import type { FishMarineLife } from "../../domain/models/OceanModels.js";
import type { IFishPropulsionCalculator } from "../contracts/IFishPropulsionCalculator.js";
/**
 * FishPropulsionCalculator - Derives forward thrust from tail physics
 *
 * Physics model:
 * - Tail position: sin(swimPhase) - oscillates side to side
 * - Tail velocity: cos(swimPhase) - derivative, peaks at center crossing
 * - Thrust: |cos(swimPhase)| - magnitude of velocity generates thrust
 *
 * This creates realistic behavior:
 * - Fish accelerate as tail crosses center (fastest sweep)
 * - Fish coast slightly at extremes (tail reversing direction)
 * - Speed varies naturally with swimming intensity
 */
export declare class FishPropulsionCalculator implements IFishPropulsionCalculator {
    calculateThrust(fish: FishMarineLife): number;
    calculateTargetSpeed(fish: FishMarineLife): number;
    getTailVelocity(fish: FishMarineLife): {
        lateral: number;
        angular: number;
    };
}
/**
 * Smoothly interpolate speed toward target
 * Used by movement controller to prevent jerky speed changes
 */
export declare function smoothSpeed(currentSpeed: number, targetSpeed: number, deltaSeconds: number): number;
//# sourceMappingURL=FishPropulsionCalculator.d.ts.map