#include <osgUtil/CubeMapGenerator>
#include <stdlib.h>

using namespace osgUtil;

CubeMapGenerator::CubeMapGenerator(int texture_size)
:    osg::Referenced(),
    texture_size_(texture_size)
{
    for (int i=0; i<6; ++i)
    {                
        osg::ref_ptr<osg::Image> image = osgNew osg::Image;
        unsigned char* data = (static_cast<unsigned char *>(malloc(texture_size*texture_size*4)));
        image->setImage(texture_size, texture_size, 1, 4, GL_RGBA, GL_UNSIGNED_BYTE, data);
        images_.push_back(image);
    }
}

CubeMapGenerator::CubeMapGenerator(const CubeMapGenerator &copy, const osg::CopyOp &copyop)
:    osg::Referenced(copy),
    texture_size_(copy.texture_size_)
{
    Image_list::const_iterator i;
    for (i=copy.images_.begin(); i!=copy.images_.end(); ++i)
    {
        images_.push_back(static_cast<osg::Image *>(copyop(i->get())));
    }
}

void CubeMapGenerator::generateMap(bool use_osg_system)
{
    const float duv = 2.0f/(texture_size_-1);
    
    float v = 1;
    for (int i=0; i<texture_size_; ++i) {
        float u = 1;
        for (int j=0; j<texture_size_; ++j) {            
            if (use_osg_system) {
                set_pixel(0, j, i, compute_color(osg::Vec3(1, -u, v)));
                set_pixel(1, j, i, compute_color(osg::Vec3(-1, u, v)));
                set_pixel(2, j, i, compute_color(osg::Vec3(-u, v, 1)));
                set_pixel(3, j, i, compute_color(osg::Vec3(-u, -v, -1)));
                set_pixel(4, j, i, compute_color(osg::Vec3(-u, -1, v)));
                set_pixel(5, j, i, compute_color(osg::Vec3(u, 1, v)));
            } else {
                set_pixel(0, j, i, compute_color(osg::Vec3(1, v, -u)));
                set_pixel(1, j, i, compute_color(osg::Vec3(-1, v, u)));
                set_pixel(2, j, i, compute_color(osg::Vec3(-u, 1, v)));
                set_pixel(3, j, i, compute_color(osg::Vec3(-u, -1, -v)));
                set_pixel(4, j, i, compute_color(osg::Vec3(-u, v, -1)));
                set_pixel(5, j, i, compute_color(osg::Vec3(u, v, 1)));
            }
            u -= duv;
        }
        v -= duv;
    }
}