import { ExtensionType } from '../../../../extensions/Extensions';
import { warn } from '../../../../utils/logging/warn';
import type { ICanvas } from '../../../../environment/canvas/ICanvas';
import type { System } from '../../shared/system/System';
import type { GpuPowerPreference } from '../../types';
import type { WebGLRenderer } from '../WebGLRenderer';
import type { GlRenderingContext } from './GlRenderingContext';
import type { WebGLExtensions } from './WebGLExtensions';
export interface ISupportDict
{
uint32Indices: boolean;
}
/**
* Options for the context system.
* @ignore
*/
export interface ContextSystemOptions
{
/** **WebGL Only.** User-provided WebGL rendering context object. */
context: WebGL2RenderingContext | null;
/**
* An optional hint indicating what configuration of GPU is suitable for the WebGL context,
* can be `'high-performance'` or `'low-power'`.
* Setting to `'high-performance'` will prioritize rendering performance over power consumption,
* while setting to `'low-power'` will prioritize power saving over rendering performance.
*/
powerPreference?: GpuPowerPreference;
/** **WebGL Only.** Whether the compositor will assume the drawing buffer contains colors with premultiplied alpha. */
premultipliedAlpha: boolean;
/**
* **WebGL Only.** Whether to enable drawing buffer preservation. If enabled, the drawing buffer will preserve
* its value until cleared or overwritten. Enable this if you need to call `toDataUrl` on the WebGL context.
*/
preserveDrawingBuffer: boolean;
antialias?: boolean;
}
/** System plugin to the renderer to manage the context. */
export class GlContextSystem implements System<ContextSystemOptions>
{
/** @ignore */
public static extension = {
type: [
ExtensionType.WebGLSystem,
],
name: 'context',
} as const;
/** @ignore */
public static defaultOptions: ContextSystemOptions = {
/**
* context
* @default null
*/
context: null,
/**
* premultipliedAlpha
* @default true
*/
premultipliedAlpha: true,
/**
* preserveDrawingBuffer
* @default false
*/
preserveDrawingBuffer: false,
/**
* powerPreference
* @default default
*/
powerPreference: undefined,
};
/**
* Either 1 or 2 to reflect the WebGL version being used.
* @readonly
*/
public webGLVersion: number;
/**
* Features supported by current context.
* @type {object}
* @readonly
* @property {boolean} uint32Indices - Support for 32-bit indices buffer.
*/
public readonly supports: ISupportDict;
protected CONTEXT_UID: number;
protected gl: WebGL2RenderingContext;
/**
* Extensions available.
* @type {object}
* @readonly
* @property {WEBGL_draw_buffers} drawBuffers - WebGL v1 extension
* @property {WEBGL_depth_texture} depthTexture - WebGL v1 extension
* @property {OES_texture_float} floatTexture - WebGL v1 extension
* @property {WEBGL_lose_context} loseContext - WebGL v1 extension
* @property {OES_vertex_array_object} vertexArrayObject - WebGL v1 extension
* @property {EXT_texture_filter_anisotropic} anisotropicFiltering - WebGL v1 and v2 extension
*/
public extensions: WebGLExtensions;
private _renderer: WebGLRenderer;
/** @param renderer - The renderer this System works for. */
constructor(renderer: WebGLRenderer)
{
this._renderer = renderer;
this.webGLVersion = 2;
this.extensions = Object.create(null);
this.supports = {
uint32Indices: false,
};
// Bind functions
this.handleContextLost = this.handleContextLost.bind(this);
this.handleContextRestored = this.handleContextRestored.bind(this);
}
/**
* `true` if the context is lost
* @readonly
*/
get isLost(): boolean
{
return (!this.gl || this.gl.isContextLost());
}
/**
* Handles the context change event.
* @param {WebGLRenderingContext} gl - New WebGL context.
*/
protected contextChange(gl: WebGL2RenderingContext): void
{
this.gl = gl;
this._renderer.gl = gl;
// restore a context if it was previously lost
if (gl.isContextLost() && gl.getExtension('WEBGL_lose_context'))
{
gl.getExtension('WEBGL_lose_context').restoreContext();
}
}
public init(options: ContextSystemOptions): void
{
/*
* The options passed in to create a new WebGL context.
*/
if (options?.context)
{
this.initFromContext(options.context);
}
else
{
const alpha = this._renderer.background.alpha < 1;
const premultipliedAlpha = options.premultipliedAlpha ?? true;
const antialias = options.antialias && !this._renderer.backBuffer.useBackBuffer;
this.initFromOptions({
alpha,
premultipliedAlpha,
antialias,
stencil: true,
preserveDrawingBuffer: options.preserveDrawingBuffer,
powerPreference: options.powerPreference ?? 'default',
});
}
}
/**
* Initializes the context.
* @protected
* @param {WebGLRenderingContext} gl - WebGL context
*/
protected initFromContext(gl: WebGL2RenderingContext): void
{
this.gl = gl;
this.validateContext(gl);
this._renderer.runners.contextChange.emit(gl);
const element = this._renderer.view.canvas;
(element as any).addEventListener('webglcontextlost', this.handleContextLost, false);
element.addEventListener('webglcontextrestored', this.handleContextRestored, false);
}
/**
* Initialize from context options
* @protected
* @see https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/getContext
* @param {object} options - context attributes
*/
protected initFromOptions(options: WebGLContextAttributes): void
{
const gl = this.createContext(this._renderer.view.canvas, options);
this.initFromContext(gl);
}
/**
* Helper class to create a WebGL Context
* @param canvas - the canvas element that we will get the context from
* @param options - An options object that gets passed in to the canvas element containing the
* context attributes
* @see https://developer.mozilla.org/en/docs/Web/API/HTMLCanvasElement/getContext
* @returns {WebGLRenderingContext} the WebGL context
*/
public createContext(canvas: ICanvas, options: WebGLContextAttributes): GlRenderingContext
{
const gl = canvas.getContext('webgl2', options);
this.webGLVersion = 2;
this.gl = gl as WebGL2RenderingContext;
this.getExtensions();
return this.gl;
}
/** Auto-populate the extensions. */
protected getExtensions(): void
{
// time to set up default extensions that Pixi uses.
const { gl } = this;
const common = {
anisotropicFiltering: gl.getExtension('EXT_texture_filter_anisotropic'),
floatTextureLinear: gl.getExtension('OES_texture_float_linear'),
s3tc: gl.getExtension('WEBGL_compressed_texture_s3tc'),
s3tc_sRGB: gl.getExtension('WEBGL_compressed_texture_s3tc_srgb'), // eslint-disable-line camelcase
etc: gl.getExtension('WEBGL_compressed_texture_etc'),
etc1: gl.getExtension('WEBGL_compressed_texture_etc1'),
pvrtc: gl.getExtension('WEBGL_compressed_texture_pvrtc')
|| gl.getExtension('WEBKIT_WEBGL_compressed_texture_pvrtc'),
atc: gl.getExtension('WEBGL_compressed_texture_atc'),
astc: gl.getExtension('WEBGL_compressed_texture_astc'),
bptc: gl.getExtension('EXT_texture_compression_bptc')
};
Object.assign(this.extensions, common, {
// Floats and half-floats
colorBufferFloat: gl.getExtension('EXT_color_buffer_float'),
});
}
/**
* Handles a lost webgl context
* @param {WebGLContextEvent} event - The context lost event.
*/
protected handleContextLost(event: WebGLContextEvent): void
{
event.preventDefault();
}
/** Handles a restored webgl context. */
protected handleContextRestored(): void
{
this._renderer.runners.contextChange.emit(this.gl);
}
public destroy(): void
{
const element = this._renderer.view.canvas;
this._renderer = null;
// remove listeners
(element as any).removeEventListener('webglcontextlost', this.handleContextLost);
element.removeEventListener('webglcontextrestored', this.handleContextRestored);
this.gl.useProgram(null);
if (this.extensions.loseContext)
{
this.extensions.loseContext.loseContext();
}
}
/**
* Validate context.
* @param {WebGLRenderingContext} gl - Render context.
*/
protected validateContext(gl: WebGL2RenderingContext): void
{
const attributes = gl.getContextAttributes();
const isWebGl2 = 'WebGL2RenderingContext' in globalThis && gl instanceof globalThis.WebGL2RenderingContext;
if (isWebGl2)
{
this.webGLVersion = 2;
}
// this is going to be fairly simple for now.. but at least we have room to grow!
if (attributes && !attributes.stencil)
{
// #if _DEBUG
/* eslint-disable max-len, no-console */
warn('Provided WebGL context does not have a stencil buffer, masks may not render correctly');
/* eslint-enable max-len, no-console */
// #endif
}
const hasUint32 = isWebGl2 || !!(gl as WebGLRenderingContext).getExtension('OES_element_index_uint');
this.supports.uint32Indices = hasUint32;
if (!hasUint32)
{
// #if _DEBUG
/* eslint-disable max-len, no-console */
warn('Provided WebGL context does not support 32 index buffer, complex graphics may not render correctly');
/* eslint-enable max-len, no-console */
// #endif
}
}
}