public void png_set_pHYs(uint res_x, uint res_y, PNG_RESOLUTION unit_type)
{
info_ptr_x_pixels_per_unit = res_x;
info_ptr_y_pixels_per_unit = res_y;
info_ptr_phys_unit_type = unit_type;
info_ptr_valid |= PNG_INFO.pHYs;
}
public PNG_INFO png_get_pHYs(ref uint res_x, ref uint res_y, ref PNG_RESOLUTION unit_type)
{
if ((info_ptr_valid & PNG_INFO.pHYs) != PNG_INFO.pHYs)
{
return(PNG_INFO.None);
}
res_x = info_ptr_x_pixels_per_unit;
res_y = info_ptr_y_pixels_per_unit;
unit_type = info_ptr_phys_unit_type;
return(PNG_INFO.pHYs);
}
public PNG_INFO png_get_pHYs(ref uint res_x, ref uint res_y, ref PNG_RESOLUTION unit_type)
{
if((info_ptr_valid&PNG_INFO.pHYs)!=PNG_INFO.pHYs) return PNG_INFO.None;
res_x=info_ptr_x_pixels_per_unit;
res_y=info_ptr_y_pixels_per_unit;
unit_type=info_ptr_phys_unit_type;
return PNG_INFO.pHYs;
}
public void png_set_pHYs(uint res_x, uint res_y, PNG_RESOLUTION unit_type)
{
info_ptr_x_pixels_per_unit=res_x;
info_ptr_y_pixels_per_unit=res_y;
info_ptr_phys_unit_type=unit_type;
info_ptr_valid|=PNG_INFO.pHYs;
}
// write the pHYs chunk
void png_write_pHYs(uint x_pixels_per_unit, uint y_pixels_per_unit, PNG_RESOLUTION unit_type)
{
byte[] buf=new byte[9];
if(unit_type>=PNG_RESOLUTION.LAST) Debug.WriteLine("Unrecognized unit type for pHYs chunk");
png_save_uint_32(buf, x_pixels_per_unit);
png_save_uint_32(buf, 4, y_pixels_per_unit);
buf[8]=(byte)unit_type;
png_write_chunk(PNG.pHYs, buf, 9);
}