[rpi] Hardware surfaces lack transparency (198)

[GalacticEmperor1]

Issue №198 opened by illume at 2014-04-04 01:41:14

Originally reported by: Alecks Gates (Bitbucket: alecksag, GitHub: Unknown)

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I'm running pygame-1.9.2_pre20120101-r2 on Gentoo with SDL_VIDEOBACKEND=directfb, where directfb is using the hardware accelerated fbdev system on a raspberry pi.

Upon loading a png image with transparency, I can blit it to the screen surface without a hitch -- transparency is fine.

If I smoothscale the image I lose all transparency -- the transparent pixels are white on blit. convert_alpha() on the image gives a blank surface.

The same code works fine using the software renderer, i.e. on the X server on the pi and even other hardware.

Some framebuffer details:

/boot/config.txt contains:
framebuffer_depth=32
framebuffer_ignore_alpha=1
framebuffer_swap=1 (necessary for colors to work right on directfb)

/etc/directfbrc contains:
system=fbdev
pixelformat=RGB32

fbset -s gives:
rgba 8/16,8/8,8/0,8/24

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• Bitbucket: https://bitbucket.org/pygame/pygame/issue/198

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Comments

# # MyreMylar commented at 2020-05-02 09:26:42

Did some investigation into this. The main problem seems to be that the directfb project has been basically dead for many years:

DirectFB/directfb#1

Effort in this space now all seems instead to be going towards a project called Wayland which also has an sdl2 backend, but as far as I can see raspberry pi are not moving to wayland (see: https://joshondesign.com/2018/03/26/linux_graphics_state and https://www.raspberrypi.org/blog/buster-the-new-version-of-raspbian/# comment-1511261). So I'm not sure what we can do about this issue anymore, or if we should given the apparent dead-ness of directfb.

There is a chance it just works now on newer versions of pygame, but heck knows if you can even install directfb on raspberry pi anymore, I could't find any working instructions and everything online was from about 8 years ago.

I think this is the original reporter @agates so perhaps they can provide some follow up on whether we should just close this?

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# # agates commented at 2020-05-02 14:53:50

Yup, that's me!

I would close this. At least on Gentoo, you can't even install media-libs/libsdl with directfb support any more.