This is a Haxe port of the libGDX Texture Packer, which packs image assets into texture atlases for efficient rendering. libGDX is released under the Apache 2 license; see it on GitHub for more information and a full list of contributors. hxpk is a full port and includes all features of the original, including whitespace removal, alpha bleed correction, and more. You can read more about the original on the libGDX GitHub wiki.
hxpk can also be used to create textures from in-memory BitmapDatas at runtime. In other words, you can generate images after a program has started (for example, using the svg library to rasterize an SVG at an appropriate resolution for the current device) and then create a texture atlas from those images.
hxpk currently requires OpenFL and uses BitmapData for image processing.
You can run hxpk from the command line with:
haxelib run hxpk
If no other arguments are supplied, usage instructions will be displayed.
hxpk can also be used at runtime:
hxpk.Settings.environment = new hxpk.environment.OpenFL();
hxpk.TexturePacker.process("graphics/pack", "graphics-packed", "pack.atlas");
This will pack the assets included in "graphics/pack" in the asset manager, putting the atlas in "graphics-packed." You can then access the pack file and images using:
var packFile = openfl.Assets.getText("hxpk:graphics-packed/pack.atlas");
var atlas = oepnfl.Assets.getBitmapData("hxpk:graphics-packed/pack.png");
The OpenFL asset paths will be treated as a filesystem with directories. The directories will be recursively processed, and pack.json files that are embedded in these directories will be read.
When run from the command line, if the input directory contains subdirectories, hxpk will recursively parse all of those as well. Each subdirectory will be packed onto the same set of pages.
Each directory can have a pack.json file in it, which is a JSON file containing packing settings. pack.json files that are deeper in the path will take precedence, and if none are found, the defaults will be used.
Check the libGDX GitHub wiki for a full description of what can go in a settings file.
If you downloaded hxpk from source, you'll have to first build the command line tool. To do so, simply navigate to the hxpk directory and run
haxe build.hxml