Transform.md

Transform Class Documentation

Function Overview

Visibility	Function	Description
public	Transform()	Constructs a new Transform with default values.
public	addChild(Transform child)	Adds a child Transform.
public	removeChild(Transform child)	Removes a child Transform.
public	getParent()	Returns the parent Transform.
public	getChildren()	Returns the list of child Transforms.
public	getLocalPosition()	Returns the local position.
public	getLocalRotation()	Returns the local rotation.
public	getLocalScale()	Returns the local scale.
public	setLocalPosition(Vector pos)	Sets the local position.
public	setLocalRotation(Vector rot)	Sets the local rotation.
public	setLocalScale(Vector scale)	Sets the local scale.
public	getLocalMatrix()	Returns the local transformation matrix.
public	getWorldMatrix()	Returns the world transformation matrix.
public	getWorldPosition()	Returns the world position.
public	getWorldRotation()	Returns the world rotation.
public	getWorldScale()	Returns the world scale.
public	setWorldPosition(Vector pos)	Sets the world position.
public	setWorldRotation(Vector rot)	Sets the world rotation.
public	setWorldScale(Vector scale)	Sets the world scale.
public	setGameObject(GameObject go)	Sets the owning GameObject.
public	getGameObject()	Gets the owning GameObject.
public	destroy()	Destroys this Transform and its children.

Overview

The Transform class represents an object's position, rotation, and scale in the scene graph. It supports parent-child relationships, allowing for hierarchical transformations. This is similar to Unity's Transform component.

Class Definition

package org.PiEngine.GameObjects;
public class Transform

Properties

Property	Type	Description
position	Vector	Local position relative to parent
rotation	Vector	Local rotation (Z used in 2D)
scale	Vector	Local scale
parent	Transform	Reference to parent transform
childrens	List	List of child transforms
transformMatrix	Matrix4	Cached world transformation matrix
gameObject	GameObject	Reference to owning GameObject

Methods

/**
 * Constructs a new Transform with default position (0,0,0), rotation (0,0,0), and scale (1,1,1).
 */
public Transform()

/**
 * Adds a child Transform to this Transform.
 * @param child The child Transform to add
 */
public void addChild(Transform child)

/**
 * Removes a child Transform from this Transform.
 * @param child The child Transform to remove
 */
public void removeChild(Transform child)

/**
 * Returns the parent Transform.
 * @return The parent Transform, or null if root
 */
public Transform getParent()

/**
 * Returns the list of child Transforms.
 * @return List of child Transforms
 */
public List<Transform> getChildren()

/**
 * Returns the local position relative to the parent.
 * @return Local position vector
 */
public Vector getLocalPosition()

/**
 * Returns the local rotation.
 * @return Local rotation vector
 */
public Vector getLocalRotation()

/**
 * Returns the local scale.
 * @return Local scale vector
 */
public Vector getLocalScale()

/**
 * Sets the local position.
 * @param pos The new local position
 */
public void setLocalPosition(Vector pos)

/**
 * Sets the local rotation.
 * @param rot The new local rotation
 */
public void setLocalRotation(Vector rot)

/**
 * Sets the local scale.
 * @param scale The new local scale
 */
public void setLocalScale(Vector scale)

/**
 * Returns the transformation matrix built from position, rotation, and scale.
 * @return Local transformation Matrix4
 */
public Matrix4 getLocalMatrix()

/**
 * Returns the world transformation matrix by combining with parent transforms recursively.
 * @return World transformation Matrix4
 */
public Matrix4 getWorldMatrix()

/**
 * Gets the position in world space.
 * @return World position vector
 */
public Vector getWorldPosition()

/**
 * Gets the rotation in world space by recursively adding parent rotations.
 * @return World rotation vector
 */
public Vector getWorldRotation()

/**
 * Gets the scale in world space by accumulating parent scales.
 * @return World scale vector
 */
public Vector getWorldScale()

/**
 * Sets the world position, adjusting local values accordingly.
 * @param pos The new world position
 */
public void setWorldPosition(Vector pos)

/**
 * Sets the world rotation, adjusting local values accordingly.
 * @param rot The new world rotation
 */
public void setWorldRotation(Vector rot)

/**
 * Sets the world scale, adjusting local values accordingly.
 * @param scale The new world scale
 */
public void setWorldScale(Vector scale)

/**
 * Sets the owning GameObject for this Transform.
 * @param go The GameObject to set
 */
public void setGameObject(GameObject go)

/**
 * Gets the owning GameObject for this Transform.
 * @return The GameObject
 */
public GameObject getGameObject()

/**
 * Destroys this Transform and all its children, removing them from the hierarchy.
 */
public void destroy()

Example Usage

GameObject player = new GameObject("Player");
player.transform.setLocalPosition(new Vector(0, 1, 0));
player.transform.setLocalRotation(new Vector(0, 0, 45));
player.transform.setLocalScale(new Vector(2, 2, 2));

Vector worldPos = player.transform.getWorldPosition();

Best Practices

• Use addChild and removeChild to manage hierarchy
• Use getWorldPosition for rendering and physics
• Use setLocalPosition for relative movement
• Always set the GameObject reference for correct hierarchy management

See Also

• GameObject
• IDGenerator