Gzdoom

[MinerOfWorlds]

What's the difference between gzdoom's palette mode and software rendering?

[Gez]

MinerOfWorlds said:

What's the difference between gzdoom's palette mode and software rendering?

The palette mode in recent builds is a post-process effect. The scene is rendered in full colors and then the rendered image is palettized.

Other than this post-process effect, it's still hardware rendering, so the scene is turned into polygons that are then fed to the GPU.

Software rendering works differently. Doom renders walls by columns, flats by floodfill, then draw two-sided walls and sprites by columns over it. This method leads to certain fundamental differences such as letting sprites be rendered "inside" flats (an effect Doom uses to create an illusion of depth for the sprite); but with OpenGL these sprites would get clipped so monster feet get cut off by the ground for example. Kaiser wrote about how hard it was to get OpenGL to unclip the sprites in SVE, and there's some screenshots to illustrate what I mean.

Another big difference is how Doom's software rendering is always horizontal -- if you "look up" or "down", you're not changing the angle at which you see the scene (so the vertical lines of walls remain parallel to the sides of the screen) because it's actually using Y-shearing instead of changing the view pitch. Basically software rendering is "locked" in 2-point perspective.

Finally there are also other differences, because palette or not, GZDoom will render a lot of things that are not supported by software mode rendering such as 3D models, sloped 3D floors, dynamic lights, etc. Voxels are also rendered differently, as they are turned into models made out of cubes while software instead renders them as a collection of squares.

[MinerOfWorlds]

Thanks i was wondering what the difference was

[Rachael]

GZDoom's palette tonemap has about as much in common with ZDoom's software rendering as QZDoom's software rendering has in common with GZDoom with no tonemaps.

Beyond what Gez has said, its existence is purely to create a nostalgic feeling while still taking full advantage of OpenGL features. Like many not-so-status-quo ideas, it has its humble beginnings in some random ZDoom thread...

[scifista42]

Do custom vanilla-styled damage/pickup/radsuit palette effects and/or normal/invulnerability colormap effects work in the paletted mode?

EDIT: I mean effects that rely on non-standardly generated damage/pickup/radsuits palettes and/or colormap, as opposed to the default ones or the ones defined via respective ZDoom-specific features.

[MinerOfWorlds]

scifista42 said:

Do custom damage/pickup/radsuit palette effects and/or normal/invulnerability colormap effects work in the paletted mode?

I think so

[Rachael]

I don't think so. They haven't been supported inside ZDoom since a long time, now, since ZDoom now uses its own screen-blending system which GZDoom also adopted.

[Graf Zahl]

ZDoom allows fully customizable and combinable blends, which is entirely at odds with using PLAYPAL for it. And even if that wasn't the case, the palette tonemap is a postprocessing effect, it doesn't use a real palette, it just mangles the true color rendering of the scene to fit into some reduced color space.