libgta 1.2.1 Read and Write Generic Tagged Array (GTA) files

Examples written in C++: Block-based input/output
/* This file is in the public domain. */
#include <iostream>
#include <fstream>
#include <vector>
#include <gta/gta.hpp>
/* This example opens a three-dimensional GTA and then reads a small block of
* array data.
* This is useful for arrays that do not fit into memory. However, the input
* file must be seekable (i.e. it must be a real file, no pipe or network
* stream), and the GTA must not be compressed. */
int main(void)
{
try {
uintmax_t block_indices_low[] = { 20, 30, 40 };
uintmax_t block_indices_high[] = { 50, 60, 70 };
/* Read the header */
std::ifstream stream("input.gta", std::ios::in | std::ios::binary);
gta::header header;
header.read_from(stream);
/* We assume that the input GTA has three dimensions and one element
* component of type gta::uint16, and that it is large enough to contain
* the block defined above. */
std::streampos data_offset = stream.tellg();
if (data_offset == -1) {
throw std::exception();
}
/* Read the data block */
std::vector<uint16_t> block(31 * 31 * 31);
header.read_block(stream, data_offset,
block_indices_low, block_indices_high, &(block[0]));
/* do something with the data */
}
catch (std::exception &e) {
std::cerr << e.what() << std::endl;
return 1;
}
return 0;
}
gta::header
The GTA header.
Definition: gta.hpp:702
gta::header::read_block
void read_block(custom_io &io, uintmax_t data_offset, const uintmax_t *lower_coordinates, const uintmax_t *higher_coordinates, void *block) const
Read an array block.
Definition: gta.hpp:1930
gta::header::read_from
void read_from(custom_io &io)
Read a header.
Definition: gta.hpp:819
gta.hpp
The libgta C++ interface.