void LASreaderASC::populate_scale_and_offset()
{
// if not specified in the command line, set a reasonable scale_factor
if (scale_factor)
{
header.x_scale_factor = scale_factor[0];
header.y_scale_factor = scale_factor[1];
header.z_scale_factor = scale_factor[2];
}
else
{
if (-360 < header.min_x && -360 < header.min_y && header.max_x < 360 && header.max_y < 360) // do we have longitude / latitude coordinates
{
header.x_scale_factor = 1e-7;
header.y_scale_factor = 1e-7;
}
else // then we assume utm or mercator / lambertian projections
{
header.x_scale_factor = 0.01;
header.y_scale_factor = 0.01;
}
header.z_scale_factor = 0.01;
}
// if not specified in the command line, set a reasonable offset
if (offset)
{
header.x_offset = offset[0];
header.y_offset = offset[1];
header.z_offset = offset[2];
}
else
{
if (F64_IS_FINITE(header.min_x) && F64_IS_FINITE(header.max_x))
header.x_offset = ((I64)((header.min_x + header.max_x)/header.x_scale_factor/20000000))*10000000*header.x_scale_factor;
else
header.x_offset = 0;
if (F64_IS_FINITE(header.min_y) && F64_IS_FINITE(header.max_y))
header.y_offset = ((I64)((header.min_y + header.max_y)/header.y_scale_factor/20000000))*10000000*header.y_scale_factor;
else
header.y_offset = 0;
if (F64_IS_FINITE(header.min_z) && F64_IS_FINITE(header.max_z))
header.z_offset = ((I64)((header.min_z + header.max_z)/header.z_scale_factor/20000000))*10000000*header.z_scale_factor;
else
header.z_offset = 0;
}
}
int32_t laszip_auto_offset(laszip_dll_struct *laszip_dll)
{
if (laszip_dll == 0) return 1;
try
{
if (laszip_dll->reader)
{
sprintf(laszip_dll->error, "cannot auto offset after reader was opened");
return 1;
}
// get a pointer to the header
laszip_header_struct* header = &(laszip_dll->header);
// check scale factor
F64 x_scale_factor = header->x_scale_factor;
F64 y_scale_factor = header->y_scale_factor;
F64 z_scale_factor = header->z_scale_factor;
if ((x_scale_factor <= 0) || !F64_IS_FINITE(x_scale_factor))
{
sprintf(laszip_dll->error, "invalid x scale_factor %g in header", header->x_scale_factor);
return 1;
}
if ((y_scale_factor <= 0) || !F64_IS_FINITE(y_scale_factor))
{
sprintf(laszip_dll->error, "invalid y scale_factor %g in header", header->y_scale_factor);
return 1;
}
if ((z_scale_factor <= 0) || !F64_IS_FINITE(z_scale_factor))
{
sprintf(laszip_dll->error, "invalid z scale_factor %g in header", header->z_scale_factor);
return 1;
}
F64 center_bb_x = (header->min_x + header->max_x) / 2;
F64 center_bb_y = (header->min_y + header->max_y) / 2;
F64 center_bb_z = (header->min_z + header->max_z) / 2;
if (!F64_IS_FINITE(center_bb_x))
{
sprintf(laszip_dll->error, "invalid x coordinate at center of bounding box (min: %g max: %g)", header->min_x, header->max_x);
return 1;
}
if (!F64_IS_FINITE(center_bb_y))
{
sprintf(laszip_dll->error, "invalid y coordinate at center of bounding box (min: %g max: %g)", header->min_y, header->max_y);
return 1;
}
if (!F64_IS_FINITE(center_bb_z))
{
sprintf(laszip_dll->error, "invalid z coordinate at center of bounding box (min: %g max: %g)", header->min_z, header->max_z);
return 1;
}
F64 x_offset = header->x_offset;
F64 y_offset = header->y_offset;
F64 z_offset = header->z_offset;
header->x_offset = (I64_FLOOR(center_bb_x/x_scale_factor/10000000))*10000000*x_scale_factor;
header->y_offset = (I64_FLOOR(center_bb_y/y_scale_factor/10000000))*10000000*y_scale_factor;
header->z_offset = (I64_FLOOR(center_bb_z/z_scale_factor/10000000))*10000000*z_scale_factor;
if (laszip_check_for_integer_overflow(laszip_dll))
{
header->x_offset = x_offset;
header->y_offset = y_offset;
header->z_offset = z_offset;
return 1;
}
}
catch (...)
{
sprintf(laszip_dll->error, "internal error in laszip_auto_offset");
return 1;
}
laszip_dll->error[0] = '\0';
return 0;
}
