allocate the normal buffer do for example the following:
* \code
* Lib3dsVector *normals = malloc(3*3*sizeof(float)*mesh->nfaces);
* \endcode
*
* To access the normal of the i-th vertex of the j-th face do the
* following:
* \code
* normals[3*j+i]
* \endcode
*/
void
lib3ds_mesh_calculate_vertex_normals(Lib3dsMesh *mesh, float (*normals)[3]) {
Lib3dsFaces **fl;
Lib3dsFaces *fa;
int i, j;
if (!mesh->nfaces) {
return;
}
fl = (Lib3dsFaces**)calloc(sizeof(Lib3dsFaces*), mesh->nvertices);
fa = (Lib3dsFaces*)malloc(sizeof(Lib3dsFaces) * 3 * mesh->nfaces);
for (i = 0; i < mesh->nfaces; ++i) {
for (j = 0; j < 3; ++j) {
Lib3dsFaces* l = &fa[3*i+j];
float p[3], q[3], n[3];
float len, weight;
l->index = i;
l->next = fl[mesh->faces[i].index[j]];
fl[mesh->faces[i].index[j]] = l;
lib3ds_vector_sub(p, mesh->vertices[mesh->faces[i].index[j<2? j + 1 : 0]], mesh->vertices[mesh->faces[i].index[j]]);
lib3ds_vector_sub(q, mesh->vertices[mesh->faces[i].index[j>0? j - 1 : 2]], mesh->vertices[mesh->faces[i].index[j]]);
lib3ds_vector_cross(n, p, q);
len = lib3ds_vector_length(n);
if (len > 0) {
weight = (float)atan2(len, lib3ds_vector_dot(p, q));
lib3ds_vector_scalar_mul(l->normal, n, weight / len);
} else {
lib3ds_vector_zero(l->normal);
}
}
}
for (i = 0; i < mesh->nfaces; ++i) {
Lib3dsFace *f = &mesh->faces[i];
for (j = 0; j < 3; ++j) {
float n[3];
Lib3dsFaces *p;
Lib3dsFace *pf;
assert(mesh->faces[i].index[j] < mesh->nvertices);
if (f->smoothing_group) {
unsigned smoothing_group = f->smoothing_group;
lib3ds_vector_zero(n);
for (p = fl[mesh->faces[i].index[j]]; p; p = p->next) {
pf = &mesh->faces[p->index];
if (pf->smoothing_group & f->smoothing_group)
smoothing_group |= pf->smoothing_group;
}
for (p = fl[mesh->faces[i].index[j]]; p; p = p->next) {
pf = &mesh->faces[p->index];
if (smoothing_group & pf->smoothing_group) {
lib3ds_vector_add(n, n, p->normal);
}
}
} else {
lib3ds_vector_copy(n, fa[3*i+j].normal);
}
lib3ds_vector_normalize(n);
lib3ds_vector_copy(normals[3*i+j], n);
}
}
free(fa);
free(fl);
}
/*!
* Main display function; called whenever the scene needs to be redrawn.
*/
static void
display(void)
{
Lib3dsNode *c,*t;
Lib3dsFloat fov, roll;
float near, far, dist;
float *campos;
float *tgt;
Lib3dsMatrix M;
Lib3dsCamera *cam;
Lib3dsVector v;
Lib3dsNode *p;
if( file != NULL && file->background.solid.use )
glClearColor(file->background.solid.col[0],
file->background.solid.col[1],
file->background.solid.col[2], 1.);
/* TODO: fog */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
if( anti_alias )
glEnable(GL_POLYGON_SMOOTH);
else
glDisable(GL_POLYGON_SMOOTH);
if (!file) {
return;
}
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, file->ambient);
c=lib3ds_file_node_by_name(file, camera, LIB3DS_CAMERA_NODE);
t=lib3ds_file_node_by_name(file, camera, LIB3DS_TARGET_NODE);
if( t != NULL )
tgt = t->data.target.pos;
if( c != NULL ) {
fov = c->data.camera.fov;
roll = c->data.camera.roll;
campos = c->data.camera.pos;
}
if ((cam = lib3ds_file_camera_by_name(file, camera)) == NULL)
return;
near = cam->near_range;
far = cam->far_range;
if (c == NULL || t == NULL) {
if( c == NULL ) {
fov = cam->fov;
roll = cam->roll;
campos = cam->position;
}
if( t == NULL )
tgt = cam->target;
}
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
/* KLUDGE alert: OpenGL can't handle a near clip plane of zero,
* so if the camera's near plane is zero, we give it a small number.
* In addition, many .3ds files I've seen have a far plane that's
* much too close and the model gets clipped away. I haven't found
* a way to tell OpenGL not to clip the far plane, so we move it
* further away. A factor of 10 seems to make all the models I've
* seen visible.
*/
if( near <= 0. ) near = far * .001;
gluPerspective( fov, 1.0*gl_width/gl_height, near, far);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(-90, 1.0,0,0);
/* User rotates the view about the target point */
lib3ds_vector_sub(v, tgt, campos);
dist = lib3ds_vector_length(v);
glTranslatef(0.,dist, 0.);
glRotatef(view_rotx, 1., 0., 0.);
glRotatef(view_roty, 0., 1., 0.);
glRotatef(view_rotz, 0., 0., 1.);
glTranslatef(0.,-dist, 0.);
lib3ds_matrix_camera(M, campos, tgt, roll);
glMultMatrixf(&M[0][0]);
/* Lights. Set them from light nodes if possible. If not, use the
* light objects directly.
*/
{
static const GLfloat a[] = {0.0f, 0.0f, 0.0f, 1.0f};
static GLfloat c[] = {1.0f, 1.0f, 1.0f, 1.0f};
static GLfloat p[] = {0.0f, 0.0f, 0.0f, 1.0f};
Lib3dsLight *l;
int li=GL_LIGHT0;
for (l=file->lights; l; l=l->next) {
glEnable(li);
light_update(l);
c[0] = l->color[0];
c[1] = l->color[1];
c[2] = l->color[2];
glLightfv(li, GL_AMBIENT, a);
glLightfv(li, GL_DIFFUSE, c);
glLightfv(li, GL_SPECULAR, c);
p[0] = l->position[0];
p[1] = l->position[1];
p[2] = l->position[2];
glLightfv(li, GL_POSITION, p);
if (l->spot_light) {
p[0] = l->spot[0] - l->position[0];
p[1] = l->spot[1] - l->position[1];
p[2] = l->spot[2] - l->position[2];
glLightfv(li, GL_SPOT_DIRECTION, p);
}
++li;
}
}
if( show_object )
{
for (p=file->nodes; p!=0; p=p->next) {
render_node(p);
}
}
if( show_bounds )
draw_bounds(tgt);
if( show_cameras )
{
for( cam = file->cameras; cam != NULL; cam = cam->next )
{
lib3ds_matrix_camera(M, cam->position, cam->target, cam->roll);
lib3ds_matrix_inv(M);
glPushMatrix();
glMultMatrixf(&M[0][0]);
glScalef(size/20, size/20, size/20);
glCallList(cameraList);
glPopMatrix();
}
}
if( show_lights )
{
Lib3dsLight *light;
for( light = file->lights; light != NULL; light = light->next )
draw_light(light->position, light->color);
glMaterialfv(GL_FRONT, GL_EMISSION, black);
}
glutSwapBuffers();
}
