Function ballistics_calculate_trajectory 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn ballistics_calculate_trajectory(
    inputs: *const FFIBallisticInputs,
    wind: *const FFIWindConditions,
    atmosphere: *const FFIAtmosphericConditions,
    max_range: c_double,
    step_size: c_double,
) -> *mut FFITrajectoryResult

Calculate a trajectory through the C ABI.

step_size is expressed in milliseconds and must be finite and at least MIN_FFI_STEP_SIZE_MS. This boundary contract is validated for every solver mode, although adaptive RK45 chooses its integration steps internally. Invalid values return null without starting a solve. A solve that would exceed crate::MAX_TRAJECTORY_POINTS also returns null; an enabled sampling grid above crate::MAX_TRAJECTORY_SAMPLES does likewise. Callers can increase step_size, reduce max_range, or select adaptive RK45.

Safety

inputs may be null, in which case this function returns null. When non-null, it must point to a valid, properly aligned FFIBallisticInputs that remains readable and is not mutated for the duration of this call. wind and atmosphere may also be null; each non-null pointer has the same requirements for its corresponding type. The returned pointer, when non-null, must be released exactly once with ballistics_free_trajectory_result.