HumanBreak/src/core/render/sprite.ts

import {
    ERenderItemEvent,
    RenderFunction,
    RenderItem,
    RenderItemPosition
} from './item';
import { MotaOffscreenCanvas2D } from '../fx/canvas2d';
import { Transform } from './transform';

export interface ESpriteEvent extends ERenderItemEvent {}

export class Sprite<E extends ESpriteEvent = ESpriteEvent> extends RenderItem<
    E | ESpriteEvent
> {
    renderFn: RenderFunction;

    /**
     * 创建一个精灵，可以自由在上面渲染内容
     * @param type 渲染模式，absolute表示绝对位置，static表示跟随摄像机移动，只对顶层元素有效
     * @param cache 是否启用缓存机制
     */
    constructor(type: RenderItemPosition = 'static', cache: boolean = true) {
        super(cache);
        this.type = type;
        this.renderFn = () => {};
    }

    protected render(
        canvas: MotaOffscreenCanvas2D,
        transform: Transform
    ): void {
        this.renderFn(canvas, transform);
    }

    setRenderFn(fn: RenderFunction) {
        this.renderFn = fn;
        this.update(this);
    }
}