MCP 3D Printer Server
by DMontgomery40
Verified
- node_modules
- meshoptimizer
// This file is part of meshoptimizer library and is distributed under the terms of MIT License.
// Copyright (C) 2016-2022, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
// This is the reference decoder implementation by Jasper St. Pierre.
// It follows the decoder interface and should be a drop-in replacement for the actual decoder from meshopt_decoder.js
// It is provided for educational value and is not recommended for use in production because it's not performance-optimized.
const MeshoptDecoder = {};
MeshoptDecoder.supported = true;
MeshoptDecoder.ready = Promise.resolve();
function assert(cond) {
if (!cond) {
throw new Error("Assertion failed");
}
}
function dezig(v) {
return ((v & 1) !== 0) ? ~(v >>> 1) : v >>> 1;
}
MeshoptDecoder.decodeVertexBuffer = (target, elementCount, byteStride, source, filter) => {
assert(source[0] === 0xA0);
const maxBlockElements = Math.min((0x2000 / byteStride) & ~0x000F, 0x100);
const deltas = new Uint8Array(0x10);
const tailDataOffs = source.length - byteStride;
// What deltas are stored relative to
const tempData = source.slice(tailDataOffs, tailDataOffs + byteStride);
let srcOffs = 0x01;
// Attribute Blocks
for (let dstElemBase = 0; dstElemBase < elementCount; dstElemBase += maxBlockElements) {
const attrBlockElementCount = Math.min(elementCount - dstElemBase, maxBlockElements);
const groupCount = ((attrBlockElementCount + 0x0F) & ~0x0F) >>> 4;
const headerByteCount = ((groupCount + 0x03) & ~0x03) >>> 2;
// Data blocks
for (let byte = 0; byte < byteStride; byte++) {
let headerBitsOffs = srcOffs;
srcOffs += headerByteCount;
for (let group = 0; group < groupCount; group++) {
const mode = (source[headerBitsOffs] >>> ((group & 0x03) << 1)) & 0x03;
// If this is the last group, move to the next byte of header bits.
if ((group & 0x03) === 0x03)
headerBitsOffs++;
const dstElemGroup = dstElemBase + (group << 4);
if (mode === 0) {
// bits 0: All 16 byte deltas are 0; the size of the encoded block is 0 bytes
deltas.fill(0x00);
} else if (mode === 1) {
// bits 1: Deltas are using 2-bit sentinel encoding; the size of the encoded block is [4..20] bytes
const srcBase = srcOffs;
srcOffs += 0x04;
for (let m = 0; m < 0x10; m++) {
// 0 = >>> 6, 1 = >>> 4, 2 = >>> 2, 3 = >>> 0
const shift = (6 - ((m & 0x03) << 1));
let delta = (source[srcBase + (m >>> 2)] >>> shift) & 0x03;
if (delta === 3)
delta = source[srcOffs++];
deltas[m] = delta;
}
} else if (mode === 2) {
// bits 2: Deltas are using 4-bit sentinel encoding; the size of the encoded block is [8..24] bytes
const srcBase = srcOffs;
srcOffs += 0x08;
for (let m = 0; m < 0x10; m++) {
// 0 = >>> 6, 1 = >>> 4, 2 = >>> 2, 3 = >>> 0
const shift = (m & 0x01) ? 0 : 4;
let delta = (source[srcBase + (m >>> 1)] >>> shift) & 0x0f;
if (delta === 0xf)
delta = source[srcOffs++];
deltas[m] = delta;
}
} else {
// bits 3: All 16 byte deltas are stored verbatim; the size of the encoded block is 16 bytes
deltas.set(source.subarray(srcOffs, srcOffs + 0x10));
srcOffs += 0x10;
}
// Go through and apply deltas to data
for (let m = 0; m < 0x10; m++) {
const dstElem = dstElemGroup + m;
if (dstElem >= elementCount)
break;
const delta = dezig(deltas[m]);
const dstOffs = dstElem * byteStride + byte;
target[dstOffs] = (tempData[byte] += delta);
}
}
}
}
// Filters - only applied if filter isn't undefined or NONE
if (filter === 'OCTAHEDRAL') {
assert(byteStride === 4 || byteStride === 8);
let dst, maxInt;
if (byteStride === 4) {
dst = new Int8Array(target.buffer);
maxInt = 127;
} else {
dst = new Int16Array(target.buffer);
maxInt = 32767;
}
for (let i = 0; i < 4 * elementCount; i += 4) {
let x = dst[i + 0], y = dst[i + 1], one = dst[i + 2];
x /= one;
y /= one;
const z = 1.0 - Math.abs(x) - Math.abs(y);
const t = Math.max(-z, 0.0);
x -= (x >= 0) ? t : -t;
y -= (y >= 0) ? t : -t;
const h = maxInt / Math.hypot(x, y, z);
dst[i + 0] = Math.round(x * h);
dst[i + 1] = Math.round(y * h);
dst[i + 2] = Math.round(z * h);
// keep dst[i + 3] as is
}
} else if (filter === 'QUATERNION') {
assert(byteStride === 8);
const dst = new Int16Array(target.buffer);
for (let i = 0; i < 4 * elementCount; i += 4) {
const inputW = dst[i + 3];
const maxComponent = inputW & 0x03;
const s = Math.SQRT1_2 / (inputW | 0x03);
let x = dst[i + 0] * s;
let y = dst[i + 1] * s;
let z = dst[i + 2] * s;
let w = Math.sqrt(Math.max(0.0, 1.0 - x**2 - y**2 - z**2));
dst[i + (maxComponent + 1) % 4] = Math.round(x * 32767);
dst[i + (maxComponent + 2) % 4] = Math.round(y * 32767);
dst[i + (maxComponent + 3) % 4] = Math.round(z * 32767);
dst[i + (maxComponent + 0) % 4] = Math.round(w * 32767);
}
} else if (filter === 'EXPONENTIAL') {
assert((byteStride & 0x03) === 0x00);
const src = new Int32Array(target.buffer);
const dst = new Float32Array(target.buffer);
for (let i = 0; i < (byteStride * elementCount) / 4; i++) {
const v = src[i], exp = v >> 24, mantissa = (v << 8) >> 8;
dst[i] = 2.0**exp * mantissa;
}
}
};
function pushfifo(fifo, n) {
for (let i = fifo.length - 1; i > 0; i--)
fifo[i] = fifo[i - 1];
fifo[0] = n;
}
MeshoptDecoder.decodeIndexBuffer = (target, count, byteStride, source) => {
assert(source[0] === 0xE1);
assert(count % 3 === 0);
assert(byteStride === 2 || byteStride === 4);
let dst;
if (byteStride === 2)
dst = new Uint16Array(target.buffer);
else
dst = new Uint32Array(target.buffer);
const triCount = count / 3;
let codeOffs = 0x01;
let dataOffs = codeOffs + triCount;
let codeauxOffs = source.length - 0x10;
function readLEB128() {
let n = 0;
for (let i = 0; ; i += 7) {
const b = source[dataOffs++];
n |= (b & 0x7F) << i;
if (b < 0x80)
return n;
}
}
let next = 0, last = 0;
const edgefifo = new Uint32Array(32);
const vertexfifo = new Uint32Array(16);
function decodeIndex(v) {
return (last += dezig(v));
}
let dstOffs = 0;
for (let i = 0; i < triCount; i++) {
const code = source[codeOffs++];
const b0 = code >>> 4, b1 = code & 0x0F;
if (b0 < 0x0F) {
const a = edgefifo[(b0 << 1) + 0], b = edgefifo[(b0 << 1) + 1];
let c = -1;
if (b1 === 0x00) {
c = next++;
pushfifo(vertexfifo, c);
} else if (b1 < 0x0D) {
c = vertexfifo[b1];
} else if (b1 === 0x0D) {
c = --last;
pushfifo(vertexfifo, c);
} else if (b1 === 0x0E) {
c = ++last;
pushfifo(vertexfifo, c);
} else if (b1 === 0x0F) {
const v = readLEB128();
c = decodeIndex(v);
pushfifo(vertexfifo, c);
}
// fifo pushes happen backwards
pushfifo(edgefifo, b); pushfifo(edgefifo, c);
pushfifo(edgefifo, c); pushfifo(edgefifo, a);
dst[dstOffs++] = a;
dst[dstOffs++] = b;
dst[dstOffs++] = c;
} else { // b0 === 0x0F
let a = -1, b = -1, c = -1;
if (b1 < 0x0E) {
const e = source[codeauxOffs + b1];
const z = e >>> 4, w = e & 0x0F;
a = next++;
if (z === 0x00)
b = next++;
else
b = vertexfifo[z - 1];
if (w === 0x00)
c = next++;
else
c = vertexfifo[w - 1];
pushfifo(vertexfifo, a);
if (z === 0x00)
pushfifo(vertexfifo, b);
if (w === 0x00)
pushfifo(vertexfifo, c);
} else {
const e = source[dataOffs++];
if (e === 0x00)
next = 0;
const z = e >>> 4, w = e & 0x0F;
if (b1 === 0x0E)
a = next++;
else
a = decodeIndex(readLEB128());
if (z === 0x00)
b = next++;
else if (z === 0x0F)
b = decodeIndex(readLEB128());
else
b = vertexfifo[z - 1];
if (w === 0x00)
c = next++;
else if (w === 0x0F)
c = decodeIndex(readLEB128());
else
c = vertexfifo[w - 1];
pushfifo(vertexfifo, a);
if (z === 0x00 || z === 0x0F)
pushfifo(vertexfifo, b);
if (w === 0x00 || w === 0x0F)
pushfifo(vertexfifo, c);
}
pushfifo(edgefifo, a); pushfifo(edgefifo, b);
pushfifo(edgefifo, b); pushfifo(edgefifo, c);
pushfifo(edgefifo, c); pushfifo(edgefifo, a);
dst[dstOffs++] = a;
dst[dstOffs++] = b;
dst[dstOffs++] = c;
}
}
};
MeshoptDecoder.decodeIndexSequence = (target, count, byteStride, source) => {
assert(source[0] === 0xD1);
assert(byteStride === 2 || byteStride === 4);
let dst;
if (byteStride === 2)
dst = new Uint16Array(target.buffer);
else
dst = new Uint32Array(target.buffer);
let dataOffs = 0x01;
function readLEB128() {
let n = 0;
for (let i = 0; ; i += 7) {
const b = source[dataOffs++];
n |= (b & 0x7F) << i;
if (b < 0x80)
return n;
}
}
const last = new Uint32Array(2);
for (let i = 0; i < count; i++) {
const v = readLEB128();
const b = (v & 0x01);
const delta = dezig(v >>> 1);
dst[i] = (last[b] += delta);
}
};
MeshoptDecoder.decodeGltfBuffer = (target, count, size, source, mode, filter) => {
var table = {
ATTRIBUTES: MeshoptDecoder.decodeVertexBuffer,
TRIANGLES: MeshoptDecoder.decodeIndexBuffer,
INDICES: MeshoptDecoder.decodeIndexSequence,
};
assert(table[mode] !== undefined);
table[mode](target, count, size, source, filter);
};
// node.js interface:
// for (let k in MeshoptDecoder) { exports[k] = MeshoptDecoder[k]; }
export { MeshoptDecoder };