void _imd_calc_bounds(iIMDShape *s, Vector3f *p, int size)
{
int32_t xmax, ymax, zmax, count;
double dx, dy, dz, rad_sq, rad, old_to_p_sq, old_to_p, old_to_new;
double xspan, yspan, zspan, maxspan;
Vector3f dia1, dia2, cen;
Vector3f vxmin(0, 0, 0), vymin(0, 0, 0), vzmin(0, 0, 0),
vxmax(0, 0, 0), vymax(0, 0, 0), vzmax(0, 0, 0);
s->max.x = s->max.y = s->max.z = -FP12_MULTIPLIER;
s->min.x = s->min.y = s->min.z = FP12_MULTIPLIER;
vxmax.x = vymax.y = vzmax.z = -FP12_MULTIPLIER;
vxmin.x = vymin.y = vzmin.z = FP12_MULTIPLIER;
// set up bounding data for minimum number of vertices
for (count = 0; count < size; p++, count++)
{
if (p->x > s->max.x)
{
s->max.x = p->x;
}
if (p->x < s->min.x)
{
s->min.x = p->x;
}
if (p->y > s->max.y)
{
s->max.y = p->y;
}
if (p->y < s->min.y)
{
s->min.y = p->y;
}
if (p->z > s->max.z)
{
s->max.z = p->z;
}
if (p->z < s->min.z)
{
s->min.z = p->z;
}
// for tight sphere calculations
if (p->x < vxmin.x)
{
vxmin.x = p->x;
vxmin.y = p->y;
vxmin.z = p->z;
}
if (p->x > vxmax.x)
{
vxmax.x = p->x;
vxmax.y = p->y;
vxmax.z = p->z;
}
if (p->y < vymin.y)
{
vymin.x = p->x;
vymin.y = p->y;
vymin.z = p->z;
}
if (p->y > vymax.y)
{
vymax.x = p->x;
vymax.y = p->y;
vymax.z = p->z;
}
if (p->z < vzmin.z)
{
vzmin.x = p->x;
vzmin.y = p->y;
vzmin.z = p->z;
}
if (p->z > vzmax.z)
{
vzmax.x = p->x;
vzmax.y = p->y;
vzmax.z = p->z;
}
}
// no need to scale an IMD shape (only FSD)
xmax = MAX(s->max.x, -s->min.x);
ymax = MAX(s->max.y, -s->min.y);
zmax = MAX(s->max.z, -s->min.z);
s->radius = MAX(xmax, MAX(ymax, zmax));
s->sradius = sqrtf(xmax * xmax + ymax * ymax + zmax * zmax);
// START: tight bounding sphere
// set xspan = distance between 2 points xmin & xmax (squared)
dx = vxmax.x - vxmin.x;
dy = vxmax.y - vxmin.y;
dz = vxmax.z - vxmin.z;
xspan = dx * dx + dy * dy + dz * dz;
// same for yspan
dx = vymax.x - vymin.x;
dy = vymax.y - vymin.y;
dz = vymax.z - vymin.z;
yspan = dx * dx + dy * dy + dz * dz;
// and ofcourse zspan
dx = vzmax.x - vzmin.x;
dy = vzmax.y - vzmin.y;
dz = vzmax.z - vzmin.z;
zspan = dx * dx + dy * dy + dz * dz;
// set points dia1 & dia2 to maximally seperated pair
// assume xspan biggest
dia1 = vxmin;
dia2 = vxmax;
maxspan = xspan;
if (yspan > maxspan)
{
maxspan = yspan;
dia1 = vymin;
dia2 = vymax;
}
if (zspan > maxspan)
{
dia1 = vzmin;
dia2 = vzmax;
}
// dia1, dia2 diameter of initial sphere
cen.x = (dia1.x + dia2.x) / 2.;
cen.y = (dia1.y + dia2.y) / 2.;
cen.z = (dia1.z + dia2.z) / 2.;
// calc initial radius
dx = dia2.x - cen.x;
dy = dia2.y - cen.y;
dz = dia2.z - cen.z;
rad_sq = dx * dx + dy * dy + dz * dz;
rad = sqrt((double)rad_sq);
// second pass (find tight sphere)
for (p = s->points; p < s->points + s->npoints; p++)
{
dx = p->x - cen.x;
dy = p->y - cen.y;
dz = p->z - cen.z;
old_to_p_sq = dx * dx + dy * dy + dz * dz;
// do r**2 first
if (old_to_p_sq > rad_sq)
{
// this point outside current sphere
old_to_p = sqrt((double)old_to_p_sq);
// radius of new sphere
rad = (rad + old_to_p) / 2.;
// rad**2 for next compare
rad_sq = rad * rad;
old_to_new = old_to_p - rad;
// centre of new sphere
cen.x = (rad * cen.x + old_to_new * p->x) / old_to_p;
cen.y = (rad * cen.y + old_to_new * p->y) / old_to_p;
cen.z = (rad * cen.z + old_to_new * p->z) / old_to_p;
}
}
s->ocen = cen;
// END: tight bounding sphere
}
static bool _imd_load_points( const char **ppFileData, iIMDShape *s )
{
Vector3f *p = NULL;
int32_t xmax, ymax, zmax;
double dx, dy, dz, rad_sq, rad, old_to_p_sq, old_to_p, old_to_new;
double xspan, yspan, zspan, maxspan;
Vector3f dia1, dia2, cen;
Vector3f vxmin(0, 0, 0), vymin(0, 0, 0), vzmin(0, 0, 0),
vxmax(0, 0, 0), vymax(0, 0, 0), vzmax(0, 0, 0);
//load the points then pass through a second time to setup bounding datavalues
s->points = (Vector3f*)malloc(sizeof(Vector3f) * s->npoints);
if (s->points == NULL)
{
return false;
}
// Read in points and remove duplicates (!)
if ( ReadPoints( ppFileData, s ) == false )
{
free(s->points);
s->points = NULL;
return false;
}
s->max.x = s->max.y = s->max.z = -FP12_MULTIPLIER;
s->min.x = s->min.y = s->min.z = FP12_MULTIPLIER;
vxmax.x = vymax.y = vzmax.z = -FP12_MULTIPLIER;
vxmin.x = vymin.y = vzmin.z = FP12_MULTIPLIER;
// set up bounding data for minimum number of vertices
for (p = s->points; p < s->points + s->npoints; p++)
{
if (p->x > s->max.x)
{
s->max.x = p->x;
}
if (p->x < s->min.x)
{
s->min.x = p->x;
}
if (p->y > s->max.y)
{
s->max.y = p->y;
}
if (p->y < s->min.y)
{
s->min.y = p->y;
}
if (p->z > s->max.z)
{
s->max.z = p->z;
}
if (p->z < s->min.z)
{
s->min.z = p->z;
}
// for tight sphere calculations
if (p->x < vxmin.x)
{
vxmin.x = p->x;
vxmin.y = p->y;
vxmin.z = p->z;
}
if (p->x > vxmax.x)
{
vxmax.x = p->x;
vxmax.y = p->y;
vxmax.z = p->z;
}
if (p->y < vymin.y)
{
vymin.x = p->x;
vymin.y = p->y;
vymin.z = p->z;
}
if (p->y > vymax.y)
{
vymax.x = p->x;
vymax.y = p->y;
vymax.z = p->z;
}
if (p->z < vzmin.z)
{
vzmin.x = p->x;
vzmin.y = p->y;
vzmin.z = p->z;
}
if (p->z > vzmax.z)
{
vzmax.x = p->x;
vzmax.y = p->y;
vzmax.z = p->z;
}
}
// no need to scale an IMD shape (only FSD)
xmax = MAX(s->max.x, -s->min.x);
ymax = MAX(s->max.y, -s->min.y);
zmax = MAX(s->max.z, -s->min.z);
s->radius = MAX(xmax, MAX(ymax, zmax));
s->sradius = sqrtf(xmax*xmax + ymax*ymax + zmax*zmax);
// START: tight bounding sphere
// set xspan = distance between 2 points xmin & xmax (squared)
dx = vxmax.x - vxmin.x;
dy = vxmax.y - vxmin.y;
dz = vxmax.z - vxmin.z;
xspan = dx*dx + dy*dy + dz*dz;
// same for yspan
dx = vymax.x - vymin.x;
dy = vymax.y - vymin.y;
dz = vymax.z - vymin.z;
yspan = dx*dx + dy*dy + dz*dz;
// and ofcourse zspan
dx = vzmax.x - vzmin.x;
dy = vzmax.y - vzmin.y;
dz = vzmax.z - vzmin.z;
zspan = dx*dx + dy*dy + dz*dz;
// set points dia1 & dia2 to maximally seperated pair
// assume xspan biggest
dia1 = vxmin;
dia2 = vxmax;
maxspan = xspan;
if (yspan > maxspan)
{
maxspan = yspan;
dia1 = vymin;
dia2 = vymax;
}
if (zspan > maxspan)
{
dia1 = vzmin;
dia2 = vzmax;
}
// dia1, dia2 diameter of initial sphere
cen.x = (dia1.x + dia2.x) / 2.;
cen.y = (dia1.y + dia2.y) / 2.;
cen.z = (dia1.z + dia2.z) / 2.;
// calc initial radius
dx = dia2.x - cen.x;
dy = dia2.y - cen.y;
dz = dia2.z - cen.z;
rad_sq = dx*dx + dy*dy + dz*dz;
rad = sqrt((double)rad_sq);
// second pass (find tight sphere)
for (p = s->points; p < s->points + s->npoints; p++)
{
dx = p->x - cen.x;
dy = p->y - cen.y;
dz = p->z - cen.z;
old_to_p_sq = dx*dx + dy*dy + dz*dz;
// do r**2 first
if (old_to_p_sq>rad_sq)
{
// this point outside current sphere
old_to_p = sqrt((double)old_to_p_sq);
// radius of new sphere
rad = (rad + old_to_p) / 2.;
// rad**2 for next compare
rad_sq = rad*rad;
old_to_new = old_to_p - rad;
// centre of new sphere
cen.x = (rad*cen.x + old_to_new*p->x) / old_to_p;
cen.y = (rad*cen.y + old_to_new*p->y) / old_to_p;
cen.z = (rad*cen.z + old_to_new*p->z) / old_to_p;
}
}
s->ocen = cen;
// END: tight bounding sphere
return true;
}