haliumqsgcontext

A Qt Scene Graph plugin for better hardware integration

General info

This plugin allows for tighter integration of Qt and Halium-based distributions.

• Uses Android's GraphicBuffer to upload textures to the GPU
• Using multiple threads
• Exposes those GraphicBuffers to OpenGL as any other texture
• Replaces the default QAnimationDriver with a solely VSync-based one

Usage

Enable the plugin by exporting QMLSCENE_DEVICE=haliumqsgcontext in the environment.

Tweaking the settings

There are a handful of libdeviceinfo settings that allow adjusting the behavior of haliumqsgcontext.

• HaliumQsgUseShaders (default: true): Determines shader-based swizzling, falling back to Qt for texture uploads
• HaliumQsgAnimationDriver (default: true): Enable or disable the custom QAnimationDriver
• HaliumQsgUploadThreads (default: number of cores - 2): Raise or lower thread count for texture uploads, or disable with 0.

For example:

# cat /etc/deviceinfo/devices/halium.yaml
sargo:
  Vendor: Google
  PrettyName: Pixel 3a
  DeviceType: phone
  GridUnit: 25
  HaliumQsgUseShaders: true
  HaliumQsgUploadThreads: 4