Entry 145

The fog by each vertex's depth, as VU1 writes it

2026-09-26render

Filescrates/piney-draw/src/lib.rscrates/piney-gs/src/convert.rscrates/piney-gs/src/lib.rscrates/piney-desktop/src/soft.rscrates/piney-world/src/draw.rscrates/piney-world/src/body.rscrates/piney-world/src/town.rscrates/piney-world/src/gate.rscrates/piney-world/src/foe.rscrates/piney-world/src/field_area.rscrates/piney-world/src/dungeon_area.rscrates/piney-world/src/evarea.rscrates/piney-world/src/evarea_b0.rsdocs/engine/render.md

A GAPS drawing item. VU1 writes each vertex's F as clamp(fogB + fogA * w, fMin, fMax) from ccDrawEnv::SetFog's terms (render.md). The GS then interpolates F across the triangle.

Before

The port's draw list carried only one F per model.

• Fields and dungeons took each piece's F at its centre's distance. A whole room or ground tile was one shade: the far wall of a corridor no hazier than its near end.
• Towns and story maps had no fog at all. Mac Anu's orange-brown haze (SetFog(1000, 7500, 0, 85, ...)) and Dun Loireag's pale blue one (SetFog(1500, 10000, 0, 75, ...)) were missing, and so was the characters' fog everywhere.

The change

• The draw list. piney_draw::DepthFog (fogA, fogB, fMin, fMax, FOGCOL; DepthFog::set_fog is SetFog's arithmetic) is a new ModelDraw::depth_fog. A constant fog (ccChar::Draw's blend) still wins over it, as SetFogBlend does.
• piney-gs. Each vertex gets its F (GVertex::fog_f), computed from its clip w, also for the vertices made by the near-plane cut. The shader interpolates it linearly in screen space under a new Params::DEPTH_FOG bit.
• The software rasterizer. Its vertices carry F and it interpolates it the same way.
• piney-world. draw::Fogging (none, constant, by depth) replaces the Option<Fog> of the model draws.
• The draw environment. TownLights gains the environment's fog. The town sets it from its class's SetFog, the field from its background row, the dungeon from the room's fog row (again at each room), and the story maps from their blocks' SetFog.
• Who is fogged. The characters' bodies, the enemies and the Chaos Gate fall back to the environment's fog when they have no blend of their own. The town's rows and objects, and the story maps' models and objects, are fogged. Their skies, clouds, background clumps and water are not, being the ones the game gives SetFogSw(0).

Checks

• All 572 workspace tests pass. The one draw-list comparison that fogs (Dun Loireag's) compares pieces, not F.
• Pictures: dun_loireag_shots shows the distant canyon wall and the balloon in the town's blue haze where they were sharp before. Kite, at a few hundred units, is unchanged. In target_cursor_shot's small dungeon room the change is at most ten levels a channel.