\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.14.3 - 3D Mesh Generation
Mesh_3/random_labeled_image.h
#include <CGAL/Image_3.h>
#include <CGAL/Random.h>
#include <algorithm>
CGAL::Image_3 random_labeled_image()
{
const int dim = 400;
const unsigned char number_of_spheres = 50;
const int max_radius_of_spheres = 10;
const int radius_of_big_sphere = 80;
_image* image = _createImage(dim, dim, dim, 1,
1.f, 1.f, 1.f, 1,
WK_FIXED, SGN_UNSIGNED);
unsigned char* ptr = (unsigned char*)(image->data);
std::fill(ptr, ptr+dim*dim*dim, '\0');
std::ptrdiff_t center = dim / 2;
CGAL::Random rand(0);
for(unsigned char n = number_of_spheres; n > 0 ; --n) {
std::size_t i, j, k;
do {
i = rand.uniform_smallint(1 + max_radius_of_spheres,
dim-2 - max_radius_of_spheres);
j = rand.uniform_smallint(1 + max_radius_of_spheres,
dim-2 - max_radius_of_spheres);
k = rand.uniform_smallint(1 + max_radius_of_spheres,
dim-2 - max_radius_of_spheres);
} while ( ( CGAL::square(double(center) - double(i)) +
CGAL::square(double(center) - double(j)) +
CGAL::square(double(center) - double(k)) )
<
CGAL::square(double(radius_of_big_sphere) + 4 * max_radius_of_spheres) );
std::ptrdiff_t radius = max_radius_of_spheres;
if(n==1) {
i = j = k = center;
radius = radius_of_big_sphere;
}
for(std::ptrdiff_t ii = - radius; ii <= radius; ++ii)
{
for(std::ptrdiff_t jj = - radius; jj <= radius; ++jj)
{
for(std::ptrdiff_t kk = - radius; kk <= radius; ++kk)
{
if(ii*ii + jj*jj + kk*kk > radius * radius) continue;
using CGAL::IMAGEIO::static_evaluate;
static_evaluate<unsigned char>(image, i+ii, j+jj, k+kk) = n;
}
}
}
}
_writeImage(image, "random-image.inr");
return CGAL::Image_3(image);
}