This code plugin provides functions that drastically improve the quality of life during the implementation of game flow in C++.
It works very well with gameplay programming, UI programming with a lot of transitions or in any other situation.
The plugin has been tested on the Engine's versions: 4.27, 5.2, 5.3 and 5.4.
- Unreal Engine Marketplace
- Example Project
- Used in...
- Contact
- Support and Contribution
- Changelog
- LEGACY VERSIONS
- Installation
- Usage
- Extra Settings
- Instanced Actions
- Coroutines (experimental)
- Pausing and Resuming
- Stopping Actions
- Measuring Performance
- Extending Plugin
- Extra Links
- Special Thanks
The plugin is finally available on the Unreal Engine Marketplace! It is free, of course.
If you don't want to build this plugin by yourself, you can download it from here.
Unreal Engine Marketplace allow to publish the code plugins for new versions of the Unreal Engine only, so currently only 5.4, 5.3 and 5.2 are available.
If you are using 4.27 you can download the precompiled package from here.
The plugin's version that's on the Marketplace is 3.3.11.
The example project wich uses this plugin can be found in this repository. Example project is compatible with the newest version of the plugin only.
!!!IMPORTANT!!!
Currently Example Project will work with Unreal Engine 5! The last version of the example project that can be run on UE4 can be found here. This is a legacy example project which works with ECF 3.1.1. It is not guaranteed that it will work with the newest version of ECF.
Enhanced Code Flow has been used in the following projects:
If you are using ECF in your project, let me know :)
If you have any question or suggestion regardles this plugin simply add an Issue to the github project or write an e-mail to me: zompi2@gmail.com I will try my best to answer it quickly :)
This plugin is free and open source forever. However, if you want to show appretiation to my work any support will warm my heart.
If you have any suggestions on how to fix or improve this plugin feel free to create a Pull Request.
The Changelog has been put into this file: Changelog.txt
Version 3.1.1
was the last one that had an example project implemented in UE4. Next versions' example projects require UE5 to run.
Version 3.1.1
can be found on a separate branch here: Legacy-3.1.1
Version 3.0.0
will probably break code and Blueprint nodes from previous version. Update with caution!
Version 2.1.2
can be found on a separate branch here: Legacy-2.1
Version 2.0.0
will probably break Blueprint nodes from previous versions. Update with caution!
Version 1.6.1
can be found on a separate branch here: Legacy-1.6
- Get ECF plugin. You can do this by either:
- Getting it from the Epic Games Launcher. It will be installed in the Engine's directory:
Engine/Plugins/Marketplace/EnhancedCodeFlow
. - Cloning it or downloading it from this repository and putting it into your project's (
MyProject/Plugins/EnhancedCodeFlow
) or engine's (Engine/Plugins/EnhancedCodeFlow
) plugins directory.
- Getting it from the Epic Games Launcher. It will be installed in the Engine's directory:
- Add "EnhancedCodeFlow" entry to the
PublicDependencyModuleNames
list in your project's.Build.cs
file. - Enable the plugin in the Editor's Plugins manager (or by changing manually your project's
.uproject
file). - If you want to use this plugin in your code add
#include "EnhancedCodeFlow.h
to the file in which you want to use the plugin.
Check out the Example Project to see how the plugin is integrated into it.
- Delay
- Delay Ticks
- Add Ticker
- Wait And Execute
- While True Execute
- Run Async Then
- Add Timeline
- Add Custom Timeline
- Time Lock
- Do Once
- Do N Times
- Do No More Than X Time
Run the following functions to use enhanced code flow!
Note that every function must receive a pointer to an owner that runs this function in it's first argument.
The owner must be able to return a World via GetWorld() function.
Execute specified action after some time. This can be useful in many various situations. Everytime when I was using a Delay node in blueprints I wish there was an equivalent of it in c++.
The bStopped
tells if this action has been stopped by a Stop function. This argument is optional.
FFlow::Delay(this, 2.f, [this](bool bStopped)
{
// Code to execute after 2 seconds.
});
An ECF-Delay BP node has few advantages over the built in Unreal's Delay node.
You can plan to execute delayed code without delaying the whole Blueprint, you can cancel the delayed code's execution or make the dilation game pause and time dilation independent.
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Execute specified action after some ticks. Can be useful if we want to execute some code in next game tick.
The bStopped
tells if this action has been stopped by a Stop function. This argument is optional.
FFlow::DelayTicks(this, 1, [this](bool bStopped)
{
// Code to execute after 1 tick.
});
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Creates a ticker. It can tick specified amount of time or until it won't be stopped or when owning object won't be destroyed.
Useful for actors and components that you don't want to be tickeable, but needs one tick to do something.
Run ticker for 10 seconds
FFlow::AddTicker(this, 10.f, [this](float DeltaTime)
{
// Code to execute every tick
});
Run ticker for 10 seconds and run a callback when it finishes
FFlow::AddTicker(this, 10.f, [this](float DeltaTime)
{
// Code to execute every tick
}, [this](bool bStopped)
{
// Code to execute when ticker finishes ticking.
// The bStopped tells if this action has been stopped by a Stop function.
// The bStopped argument is optional.
});
Run ticker for infinite time and stop it when you want to
FFlow::AddTicker(this, [this](float DeltaTime, FECFHandle TickerHandle)
{
// Code to execute in every tick.
// Use this to stop the ticker
FFlow::StopAction(this, TickerHandle);
});
Run ticker for infinite time and something else stops it
FECFHandle TickerHandle = FFlow::AddTicker(this, [this](float DeltaTime)
{
// Code to execute in every tick.
});
// Use this to stop the ticker
FFlow::StopAction(this, TickerHandle);
Note 1: Tickers and every other plugin actions are impacted by global time dilation.
Note 2: You can check if the ticker (or any other action) is running using FFlow::IsActionRunning(TickerHandle)
Note 3: You can also run ticker infinitely by setting Ticking Time to -1
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Waits until specific conditions are met and then executes code.
The conditions are defined in a form of a predicate.
You can specify a timeout, which will stop this action after the given time. Setting the timeout value to less or equal 0 will cause this function to run infinitely untill the predicate returns true or when it is explicitly stopped.
The bStopped
tells if this action has been stopped by a Stop function. This argument is optional.
The bTimedOut
tells if this action has been stopped because it timed out. This argument is optional.
Perfect solution if code needs a reference to an object, which spawn moment is not clearly defined, or if you can execute a specific code only when the game reaches a specific state.
FFlow::WaitAndExecute(this, [this](float DeltaTime)
{
// Write your own predicate.
// Return true when you want to execute the code below.
// The DeltaTime parameter is optional.
return bIsReadyToUse;
},
[this](bool bTimedOut, bool bStopped)
{
// Implement code to execute when conditions are met or when this action has ran for 5 seconds (time specified in a timeout parameter)
}, 5.f);
BP version of this function uses a Predicate
function which controls when the On Execution
pin will execute.
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While the specified conditions are true tick the given code.
This one is useful when you want to write a loop that executes one run every tick until it finishes it's job.
You can specify a timeout, which will stop this action after the given time. Setting the timeout value to less or equal 0 will cause this function to run infinitely untill the predicate returns false or when it is explicitly stopped.
You can optionally defined what happens when the loop ends.
FFlow::WhileTrueExecute(this, [this]()
{
// Write your own predicate.
// Return true when you want this action to continue.
return bIsRunning;
},
[this](float DeltaTime)
{
// Implement code to tick when predicate returns true.
},
[this](bool bTimedOut, bool bStopped)
{
// Optionally implement a code that runs when this action ends, even when the condition
// in the predicate returns false or it is timed out or it is explicitly stopped.
// Both bTimedOut and bStopped arguments are optional.
}, 0.f);
BP version of this function uses a Predicate
function which controls when the On Execution
pin with Delta Time
will execute.
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Runs the given task function on a separate thread and calls the callback function when this task ends. You can specify a timeout, which will stop this action after the given time.
Have in mind, that the neither the timeout nor stopping the action will not stop the running async thread. It just won't trigger the callback when the async task ends. Handle timeout on the side of the async task itself.
The bStopped
tells if this action has been stopped by a Stop function. This argument is optional.
You can define the priority of the running task as Normal
(AnyBackgroundThreadNormalTask
) or HiPriority
(AnyBackgroundHiPriTask
).
Have in mind, that you can start this function from GameThread only!
FFlow::RunAsyncThen(this, [this]()
{
// This code runs on the background thread.
},
[this](bool bTimedOut, bool bStopped)
{
// This code runs on a game thread after the previous block of code finishes it's run.
}, 0.f, EECFAsyncPrio::Normal);
The BP node exists for this function, but have in mind that Unreal does not allow for many non-gamethread operations in Blueprints! Use this node with caution!
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Easily launch the timeline and update your game based on them. Great solution for any kind of blends and transitions. The function requires the following parameters:
- StartValue - a value with which the timeline will begin;
- StopValue - a value with which the timeline will end. StopValue can be lesser than StartValue;
- Time - how long the timeline will work;
- TickFunc - a function that will tick with the timeline. It has the following arguments:
- Value - a current value on this timeline;
- Time - a time that passed on this timeline;
- CallbackFunc - a function that will run when the timeline comes to an end. Has the same arguments as TickFunc. This function is optional;
- BlendFunc - a function that describes a shape of the timeline:
- Linear (default)
- Cubic
- EaseIn
- EaseOut
- EaseInOut
- BlendExp - an exponent defining a shape of EaseIn, EaseOut and EaseInOut function shapes. (default value: 1.f);
The bStopped
tells if this action has been stopped by a Stop function. This argument is optional.
FFlow::AddTimeline(this, 0.f, 1.f, 2.f, [this](float Value, float Time)
{
// Code to run every time the timeline tick
},
[this](float Value, float Time, bool bStopped)
{
// Code to run when timeline stops
},
EECFBlendFunc::ECFBlend_Linear, 2.f);
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Creates a discrete timeline which shape is based on a UCurveFloat. Works like the previously described timeline, but an asset with a curve must be given.
FFlow::AddCustomTimeline(this, Curve, [this](float Value, float Time)
{
// Code to run every time the timeline tick
},
[this](float Value, float Time, bool bStopped)
{
// Code to run when timeline stops. bStopped argument is optional.
});
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(Instanced)
Blocks execution of the block of code until the given time has passed.
static FECFInstanceId InstanceId = FECFInstanceId::NewId();
FFlow::TimeLock(this, 2.f, [this]()
{
// This code will run now, and won't be able to execute for 2 seconds.
}, InstanceId);
BP version of this function requires InstanceId
too. The BP node will validate the InstandeId
from the handler so it just need to be passed into it.
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(Instanced)
Allow to execute the given block of code only once.
static FECFInstanceId InstanceId = FECFInstanceId::NewId();
FFlow::DoOnce(this, [this]()
{
// This code can be run only once.
}, InstanceId);
This function doesn't have a BP version, because Unreal has one already.
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(Instanced)
Allow to execute the given block of code only given amount of times.
static FECFInstanceId InstanceId = FECFInstanceId::NewId();
FFlow::DoNTimes(this, 5, [this](int32 Counter)
{
// This code can be run only 5 times.
}, InstanceId);
This function doesn't have a BP version, because Unreal has one already.
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(Instanced)
It will execute the given block of code immediately, but the next execution will be enqueued and will be called after specified time. There is a parameter which allow to define how many next executions can be enqueued (must be at least 1). If this code will be used when the queue is full - the code will be discarded (not enqueued).
static FECFInstanceId InstanceId = FECFInstanceId::NewId();
FFlow::DoNoMoreThanXTime(this, [this]()
{
// This code will run now and if called again it will run no earlier than after 5 seconds after the last execution.
// If this will be called again before the second execution - it will be discarded.
}, 5.f, 1, InstanceId);
BP version of this function requires InstanceId
too. The BP node will validate the InstandeId
from the handler so it just need to be passed into it.
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You can define extra settings at the end of each action launch. Currently the following actions are available:
- Time Intervals - defines the length of one tick.
- First Delay - defines when the first tick should be performed.
- Ignore Game Pause - it will ignore the game pause.
- Ignore Global Time Dilation - it will ignore global time dilation when ticking.
- Start Paused - the action will start in paused state and must be resumed manually.
FFlow::AddTicker(this, 10.f, [this](float DeltaTime)
{
// Code to execute every 1 second for 10 seconds.
}, nullptr, FECFActionSettings(1.f, 0.f, false, false, false));
FFlow::AddTicker(this, 10.f, [this](float DeltaTime)
{
// Code to execute every tick for 10 seconds
// while ignoring global time dilation.
}, nullptr, FECFActionSettings(0.f, 0.f, true, false, false));
FFlow::AddTicker(this, 10.f, [this](float DeltaTime)
{
// Code to execute every 1 seconds for 10 seconds,
// after 5 seconds have passed, while ignoring
// global time dilation and pause.
}, nullptr, FECFActionSettings(1.f, 5.f, true, true, false));
To make defining these settings easier there are few macros that creates a settings structure with just one option:
ECF_TICKINTERVAL(5.f)
- settings which sets tick interval to 5 secondECF_DELAYFIRST(1.f)
- settings which makes this action to run after 1 second delayECF_IGNOREPAUSE
- settings which makes this action ignore game pauseECF_IGNORETIMEDILATION
- settings which makes this action ignore global time dilationECF_IGNOREPAUSEDILATION
- settings which makes this action ignore pause and global time dilationECF_STARTPAUSED
- settings which makes this action started in paused state
FFlow::Delay(this, 2.f, [this]()
{
// Run this code after 2 seconds, while ignoring game pause.
}, ECF_IGNOREPAUSE);
Some actions can be Instanced. Instanced action is an action that has valid FECFInstanceId
. Such action can be executed only once.
As long as the action with given valid FECFInstanceId
is running, no other action with the same FECFInstanceId
can be executed.
To get next valid InstanceId use the NewId()
function
FECFInstanceId::NewId();
There is additional BP node which will validate an InstanceId
if it is not valid.
Coroutines are treated as an experimental feature. You can use them at your own risk! They are experimental, because c++ coroutines are relatively new features and I'm still learning how to implement them correctly. It is highly probable there will be stability or performance issues.
Coroutines are functions that can suspend their execution and be resumed later. They require C++20 which is supported in Unreal Engine from verion 5.3. To make sure that your project supports C++20 add the following line to your project's Build.cs
:
CppStandard = CppStandardVersion.Cpp20;
Every coroutine must return the FECFCoroutine
. ECF implements some helpful coroutines described below. Every coroutine implemented in ECF works simillar to typical ECF action, but they use the coroutine suspension mechanisms instead of lambdas.
They can be paused, resumed, cancelled and they can accept FECFActionSettings
.
Coroutines doesn't have BP nodes as they are purely code feature.
Suspends the coroutine for a specified amount of seconds. It works like Delay in Blueprints.
FECFCoroutine UMyClass::SuspandableFunction()
{
// Do something
co_await FFlow::WaitSeconds(this, 2.f);
// Do something after 2 seconds
}
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Suspends the coroutine for a specified amount of tick.
FECFCoroutine UMyClass::SuspandableFunction()
{
// Do something
co_await FFlow::WaitTicks(this, 1);
// Do something after 1 tick
}
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Suspends the coroutine until the given predicate conditions are met.
FECFCoroutine UMyClass::SuspandableFunction()
{
// Do something
co_await FFlow::WaitUntil(this, [this](float DeltaTime)
{
// Write your own predicate.
// Return true when you want to resume the coroutine function.
return bIsReadyToUse;
}, TimeOut);
// Do something after conditions specified in the predicate are met.
}
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Runs the given block of code on a background thread and wait for it's completion before moving on.
Have in mind, that you can start this coroutine from GameThread only!
FECFCoroutine UMyClass::SuspandableFunction()
{
// Do something
co_await FFlow::RunAsyncAndWait(this, [this]()
{
// This code will run on a separate background thread.
}, TimeOut, EECFAsyncPrio::Normal);
// Do something after the above code has finished.
}
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Every running action can be paused and resumed.
FFlow::PauseAction(GetWorld(), Handle); // Pause Action
FFlow::ResumeAction(GetWorld(), Handle); // Resume Action
// Checks if the Action is Running and if it is Paused or not
bool bIsPaused;
bool bIsRunning = FFlow::IsActionPaused(WorldContextObject, Handle, bIsPaused);
Whole Enhanced Code Subsystem can be paused and resumed as well.
FFlow::SetPause(GetWorld(), true); // Pauses the whole ECF Subsystem
FFlow::SetPause(GetWorld(), false); // Unpauses the whole ECF Subsystem
FFlow::GetPause(GetWorld()); // Check if the whole ECF Subsystem is paused or not
Every function described earlier can be checked if it's running and it can be stopped.
FFlow::IsActionRunning(GetWorld(), Handle); // <- is this action running?
FFlow::StopAction(GetWorld(), Handle); // <- stops this action!
You can also stop all of the actions from a specific owner or from everywhere.
Stopped actions can launch their completion callbacks or not, depending on the given argument:
FFlow::StopAllActions(GetWorld()); // <- stops all of the actions
FFlow::StopAllActions(GetWorld(), true); // <- stops all of the actions and launch their callbacks
FFlow::StopAllActions(GetWorld(), false, Owner); // <- stops all of the actions started from this specific owner
When the completion callback will run after the Stop Function, the bStopped
argument in the completion function of the action will be set to true
.
You can also stop a specific Instanced action with the FECFInstanceId
:
FFlow::StopInstancedAction(GetWorld(), InstanceId); // <- stops all actions with this InstanceId
FFlow::StopInstancedAction(GetWorld(), InstanceId, true); // <- stops all actions with this InstanceId and launch their callbacks
You can also stop all of the specific actions. In this case you can also optionally specifiy an owner of this actions, or simply stop all of them. You can also specify if stopped actions should launch their completion callbacks or not.
FFlow::RemoveAllDelays(GetWorld());
FFlow::RemoveAllTickers(GetWorld());
FFlow::RemoveAllWaitAndExecutes(GetWorld());
FFlow::RemoveAllWhileTrueExecutes(GetWorld());
FFlow::RemoveAllRunAsyncThen(GetWorld());
FFlow::RemoveAllTimelines(GetWorld());
FFlow::RemoveAllCustomTimelines(GetWorld());
FFlow::RemoveAllTimeLocks(GetWorld());
FFlow::RemoveAllDoNoMoreThanXTimes(GetWorld());
You can also stop all of the running actions that handle coroutines.
FFlow::RemoveAllWaitSeconds(GetWorld(), true);
FFlow::RemoveAllWaitTicks(GetWorld(), true);
FFlow::RemoveAllWaitUntil(GetWorld(), true);
FFlow::RemoveAllRunAsyncAndWait(GetWorld(), true);
IMPORTANT! If you stop the action which handles a coroutine be aware that if you won't set bComplete
to true, the suspended coroutine will never be resumed!
To measure plugin's performance you can use the stat command designed for it: stat ecf
There are the following stats:
- Tick - the time in
ms
the plugin needs to perform one full update. - Actions - the amount of actions that are currently running.
- Instances - describes how many of the running actions are the instanced ones.
- Action Objects - the amount of the real action UObjects residing in the memory.
- Async BP Objects - the amount of the real UObjects handling async BP calls residenting in the memory.
Have in mind that
Action Objects
andAsync BP Objects
counts Class Default Objects (CDO) too, so their values will never be 0.
Tick
measures not only the time the plugin needs to do it's job, but also the time needed to run the code inside action's callbacks.
You can also display more detailed plugin's performance info with stat ecfdetails
. It will display the time needed by every type of action.
Have in mind that custom tick intervals might alter the values of stats, especially the
CallCounts
.
You can measure performence using Unreal Insights tool. Currently there is only one cpu timing trace available:
- ECF-Actions-Tick - measures the time the plugin needs to perform one full update.
You can disable Unreal Insights traces for this plugin by setting bEnableInsightProfiling
in EnhancedCodeFlow.Build.cs
to false
.
You have a source code of this plugin you can easily extend it's functionalities!
Check how other actions are made to easier understand how to extend the plugin.
- Create a class that inherits from
UECFActionBase
- Implement
Setup
function, which accepts all parameters you want to pass to this action.Setup
function must return true if the given parameters are valid.
bool Setup(int32 Param1, int32 Param2, TUniqueFunction<void(bool)>&& Callback)
{
CallbackFunc = MoveTemp(Callback);
if (CallbackFunc) return true;
return false;
}
Any callback must be passed as an r-value reference and be moved to the action's variable.
- Override
Init
andTick
functions if needed. - If you want this action to be stopped while ticking - use
MarkAsFinished()
function. - If you want to launch a callback when this action is stopped by
StopAction
method withbComplete
set to true - overrideComplete(bool bStopped)
function. - If this is an instanced action you can optionally override
RetriggeredInstancedAction()
function to add any logic that should be executed when the instanced action is called while already existing. - You can optionally run
SetMaxActionTime
in action'sInit
function to determine the maximum time in seconds this action should run.
IMMPORTANT! SetMaxActionTime is only to help ticker run ticks with proper delta times.
It will not stop the action itself!
- In the
FEnhancedCodeFlow
class implement static function that launches the action usingAddAction
function. The function must receive a pointer to the launchingUObject
,FECFActionSettings
,FECFInstanceId
(use invalid one if the action shouldn't be instanced) and every other argument that is used in the action'sSetup
function in the same order. It must returnFECFHandle
.
FECFHandle FEnhancedCodeFlow::NewAction(const UObject* InOwner, int32 Param1, int32 Param2, TUniqueFunction<void(bool)>&& Callback, const FECFActionSettings& Settings = {})
{
if (UECFSubsystem* ECF = UECFSubsystem::Get(InOwner))
return ECF->AddAction<UECFNewAction>(InOwner, Settings, FECFInstanceId(), Param1, Param2, MoveTemp(Callback));
else
return FECFHandle();
}
- You can optionally add the stats counter to your action's
Tick
function, in order to measure it's performence withstat ecfdetails
.
DECLARE_SCOPE_CYCLE_COUNTER(TEXT("NewAction - Tick"), STAT_ECFDETAILS_NEWACTION, STATGROUP_ECFDETAILS);
It is done! Now you can run your own action:
FFlow::NewAction(this, 1, 2, [this](bool bStopped)
{
// Callback code.
}, ECF_IGNOREPAUSE);
Adding actions that supports coroutine is simillar to adding new actions but there are few steps that must be made:
- Action class must inherits from
UECFCoroutineActionBase
instead ofUECFActionBase
. - Add coroutine task to
ECFCoroutineTasks.h
class ENHANCEDCODEFLOW_API FECFCoroutineTask_NewCoroAction : public FECFCoroutineTask
{
public:
FECFCoroutineTask_NewCoroAction(const UObject* InOwner, const FECFActionSettings& InSettings, int32 InParam1);
void await_suspend(FECFCoroutineHandle CoroHandle);
private:
int32 Param1 = 0;
};
- Implement coroutine task in
ECFCoroutineTasks.cpp
. Use `AddCoroutineAction`` function there.
FECFCoroutineTask_NewCoroAction::FECFCoroutineTask_NewCoroAction(const UObject* InOwner, const FECFActionSettings& InSettings, int32 InParam1)
{
Owner = InOwner;
Settings = InSettings;
Param1 = InParam1;
}
void FECFCoroutineTask_NewCoroAction::await_suspend(FECFCoroutineHandle CoroHandle)
{
AddCoroutineAction<UNewCoroAction>(Owner, CoroHandle, Settings, Param1);
}
- Coroutine action implementation must resume coroutine in
Complete
function:
void Complete(bool bStopped) override
{
CoroutineHandle.resume();
}
- The coroutine should be called from
FEnhancedCodeFlow
class and it's implementation should return the defined coroutine task:
FECFCoroutineTask_NewCoroAction FEnhancedCodeFlow::NewCoroAction(const UObject* InOwner, int32 InParam1, const FECFActionSettings& Settings)
{
return FECFCoroutineTask_NewCoroAction(InOwner, Settings, InParam1);
}
You can temporarily disable plugin's build optimizations by setting the bDisableOptimization
parameter in EnhancedCodeFlow.Build.cs
file to true
. It can help with debugging.
I want to send special thanks to Monika, because she always supports me and believes in me, to Pawel, for allowing me to test this plugin on his project and to everyone that contributed to this project.
Also, I want to thank You for using this plugin! It is very important for me that my work is useful for someone!
Happy coding!