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#include "garminimg.h"
ImgRGN::ImgRGN (class ImgFile *ifilein, off_t offset)
{
ifile= ifilein;
header_offset= imgfile_offset= offset;
}
ImgRGN::~ImgRGN ()
{
}
//----------------------------------------------------------------------
// Bitstream functions
//----------------------------------------------------------------------
int ImgRGN::_bits_per_coord (byte_t base, bool is_signed, bool extra_bit)
{
int n= 2;
if ( base <= 9 ) n+= base;
else n+= (2*base-9);
if ( is_signed ) ++n;
if ( extra_bit ) ++n;
return n;
}
void ImgRGN::bits_per_coord (byte_t base, byte_t bfirst, bool extra_bit,
int *blong, int *blat, int *sbits)
{
bool x_sign_same, y_sign_same;
bool sign_bit;
// Get bits per longitude
*sbits= 2;
x_sign_same= bfirst & 0x1;
if ( x_sign_same ) {
sign_bit= 0;
*sbits++;
} else {
sign_bit= 1;
}
*blong= _bits_per_coord(base&0xF, sign_bit, extra_bit);
// Get bits per latitude
if ( x_sign_same ) y_sign_same= bfirst & 0x4;
else y_sign_same= bfirst & 0x2;
if ( y_sign_same ) {
sign_bit= 0;
*sbits++;
} else {
sign_bit= 1;
}
*blat= _bits_per_coord((base&0xF0)>>4, sign_bit, extra_bit);
}