Octagon Texture Packer

What this does:

1. It packing 2D sprites into one texture. similiar tool woudl be TexturePacker

2. Most texture packing tool using 4 point to pack sprites, however it can wast many empty spaces.

   These empty spaces can cause three problems:
   a. larger final texture file size. b. larger memory footprint when loading into GPU. c. empty space wast GPU fillrate.

3. This tool cut images using 8 points instead of 4 points (just like octagon instead of rectangle).
   (light blue means wasted empty pixe)
   a. rectangle cutting

   

   b. octagon cutting
   

4. Example packing results from regular texure packer vs octagon packer. you can see the result is much more dense.

   a. rectangle packing

   

   b. octagon packing

   

How to Build

1. prerequisite
   a. OpenCL library/Headers

    a). install cuda toolkit for nvidia graphic cards  
    b). install amd app sdk for amd graphic cards    
   

   b. cmake

2. clone repository

3. build
   a. Linux

       bash> cd packing
       bash> mkdir -p build/make
       bash> cmake ../.. -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release
       bash> cmake --build . --config Release

   b. Windows

       bash> cd packing
       bash> mkdir -p build\make
       bash> cmake ../.. -G "Visual Studio 15 2017" -DCMAKE_BUILD_TYPE=Release
       bash> cmake --build . --config Release

How to use

1. prerequisite
   a. OpenCL driver (usually nvidia or amd graphic driver will preinstall opencl drivers)
   b. python 3.x
   c. python modules:
   1. Pillow
2. usage:
   a. cutting images
   python atlas.py -d <sprite folder> -o <cutting output folder>
   b. packing images
   python mergeAtlas.py -d <cutting output folder> -size <max image size in pixels> c. it will generate packed image plus meta json within , it will output multiple images if total size exceed max size defined.
   e.g atlas-0.png, atlas-0.json
3. packing image meta

                        octagon points order:
                             1 ------ 0
                            /          \
                           2            7
                           |            |
                           3            6
                            \          /
                             4 ------ 5 
{
        "boxMaxX": 135,     // max x in pixel relative to anchor point
        "boxMaxY": 160,     // max y in pixel relative to anchor point
        "boxMinX": -136,    // min y in pixel relative to anchor point
        "boxMinY": -161,    // min y in pixel relative to anchor point
        "file": "stairsOpenSingle_NW.png",  // file name
        "pixelToWorld": 1,  // used for scale up image, useless now
        "points": [
            [
                -57,        // point #0 x, y in pixel  relative to anchor point
                160         
            ],
            [
                -136,       // point #1 x, y in pixel  relative to anchor point
                105
            ],
            [
                -136,       // point #2 x, y in pixel  relative to anchor point
                96
            ],
            [
                41,         // point #3 x, y in pixel  relative to anchor point
                -161
            ],
            [   
                75,         // point #4 x, y in pixel  relative to anchor point
                -161
            ],
            [
                135,        // point #5 x, y in pixel  relative to anchor point
                -106
            ],
            [
                135,        // point #6 x, y in pixel  relative to anchor point
                -96
            ],
            [
                -43,        // point #7 x, y in pixel  relative to anchor point
                160
            ]
        ],
        "reverse": true,    // useless now
        "uv": [
            [
                0.8911468178954002,     // point #0 x, y UV  relative packed image
                0.04436383928571429
            ],
            [
                0.8738185255198487,     // point #1 x, y UV  relative packed image
                0.00027901785714285713
            ],
            [
                0.8709829867674859,     // point #2 x, y UV  relative packed image
                0.00027901785714285713
            ],
            [
                0.7903276622558286,     // point #3 x, y UV  relative packed image
                0.09849330357142858
            ],
            [
                0.7903276622558286,     // point #4 x, y UV  relative packed image
                0.11746651785714286
            ],
            [
                0.80765595463138,       // point #5 x, y UV  relative packed image
                0.15094866071428573
            ],
            [
                0.8108065532451165,     // point #6 x, y UV  relative packed image
                0.15094866071428573
            ],
            [
                0.8911468178954002,     // point #7 x, y UV  relative packed image
                0.05217633928571429
            ]
        ]
    },

TODOS

• [] Add Unity Plugin for import texture atlas
• [] Add Cocos2d Plugin for import texture atlas

Downloads

• Release Pre-Build Binary