47 lines
2.0 KiB
Markdown
47 lines
2.0 KiB
Markdown
This is Cram, a texture packing system in C.
|
|
|
|
About Cram
|
|
----------------
|
|
Cram is a portable C texture packing system intended for use in games, particularly 2D sprite games. Texture switching is an expensive operation, especially on low-end GPUs, so for performance it is imperative to pack sprites into textures to enable sprite batching.
|
|
|
|
Cram uses the maximal rectangles algorithm with the best area fit heuristic to pack your images. It automatically de-duplicates images to save space.
|
|
|
|
Cram ships with a default command line interface implemented in C, but if you wish you can configure CMake to build a shared library which will allow you to bind its essential functions to another language.
|
|
|
|
Usage
|
|
-----
|
|
```sh
|
|
Usage: cram input_dir output_dir atlas_name [--padding padding_value] [--notrim] [--dimension max_dimension]
|
|
```
|
|
|
|
Cram expects input in PNG and outputs a PNG and a JSON metadata file that you can use to properly display the images in your game. Cram will recursively walk all the subdirectories of `input_dir` to generate your texture atlas.
|
|
|
|
Padding is set to 0 by default. If you need to use linear filtering, set padding to at least 1. If you need to use texture compression, set padding to at least 4.
|
|
|
|
Trimming is on by default. Use `--notrim` if for some weird reason you want it off.
|
|
|
|
Max dimension value is set to 8192 by default since that is a common max texture size for basically every GPU out there. Use `--dimension [max_dimension]` to override this maximum.
|
|
|
|
Dependencies
|
|
------------
|
|
Cram depends on the C runtime.
|
|
|
|
libCram uses `stb_ds` for image hashing, and `stb_image` for image loading.
|
|
|
|
The CLI uses `stb_image_write` to output PNG images, and a portable `dirent.h` for a Windows-compatible dirent implemention.
|
|
|
|
Building Cram
|
|
-------------------
|
|
For *nix platforms, use CMake:
|
|
|
|
$ mkdir build/
|
|
$ cd build
|
|
$ cmake ../
|
|
$ make
|
|
|
|
For Windows, use CMake to generate a visualc project.
|
|
|
|
License
|
|
-------
|
|
Cram is licensed under the zlib license. See LICENSE for details.
|