[Regression] OpenGL renderer colors are wrong

[weirddan455]

I've bisected the problem to commit 12cee1c

I'm not on a big endian machine. I'm on x86_64 with Arch Linux as my OS.

I found the problem by building SDL from tip of tree and running DOSBox Staging with this in the config:

[sdl]
output = texture

This tells DOSBox to use SDL's renderer instead of DOSBox's own OpenGL code (which does not reproduce this issue).

[slouken]

Do you know what texture format is being used here?

[weirddan455]

Hmm... maybe DOSBox Staging is making bad assumptions. We're choosing the first supported texture format the renderer returns like so:

// Retrieve available texture formats.
SDL_RendererInfo renderer_info;
if (SDL_GetRendererInfo(renderer, &renderer_info) < 0) {
	LOG_ERR("SDL: Error retrieving SDL renderer info: %s",
			SDL_GetError());
	return false;
}

if (texture) {
	SDL_DestroyTexture(texture);
}

texture = SDL_CreateTexture(renderer,
							renderer_info.texture_formats[0],
							SDL_TEXTUREACCESS_STREAMING,
							render_width_px,
							render_height_px);

The commit I bisected to must have changed the order the formats are returned. SDL_PIXELFORMAT_ARGB8888 is the one that looks correct and SDL_PIXELFORMAT_ABGR8888 is the one that looks incorrect.

[slouken]

Is DOSBox assuming that the texture is a particular format?

The intent is for SDL_PIXELFORMAT_ARGB8888 to be the first format on all renderers, so I'll investigate that here as well.

[slouken]

Yes, we flipped the default channel ordering for the OpenGL renderer, I'll fix that.

[weirddan455]

Is DOSBox assuming that the texture is a particular format?

Yeah, I think there's a DOSBox bug that I'm going to investigate later. I believe our renderer doesn't work right unless it's in ARGB8888 format. I hardcoded it as a test and it fixed the color bug.

[slouken]

Fixed in 1fb663b, thanks!

[weirddan455]

Thanks for the fix @slouken

Just FYI it looks like you had a typo in the commit message and closed #1440 by mistake

[slouken]

Thanks for the fix @slouken

Just FYI it looks like you had a typo in the commit message and closed #1440 by mistake

Yep, it's already on the public repo so I can't change it, but thanks for the heads up!