Victor Anton Dominguez sephirot47

## UE4 Get Actor's components
UComponentType *myComponent;
TArray<UComponentType*> comps;
actor->GetComponents(comps);
if (comps.Num() > 0) myComponent = comps[0];

## UE4 Bind function to Axis Input

                               //Input name        //Function to handle the input
this->InputComponent->BindAxis("MoveForward", this, &UMyActor::HandleVerticalAxis);

void UMyActor::HandleVerticalAxis(float v)
{
  //v is the float value for the input
}

## UE4 Common crash causes
- GameMode, make sure none of them is null
- Null pointer exceptions
- Having instantiated in the level the same PlayerBP than the one in GameMode
  (so when the game starts the GameMode puts another one and it gets duplicated )

- Having BAD CODE(code that can cause a crash), even on startup. Ye, if u have bad code it can crash on startup!!! UE4 does some sort of prebuild or something. Beware of putting code on the constructor that must go in the BeginPlay instead, this happened to me <3

## UE4 World to screen point
//From the actor's viewport (camera)
FVector2D result;
UGameplayStatics::GetPlayerController(actor, 0)->ProjectWorldLocationToScreen(pointInWorld, result);
//result now has the screen point(x,y)

## UE4 Get Player Controller of an Actor
UGameplayStatics::GetPlayerController(actor, 0)

## UE4 Bind Action
character->InputComponent->BindAction("Jump", IE_Pressed, this, &AMyCharacter::HandleJump);
character->InputComponent->BindAction("Jump", IE_Released, this, &AMyCharacter::HandleJump);

## UE4 UPROPERTY UFUNCTION
UPROPERTY(EditAnywhere, Category=Pawn)
float speed;

UFUNCTION(BlueprintCallable, Category=Attachment)
void do() { }

## UE4 Interesting documentation links
UFUNCTION: https://docs.unrealengine.com/latest/INT/Programming/UnrealArchitecture/Reference/Functions/index.html
RAY TRACING: https://wiki.unrealengine.com/Trace_Functions

## WORST CODE OF ALL MY LIFE .class
  buttonTwoDatesPayments.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v)
            {
                Calendar c = Calendar.getInstance();
                int mYear = c.get(Calendar.YEAR);
                int mMonth = c.get(Calendar.MONTH);
                int mDay = c.get(Calendar.DAY_OF_MONTH);

                DatePickerDialog datePicker = new DatePickerDialog( MainActivity.act,
                    new DatePickerDialog.OnDateSetListener()

## UE4 Little UMG or Set UMG size or Set UMG Position .cpp
/*
The key to this is to make a normal UMG, but use the Blueprint function SetAnchors, where Minimum and Maximum inputs to this function go from 0.0 -> 1.0 (normalized screen size).
For example, if I want to put an UMG which only occupies the right bottom corner of the screen, I would use:
	SetAnchors, where Minimum = (0.5, 0.5) and Maximum = (1.0, 1.0)
*/
	UComponentType *myComponent;
	TArray<UComponentType*> comps;
	actor->GetComponents(comps);
	if (comps.Num() > 0) myComponent = comps[0];

	//Input name //Function to handle the input
	this->InputComponent->BindAxis("MoveForward", this, &UMyActor::HandleVerticalAxis);

	void UMyActor::HandleVerticalAxis(float v)
	{
	//v is the float value for the input
	}
	- GameMode, make sure none of them is null
	- Null pointer exceptions
	- Having instantiated in the level the same PlayerBP than the one in GameMode
	(so when the game starts the GameMode puts another one and it gets duplicated )

	- Having BAD CODE(code that can cause a crash), even on startup. Ye, if u have bad code it can crash on startup!!! UE4 does some sort of prebuild or something. Beware of putting code on the constructor that must go in the BeginPlay instead, this happened to me <3
	//From the actor's viewport (camera)
	FVector2D result;
	UGameplayStatics::GetPlayerController(actor, 0)->ProjectWorldLocationToScreen(pointInWorld, result);
	//result now has the screen point(x,y)
	character->InputComponent->BindAction("Jump", IE_Pressed, this, &AMyCharacter::HandleJump);
	character->InputComponent->BindAction("Jump", IE_Released, this, &AMyCharacter::HandleJump);
	UPROPERTY(EditAnywhere, Category=Pawn)
	float speed;

	UFUNCTION(BlueprintCallable, Category=Attachment)
	void do() { }
	UFUNCTION: https://docs.unrealengine.com/latest/INT/Programming/UnrealArchitecture/Reference/Functions/index.html
	RAY TRACING: https://wiki.unrealengine.com/Trace_Functions
	buttonTwoDatesPayments.setOnClickListener(new View.OnClickListener() {
	public void onClick(View v)
	{
	Calendar c = Calendar.getInstance();
	int mYear = c.get(Calendar.YEAR);
	int mMonth = c.get(Calendar.MONTH);
	int mDay = c.get(Calendar.DAY_OF_MONTH);

	DatePickerDialog datePicker = new DatePickerDialog( MainActivity.act,
	new DatePickerDialog.OnDateSetListener()
	/*
	The key to this is to make a normal UMG, but use the Blueprint function SetAnchors, where Minimum and Maximum inputs to this function go from 0.0 -> 1.0 (normalized screen size).
	For example, if I want to put an UMG which only occupies the right bottom corner of the screen, I would use:
	SetAnchors, where Minimum = (0.5, 0.5) and Maximum = (1.0, 1.0)
	*/