/** A function to read a pixel */
double& pixel(size_t i, size_t j) { return data[vertid(i,j)]; }
double pixel(size_t i, size_t j) const { return data[vertid(i,j)]; }
/**
* triangulate the cube directly, without decomposition
*/
static void docube(PROCESS *process, CUBE *cube)
{
INTLISTS *polys;
CORNER *c1, *c2;
int i, index = 0, count, indexar[8];
/* Determine which case cube falls into. */
for (i = 0; i < 8; i++) {
if (cube->corners[i]->value > 0.0f) {
index += (1 << i);
}
}
/* Using faces[] table, adds neighbouring cube if surface intersects face in this direction. */
if (MB_BIT(faces[index], 0)) add_cube(process, cube->i - 1, cube->j, cube->k);
if (MB_BIT(faces[index], 1)) add_cube(process, cube->i + 1, cube->j, cube->k);
if (MB_BIT(faces[index], 2)) add_cube(process, cube->i, cube->j - 1, cube->k);
if (MB_BIT(faces[index], 3)) add_cube(process, cube->i, cube->j + 1, cube->k);
if (MB_BIT(faces[index], 4)) add_cube(process, cube->i, cube->j, cube->k - 1);
if (MB_BIT(faces[index], 5)) add_cube(process, cube->i, cube->j, cube->k + 1);
/* Using cubetable[], determines polygons for output. */
for (polys = cubetable[index]; polys; polys = polys->next) {
INTLIST *edges;
count = 0;
/* Sets needed vertex id's lying on the edges. */
for (edges = polys->list; edges; edges = edges->next) {
c1 = cube->corners[corner1[edges->i]];
c2 = cube->corners[corner2[edges->i]];
indexar[count] = vertid(process, c1, c2);
count++;
}
/* Adds faces to output. */
if (count > 2) {
switch (count) {
case 3:
make_face(process, indexar[2], indexar[1], indexar[0], 0);
break;
case 4:
if (indexar[0] == 0) make_face(process, indexar[0], indexar[3], indexar[2], indexar[1]);
else make_face(process, indexar[3], indexar[2], indexar[1], indexar[0]);
break;
case 5:
if (indexar[0] == 0) make_face(process, indexar[0], indexar[3], indexar[2], indexar[1]);
else make_face(process, indexar[3], indexar[2], indexar[1], indexar[0]);
make_face(process, indexar[4], indexar[3], indexar[0], 0);
break;
case 6:
if (indexar[0] == 0) {
make_face(process, indexar[0], indexar[3], indexar[2], indexar[1]);
make_face(process, indexar[0], indexar[5], indexar[4], indexar[3]);
}
else {
make_face(process, indexar[3], indexar[2], indexar[1], indexar[0]);
make_face(process, indexar[5], indexar[4], indexar[3], indexar[0]);
}
break;
case 7:
if (indexar[0] == 0) {
make_face(process, indexar[0], indexar[3], indexar[2], indexar[1]);
make_face(process, indexar[0], indexar[5], indexar[4], indexar[3]);
}
else {
make_face(process, indexar[3], indexar[2], indexar[1], indexar[0]);
make_face(process, indexar[5], indexar[4], indexar[3], indexar[0]);
}
make_face(process, indexar[6], indexar[5], indexar[0], 0);
break;
}
}
}
}
