State
Generated from engine/core/state.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.
#include "engine/core/state.h" · namespace labrador
class State
Section titled “class State”State · ~State
Section titled “State · ~State”virtual ~State() = default;update
Section titled “update”virtual void update(float dt) = 0;The seconds since the last update. Frame time is a parameter, not shared state, for the reason GameObject::update gives (PHILOSOPHY, Services and lifetimes).
Only the top of the stack is updated. A state with something above it is suspended: see on_suspend().
const, and taking the renderer.
const is not decoration here. Every draw below this line runs on the same objects from every render worker at once, and this is the line where the compiler starts holding them to it: a draw helper that writes a member is a compile error rather than a race.
The state declares how many views this frame has and fills them; it does not submit. begin_frame / submit / end_frame belong to whoever owns the frame, which is the shell.
virtual void init() = 0;covers_screen
Section titled “covers_screen”virtual bool covers_screen() const;Whether this state fills the frame on its own.
The stack draws from the topmost state that says yes, upward - so a pause menu, which is a box over a running match, says no and the match underneath keeps drawing. Everything else is a screen and the default is therefore true: a state that replaced the whole frame and forgot to say so would be drawn over a stale one below it, which is a bug you see; a state that covers the screen and pays for one hidden draw of what is under it is a bug you do not.
It is asked once per frame, before any drawing, so it is not on the per-object path and there is no T8 cost to it being virtual.
on_suspend
Section titled “on_suspend”virtual void on_suspend();Something was pushed above this state. It stops receiving update() and - unless the state above covers the screen - keeps receiving draw() until that thing pops.
This is where "quiet down while something is above me" goes, because not being updated cannot do it: a looping voice keeps playing precisely because the update that would have stopped it is the one being skipped.
on_resume
Section titled “on_resume”virtual void on_resume();Whatever was above this state popped, and it is the top again. Runs before the result callback the push was given, so the callback sees a stack that has already finished changing shape.
on_activated · on_deactivated
Section titled “on_activated · on_deactivated”virtual void on_activated();virtual void on_deactivated();The application got or lost the foreground: alt-tab, minimise, a power suspend, or coming back from any of them.
A DIFFERENT QUESTION FROM on_suspend. on_suspend means "something was pushed above me" and is asked of one state; these mean "nobody is looking at any of us", which is a fact about the window that no state can see. While the application is in the background the pad reader is suspended and answers "disconnected" for every slot, which is a neutral input that nothing downstream questions - so a match that is not told plays itself out with nobody in it: the characters standing still, the clock running down, and the music at full volume over whatever the player switched to.
EVERY FRAME IS TOLD, top down, not the top one alone. A match under a pause menu is not being updated and is still holding the music and a looping weapon voice, so the frame that most needs to hear this is the one furthest from the top.
AN EDGE, so a state may pause here and resume there without keeping a bool of its own. Windows offers no such guarantee - deactivating and then minimising is two separate messages that both mean "not in front of the player" - and StateContext::notify_activation is where the sources collapse into one question, so it is where the edge is made. A state constructed while the application is already inactive missed the edge and is told nothing; it asks StateContext::active().
set_context
Section titled “set_context”context (protected)
Section titled “context (protected)”Related types
Section titled “Related types”Named in the public declarations above: Renderer, StateContext.
In the samples and tests
Section titled “In the samples and tests”The files that include this header directly. A file can also reach it through another header.
samples/audio/audio_state.hsamples/linesweeper/states/pause_state.h,play_state.hsamples/local_multiplayer/play_state.hsamples/minimal/states/confirm_state.h,hello_state.htests/scene/fanout_tests.cpp
Development documentation (unreleased). Built from Labrador 862e08b of 2026-10-08.