## Summary
The "classic icons" graphics setting currently renders structure icon
glyphs as flat black. In the v0.31 canvas renderer, classic icons used
`structureColors().dark` — a darkened version of the owning player's
territory color. This PR restores that look in the WebGL renderer.
- New `structure.iconDarken` render setting (HSV value multiplier on the
player fill color; `0` = off, default).
- New `uIconDarken` uniform in `structure.frag.glsl`: when > 0, the
glyph color is `darken(playerFill, uIconDarken)` instead of the flat
`uIconColor`.
- Classic mode (`classicIcons: true`) now sets `iconDarken = 0.45`
instead of `iconR/G/B = 0`. Border darken, fill, and the 0.75
translucency are unchanged.
- Default (non-classic) icons are unaffected (white glyph, `iconDarken =
0`).
Under-construction structures keep the gray fill, so their glyph darkens
to a darker gray — matching v31's construction styling.
## Verification
Drove a solo game headlessly with classic icons on and built structures:
glyphs render as darkened versions of each player's color (dark purple
on a purple player, per-bot hues on bot structures). Pixel-sampled the
screenshot: glyph measured `rgb(89,58,142)` vs `rgb(84,50,139)`
predicted for the 0.45-darkened player color at 0.75 alpha (flat black
would measure `rgb(38,26,60)`). Control run with classic off shows the
unchanged white glyph. `tests/GraphicsOverrides.test.ts` updated; all
pass.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
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Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Evan
5648a37317