seed-engine
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A Lightweight 2D game engine using WebGL2. The engine is designed on the focus of creating a bridge between creating and publishing games to the Seed Network as modules.
197 lines (182 loc) • 6.34 kB
JavaScript
import Component from './Component';
import Point from '../internal/Point';
/**
* A component all GameObjects are given by default on instantiation.
*
* Transform components are unique to the object, meaning there cannot be more than
* one Transform on a GameObject.
*
* Transforms keep track of GameObject position, scale (size), rotation, and
* origin offset. These should be changes with their respective setters, and not directly,
* to ensure the correct components are notified of these changes.
*
* TODO: Make rotation work on 3 axis like position and scale.
* TODO: Change the updates and setters of the position/scale/rotation to use funcions in their base
* definitions and remove the wrappers here to reduce code.
*/
export default class Transform extends Component {
constructor(position = new Point(0, 0, 0), scale = new Point(1, 1, 1), rotation = 0) {
super(true);
this.className='Transform';
this._position = position;
this._rotation = rotation;
this._scale = scale;
this._originOffset = new Point(0, 0, 0);
this.renderable = null;
}
/**
* Sets the Transforms position.
*
* @param {number} x X position. Defaults to current X position.
* @param {number} y Y position. Defaults to current Y position.
* @param {number} z Z position. Defaults to current Z position.
*/
setPosition(x = this._position.x, y = this._position.y, z = this._position.z) {
this._position.set(x, y, z);
if (this.renderable != null) {
this.renderable.setPosition(this._position);
}
}
/**
* Triggers between two types of regularly used origin points.
*
* Origin points are used with Renderables and other components to offset the origin different from the Transform's position.
*
* "Center": (-0.5, -0.5, -0.5) centered to the Tranform's position, and "Default": (0, 0, 0), beginning at the top left of the Transform.
*
* @param {boolean} center "Center" if true, "Default" if false.
*/
centerOrigin(center = true) {
if (center) {
this.setOriginOffset(-0.5, -0.5, -0.5);
} else {
this.setOriginOffset(0, 0, 0);
}
}
/**
* Sets the origin offset position.
*
* If you want an object to exist at a
* position, but do something else (like drawing, animations)
* in a relative position the the Tranform, use this to change the
* offset from the Transfrom.
*
* (0, 0, 0) would be top left of the transform.
* (-0.5, -0.5, -0.5) would be center of the transform.
* (-1, -1, -1) would be bottom right of transform.
*
* Parameters default to their current values.
*
* @param {number} x X axis offset. Defaults to current origin offset X.
* @param {number} y Y axis offset. Defaults to current origin offset Y.
* @param {number} z Z axis offset. Defaults to current origin offset Z.
*/
setOriginOffset(x = this._originOffset.x, y = this._originOffset.y, z = this._originOffset.z) {
this._originOffset.set(x, y, z);
if (this.renderable != null) {
this.renderable.setOriginOffset(this._originOffset);
}
}
/**
* Rotates the transform to face a different direction.
*
* TODO: implement more than z axis rotation.
*
* @param {number} rotation Rotation around the Z axis (in degrees).
*/
setRotation(rotation) {
this._rotation = rotation;
if (this.renderable != null) {
this.renderable.setRotation(this._rotation);
}
}
/**
*
* @param {number} scaleX X scale from 1. Defaults to current scale X.
* @param {number} scaleY Y scale from 1. Defaults to current scale Y.
* @param {number} scaleZ Z scale from 1. Defaults to current scale Z.
*/
setScale(scaleX = this.scaleX, scaleY = this.scaleY, scaleZ = this.scaleZ) {
this._scale.set(scaleX, scaleY, scaleZ);
if (this.renderable != null) {
this.renderable.setScale(this._scale);
}
}
/**
* Adds the parameters of this function to the Transforms position.
*
* @param {number} x X position. Defaults to 0.
* @param {number} y Y position. Defaults to 0.
* @param {number} z Z position. Defaults to 0.
*/
translate(x = 0, y = 0, z = 0) {
this._position.x += x;
this._position.y += y;
this._position.z += z;
if (this.renderable != null) {
this.renderable.setPosition(this._position);
}
}
flipX() {
this._scale.x = -this._scale.x;
if (this.renderable != null) {
this.renderable.setScale(this._scale);
}
}
flipY() {
this._scale.y = -this._scale.y;
if (this.renderable != null) {
this.renderable.setScale(this._scale);
}
}
/**
* Adds the rotation parameter to the current Transform rotation.
*
* @param {number} rotation Rotation to add.
*/
rotate(rotation) {
this._rotation += rotation;
if (this.renderable != null) {
this.renderable.setRotation(this._rotation);
}
}
/**
* Adds the parameters of this function to the Transforms scale.
*
* @param {number} scaleX X scale. Defaults to 0.
* @param {number} scaleY Y scale. Defaults to 0.
* @param {number} scaleZ Z scale. Defaults to 0.
*/
scale(scaleX = 0, scaleY = 0, scaleZ = 0) {
this._scale.x += scaleX;
this._scale.y += scaleY;
this._scale.z += scaleZ;
if (this.renderable != null) {
this.renderable.setScale(this._scale);
}
}
/**
* @returns {Point} The transform's position.
*/
getPosition() {
return Point.copy(this._position);
}
/**
* @returns {Point} The transform's scale.
*/
getScale() {
return Point.copy(this._scale);
}
/**
* @returns {number} The transform's rotation.
*/
getRotation() {
return this._rotation;
}
/**
* @returns {Point} The transform's origin offset.
*/
getOriginOffset() {
return Point.copy(this._originOffset);
}
}