v2.2.6 — water caustic net

Old-Mac-Quake2 v2.2.6 — water caustic fix

Fixes the water-surface rendering and improves the caustic effect.

Fixed

• Water showed a tiled grid of soft circles ("shotgun-blast" pattern all
  over the surface). The gl_caustics overlay texture was built as the
  product of two sine gratings, which peaks at a regular lattice of dots.
  Rebuilt it as the zero-crossing contour of a sum of interference waves →
  a connected, organic caustic net.

Improved

• Caustic brightness tuned against live G5 in-game testing → subtle shimmer
  that layers with the water texture instead of washing it out.
• Caustic net now morphs/breathes over time (warped through the water
  warp's r_turbsin table), not just scrolling — a cheap table lookup, no
  per-pixel math, fine on PPC fillrate.
• Caustic texture generator is parameterised (CAUSTIC_WAVES / _POWER /
  _GAIN) with an in-source how-to-tweak guide.

Validated

Smoke demo (base2) clean on the fleet — world render OK, no ERR/DROP:
G5 62.6 fps, G4-mini 50.3 fps, G3 23.1 fps. G5 also manually confirmed
in-game. Caustics remain off on the G3/sawtooth (fillrate-bound). Decal
system unchanged — bullet/blood/scorch marks unaffected.

Install

One universal .dmg for the whole fleet (G3 Panther → G4 Tiger → G5 Leopard
→ Intel Lion → modern). Mount, drop Quake2.app next to your own baseq2/
pak files. DMG contents verified byte-identical to the built binaries.