Tunnelling

Generated from engine/collision/tunnelling.h at 862e08b. The text under each declaration is the header's own comment, word for word. About the reference says how these pages are made.

Browse the collision module

#include "engine/collision/tunnelling.h" · namespace labrador

max_safe_displacement

constexpr float max_safe_displacement(float extent_a, float extent_b);

A one-dimensional displacement budget for discrete collision detection. This is exact for fixed-size axis-aligned boxes translating along one shared coordinate axis, with strictly overlapping intervals on the other axis throughout the step. Extents are their positive widths or heights on the travel axis; displacement is a nonnegative relative travel distance and the step duration is positive.

Under those assumptions, the interval of travel with positive overlap has length extent_a + extent_b. A shorter step cannot cross it entirely. The boundary itself is unsafe: both sampled endpoints can merely touch, and narrow_phase.h treats touching as no contact.

Projecting arbitrary shapes onto a diagonal does NOT establish this interval. An off-center corner crossing can have an arbitrarily short contact interval despite large projected extents. For diagonal motion, rotation, or other geometry these helpers are only a tuning heuristic; a false can_tunnel result does not prove safety. Clients choosing the discrete model (PHILOSOPHY T3) must constrain their content and motion, or separately test the trajectories that matter.

can_tunnel

constexpr bool can_tunnel(float displacement, float extent_a, float extent_b);

Whether the one-dimensional budget above is reached or exceeded. NaN displacement answers true. This does not test an actual trajectory.

max_safe_speed

constexpr float max_safe_speed(float extent_a, float extent_b,
  float seconds_per_step);

The boundary speed under the same assumptions, in world units/second. A safe working speed is strictly less than this boundary.

In the samples and tests

The files that include this header directly. A file can also reach it through another header.

• tests/collision/ tunnelling_tests.cpp