Battery Collector #4 – Adding Variables and Functions

Posted on 2015/10/12 by

Guronzor Posted in Battery Collector — No Comments ↓

I am following the video tutorial Battery Collector for Unreal Engine. The previous steps can be read here.

Adding Variables and Functions

In Pickup.h, I add the protected variable bIsActive:

protected:
	/** True when the pickup cab be used, and false when pickup is deactivated */
	bool bIsActive;

I set it to true in the constructor In Pickup.c:

// All pickups start active
bIsActive = true;

In the public section of Pickup.h, I declare getter and setter functions for this variable:

UFUNCTION(BlueprintPure, Category = "Pickup")
bool IsActive();

UFUNCTION(BlueprintCallable, Category = "Pickup")
void SetActive(bool NewPickupState);

The difference between BlueprintPure and BlueprintCallable is described in the “Blueprints, Creating C++ Functions as new Blueprint Nodes” wiki and in the Function documentation of Unreal Engine. To summarize, BlueprintPure functions are more efficient, but must not modify the state of the class. They are good for getter functions.

In Pickup.cpp, I add the definitions for these functions:

// Returns active state
bool APickup::IsActive()
{
	return bIsActive;
}

// Changes active state
void APickup::SetActive(bool NewPickupState)
{
	bIsActive = NewPickupState;
}

Back to the Unreal Engine Editor, I create a new folder named “Blueprints” under Content and I create a Blueprint class based on Pickup by right-clicking on the C++ Pickup object and selecting that option. I name it “Pickup_BP” and put it under Blueprints: