crunch v0.12

This is a command line tool that will pack a bunch of images into a single, larger image. It was designed for Celeste, but could be very helpful for other games.

It is designed using libraries with permissible licenses, so you are able to use it freely in your commercial and non-commercial projects. Please see each source file for its respective copyright and license.

Features

Export XML, JSON, or binary data
Trim excess transparency
Rotate images to fit
Control atlas size and padding
Premultiply pixel values
Recursively scans folders
Remove duplicate images
Caching to prevent redundant builds
Multi-image atlas when the sprites don't fit

What does it do?

Given a folder with several images, like so:

images/
    player.png
    tree.png
    enemy.png

It will output something like this:

bin/
    images.png
    images.xml
    images.hash

Where images.png is the packed image, images.xml is an xml file describing where each sub-image is located, and images.hash is used for file caching (if none of the input files have changed since the last pack, the program will terminate).

There is also an option to use a binary format instead of xml.

Usage

crunch [OUTPUT] [INPUT1,INPUT2,INPUT3...] [OPTIONS...]

For example...

crunch bin/atlases/atlas assets/characters,assets/tiles -p -t -v -u -r -j

This will output the following files:

bin/atlases/atlas.png
bin/atlases/atlas.json
bin/atlases/atlas.hash

Options

option	alias	description
`-d`	`--default`	use default settings (`-x -p -t -u`)
`-x`	`--xml`	saves the atlas data as a `.xml` file
`-b`	`--binary`	saves the atlas data as a `.bin` file
`-j`	`--json`	saves the atlas data as a `.json` file
`-p`	`--premultiply`	premultiplies the pixels of the bitmaps by their alpha channel
`-t`	`--trim`	trims excess transparency off the bitmaps
`-v`	`--verbose`	print to the debug console as the packer works
`-f`	`--force`	ignore caching, forcing the packer to repack
`-u`	`--unique`	remove duplicate bitmaps from the atlas
`-r`	`--rotate`	enabled rotating bitmaps 90 degrees clockwise when packing
`-s#`	`--size#`	max atlas size (`#` can be `4096`, `2048`, `1024`, `512`, `256`, `128`, or `64`)
`-w#`	`--width#`	max atlas width (overrides `--size`) (`#` can be `4096`, `2048`, `1024`, `512`, `256`, `128`, or `64`)
`-h#`	`--height#`	max atlas height (overrides `--size`) (`#` can be `4096`, `2048`, `1024`, `512`, `256`, `128`, or `64`)
`-p#`	`--pad#`	padding between images (`#` can be from `0` to `16`)
`-bs%`	`--binstr%`	string type in binary format (`%` can be: `n` - null-termainated, `p` - prefixed (int16), `7` - 7-bit prefixed)
`-tm`	`--time`	use file's last write time instead of its contents for hashing
`-sp`	`--split`	split output textures by subdirectories
`-nz`	`--nozero`	if there's only one packed texture, then zero at the end of its name will be omitted (ex. `images0.png` -> `images.png`)

Binary Format

crch (0x68637263 in hex or 1751347811 in decimal (little endian))
[int16] version (current version is 0)
[byte] --trim enabled
[byte] --rotate enabled
[byte] string type (0 - null-termainated, 1 - prefixed (int16), 2 - 7-bit prefixed)
[int16] num_textures (below block is repeated this many times)
    [string] name
    [int16] num_images (below block is repeated this many times)
        [string] img_name
        [int16] img_x
        [int16] img_y
        [int16] img_width
        [int16] img_height
        [int16] img_frame_x         (if --trim enabled)
        [int16] img_frame_y         (if --trim enabled)
        [int16] img_frame_width     (if --trim enabled)
        [int16] img_frame_height    (if --trim enabled)
        [byte] img_rotated          (if --rotate enabled)

Splitting

If --split (or -sp) is enabled output textures will be split by subdirectories.

For example:

crunch bin/images images -b -sp with input images

images/
    chars/
        player.png
        enemy.png
    other/
        tree.png
        box.png

will output

bin/
    images_chars.png (with player.png and enemy.png)
    images_chars.hash
    images_chars.bin
    images_other.png (with tree.png and box.png)
    images_other.hash
    images_other.bin
    images.bin

If player.png is the only changed image then only images_chars.bin will be packed and images_other.bin will be reused in images.bin.

This can be used for faster packing: unchanged subdirectories will be skipped instead of packing unchanged images.

But there're some limitations:

multiple inputs and images as inputs are not supported
images in input directory itself will be ignored and not packed

Building on Linux

cd linux/
make

License

Unless otherwise specified in a source file, everything in this project falls under the following license:

MIT License

Copyright (c) 2017 Chevy Ray Johnston

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Nebulaxin/crunch