Rendering

/**
 * Abstract base class for renderers extending EventEmitter
 * Provides common functionality for WebGL and Canvas renderers
 */
abstract class AbstractRenderer extends EventEmitter {
  /** The resolution/device pixel ratio of the renderer */
  resolution: number;
  /** Whether to clear the canvas before rendering */
  clearBeforeRender?: boolean;
  /** Renderer configuration options */
  options: IRendererOptions;
  /** The renderer type (WEBGL or CANVAS) */
  type: RENDERER_TYPE;
  /** Screen dimensions as Rectangle */
  screen: Rectangle;
  /** The HTML canvas element */
  view: HTMLCanvasElement;
  /** Collection of renderer plugins */
  plugins: IRendererPlugins;
  /** Context alpha setting */
  useContextAlpha: boolean | 'notMultiplied';
  /** Auto-resize CSS dimensions flag */
  autoDensity: boolean;
  /** Preserve drawing buffer flag for screenshots */
  preserveDrawingBuffer: boolean;
  /** Background color as hex number */
  backgroundColor: number;
  /** Background alpha transparency (0-1) */
  backgroundAlpha: number;

  /**
   * Create a new AbstractRenderer
   * @param type - The renderer type
   * @param options - Renderer configuration options
   */
  constructor(type: RENDERER_TYPE, options?: IRendererOptions);

  /** Initialize plugins from static map */
  initPlugins(staticMap: IRendererPlugins): void;
  
  /** 
   * Resize the renderer and canvas 
   * @param desiredScreenWidth - Target width
   * @param desiredScreenHeight - Target height
   */
  resize(desiredScreenWidth: number, desiredScreenHeight: number): void;
  
  /**
   * Generate a texture from a display object
   * @param displayObject - Object to render to texture
   * @param options - Generation options
   */
  generateTexture(displayObject: IRenderableObject, options?: IGenerateTextureOptions): RenderTexture;
  
  /**
   * Destroy the renderer and cleanup resources
   * @param removeView - Remove canvas from DOM
   */
  destroy(removeView?: boolean): void;

  /** Abstract: Add a system to the renderer */
  abstract addSystem(ClassRef: ISystemConstructor, name: string): this;
  
  /** Abstract: Render a display object */
  abstract render(displayObject: IRenderableObject, options?: IRendererRenderOptions): void;
}

interface IRendererOptions {
  /** Canvas element to render to */
  view?: HTMLCanvasElement;
  /** Device pixel ratio */
  resolution?: number;
  /** Auto-resize canvas CSS */
  autoDensity?: boolean;
  /** Background color (hex) */
  backgroundColor?: number;
  /** Background alpha (0-1) */
  backgroundAlpha?: number;
  /** Clear before rendering */
  clearBeforeRender?: boolean;
  /** WebGL preserve drawing buffer */
  preserveDrawingBuffer?: boolean;
  /** Canvas width */
  width?: number;
  /** Canvas height */
  height?: number;
  /** Enable antialiasing */
  antialias?: boolean;
}

interface IRendererPlugins {
  [key: string]: any;
}

interface IRendererRenderOptions {
  /** Render texture to render to */
  renderTexture?: RenderTexture;
  /** Clear before rendering */
  clear?: boolean;
  /** Transform matrix to apply */
  transform?: Matrix;
  /** Skip updating transforms */
  skipUpdateTransform?: boolean;
}

interface IGenerateTextureOptions {
  /** Texture scale mode */
  scaleMode?: SCALE_MODES;
  /** Resolution for generated texture */
  resolution?: number;
  /** Region to capture */
  region?: Rectangle;
  /** Multisampling level */
  multisample?: MSAA_QUALITY;
}

/**
 * WebGL renderer providing hardware-accelerated 2D rendering
 * Manages WebGL context, systems, and rendering pipeline
 */
class Renderer extends AbstractRenderer {
  /** WebGL rendering context */
  gl: IRenderingContext;
  /** Global shader uniforms */
  globalUniforms: UniformGroup;
  /** Unique WebGL context identifier */
  CONTEXT_UID: number;
  /** Flag indicating if rendering to screen */
  renderingToScreen: boolean;
  /** MSAA quality level */
  multisample: MSAA_QUALITY;
  /** Event runners for system communication */
  runners: {[key: string]: Runner};

  // Rendering systems (available as properties)
  /** Mask rendering system */
  mask: MaskSystem;
  /** WebGL context management system */
  context: ContextSystem;
  /** WebGL state management system */
  state: StateSystem;
  /** Shader compilation and management system */
  shader: ShaderSystem;
  /** Texture management system */
  texture: TextureSystem;
  /** Buffer management system */
  buffer: BufferSystem;
  /** Geometry rendering system */
  geometry: GeometrySystem;
  /** Framebuffer management system */
  framebuffer: FramebufferSystem;
  /** Scissor testing system */
  scissor: ScissorSystem;
  /** Stencil testing system */
  stencil: StencilSystem;
  /** Projection matrix system */
  projection: ProjectionSystem;
  /** Texture garbage collection system */
  textureGC: TextureGCSystem;
  /** Filter rendering system */
  filter: FilterSystem;
  /** Render texture system */
  renderTexture: RenderTextureSystem;
  /** Batch rendering system */
  batch: BatchSystem;

  /**
   * Create a new WebGL Renderer
   * @param options - Renderer configuration
   */
  constructor(options?: IRendererOptions);

  /**
   * Create renderer with WebGL support detection
   * @param options - Renderer options
   */
  static create(options?: IRendererOptions): AbstractRenderer;

  /**
   * Add a system to the renderer
   * @param ClassRef - System constructor
   * @param name - System name for access
   */
  addSystem(ClassRef: ISystemConstructor, name: string): this;

  /**
   * Render a display object to the canvas or render texture
   * @param displayObject - Object to render
   * @param options - Render options
   */
  render(displayObject: IRenderableObject, options?: IRendererRenderOptions): void;

  /**
   * Resize renderer and update systems
   * @param desiredScreenWidth - Target width
   * @param desiredScreenHeight - Target height  
   */
  resize(desiredScreenWidth: number, desiredScreenHeight: number): void;

  /** Reset WebGL state to defaults */
  reset(): this;

  /** Clear the frame buffer */
  clear(): void;

  /**
   * Destroy renderer and cleanup all resources
   * @param removeView - Remove canvas from DOM
   */
  destroy(removeView?: boolean): void;
}

import { Renderer } from "@pixi/core";

// Create WebGL renderer with options
const renderer = new Renderer({
  width: 800,
  height: 600,
  backgroundColor: 0x1099bb,
  resolution: window.devicePixelRatio,
  antialias: true
});

document.body.appendChild(renderer.view);

// Access rendering systems
console.log(renderer.gl); // WebGL context
renderer.state.setState(new State()); // Set WebGL state
renderer.clear(); // Clear framebuffer

// Render a display object
renderer.render(myDisplayObject);

// Resize renderer
renderer.resize(1024, 768);

/**
 * Automatically detects and creates the best available renderer
 * Falls back to Canvas renderer if WebGL is not supported
 * @param options - Renderer configuration options
 * @returns AbstractRenderer instance (Renderer or CanvasRenderer)
 */
function autoDetectRenderer(options?: IRendererOptionsAuto): AbstractRenderer;

interface IRendererOptionsAuto extends IRendererOptions {
  /** Force canvas renderer even if WebGL is available */
  forceCanvas?: boolean;
}

import { autoDetectRenderer } from "@pixi/core";

// Auto-detect best renderer
const renderer = autoDetectRenderer({
  width: 800,
  height: 600,
  backgroundColor: 0x1099bb
});

// Force Canvas renderer
const canvasRenderer = autoDetectRenderer({
  width: 800,
  height: 600,
  forceCanvas: true
});

// Check renderer type
if (renderer.type === RENDERER_TYPE.WEBGL) {
  console.log("Using WebGL renderer");
} else {
  console.log("Using Canvas renderer");
}

interface ISystemConstructor<R = Renderer> {
  new (renderer: R): ISystem;
}

interface IRenderableObject {
  parent: IRenderableContainer;
  enableTempParent(): IRenderableContainer;
  updateTransform(): void;
  disableTempParent(parent: IRenderableContainer): void;
  render(renderer: Renderer): void;
}

interface IRenderingContext extends WebGL2RenderingContext {}

enum RENDERER_TYPE {
  UNKNOWN = 0,
  WEBGL = 1,
  CANVAS = 2
}

enum MSAA_QUALITY {
  NONE = 0,
  LOW = 2,
  MEDIUM = 4,
  HIGH = 8
}