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Water Base Color

Contract

SetWaterBaseColor(red, green, blue, alpha) is a persistent WC3 presentation override for terrain water. The game module clamps each JASS integer to 0..255, stores the authoritative RGBA value in level state, and publishes normalized components through the generic CS_SCENE_WATER_COLOR configstring. The universal client copies that scene value into viewDef_t; it does not interpret Warcraft JASS or reach into the WC3 renderer directly.

The default map value is neutral opaque white, so maps that never call the native preserve the renderer's previous appearance. A later call replaces the current tint rather than multiplying with the previous call. The state is serialized with the level and republished after load.

Data Flow

JASS SetWaterBaseColor(r, g, b, a)
    -> games/warcraft-3/game/api/api_misc.h
    -> level.water_base_color
    -> CS_SCENE_WATER_COLOR (normalized RGBA)
    -> client/cl_view.c
    -> viewDef_t.waterBaseColor
    -> WC3 W3M water layer
    -> default world shader u_baseColor
    -> texture * vertex color * water base color

The generic default-world shader carries a baseColor multiplier because the WC3 water surface already uses that shader. R_SetupGL initializes the multiplier to white, and R_DrawTerrainSegment substitutes viewDef.waterBaseColor only for MAPLAYERTYPE_WATER, restoring white afterwards. Ground, cliffs, blight, splats, models, pathing and terrain topology are unchanged.

Alpha

Water vertices already encode depth-derived opacity. The runtime alpha multiplies that authored/per-vertex alpha instead of replacing it, so alpha = 255 preserves existing water opacity and lower values reduce it. RGB likewise multiplies the sampled water texture.

Persistence and Networking

The configstring is authoritative for connected/reconnecting clients during the map lifetime. Save format version 97 adds level.water_base_color; ReadGame() republishes it after the map reload rebuilds configstrings, matching the existing environmental-fog pattern. Older save formats remain intentionally incompatible.

Verification

Automated coverage checks the game-side contract without retail assets:

  • wc3_api.set_water_base_color_clamps_and_publishes_rgba checks argument consumption, 0..255 clamping, retained RGBA state, and CS_SCENE_WATER_COLOR publication.
  • the WC3 save round-trip fixture includes a non-default water color and verifies all four components after reload.

A manual visual check can call:

call SetWaterBaseColor(255, 0, 0, 255)
call TriggerSleepAction(2.00)
call SetWaterBaseColor(0, 128, 255, 128)
call TriggerSleepAction(2.00)
call SetWaterBaseColor(255, 255, 255, 255)

Expected: existing water changes tint immediately, the second call also reduces water opacity, and the final call returns to the neutral renderer multiplier. No terrain geometry, water height, pathing, fog-of-war or simulation state changes.