Hexen/Heretic: Support Color-Translation in V_DrawTLPatch

[Noseey]

Related Issue:
None

Changes Summary

Adding a translucent and color-translated rendering function for Heretic/Hexen to be called optionally in DrawTLPatch. It is based upon drawtinttab, so the source-color remains the dominating one (for Palette), just corrected by the translation. This allows for transparent golden center-messages.

Translated Palette Lookup example:

Translated True Color Blend example:

[Noseey]

A small question regarding the True Color Blending Functions:

i_truecolor.c:

// [crispy] TINTTAB blending emulation, used for Heretic and Hexen
const uint32_t I_BlendOverTinttab (const uint32_t bg, const uint32_t fg)
{
    return I_BlendOver(bg, fg, 0x60); // 96 (38% opacity)
}

// [crispy] More opaque ("Alt") TINTTAB blending emulation, used for Hexen's MF_ALTSHADOW drawing
const uint32_t I_BlendOverAltTinttab (const uint32_t bg, const uint32_t fg)
{
    return I_BlendOver(bg, fg, 0x8E); // 142 (56% opacity)
}

Isn't the opacity the other way around (at least for Heretic)? Meaning the Alt-Tinttab has lower opacity of the source material? (see artibox-tiles in vanilla fullscreen-hud)

Edit: I think the dominant color selection changes between heretic and hexen. for me it looks like Heretic has dominant color-rows while hexen has dominant color-columns.

Heretic:

Hexen:

So the Alt funtion is more opaque in Hexen, less in Heretic, I presume. I think this game depedency might need to be considered in the blending / or the calls need to be adapted. Should I include this here?