Struct Transition 

pub struct Transition<S> { /* private fields */ }

Where a machine goes next, and how it gets there.

A state on its own reads as one that takes the default fade, so a transition that states no knob is Some(State::Idle.into()).

Implementations

impl<S> Transition<S>

pub const DEFAULT_FADE: Duration

The fade a transition takes to blend out of the state it leaves when no call sets one: 150 milliseconds.

pub fn fade(self, over: Duration) -> Self

Takes over to blend out of the state it leaves; Transition::DEFAULT_FADE until set.

The state it leaves plays on under the fade, and a fade longer than what the state it enters plays holds that motion’s last key.

Examples found in repository

examples/animation.rs (line 380)

    fn next(&self, input: &ElfInput, at: Progress) -> Option<Transition<Self>> {
        match (self, input) {
            (Self::Death, _) => None,
            (_, ElfInput { dying: true, .. }) => Some(Self::Death.fade(DEATH_FADE)),
            (_, ElfInput { hit: true, .. }) if *self != Self::Hit => {
                Some(Self::Hit.fade(HIT_ENTER_FADE))
            }
            (Self::Hit, _) if at.ended() => Some(ElfState::grounded(input).fade(HIT_EXIT_FADE)),
            (Self::Attack, ElfInput { attack: true, .. }) if at.past(ATTACK_RELEASE) => Some(
                Self::Attack
                    .restarted()
                    .entering_at(ATTACK_CHAIN_ENTRY)
                    .fade(ATTACK_CHAIN_FADE),
            ),
            (Self::Attack, _) if at.past(ATTACK_RELEASE) => {
                Some(ElfState::grounded(input).fade(ATTACK_EXIT_FADE))
            }
            (Self::SitDown | Self::Sit | Self::StandUp, i) if i.speed > WALK_THRESHOLD => {
                Some(Self::Locomotion.fade(STAND_EXIT_FADE))
            }
            (Self::SitDown | Self::Sit | Self::StandUp, ElfInput { attack: true, .. }) => {
                Some(Self::Attack.fade(ATTACK_ENTER_FADE))
            }
            (Self::SitDown | Self::Sit | Self::StandUp, ElfInput { jump: true, .. }) => {
                Some(Self::Jump.fade(JUMP_ENTER_FADE))
            }
            (Self::SitDown, _) if at.ended() => Some(Self::Sit.at_once()),
            (Self::Sit, ElfInput { interact: true, .. }) => Some(Self::StandUp.fade(STAND_UP_FADE)),
            (Self::StandUp, _) if at.ended() => Some(Self::Idle.fade(STAND_EXIT_FADE)),
            (Self::Jump, ElfInput { landed: true, .. }) => {
                Some(ElfState::grounded(input).fade(JUMP_EXIT_FADE))
            }
            (Self::Jump, _) if at.ended() => Some(ElfState::grounded(input).fade(JUMP_EXIT_FADE)),
            (
                Self::Idle | Self::Locomotion,
                ElfInput {
                    interact: true,
                    near_seat: true,
                    ..
                },
            ) => Some(Self::SitDown.fade(SIT_DOWN_FADE)),
            (Self::Idle | Self::Locomotion, ElfInput { attack: true, .. }) => {
                Some(Self::Attack.fade(ATTACK_ENTER_FADE))
            }
            (Self::Idle | Self::Locomotion, ElfInput { jump: true, .. }) => {
                Some(Self::Jump.fade(JUMP_ENTER_FADE))
            }
            (Self::Idle, ElfInput { dance: true, .. }) => Some(Self::Dance.fade(DANCE_FADE)),
            (Self::Dance, i) if i.speed > WALK_THRESHOLD => {
                Some(Self::Locomotion.fade(IDLE_LOCOMOTION_FADE))
            }
            (Self::Idle, i) if i.speed > WALK_THRESHOLD => {
                Some(Self::Locomotion.fade(IDLE_LOCOMOTION_FADE))
            }
            (Self::Locomotion, i) if i.speed <= WALK_THRESHOLD => {
                Some(Self::Idle.fade(IDLE_LOCOMOTION_FADE))
            }
            _ => None,
        }
    }

pub fn at_once(self) -> Self

Enters with no fade, which drops the state it leaves at the instant it enters.

pub fn entering_at(self, fraction: f32) -> Self

Enters fraction of the way into what the state it enters plays, a fraction held inside 0.0..=1.0; the start of it until set.

Required if you want to skip the first part of a clip a state enters part way through.

Examples found in repository

examples/animation.rs (line 379)

    fn next(&self, input: &ElfInput, at: Progress) -> Option<Transition<Self>> {
        match (self, input) {
            (Self::Death, _) => None,
            (_, ElfInput { dying: true, .. }) => Some(Self::Death.fade(DEATH_FADE)),
            (_, ElfInput { hit: true, .. }) if *self != Self::Hit => {
                Some(Self::Hit.fade(HIT_ENTER_FADE))
            }
            (Self::Hit, _) if at.ended() => Some(ElfState::grounded(input).fade(HIT_EXIT_FADE)),
            (Self::Attack, ElfInput { attack: true, .. }) if at.past(ATTACK_RELEASE) => Some(
                Self::Attack
                    .restarted()
                    .entering_at(ATTACK_CHAIN_ENTRY)
                    .fade(ATTACK_CHAIN_FADE),
            ),
            (Self::Attack, _) if at.past(ATTACK_RELEASE) => {
                Some(ElfState::grounded(input).fade(ATTACK_EXIT_FADE))
            }
            (Self::SitDown | Self::Sit | Self::StandUp, i) if i.speed > WALK_THRESHOLD => {
                Some(Self::Locomotion.fade(STAND_EXIT_FADE))
            }
            (Self::SitDown | Self::Sit | Self::StandUp, ElfInput { attack: true, .. }) => {
                Some(Self::Attack.fade(ATTACK_ENTER_FADE))
            }
            (Self::SitDown | Self::Sit | Self::StandUp, ElfInput { jump: true, .. }) => {
                Some(Self::Jump.fade(JUMP_ENTER_FADE))
            }
            (Self::SitDown, _) if at.ended() => Some(Self::Sit.at_once()),
            (Self::Sit, ElfInput { interact: true, .. }) => Some(Self::StandUp.fade(STAND_UP_FADE)),
            (Self::StandUp, _) if at.ended() => Some(Self::Idle.fade(STAND_EXIT_FADE)),
            (Self::Jump, ElfInput { landed: true, .. }) => {
                Some(ElfState::grounded(input).fade(JUMP_EXIT_FADE))
            }
            (Self::Jump, _) if at.ended() => Some(ElfState::grounded(input).fade(JUMP_EXIT_FADE)),
            (
                Self::Idle | Self::Locomotion,
                ElfInput {
                    interact: true,
                    near_seat: true,
                    ..
                },
            ) => Some(Self::SitDown.fade(SIT_DOWN_FADE)),
            (Self::Idle | Self::Locomotion, ElfInput { attack: true, .. }) => {
                Some(Self::Attack.fade(ATTACK_ENTER_FADE))
            }
            (Self::Idle | Self::Locomotion, ElfInput { jump: true, .. }) => {
                Some(Self::Jump.fade(JUMP_ENTER_FADE))
            }
            (Self::Idle, ElfInput { dance: true, .. }) => Some(Self::Dance.fade(DANCE_FADE)),
            (Self::Dance, i) if i.speed > WALK_THRESHOLD => {
                Some(Self::Locomotion.fade(IDLE_LOCOMOTION_FADE))
            }
            (Self::Idle, i) if i.speed > WALK_THRESHOLD => {
                Some(Self::Locomotion.fade(IDLE_LOCOMOTION_FADE))
            }
            (Self::Locomotion, i) if i.speed <= WALK_THRESHOLD => {
                Some(Self::Idle.fade(IDLE_LOCOMOTION_FADE))
            }
            _ => None,
        }
    }

pub fn restarted(self) -> Self

Plays what the state it enters plays from the start again, which is what moves a machine to the state it is already in.

Trait Implementations

impl<S: Clone> Clone for Transition<S>

fn clone(&self) -> Transition<S>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<S: Debug> Debug for Transition<S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<S> From<S> for Transition<S>

fn from(into: S) -> Self

Into into over Transition::DEFAULT_FADE, from the start of what it plays.