include/rive/animation/state_transition.hpp

#ifndef _RIVE_STATE_TRANSITION_HPP_
#define _RIVE_STATE_TRANSITION_HPP_
#include "rive/animation/state_transition_flags.hpp"
#include "rive/generated/animation/state_transition_base.hpp"
#include <stdio.h>
#include <vector>

namespace rive
{
	class LayerState;
	class StateMachineLayerImporter;
	class StateTransitionImporter;
	class TransitionCondition;
	class StateInstance;
	class SMIInput;
	class LinearAnimation;
	class LinearAnimationInstance;

	enum class AllowTransition : unsigned char
	{
		no,
		waitingForExit,
		yes
	};

	class StateTransition : public StateTransitionBase
	{
		friend class StateMachineLayerImporter;
		friend class StateTransitionImporter;

	private:
		StateTransitionFlags transitionFlags() const
		{
			return static_cast<StateTransitionFlags>(flags());
		}
		LayerState* m_StateTo = nullptr;

		std::vector<TransitionCondition*> m_Conditions;
		void addCondition(TransitionCondition* condition);

	public:
		~StateTransition();
		const LayerState* stateTo() const { return m_StateTo; }

		StatusCode onAddedDirty(CoreContext* context) override;
		StatusCode onAddedClean(CoreContext* context) override;

		/// Whether the transition is marked disabled (usually done in the
		/// editor).
		bool isDisabled() const
		{
			return (transitionFlags() & StateTransitionFlags::Disabled) ==
			       StateTransitionFlags::Disabled;
		}

		/// Returns AllowTransition::yes when this transition can be taken from
		/// stateFrom with the given inputs.
		AllowTransition allowed(StateInstance* stateFrom,
		                        SMIInput** inputs,
		                        bool ignoreTriggers) const;

		/// Whether the animation is held at exit or if it keeps advancing
		/// during mixing.
		bool pauseOnExit() const
		{
			return (transitionFlags() & StateTransitionFlags::PauseOnExit) ==
			       StateTransitionFlags::PauseOnExit;
		}

		/// Whether exit time is enabled. All other conditions still apply, the
		/// exit time is effectively an AND with the rest of the conditions.
		bool enableExitTime() const
		{
			return (transitionFlags() & StateTransitionFlags::EnableExitTime) ==
			       StateTransitionFlags::EnableExitTime;
		}

		StatusCode import(ImportStack& importStack) override;

		size_t conditionCount() const { return m_Conditions.size(); }
		TransitionCondition* condition(size_t index) const
		{
			if (index < m_Conditions.size())
			{
				return m_Conditions[index];
			}
			return nullptr;
		}

		/// The amount of time to mix the outgoing animation onto the incoming
		/// one when changing state. Only applies when going out from an
		/// AnimationState.
		float mixTime(const LayerState* stateFrom) const;

		/// Computes the exit time in seconds of the stateFrom. Set absolute to
		/// true if you want the returned time to be relative to the entire
		/// animation. Set absolute to false if you want it relative to the work
		/// area.
		float exitTimeSeconds(const LayerState* stateFrom,
		                      bool absolute = false) const;

		/// Provide the animation instance to use for computing percentage
		/// durations for exit time.
		virtual const LinearAnimationInstance*
		exitTimeAnimationInstance(const StateInstance* from) const;

		/// Provide the animation to use for computing percentage durations for
		/// exit time.
		virtual const LinearAnimation*
		exitTimeAnimation(const LayerState* from) const;

		/// Retruns true when we need to hold the exit time, also applies the
		/// correct time to the animation instance in the stateFrom, when
		/// applicable (when it's an AnimationState).
		bool applyExitCondition(StateInstance* stateFrom) const;
	};
} // namespace rive

#endif