libtmj

A library for loading Tiled maps in JSON format

Bear in mind that this library is relatively new. If you find bugs, or find that the library is missing an important feature, please file an issue.

Dependencies

• jansson
• zlib (Optional, for zlib and gzip decompression support)
• zstd (Optional, for zstd decompression support)
• Doxygen (Optional, for building documentation)
  • Graphviz (Optional, for drawing graphs in the generated docs)

To build in Windows, use vcpkg to fetch and install the above dependencies:

vcpkg install jansson:x64-windows zstd:x64-windows zlib:x64-windows

Building

From the repository root, run:

cmake -DCMAKE_BUILD_TYPE=Release -DLIBTMJ_ZSTD=ON -DLIBTMJ_ZLIB=ON . && make

For Windows users, make sure to include the vcpkg toolchain file:

cmake -DCMAKE_BUILD_TYPE=Release -DLIBTMJ_ZSTD=ON -DLIBTMJ_ZLIB=ON -DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake .
cmake --build . --config Release

Available cmake build options:

Option	Description
BUILD_SHARED_LIBS	Builds a shared library instead of a static library.
CMAKE_BUILD_TYPE	One of "Release" (optimization) or "Debug" (runtime sanitizers + debug symbols)
LIBTMJ_DOCS	Also build documentation.
LIBTMJ_ZSTD	Build zstd decompression routines.
LIBTMJ_ZLIB	Build zlib and gzip decompression routines.
LIBTMJ_TEST	Build the test suite.

Testing

If you're going to build and run tests, don't forget to pull the Unity submodule:

git submodule update --init

To enable the test suite, invoke cmake with:

-DCMAKE_BUILD_TYPE=Debug -DLIBTMJ_TEST=True

Then run the tests with:

ctest // For *nix
ctest -C Debug // For Windows

Usage example

Below is a brief example of how to use libtmj. For more detail, see the API documentation. Specifically, refer to the Data Structures page for a list of fields provided by each structure. They match the names given in the Tiled documentation, with the exception of added fields which give the number of elements in array fields, whose names are {field}_count (as shown below for the "layer" field).

#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>

#include <tmj.h>

// Logging callback
void log_cb(tmj_log_priority priority, const char* msg){
    switch(priority){
        case TMJ_LOG_DEBUG:
            printf("DEBUG: %s\n", msg);
            break;
        case TMJ_LOG_INFO:
            printf("INFO: %s\n", msg);
            break;
        case TMJ_LOG_WARNING:
            printf("WARNING: %s\n", msg);
            break;
        case TMJ_LOG_ERR:
            printf("ERR: %s\n", msg);
            break;
        case TMJ_LOG_CRIT:
            printf("CRIT: %s\n", msg);
            break;
    }
}

// Layers are organized into a tree, so descend recursively
void enumerate_layers(Layer* layers, size_t count){
    for(size_t i = 0; i < count; i++){
        printf("Layer %d: %s\n", layers[i].id, layers[i].name);

        if(layers[i].layers){
            enumerate_layers(layers[i].layers, layers[i].layer_count);
        }
    }
}

int main(){
    // Register logging callback
    tmj_log_regcb(true, log_cb);

    Map* map = tmj_map_loadf("overworld.tmj", false);

    if(!map){
        _exit(-1);
    }

    // Print the map width and height
    printf("This map is %d tiles high and %d tiles wide\n", map->height, map->width);

    // Print the names of all layers in the map
    enumerate_layers(map->layers, map->layer_count);

    // Free the map
    tmj_map_free(map);
}

Notes

JSON only defines a single number type, meant to accomodate both floating point values and integers of arbitrary length. This library truncates all input integers to the size of int on your platform, and all input floating point numbers to the size of double on your platform. My estimation is that this is acceptable for a Tiled map. If you find a case in which this breaks your map, please let me know.

License

BSD 2-Clause License

Copyright (c) 2023-2024, David Zero
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.