Struct TrajectoryParams 

pub struct TrajectoryParams {

    pub mass_kg: f64,
    pub bc: f64,
    pub drag_model: DragModel,
    pub wind_segments: Vec<WindSegment>,
    pub atmos_params: (f64, f64, f64, f64),
    pub omega_vector: Option<Vector3<f64>>,
    pub enable_spin_drift: bool,
    pub enable_magnus: bool,
    pub enable_coriolis: bool,
    pub target_distance_m: f64,
    pub enable_wind_shear: bool,
    pub wind_shear_model: String,
    pub shooter_altitude_m: f64,
    pub is_twist_right: bool,
    pub shooting_angle: f64,
    pub bullet_diameter: f64,
    pub bullet_length: f64,
    pub twist_rate: f64,
    pub custom_drag_table: Option<DragTable>,
    pub cd_scale: f64,
    pub custom_drag_reference: bool,
    pub bc_segments: Option<Vec<(f64, f64)>>,
    pub use_bc_segments: bool,
    pub bc_segments_data: Option<Vec<BCSegmentData>>,
    pub ground_threshold: f64,
    pub atmo_sock: Option<AtmoSock>,
}

Parameters for trajectory computation

Fields

mass_kg: f64

bc: f64

drag_model: DragModel

wind_segments: Vec<WindSegment>

Downrange wind zones, normalized by until_distance_m when integration begins.

atmos_params: (f64, f64, f64, f64)

Dual-mode atmosphere tuple consumed by compute_derivatives: Standard (base_alt_m, base_temp_c, base_pressure_hPa, base_density_ratio) — note slot 3 is a density RATIO, NOT humidity, even though it rides in the humidity field; or Direct (air_density, speed_of_sound, 0.0, 0.0) — slots 2 and 3 are zero sentinels. A pressure of 0 that is not the direct-mode sentinel disables drag.

omega_vector: Option<Vector3<f64>>

Earth rotation in level downrange/up/lateral axes. The derivative kernel projects it into the inclined shot frame using shooting_angle before applying Coriolis acceleration.

enable_spin_drift: bool

enable_magnus: bool

enable_coriolis: bool

target_distance_m: f64

enable_wind_shear: bool

wind_shear_model: String

shooter_altitude_m: f64

is_twist_right: bool

shooting_angle: f64

bullet_diameter: f64

bullet_length: f64

twist_rate: f64

custom_drag_table: Option<DragTable>

cd_scale: f64

MBA-1356: whole-curve scale for the custom deck (1.0 = neutral). Threaded so the binding entry point (fast_integrate_with_segments) cannot silently drop it.

custom_drag_reference: bool

Whether custom_drag_table is a reference curve that the BCs were measured against, flown as Cd / BC with the BC the kernel resolves (a ladder’s band BC, else the scalar bc), rather than the projectile’s own Cd over sectional density. Mirrors BallisticInputs::custom_drag_reference and is threaded beside cd_scale for the same reason: build_inputs copies it onto the derivative inputs, and a flag dropped beside cd_scale = 1.0 would fly a reference curve as the projectile’s own Cd. false for a caller with no table, or with the projectile’s own curve.

bc_segments: Option<Vec<(f64, f64)>>

use_bc_segments: bool

bc_segments_data: Option<Vec<BCSegmentData>>

MBA-1602: the caller’s velocity-keyed BC ladder (fps bands), flown when use_bc_segments is on and the ladder is non-empty. None or an empty ladder is no ladder: with use_bc_segments on and no Mach bc_segments, the kernel keeps its historical opt-in auto-estimate (MBA-955). Threaded so the binding entry point (fast_integrate_with_segments) cannot silently drop it.

ground_threshold: f64

MBA-954: altitude (m, relative to launch) below which integration stops. -1000.0 is the historical default — effectively “no early ground impact” for normal flat-fire shots.

atmo_sock: Option<AtmoSock>

MBA-1137: optional downrange-segmented atmosphere. When Some, compute_derivatives swaps the standard-mode base T/P/H for the zone selected by downrange distance before the altitude lapse. None (default) is byte-identical to pre-feature behavior.