abzico / texpackr

Textures packer into texture atlas, spit out atlas, and meta data. Aim to support .png, and .dds

texpackr

Textures packer into texture atlas, spit out atlas, and meta data. Aim to support .png, and .dds

Build

Based on autotools.

• ./autogen.sh
• ./configure
• make
• (optional) make check
• make install - then you will get executable file texpackr, shared and dynamic libraries along with header files necessary to develop the program.

Dependencies

• libpng - installed on your system
• hashmap_c - installed on your system.

ndk-build support

This project has Android.mk build support for Android.

To be able to use Android.mk to build, you need to download the following dependencies source code to your system

• libpng - download libpng source then place at ../libpng from this project directory, then use our Android.mk by following instruction there.
• libhashmap_c - clone source code from abzico/hashmap_c then place at ../hashmap_c

Meta File Format

When export into a spritesheet and meta file, the latter has the following format. You can see texcoord_min_u and other similar names. That's the pre-computed texture coordinate for such sprite. So user doesn't have to query it, compute texture coordinate for each sprite, then save it somewhere to in memory to use in rendering.

# generated by texpackr (....), this is comment line and ignored by texpackr's processor
sheet_width sheet_height
number_of_sprites
path/to/sprite/1.png offset_x offset_y size_x size_y texcoord_min_u texcoord_max_u texcoord_min_v texcoord_max_v
path/to/sprite/2.png offset_x offset_y size_x size_y texcoord_min_u texcoord_max_u texcoord_min_v texcoord_max_v
...
path/to/sprite/N.png offset_x offset_y size_x size_y texcoord_min_u texcoord_max_u texcoord_min_v texcoord_max_v

Example is as follows

# generated by texpackr (....), this is comment line and ignored by texpackr's processor
1024 1024
8
images/1.png 0 0 380 231 0.000000 0.371094 0.000000 0.225586
images/2.png 380 0 128 87 0.371094 0.496094 0.000000 0.084961
images/3.png 0 231 636 264 0.000000 0.621094 0.225586 0.483398
images/4.png 0 495 400 400 0.000000 0.390625 0.483398 0.874023
images/5.png 636 231 256 259 0.621094 0.871094 0.225586 0.478516
images/6.png 400 495 400 260 0.390625 0.781250 0.483398 0.737305
images/7.png 400 755 510 254 0.390625 0.888672 0.737305 0.985352
images/8.png 508 0 128 151 0.496094 0.621094 0.000000 0.147461

TODO

Phase I

• packing algorithm for multiple images into a single texture atlas
• read .png (support 1-4 channels: gray, gray-alpha, RGB, and RGBA) image as input
• save into a texture atlas as .png image
• read .jpg image as input
• save into a texture atlas as .dds image
• save meta data into file (with file extension .tpr)
• parse meta file and get sheet + sprites info
• C API
• command line for all major operations supported by C API

Phase II

• ability to scale input images then output it
• cut out alpha pixels to maximize capacity of sprite storage in result spritesheet
• spacing between sprites packed in sheet

License

MIT, ABZI