OpenGL on Android - seems colour depth is hardcoded to 8bpp per colour?

[andrewhaighcell]

Hi,
I've a pre-existing C++ library which renders to an externally supplier OpenGL context, and it wants a buffer format which is RGB565 (no alpha channel). But trying to configure this via QSurfaceFormat() just doesnt seem to change from 8bpp for Alpha, Red, Green, and Blue channels. When I looked into the Android platform abstraction code, I saw this:

https://github.com/qt/qtbase/blob/dev/src/plugins/platforms/android/qandroidplatformintegration.cpp
...
QPlatformOpenGLContext *QAndroidPlatformIntegration::createPlatformOpenGLContext(QOpenGLContext *context) const
{
QSurfaceFormat format(context->format());
format.setAlphaBufferSize(8);
format.setRedBufferSize(8);
format.setGreenBufferSize(8);
format.setBlueBufferSize(8);
return new QAndroidPlatformOpenGLContext(format, context->shareHandle(), m_eglDisplay);
}
...

Can anyone explain why this is, and is it possible to change the surface format as I want? I am sure the underlying device supports it, as this library is used in other applications without problems...

[SGaist]

Hi,

You should rather bring that questions to the Qt Android development mailing list. You'll find there Qt Android port developers/maintainers. This forum is more user oriented.

[andrewhaighcell]

Thanks, I have asked the question there. When I have some time, I will see about checking for sure that this is the code path that is followed in the plugin, but dont have a debug build of Qt at present to step through.