Light glow & flare sync (target_light material toggles, light-style/pulse sync, sprite lighting refactor)

[skies912]

Per-surface switchable and animated emissive glow stages + flares, driven by target_light entities and baked BSP lights, with no BSP format/version bump (reuses a spare surface bit).

What this adds

• SURF_TOGGLE (0x2000) + toggle stage keyword (STAGE_TOGGLE) — a target_light switches a material's glow stages and flares on/off per-surface, bound by a material key on the light. quemap FaceCmp splits SURF_TOGGLE faces per brush side so panels sharing one material can chase independently.
• Continuous brightness sync — glow stages and flares track a controlling light's brightness via toggle_alpha. A styled light makes them flicker/pulse; a target_light switches them (style × on/off). Bound to baked BSP lights (phase-correct style/drift) or target_light entities.
• Pulse→light sync — a styleless light with a material key whose material has a pulse stage drives its own cast intensity from that pulse (e.g. jump pads breathing), using the same sine/clock/drift as the shader so the cast light and the glow stay phase-locked.
• target_light extras — intensity key (matches point lights, via s.termination.y) and a back_and_forth spawnflag (teamed chases bounce instead of wrapping).
• quemap warning when a SURF_TOGGLE face's material has no drawable/flare stage (catches mapper mistakes at compile).

Sprite lighting refactor

Replaces sprite_vs's bespoke distance-only lighting loop with a call to light.glsl::vertex_lighting via a local common_vertex_t, so particles get the full lighting model (ambient, occlusion, exposure, per-light diffuse, caustics) instead of flat distance attenuation. Billboards have no surface normal, so a camera-facing normal is synthesized for the lambert/sky terms. This also fixes dust/sprites staying flatly lit in shadowed corners — they're now properly grounded (net −10 lines in the shader path).

Compatibility

SURF_TOGGLE is a spare surface bit, so existing BSPs and the current release branch load unchanged and simply ignore the new entity keys.

Testing

Verified in-game (rage): per-surface glow + flare toggling, light-style sync on a flickering fluorescent, pulse→light on a jump pad, and grounded dust under the refactored sprite path. Perf under heavy particle scenes still wants more soak testing (the sprite path now does a few more per-vertex samples).

🤖 Generated with Claude Code

[skies912]

rage.zip
Didn't want to push this in update just yet. Has updated stuffs used in testing this feature branch (target_lights and light-pulse sync).