Introduction

Gum screens support animations which can be played through code. This article shows how to access a Gum animation and play it in your FlatRedBall project.

Setup

To access a Gum screen in code you must first create an object in Glue for the Gum screen. For information on how to do this, see this article. Animations can be defined in Gum or in code. To define an animation in Gum, see the Gum Usage Guide.

Accessing animations in code

Animations added to Gum screens can be accessed in code. The Glue code generator will append the word "Animation" to animation names. For example, consider a Gum screen containing an animation called MoveToRight: Then this animation can be accessed in code:

// Assuming the object is called "GumScreen":
GumScreen.MoveToRightAnimation.Play();

Playing Animations on Component Instances

Similar to screens, components can also contain animations which can be played at runtime. To play an animation on a component at runtime:

1. Add an animation to a Gum component

2. Obtain a reference to the component at runtime. For example, get a reference from a Gum screen in a Glue screen's Objects.
3. Call the Play method on the desired animation within the component instance in code. For example, if the ButtonRuntime has an animation called FadeOutAnimation, the following code could be used to play the animation:

ButtonInstance.FadeOutAnimation.Play();

GumAnimation Details

All animations are instances of the GumAnimation class, which provides useful variables, methods, and events.

EndReached Event

The EndReached event is raised by the animation after the animation reaches its end (which is defined by its Length property). To use the EndReached event, you can add an Action to it, as follows:

void CustomInitialize()
{
    // Assign the event somewhere, like in CustomInitialize of a screen or entity:
    Button.FadeOutAnimation.EndReached += HandleEndReached;
}

// Implement the HandleEndReached method:
void HandleEndReached()
{
   // The animation ended, so do whatever, like play a sound
   BeepSound.Play();
}

Introduction

Gum objects support playing .achx animations. This enables the use of the familiar AnimationEditor to create texture-based animations for Gum objects. Note that AnimationChain animations are used to change texture or texture coordinates. These are typically used for animated characters in 2D games. AnimationChain animations cannot change the size, orientation, or other common Gum properties.

Note About Glue Version

Glue Version 12 introduces automatic calling of AnimateSelf on the top-level Gum screen. If your Glue project is using an earlier version than version 12, you will need to explicitly add the following to your CustomActivity:

For more information on Glue versions, see the .

Setting Animations

For this example we will assume a Sprite named SpriteInstance.

This Sprite is contained in a page named MainMenuGum which is assumed to be inside a FlatRedBall Screen named MainMenu.

We can set the Sprite to be animated using the following code in CustomInitialize:

The Gum Sprite now animates when running the game.

Introduction

Named events can be used to perform custom logic at certain times in an animation. Since named events are created in Gum, the animator can align the performance of logic visually. For example, a Gum animation may be used to move components of a title screen into view. While this animation is playing the game may need to play sound effects and music at certain times. Named events can be used to play music and sound effects at certain times.

Example

Named events can be added to animations in Gum in the animation window. To add a named event to an existing animation:

1. Select the animation

2. Click the Add Named Event button

3. Enter a name for the event

4. Select the event

5. Enter a time for the event

Gum animations have an AddAction method which can be used to add custom actions at certain times: For example, if the screen were accessible in code as GameScreenGumRuntime in a Glue screen, the MakeYellow named event could be reacted to as shown in the following code:

void CustomInitialize()
{
    // AddAction can be used to handle the MakeYellow named event
    GameScreenGumRuntime.MoveToLeftAnimation.AddAction("MakeYellow", HandleMakeYellow);
}

// HandleMakeYellow can be used to handle the event:
private void HandleMakeYellow()
{
    
}