Squad logos look faded

[Goober5000]

For some time, squad logos have been rendered in a way that makes them barely visible. Apparently this has been known but was never documented in a GitHub ticket. So, here's the ticket. Scroll has a lot of nice squad logos and we want to show them off properly.

[tomimaki]

Similar? #1309

[Goober5000]

Curiously, here one logo appears normally while one logo is faded:

[Goober5000]

Similar? #1309

Oh yes, this looks like the same issue. Wonder why it didn't come up in my search.

[MoerasGrizzly]

#5046

[MoerasGrizzly]

Okay I have had another look at this and I'm pretty sure I know why this happens now - at least from a visual perspective.

They become more transparant as more light is applied to them. Can easily be tested in the lab when you turn up or down emissive light or load a background and rotate towards the sun. Or both. It's as if the engine, rather then making the decal whiter when exposed to light, is adding more alpha to the image.

[Goober5000]

Well I took a look through modelrender.cpp with this in mind, and I couldn't see anything obviously out of place. This will require someone with actual graphics knowledge.

[Goober5000]

There is this bit of code in material_set_unlit():

	if ( blend_mode == ALPHA_BLEND_ADDITIVE ) {
		mat_info->set_color(alpha, alpha, alpha, 1.0f);
	} else {
		mat_info->set_color(1.0f, 1.0f, 1.0f, alpha);
	}

Since PCX logos don't have an alpha channel, they use ALPHA_BLEND_ADDITIVE. I tweaked the code to use the other set_color branch but it didn't fix the issue. The logo still faded out when exposed to bright light.