expo-gl/src/GLView.types.ts

Provides GLView that acts as OpenGL ES render target and gives GL context object implementing WebGL 2.0 specification.

import { Component, ComponentClass } from 'react';
import { ViewProps } from 'react-native';

import WebGL2RenderingContext from './WebGL2RenderingContext';

export type SurfaceCreateEvent = {
  nativeEvent: {
    exglCtxId: number;
  };
};

export type SnapshotOptions = {
  flip?: boolean;
  framebuffer?: WebGLFramebuffer;
  rect?: {
    x: number;
    y: number;
    width: number;
    height: number;
  };
  format?: 'jpeg' | 'png';
  compress?: number;
};

export type GLSnapshot = {
  uri: string | Blob | null;
  localUri: string;
  width: number;
  height: number;
};

export interface ExpoWebGLRenderingContext extends WebGL2RenderingContext {
  __exglCtxId: number;
  endFrameEXP(): void;
  __expoSetLogging(option: GLLoggingOption): void;
}

export type ComponentOrHandle = null | number | Component<any, any> | ComponentClass<any>;

/**
 *
 * A View that acts as an OpenGL ES render target. On mounting, an OpenGL ES
 * context is created. Its drawing buffer is presented as the contents of
 * the View every frame.
 */
export interface BaseGLViewProps extends ViewProps {
  /**
   * Called when the OpenGL context is created, with the context object as a parameter. The context
   * object has an API mirroring WebGL's WebGLRenderingContext.
   */
  onContextCreate(gl: ExpoWebGLRenderingContext): void;

  /**
   * [iOS only] Number of samples for Apple's built-in multisampling.
   */
  msaaSamples?: number;
}

export enum GLLoggingOption {
  /**
   * Disables logging entirely.
   */
  DISABLED = 0,

  /**
   * Logs method calls, their parameters and results.
   */
  METHOD_CALLS = 1,

  /**
   * Calls `gl.getError()` after each other method call and prints an error if any is returned.
   * This option has a significant impact on the performance as this method is blocking.
   */
  GET_ERRORS = 2,

  /**
   * Resolves parameters of type `number` to their constant names.
   */
  RESOLVE_CONSTANTS = 4,

  /**
   * When this option is enabled, long strings will be truncated.
   * It's useful if your shaders are really big and logging them significantly reduces performance.
   */
  TRUNCATE_STRINGS = 8,

  /**
   * Enables all other options. It implies `GET_ERRORS` so be aware of the slowdown.
   */
  ALL = METHOD_CALLS | GET_ERRORS | RESOLVE_CONSTANTS | TRUNCATE_STRINGS,
}