edgar: player character sprite transparency missing

[smcv]

Prerequisites:

• Debian testing (Debian 12 alpha)
• Video: GNOME 43 in Wayland mode (with Mesa 22.2.0 on AMD Vega, if it matters)
• Audio: Pipewire 0.3.59, with pipewire-pulse emulating PulseAudio
• apt install edgar (Debian package version 1.23-1)
• Some relevant libraries:
  • libsdl1.2-compat either 1.2.58-1 (packaged in Debian experimental) or commit 63e4393 (locally built)
  • libsdl2-2.0-0 version 2.24.1+dfsg-1
  • libsdl-image1.2 version 1.2.12-13+b1
  • libsdl-mixer1.2 version 1.2.12-17+b2
  • libsdl-ttf2.0-0 version 2.0.11-6
  • libsdl1.2debian (real SDL 1.2) vwrsion 1.2.165+dfsg2-8

To reproduce:

• edgar
• LD_LIBRARY_PATH=.../sdl12-compat/_build edgar
• SDL_VIDEODRIVER=wayland LD_LIBRARY_PATH=.../sdl12-compat/_build edgar

Start a new game, and look at the player character (human near the right side of the screen) during the opening conversation.

Expected result: all work

Actual result: with sdl12-compat (either X11 or Wayland), the player character's sprite is in a lime green non-transparent rectangle. With real SDL 1.2, those parts of the sprite are transparent.

[icculus]

This looks like a colorkey issue:

[icculus]

Actually, it seems to be a flipping-horizontally problem:

When sprites face right (unflipped) ...

(I drew a little "X" on edgar's idle stance png with Gimp, so I knew I had the right one.)

[icculus]

In the flipImage function, we hit this code:

if (image->flags & SDL_SRCCOLORKEY)
    SDL_SetColorKey(flipped, SDL_RLEACCEL|SDL_SRCCOLORKEY, image->format->colorkey);

In classic 1.2, this calls SDL_SetColorKey, in sdl12-compat, it doesn't. So somewhere we lost or failed to set SDL_SRCCOLORKEY. Digging further.

[smcv]

Confirmed fixed as of https://github.com/libsdl-org/sdl12-compat/commit/67f8b3a85b782eefb4db90f34d5b0742ef2cb5fc (1.2.58 + 29 commits)