Context and Results

Context

LobContext (include/lob/lob.h) is the solver's immutable input. lob::Context (include/lob/lob.hpp) is layout-identical; a set of static_asserts guarantee no drift.

Selected fields (units in the comments in the header):

drag_coeff — density term ρ·π / 8 applied to Cd(Mach) inside DsDx (source/solve_step.cpp). For standard and BC-band paths the 1/BC scaling is already baked into the spline drags[60]; for custom tables drag_coeff scales density only.
speed_of_sound — fps, local value including humidity correction (source/calc.hpp).
mass — pounds, LbsT(mass).Value().
optic_height — feet.
gravity — {x,y} ft/s² rotated by range angle (source/lob_builder.cpp).
wind — {x,z} fps from heading+speed.
coriolis — three scalars 2Ω cos(lat) sin(az) etc.
zero_angle — MOA bore-vs-sight angle that zeros at the requested distance.
stability_factor — Miller sg, NaN if not computable.
aerodynamic_jump — MOA, 0 if not computed.
spindrift_factor — NaN if Litz path should be used instead.
max_time, minimum_speed, step_size, error, drags[60] (spline coefs).

Context is built only via Builder; do not fill it by hand.

Output

LobOutput (include/lob/lob.h) / lob::Output:

uint32_t range;         // feet actually reached
uint16_t velocity;      // fps
uint32_t energy;        // ft·lbf  (½·m·v²)
double elevation;       // inches (forward) or MOA (inverse)
double deflection;      // inches (forward) or MOA (inverse)
double time_of_flight;  // seconds

All outputs are produced by LobSolve / LobSolveInverse; callers provide the storage. No allocation occurs.

Error handling

Context::error (LobErrorT) is checked at the top of every solve. Any non-kLobErrorNone value causes the solve to return 0 immediately (source/lob_solve.cpp). Builder never throws; errors are values.

Lifetime

Builder and the drag tables it points to must outlive Build() only. After Build(), Context is self-contained (coefficients copied). Context and Output are plain aggregates suitable for memcpy.