import { LoaderResource } from '@pixi/loaders';
import type { Loader } from '@pixi/loaders';
import type { INTERNAL_FORMATS } from '../const';
import type { ILoaderResource } from '@pixi/loaders';
/**
* Schema for compressed-texture manifests
*
* @ignore
* @see PIXI.CompressedTextureLoader
*/
export type CompressedTextureManifest = {
textures: Array<{ src: string, format?: keyof INTERNAL_FORMATS}>,
cacheID: string;
};
// Missing typings? - https://github.com/microsoft/TypeScript/issues/39655
/**
* Compressed texture extensions
*/
/* eslint-disable camelcase */
export type CompressedTextureExtensions = {
s3tc?: WEBGL_compressed_texture_s3tc,
s3tc_sRGB: WEBGL_compressed_texture_s3tc_srgb,
etc: any,
etc1: any,
pvrtc: any,
atc: any,
astc: WEBGL_compressed_texture_astc
};
export type CompressedTextureExtensionRef = keyof CompressedTextureExtensions;
/* eslint-enable camelcase */
/**
* Loader plugin for handling compressed textures for all platforms.
*
* @class
* @memberof PIXI
* @implements PIXI.ILoaderPlugin
*/
export class CompressedTextureLoader
{
static textureExtensions: Partial<CompressedTextureExtensions>;
static textureFormats: { [P in keyof INTERNAL_FORMATS]?: number };
/**
* Called after a compressed-textures manifest is loaded.
*
* This will then load the correct compression format for the device. Your manifest should adhere
* to the following schema:
*
* ```js
* import { INTERNAL_FORMATS } from '@pixi/constants';
*
* // The following should be present in a *.compressed-texture.json file!
* const manifest = JSON.stringify({
* COMPRESSED_RGBA_S3TC_DXT5_EXT: "asset.s3tc.ktx",
* COMPRESSED_RGBA8_ETC2_EAC: "asset.etc.ktx",
* RGBA_PVRTC_4BPPV1_IMG: "asset.pvrtc.ktx",
* textureID: "asset.png",
* fallback: "asset.png"
* });
* ```
*
* @param resource
* @param next
*/
static use(resource: ILoaderResource, next: (...args: any[]) => void): void
{
const data: CompressedTextureManifest = resource.data;
const loader = (this as any) as Loader;
if (!CompressedTextureLoader.textureExtensions)
{
CompressedTextureLoader.autoDetectExtensions();
}
if (resource.type === LoaderResource.TYPE.JSON
&& data
&& data.cacheID
&& data.textures)
{
const textures = data.textures;
let textureURL: string;
let fallbackURL: string;
// Search for an extension that holds one the formats
for (let i = 0, j = textures.length; i < j; i++)
{
const texture = textures[i];
const url = texture.src;
const format = texture.format;
if (!format)
{
fallbackURL = url;
}
if (CompressedTextureLoader.textureFormats[format])
{
textureURL = url;
break;
}
}
textureURL = textureURL || fallbackURL;
// Make sure we have a URL
if (!textureURL)
{
throw new Error(`Cannot load compressed-textures in ${resource.url}, make sure you provide a fallback`);
}
if (textureURL === resource.url)
{
// Prevent infinite loops
throw new Error('URL of compressed texture cannot be the same as the manifest\'s URL');
}
const loadOptions = {
crossOrigin: resource.crossOrigin,
metadata: resource.metadata.imageMetadata,
parentResource: resource
};
// The appropriate loader should register the texture
loader.add(data.cacheID, textureURL, loadOptions, function onCompressedTextureLoaded()
{
next();
});
}
else
{
next();
}
}
/**
* Detects the available compressed texture extensions on the device.
*
* @param extensions - extensions provided by a WebGL context
* @ignore
*/
static autoDetectExtensions(extensions?: Partial<CompressedTextureExtensions>): void
{
// Auto-detect WebGL compressed-texture extensions
if (!extensions)
{
const canvas = document.createElement('canvas');
const gl = canvas.getContext('webgl');
if (!gl)
{
console.error('WebGL not available for compressed textures. Silently failing.');
return;
}
extensions = {
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')
};
}
CompressedTextureLoader.textureExtensions = extensions;
CompressedTextureLoader.textureFormats = {};
// Assign all available compressed-texture formats
for (const extensionName in extensions)
{
const extension = extensions[extensionName as CompressedTextureExtensionRef];
if (!extension)
{
continue;
}
Object.assign(
CompressedTextureLoader.textureFormats,
Object.getPrototypeOf(extension));
}
}
}