texture.C

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#include "std/config.H"
#include "texture.H"

static bool debug = Config::get_var_bool("DEBUG_TEXTURE",false);

/***********************************************************************P5
 * Method : TEXTURE::load_image
 * Params : 
 * Returns: int (success/failure)
 * Effects: load image from file,
 *          expand it so dimensions are powers of 2
 ***********************************************************************/
int 
TEXTURE::load_image()
{
   if (_image_not_available)
      return 0;

   _img.load_file(**_file);
   expand_image();
   if (_img.empty()) {
      _image_not_available = true;
      cerr << "TEXTURE::load_image - could not load " << _file << endl;
   }
   return !_img.empty();
}

/***********************************************************************P5
 * Method : TEXTURE::set_image
 * Params : GLubyte *data, int w, int h, uint bpp
 * Returns: int (success/failure)
 * Effects: set image from data (not from file)
 *          expand it so dimensions are powers of 2
 ***********************************************************************/
int
TEXTURE::set_image(unsigned char *data, int w, int h, uint bpp)
{
   _img.set(w,h,bpp,data);
   expand_image();
   return !_img.empty();
}

void 
TEXTURE::expand_image() 
{
   // expand image so dimensions are powers of two:
   // also computes the scale factors so texture coordinates
   // in [0,1]x[0,1] map to the real image, not the padded
   // extra parts that are added to reach a full power of 2 size:
   if (!_img.empty() && _expand_image) {
      int w = _img.width();
      int h = _img.height();
      if (!_img.expand_power2())
         return; // no change occurred
      err_adv(debug, "TEXTURE::expand_image: expanding from %dx%d to %dx%d",
              w, h, _img.width(), _img.height());
      _scale = mlib::Wtransf::scaling(
         mlib::Wvec((double)w/_img.width(), (double)h/_img.height(), 1)
         );
   }
}

void
TEXTURE::expand_power2(int width, int height)
{
   _img.resize(width, height, _img.bpp());
   _img.expand_power2();
}

/* end of file texture.C */

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