/******************************************************************************\
Computes tile vectors for the parameter array.
\******************************************************************************/
static void compute_tile_vectors(int i)
{
c_vec3_t ab, ac;
/* Set tile normal vector */
ab = C_vec3_sub(r_globe_verts[3 * i].v.co,
r_globe_verts[3 * i + 1].v.co);
ac = C_vec3_sub(r_globe_verts[3 * i].v.co,
r_globe_verts[3 * i + 2].v.co);
r_tiles[i].normal = C_vec3_norm(C_vec3_cross(ab, ac));
r_globe_verts[3 * i].v.no = r_tiles[i].normal;
r_globe_verts[3 * i + 1].v.no = r_tiles[i].normal;
r_globe_verts[3 * i + 2].v.no = r_tiles[i].normal;
/* Centroid */
r_tiles[i].origin = C_vec3_add(r_globe_verts[3 * i].v.co,
r_globe_verts[3 * i + 1].v.co);
r_tiles[i].origin = C_vec3_add(r_tiles[i].origin,
r_globe_verts[3 * i + 2].v.co);
r_tiles[i].origin = C_vec3_divf(r_tiles[i].origin, 3.f);
/* Forward vector */
r_tiles[i].forward = C_vec3_sub(r_globe_verts[3 * i].v.co,
r_tiles[i].origin);
r_tiles[i].forward = C_vec3_norm(r_tiles[i].forward);
}
/******************************************************************************\
Use the previous camera move to calculate camera velocity and let the globe
spin by itself until it is grabbed again.
\******************************************************************************/
void R_release_cam(void)
{
cam_gradual = FALSE;
cam_momentum = TRUE;
if (c_frame - last_cam_move > 1)
return;
cam_rot_diff = C_vec3_divf(cam_rot_diff, c_frame_sec);
}
/******************************************************************************\
Subdivide each globe tile into four tiles. Partioned tile vertices are
numbered in the following manner:
3
/ \
4---5
6 2---1 9
/ \ \ / / \
7---8 0 10-11
A vertex's neighbor is the vertex of the tile that shares the next counter-
clockwise edge of the tile from that vertex.
\******************************************************************************/
static void subdivide4(void)
{
c_vec3_t mid_0_1, mid_0_2, mid_1_2;
r_globe_vertex_t *verts;
int i, i_flip, j, n[3], n_flip[3];
for (i = r_tiles_max - 1; i >= 0; i--) {
verts = r_globe_verts + 12 * i;
/* Determine which faces are flipped (over 0 vertex) */
i_flip = i < flip_limit;
for (j = 0; j < 3; j++) {
n[j] = r_globe_verts[3 * i + j].next / 3;
n_flip[j] = (n[j] < flip_limit) != i_flip;
}
/* Compute mid-point coordinates */
mid_0_1 = C_vec3_add(r_globe_verts[3 * i].v.co,
r_globe_verts[3 * i + 1].v.co);
mid_0_1 = C_vec3_divf(mid_0_1, 2.f);
mid_0_2 = C_vec3_add(r_globe_verts[3 * i].v.co,
r_globe_verts[3 * i + 2].v.co);
mid_0_2 = C_vec3_divf(mid_0_2, 2.f);
mid_1_2 = C_vec3_add(r_globe_verts[3 * i + 1].v.co,
r_globe_verts[3 * i + 2].v.co);
mid_1_2 = C_vec3_divf(mid_1_2, 2.f);
/* Bottom-right triangle */
verts[9].v.co = mid_0_2;
verts[9].next = 12 * i + 1;
verts[10].v.co = mid_1_2;
verts[10].next = 12 * n[1] + 8;
verts[11].v.co = r_globe_verts[3 * i + 2].v.co;
verts[11].next = 12 * n[2] + (n_flip[2] ? 7 : 3);
/* Bottom-left triangle */
verts[6].v.co = mid_0_1;
verts[6].next = 12 * n[0] + (n_flip[0] ? 9 : 4);
verts[7].v.co = r_globe_verts[3 * i + 1].v.co;
verts[7].next = 12 * n[1] + 11;
verts[8].v.co = mid_1_2;
verts[8].next = 12 * i;
/* Top triangle */
verts[3].v.co = r_globe_verts[3 * i].v.co;
verts[3].next = 12 * n[0] + (n_flip[0] ? 3 : 7);
verts[4].v.co = mid_0_1;
verts[4].next = 12 * i + 2;
verts[5].v.co = mid_0_2;
verts[5].next = 12 * n[2] + (n_flip[2] ? 4 : 9);
/* Center triangle */
verts[0].v.co = mid_1_2;
verts[0].next = 12 * i + 10;
verts[1].v.co = mid_0_2;
verts[1].next = 12 * i + 5;
verts[2].v.co = mid_0_1;
verts[2].next = 12 * i + 6;
}
flip_limit *= 4;
r_tiles_max *= 4;
r_globe_radius *= 2;
sphericize();
}
