WOWCube Apps Examples

Application examples and demos.

Table of Content

• Cubios ResourcesV2
  • Requirements
    • Installing
  • Build rootfs
    • Windows (with WSL)
    • Windows (without WSL)
    • Linux
  • Flashing rootfs
    • Windows
    • Linux
  • Flashing cubelet
• HowTo's
  • New Pawn game integration
  • Converting png to webp
  • Audio
    • WAV requirements
    • MP3 requirements

Requirements

• Python
• Pillow, IntelHex, pySerial

Installing

1. Install Python 3 with PIP
2. Install Python dependencies

   pip install -r requirements.txt

Build rootfs

Windows (with WSL)

Simply build all:

./build.sh

Windows (without WSL)

1. Remove old cublets and rootfs images if they are exists:

   rd /s /q Resources_prj\build_output

2. Build Pawn scripts:

    cd pawn
    .\_build.bat

3. Build cubelets:

   cd ..\Resources_prj
   python build_cubios_apps.py

4. Pack all cublets as cubios_rootfs.img:

   buildImage.exe -g build_output

   Then convert it to rootfs.img:

   python convert.py -s cubios_rootfs.img -d build_output\rootfs.img 

Linux

./build.sh

Flashing rootfs

Connect WOWCube module first.

Windows

Find your COM Port:

reg query HKLM\HARDWARE\DEVICEMAP\SERIALCOMM

Flash binary file into internal memory:

python Resources_prj/flashBurn.py Resources_prj/build_output/rootfs.img -c COM5

Linux

python flashBurn.py rootfs.img -c /dev/ttyACM0

Flashing cubelet

Same as Flashing rootfs, but instead of rootfs.img use the name of your cubelet, for example pipes.cub.

HowTo's

New Pawn game integration

1. Create script inside pawn folder

2. Add it to build files (Makefile, _build.bat and build.sh)

3. Inside Resources_prj/pawn_scripts.py, create game description class inherited from PawnModule:

   • self.name - name of game that will be displayed in WOWCube's menu

   • self.scriptId (obsolete) - id that reflects script order. The same id should be assigned in menu script.

   • self.ScriptFileName - name of built file.

   • self.ScriptResourcePath - folder name with sprites inside Contents folder.

   • self.ScriptResourceList - list of sprites. An order of resources is important because it represents linkage between pawn and platform. When pawn requests to load and show some resource it is referenced by id.

     Resource id is and index in resource list associated with loaded script.

   • self.MenuIcon - menu icon (only png images)

4. Update script_list in Resources_prj/apps.py

Converting png to webp

NOTE: Lossless WebP image, or WebP image with alpha channel, requires more memory on the platform to decode it. The larger lossless or transparent image is, the more memory is required to decode it.

You can use squoosh.app to find the best settings for your needs.

Or you can use cwebp tool:

cwebp [-preset <...>] [options] [-o out_file] -- in_file

Docs: https://developers.google.com/speed/webp/docs/cwebp#options

Installation:

sudo apt install webp

Examples:

• Default batch processing for all sprites:

  find ./Content -name "*.png" -exec bash -c 'cwebp -q 100 -blend_alpha 0x000000 -o "${0%.png}.webp" -- $0' {} \;

  • -q 100 quality level 100. This value is used because black pixels can be lighter, or some lighter pixels can be black after encoding with lower quality level. So transparent pixel may become opaque or vice-versa.
  • -blend_alpha 0x000000 blends alpha with provided color and discards alpha channel. Avoid -noalpha.

  Note:

  • -sharp_yuv should not be used here, see -q 100 explanation above.
  • Try also -pass <num> and -m <num> controls with low values to reach higher PSNR, see -q 100 explanation above.

• For games with a lot of content, where transparency quality is not significant, such as Manga:

  find ./Content -name "*.png" -exec bash -c 'cwebp -q 90 -sharp_yuv -pass 10 -m 6 -noalpha -o "${0%.png}.webp" -- $0' {} \;

  • -q 90 is quality level 90. It may be even lower to fit more content.
  • -sharp_yuv significantly improves visual image quality.
  • -pass 10 produces better PSNR/size ratio.
  • -m 6 controls the trade off between encoding speed and the compressed file size and quality.

Audio

WAV requirements

• Channels: 1 (mono)
• Sample rate: 22050 Hz
• Audio codec: pcm_s16le (others not tested)

ffmpeg -y -i input.wav -ac 1 -acodec pcm_s16le -ar 22050 output.wav

MP3 requirements

WIP.

• Channels: 1 (mono)
• Bitrate: 48 kb/s
• Sample rate: 48000 Hz

ffmpeg -y -i input.wav -vn -ac 1 -ar 48000 -b:a 48k output.mp3

Batch processing:

for i in *.wav; do ffmpeg -i "$i" -vn -ac 2 -ar 48000 -b:a 48k "${i%}.mp3"; done