playcanvas
Version:
Open-source WebGL/WebGPU 3D engine for the web
111 lines (110 loc) • 3.33 kB
JavaScript
import { ReadStream } from "../../../core/read-stream.js";
import { ADDRESS_CLAMP_TO_EDGE, ADDRESS_REPEAT, TEXHINT_ASSET } from "../../../platform/graphics/constants.js";
import { Texture } from "../../../platform/graphics/texture.js";
import { Http } from "../../../platform/net/http.js";
import { basisTranscode } from "../../handlers/basis.js";
import { TextureParser } from "./texture.js";
const KHRConstants = {
KHR_DF_MODEL_ETC1S: 163,
KHR_DF_MODEL_UASTC: 166
};
class Ktx2Parser extends TextureParser {
constructor(device) {
super();
this.device = device;
}
canParse(context) {
return context.ext === "ktx2";
}
load(url, callback, asset) {
this.handler.fetch(url, Http.ResponseType.ARRAY_BUFFER, (err, result) => {
if (err) {
callback(err, result);
} else {
this.parse(result, url, callback, asset);
}
}, asset);
}
open(url, data, device, textureOptions = {}) {
const texture = new Texture(device, {
name: url,
addressU: data.cubemap ? ADDRESS_CLAMP_TO_EDGE : ADDRESS_REPEAT,
addressV: data.cubemap ? ADDRESS_CLAMP_TO_EDGE : ADDRESS_REPEAT,
width: data.width,
height: data.height,
format: data.format,
cubemap: data.cubemap,
levels: data.levels,
// derive mipmaps from the actual level count, so a single-level file isn't treated as an
// incomplete mip chain (which renders black); matches the dds parser
mipmaps: data.levels.length > 1,
...textureOptions
});
texture.upload();
return texture;
}
parse(arraybuffer, url, callback, asset) {
const rs = new ReadStream(arraybuffer);
const magic = [rs.readU32be(), rs.readU32be(), rs.readU32be()];
if (magic[0] !== 2873840728 || magic[1] !== 540160187 || magic[2] !== 218765834) {
return null;
}
const header = {
vkFormat: rs.readU32(),
typeSize: rs.readU32(),
pixelWidth: rs.readU32(),
pixelHeight: rs.readU32(),
pixelDepth: rs.readU32(),
layerCount: rs.readU32(),
faceCount: rs.readU32(),
levelCount: rs.readU32(),
supercompressionScheme: rs.readU32()
};
const index = {
dfdByteOffset: rs.readU32(),
dfdByteLength: rs.readU32(),
kvdByteOffset: rs.readU32(),
kvdByteLength: rs.readU32(),
sgdByteOffset: rs.readU64(),
sgdByteLength: rs.readU64()
};
const levels = [];
for (let i = 0; i < Math.max(1, header.levelCount); ++i) {
levels.push({
byteOffset: rs.readU64(),
byteLength: rs.readU64(),
uncompressedByteLength: rs.readU64()
});
}
const dfdTotalSize = rs.readU32();
if (dfdTotalSize !== index.kvdByteOffset - index.dfdByteOffset) {
return null;
}
rs.skip(8);
const colorModel = rs.readU8();
rs.skip(index.dfdByteLength - 9);
rs.skip(index.kvdByteLength);
if (header.supercompressionScheme === 1 || colorModel === KHRConstants.KHR_DF_MODEL_UASTC) {
const basisModuleFound = basisTranscode(
this.device,
url.load,
arraybuffer,
callback,
{
isGGGR: (asset?.file?.variants?.basis?.opt & 8) !== 0,
isKTX2: true,
// a six-face ktx2 file is a cubemap
isCubemap: header.faceCount === 6
}
);
if (!basisModuleFound) {
callback(`Basis module not found. Asset [${asset.name}](${asset.getFileUrl()}) basis texture variant will not be loaded.`);
}
} else {
callback("unsupported KTX2 pixel format");
}
}
}
export {
Ktx2Parser
};