How to draw text from c++

Development Programming & Scripting
1

I’m trying to draw text on the screen from c++ with the following code but it gives me a Access violation reading location

void UHelpers::DisplayText(UWorld* World, FString Text, FVector2D Position, FColor TextColor)
{
	/* If no position is set */
	if (Position == FVector2D(-1.f, -1.f))
	{
		const FVector2D ViewportSize = FVector2D(GEngine->GameViewport->Viewport->GetSizeXY());
		Position = FVector2D(ViewportSize.X / 2, ViewportSize.Y / 2);
	}
	if (GEngine->GetMediumFont())
	{
		UGameplayStatics::GetPlayerController(World, 0)->GetHUD()->DrawText(Text, Position, GEngine->GetMediumFont(), Position, TextColor);
	}
}

I have checked all pointers and values and they all seem to passed probably to the function.

2

So I compeltly missed that the draw functions only works in a Draw call (like DrawHUD) and came up with the following solution for our problem.

.h

#pragma once

#include "GameFramework/HUD.h"
#include "MainHUD.generated.h"

USTRUCT(BlueprintType)
struct FDisplayString
{
	GENERATED_USTRUCT_BODY()

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	FString Text;
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	FVector2D Position;
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	FColor Color;
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	UFont* Font;
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	FVector2D Scale;
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	int32 DisplayTime;

	int32 StartTime;
};

/**
 * 
 */
UCLASS()
class MOONSHINEWORKS_API AMainHUD : public AHUD
{
	GENERATED_BODY()
public:
	AMainHUD(const class FObjectInitializer& PCIP);

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	UFont* Font;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MOO)
	TArray<FDisplayString> DisplayStrings;

	UFUNCTION(BlueprintCallable, Category = MOOnshine)
	void AddDisplayString(FDisplayString DisplayStringToAdd);

protected:
	void DrawHUD() override;
	virtual void Tick(float DeltaSeconds) override;
};

.cpp
#include “MOOnshineWorks.h”
#include “MainHUD.h”

AMainHUD::AMainHUD(const class FObjectInitializer& PCIP)
	: Super(PCIP)
{

}


void AMainHUD::DrawHUD()
{
	Super::DrawHUD();

	int DisplayStringsCount = DisplayStrings.Num();

	for (int i = DisplayStringsCount - 1; i >= 0; i--)
	{
		FDisplayString* DisplayString = &DisplayStrings[i];

		FVector2D Position = FVector2D(DisplayString->Position.X, DisplayString->Position.Y + i * 20);
		DrawText(DisplayString->Text, Position, Font, DisplayString->Scale, DisplayString->Color);
	}
}

void AMainHUD::AddDisplayString(FDisplayString DisplayStringToAdd)
{

	int32 DisplayStringsCount = DisplayStrings.Num();

	for (int32 i = 0; i < DisplayStringsCount; i++)
	{
		if (DisplayStrings[i].Text == DisplayStringToAdd.Text)
		{
			return;
		}
	}
	DisplayStringToAdd.StartTime = FDateTime::Now().ToUnixTimestamp();

	DisplayStrings.Add(DisplayStringToAdd);
}

void AMainHUD::Tick(float DeltaSeconds)
{
	Super::Tick(DeltaSeconds);

	int DisplayStringsCount = DisplayStrings.Num();
	FDateTime CurrentTime = FDateTime::Now();

	for (int i = DisplayStringsCount - 1; i >= 0; i--)
	{
		FDisplayString* DisplayString = &DisplayStrings[i];

		FVector2D Position = FVector2D(DisplayString->Position.X, DisplayString->Position.Y + i * 20);

		if (DisplayString->DisplayTime == 0)
		{
			DisplayStrings.RemoveAt(i, 1);
		}
		else if (DisplayString->DisplayTime <= CurrentTime.ToUnixTimestamp() - DisplayString->StartTime)
		{
			DisplayStrings.RemoveAt(i, 1);
		}
	}
}