87 lines
2.4 KiB
C++
87 lines
2.4 KiB
C++
#pragma once
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#include "animatable.hh"
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namespace creeper {
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template <class T>
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concept transition_state_trait = requires(T& t) {
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typename T::ValueT;
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{ t.get_value() } -> std::same_as<typename T::ValueT>;
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{ t.get_target() } -> std::same_as<typename T::ValueT>;
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{ t.set_value(std::declval<typename T::ValueT>()) };
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{ t.set_target(std::declval<typename T::ValueT>()) };
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{ t.update() } -> std::same_as<bool>;
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};
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// Functor like lambda
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template <transition_state_trait State>
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struct TransitionTask : public ITransitionTask {
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public:
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explicit TransitionTask(std::shared_ptr<State> state, std::shared_ptr<bool> token) noexcept
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: state { std::move(state) }
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, running { std::move(token) } { }
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~TransitionTask() override = default;
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auto update() noexcept -> bool override {
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return *running && state->update(); //
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}
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private:
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std::shared_ptr<State> state;
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std::shared_ptr<bool> running;
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};
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template <transition_state_trait State>
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struct TransitionValue {
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public:
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using T = State::ValueT;
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explicit TransitionValue(Animatable& animatable, std::shared_ptr<State> state) noexcept
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: animatable { animatable }
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, state { std::move(state) } { }
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auto get_state() const noexcept -> const State& { return *state; }
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auto get_value() const noexcept { return state->get_value(); }
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auto get_target() const noexcept { return state->get_target(); }
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operator T() const noexcept { return state->get_value(); }
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auto transition_to(const T& to) noexcept -> void {
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// Update target of state
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state->set_target(to);
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// Clear last transition task
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if (running) {
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*running = false;
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}
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running = std::make_shared<bool>(true);
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// Push new transition task
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auto task = std::make_unique<TransitionTask<State>>(state, running);
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animatable.push_transition_task(std::move(task));
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}
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auto snap_to(T to) noexcept -> void {
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state->set_value(std::move(to));
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state->set_target(std::move(to));
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if (running) *running = false;
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}
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private:
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std::shared_ptr<State> state;
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std::shared_ptr<bool> running;
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Animatable& animatable;
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};
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template <transition_state_trait State>
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inline auto make_transition(Animatable& core, std::shared_ptr<State> state) {
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return std::make_unique<TransitionValue<State>>(core, state);
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}
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}
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