/*!
* \ingroup matrix
*/
void
lib3ds_matrix_camera(Lib3dsMatrix matrix, Lib3dsVector pos,
Lib3dsVector tgt, Lib3dsFloat roll)
{
Lib3dsMatrix M,R;
Lib3dsVector x, y, z;
lib3ds_vector_sub(y, tgt, pos);
lib3ds_vector_normalize(y);
z[0] = 0;
z[1] = 0;
z[2] = 1.0;
lib3ds_vector_cross(x, y, z);
lib3ds_vector_cross(z, x, y);
lib3ds_vector_normalize(x);
lib3ds_vector_normalize(y);
lib3ds_matrix_identity(M);
M[0][0] = x[0];
M[1][0] = x[1];
M[2][0] = x[2];
M[0][1] = y[0];
M[1][1] = y[1];
M[2][1] = y[2];
M[0][2] = z[0];
M[1][2] = z[1];
M[2][2] = z[2];
lib3ds_matrix_identity(R);
lib3ds_matrix_rotate_y(R, roll);
lib3ds_matrix_mul(matrix, R,M);
lib3ds_matrix_translate_xyz(matrix, -pos[0],-pos[1],-pos[2]);
}
/*!
* Compute a vector normal to two line segments.
*
* Computes the normal vector to the lines b-a and b-c.
*
* \param n Returned normal vector.
* \param a Endpoint of first line.
* \param b Base point of both lines.
* \param c Endpoint of second line.
*/
void
lib3ds_vector_normal(float n[3], float a[3], float b[3], float c[3]) {
float p[3], q[3];
lib3ds_vector_sub(p, c, b);
lib3ds_vector_sub(q, a, b);
lib3ds_vector_cross(n, p, q);
lib3ds_vector_normalize(n);
}
/*!
* Compute a vector normal to two line segments.
*
* Computes the normal vector to the lines b-a and b-c.
*
* \param n Returned normal vector.
* \param a Endpoint of first line.
* \param b Base point of both lines.
* \param c Endpoint of second line.
*
* \ingroup vector
*/
void
lib3ds_vector_normal(Lib3dsVector n, Lib3dsVector a, Lib3dsVector b, Lib3dsVector c)
{
Lib3dsVector p,q;
lib3ds_vector_sub(p,c,b);
lib3ds_vector_sub(q,a,b);
lib3ds_vector_cross(n,p,q);
lib3ds_vector_normalize(n);
}
/*!
* Compute a camera matrix based on position, target and roll.
*
* Generates a translate/rotate matrix that maps world coordinates
* to camera coordinates. Resulting matrix does not include perspective
* transform.
*
* \param matrix Destination matrix.
* \param pos Camera position
* \param tgt Camera target
* \param roll Roll angle
*
* \ingroup matrix
*/
void
lib3ds_matrix_camera(Lib3dsMatrix matrix, Lib3dsVector pos,
Lib3dsVector tgt, Lib3dsFloat roll)
{
Lib3dsMatrix M;
Lib3dsVector x, y, z;
lib3ds_vector_sub(y, tgt, pos);
lib3ds_vector_normalize(y);
if (y[0] != 0. || y[1] != 0) {
z[0] = 0;
z[1] = 0;
z[2] = 1.0;
}
else { /* Special case: looking straight up or down z axis */
z[0] = -1.0;
z[1] = 0;
z[2] = 0;
}
lib3ds_vector_cross(x, y, z);
lib3ds_vector_cross(z, x, y);
lib3ds_vector_normalize(x);
lib3ds_vector_normalize(z);
lib3ds_matrix_identity(M);
M[0][0] = x[0];
M[1][0] = x[1];
M[2][0] = x[2];
M[0][1] = y[0];
M[1][1] = y[1];
M[2][1] = y[2];
M[0][2] = z[0];
M[1][2] = z[1];
M[2][2] = z[2];
lib3ds_matrix_identity(matrix);
lib3ds_matrix_rotate_y(matrix, roll);
lib3ds_matrix_mult(matrix, M);
lib3ds_matrix_translate_xyz(matrix, -pos[0],-pos[1],-pos[2]);
}
/*!
* Compute a camera matrix based on position, target and roll.
*
* Generates a translate/rotate matrix that maps world coordinates
* to camera coordinates. Resulting matrix does not include perspective
* transform.
*
* \param matrix Destination matrix.
* \param pos Camera position
* \param tgt Camera target
* \param roll Roll angle
*/
void
lib3ds_matrix_camera(float matrix[4][4], float pos[3], float tgt[3], float roll) {
float M[4][4];
float x[3], y[3], z[3];
lib3ds_vector_sub(y, tgt, pos);
lib3ds_vector_normalize(y);
if (y[0] != 0. || y[1] != 0) {
z[0] = 0;
z[1] = 0;
z[2] = 1.0;
} else { /* Special case: looking straight up or down z axis */
z[0] = -1.0;
z[1] = 0;
z[2] = 0;
}
lib3ds_vector_cross(x, y, z);
lib3ds_vector_cross(z, x, y);
lib3ds_vector_normalize(x);
lib3ds_vector_normalize(z);
lib3ds_matrix_identity(M);
M[0][0] = x[0];
M[1][0] = x[1];
M[2][0] = x[2];
M[0][1] = y[0];
M[1][1] = y[1];
M[2][1] = y[2];
M[0][2] = z[0];
M[1][2] = z[1];
M[2][2] = z[2];
lib3ds_matrix_identity(matrix);
lib3ds_matrix_rotate(matrix, roll, 0, 1, 0);
lib3ds_matrix_mult(matrix, matrix, M);
lib3ds_matrix_translate(matrix, -pos[0], -pos[1], -pos[2]);
}
/*!
* 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);
}