gl-react/src/Visitor.ts

Universal React library, write and compose WebGL shaders, implement complex effects using a descriptive paradigm

import type { Surface } from "./createSurface";
import type Node from "./Node";
import type Bus from "./Bus";

export interface VisitorLike {
  onSurfaceMount(surface: Surface): void;
  onSurfaceUnmount(surface: Surface): void;
  onSurfaceGLContextChange(
    surface: Surface,
    gl: WebGLRenderingContext | null
  ): void;
  onSurfaceDrawSkipped(surface: Surface): void;
  onSurfaceDrawStart(surface: Surface): void;
  onSurfaceDrawError(e: Error): any;
  onSurfaceDrawEnd(surface: Surface): void;
  onNodeDrawSkipped(node: Node): void;
  onNodeDrawStart(node: Node): void;
  onNodeSyncDeps(
    node: Node,
    additions: Array<Node | Bus>,
    deletions: Array<Node | Bus>
  ): void;
  onNodeDraw(node: Node, preparedUniforms: Array<any>): void;
  onNodeDrawEnd(node: Node): void;
}

export default class Visitor {
  onSurfaceMount(surface: Surface) {}
  onSurfaceUnmount(surface: Surface) {}
  onSurfaceGLContextChange(
    surface: Surface,
    gl: WebGLRenderingContext | null
  ) {}
  onSurfaceDrawSkipped(surface: Surface) {}
  onSurfaceDrawStart(surface: Surface) {}
  /**
   * if returns true, it prevent a throw to happen from the request animation frame loop (or from a surface.flush() call).
   */
  onSurfaceDrawError(e: Error) {
    return false;
  }
  onSurfaceDrawEnd(surface: Surface) {}
  onNodeDrawSkipped(node: Node) {}
  onNodeDrawStart(node: Node) {}
  onNodeSyncDeps(
    node: Node,
    additions: Array<Node | Bus>,
    deletions: Array<Node | Bus>
  ) {}
  onNodeDraw(node: Node, preparedUniforms: Array<any>) {}
  onNodeDrawEnd(node: Node) {}
}