STemWin Alpha channel

[frackers]

I'm using an stm32f769 on an ARGB8888 system.

I'm creating a bitmap image in RAM from a JPEG using the hardware decoder. This is decode process does NOT set the alpha byte to 0xff so the GUI_DrawBitmap function using the GUI_DRAW_BMP8888 method doesn't display anything (its all transparent).

How do I force STemWin to ignore the alpha channel (or lack of it) so that my image displays.

I've tried  GUI_SetAlpha() and GUI_EnableAlpha () in various combinations but to no effect.

[frackers]

Further research reveals that neither GUI_SetAlpha or GUI_SetUserAlpha ever calls LCD_X_SETALPHA cmd in the LCD driver so the layer Alpha value never gets updated.

Is it really this broken or am I just lucky?