React client app #5
2
Makefile
2
Makefile
@ -3,3 +3,5 @@ build-wasm:
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||||
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build-react:
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cd client && npm run build
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all: build-wasm build-react
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@ -15,6 +15,38 @@
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</head>
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<body>
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<noscript>You need to enable JavaScript to run this app.</noscript>
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<article>
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<h1>Go+Wasm image dithering tool</h1>
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<aside>Featuring the Nord Color Palette</aside>
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<p>
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Load an image, click Go and wait (potentially for a while) for the image
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to be dithered using the Nord color palette and the Floyd-Steinberg
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algorithm.
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</p>
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<p>
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Running in the browser with Wasm causes a bit of a performance penalty.
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Multithreading is not available (not that it matters much since
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Floyd-Steinberg is single-threaded), and sending data back and forth
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between JS and Wasm can take a little while.
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</p>
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<p>
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I've re-used code from
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<a
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href="https://www.sitepen.com/blog/using-webassembly-with-web-workers"
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>
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this article
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</a>
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to make the Wasm code run in a web worker, with some adaptations for Go
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oddities.
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</p>
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<p>
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If you're into that sort of thing, source code is available on
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<a href="https://github.com/CrispyBaguette/wasm-palette-converter">
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GitHub
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</a>
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.
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</p>
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</article>
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<div id="root"></div>
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</body>
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</html>
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744
client/public/wasm_exec.js
Normal file
744
client/public/wasm_exec.js
Normal file
@ -0,0 +1,744 @@
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/* eslint-disable no-undef */
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/* eslint-disable no-restricted-globals */
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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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(() => {
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// Map multiple JavaScript environments to a single common API,
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// preferring web standards over Node.js API.
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//
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// Environments considered:
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// - Browsers
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// - Node.js
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// - Electron
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// - Parcel
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// - Webpack
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if (typeof global !== "undefined") {
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// global already exists
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} else if (typeof window !== "undefined") {
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window.global = window;
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} else if (typeof self !== "undefined") {
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self.global = self;
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} else {
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throw new Error(
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"cannot export Go (neither global, window nor self is defined)"
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);
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}
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if (!global.require && typeof require !== "undefined") {
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global.require = require;
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}
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if (!global.fs && global.require) {
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const fs = require("fs");
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if (typeof fs === "object" && fs !== null && Object.keys(fs).length !== 0) {
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global.fs = fs;
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}
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}
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const enosys = () => {
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const err = new Error("not implemented");
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err.code = "ENOSYS";
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return err;
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||||
};
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||||
|
||||
if (!global.fs) {
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let outputBuf = "";
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||||
global.fs = {
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||||
constants: {
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||||
O_WRONLY: -1,
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||||
O_RDWR: -1,
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||||
O_CREAT: -1,
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O_TRUNC: -1,
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||||
O_APPEND: -1,
|
||||
O_EXCL: -1,
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}, // unused
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||||
writeSync(fd, buf) {
|
||||
outputBuf += decoder.decode(buf);
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||||
const nl = outputBuf.lastIndexOf("\n");
|
||||
if (nl != -1) {
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||||
console.log(outputBuf.substr(0, nl));
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outputBuf = outputBuf.substr(nl + 1);
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}
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return buf.length;
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},
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write(fd, buf, offset, length, position, callback) {
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if (offset !== 0 || length !== buf.length || position !== null) {
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callback(enosys());
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return;
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||||
}
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||||
const n = this.writeSync(fd, buf);
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||||
callback(null, n);
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},
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chmod(path, mode, callback) {
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callback(enosys());
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},
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chown(path, uid, gid, callback) {
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callback(enosys());
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},
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close(fd, callback) {
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callback(enosys());
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},
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||||
fchmod(fd, mode, callback) {
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callback(enosys());
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},
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fchown(fd, uid, gid, callback) {
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||||
callback(enosys());
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||||
},
|
||||
fstat(fd, callback) {
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||||
callback(enosys());
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||||
},
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||||
fsync(fd, callback) {
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||||
callback(null);
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||||
},
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||||
ftruncate(fd, length, callback) {
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||||
callback(enosys());
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||||
},
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||||
lchown(path, uid, gid, callback) {
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||||
callback(enosys());
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||||
},
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||||
link(path, link, callback) {
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||||
callback(enosys());
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||||
},
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||||
lstat(path, callback) {
|
||||
callback(enosys());
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||||
},
|
||||
mkdir(path, perm, callback) {
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||||
callback(enosys());
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||||
},
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open(path, flags, mode, callback) {
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||||
callback(enosys());
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||||
},
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||||
read(fd, buffer, offset, length, position, callback) {
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callback(enosys());
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},
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||||
readdir(path, callback) {
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||||
callback(enosys());
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||||
},
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||||
readlink(path, callback) {
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||||
callback(enosys());
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||||
},
|
||||
rename(from, to, callback) {
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||||
callback(enosys());
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||||
},
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||||
rmdir(path, callback) {
|
||||
callback(enosys());
|
||||
},
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||||
stat(path, callback) {
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||||
callback(enosys());
|
||||
},
|
||||
symlink(path, link, callback) {
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||||
callback(enosys());
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||||
},
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||||
truncate(path, length, callback) {
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||||
callback(enosys());
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||||
},
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||||
unlink(path, callback) {
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||||
callback(enosys());
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||||
},
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||||
utimes(path, atime, mtime, callback) {
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||||
callback(enosys());
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||||
},
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||||
};
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||||
}
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||||
|
||||
if (!global.process) {
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||||
global.process = {
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||||
getuid() {
|
||||
return -1;
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||||
},
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||||
getgid() {
|
||||
return -1;
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||||
},
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||||
geteuid() {
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||||
return -1;
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||||
},
|
||||
getegid() {
|
||||
return -1;
|
||||
},
|
||||
getgroups() {
|
||||
throw enosys();
|
||||
},
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||||
pid: -1,
|
||||
ppid: -1,
|
||||
umask() {
|
||||
throw enosys();
|
||||
},
|
||||
cwd() {
|
||||
throw enosys();
|
||||
},
|
||||
chdir() {
|
||||
throw enosys();
|
||||
},
|
||||
};
|
||||
}
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||||
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||||
if (!global.crypto && global.require) {
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||||
const nodeCrypto = require("crypto");
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||||
global.crypto = {
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||||
getRandomValues(b) {
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nodeCrypto.randomFillSync(b);
|
||||
},
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||||
};
|
||||
}
|
||||
if (!global.crypto) {
|
||||
throw new Error(
|
||||
"global.crypto is not available, polyfill required (getRandomValues only)"
|
||||
);
|
||||
}
|
||||
|
||||
if (!global.performance) {
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||||
global.performance = {
|
||||
now() {
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const [sec, nsec] = process.hrtime();
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return sec * 1000 + nsec / 1000000;
|
||||
},
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};
|
||||
}
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if (!global.TextEncoder && global.require) {
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global.TextEncoder = require("util").TextEncoder;
|
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}
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if (!global.TextEncoder) {
|
||||
throw new Error("global.TextEncoder is not available, polyfill required");
|
||||
}
|
||||
|
||||
if (!global.TextDecoder && global.require) {
|
||||
global.TextDecoder = require("util").TextDecoder;
|
||||
}
|
||||
if (!global.TextDecoder) {
|
||||
throw new Error("global.TextDecoder is not available, polyfill required");
|
||||
}
|
||||
|
||||
// End of polyfills for common API.
|
||||
|
||||
const encoder = new TextEncoder("utf-8");
|
||||
const decoder = new TextDecoder("utf-8");
|
||||
|
||||
global.Go = class {
|
||||
constructor() {
|
||||
this.argv = ["js"];
|
||||
this.env = {};
|
||||
this.exit = (code) => {
|
||||
if (code !== 0) {
|
||||
console.warn("exit code:", code);
|
||||
}
|
||||
};
|
||||
this._exitPromise = new Promise((resolve) => {
|
||||
this._resolveExitPromise = resolve;
|
||||
});
|
||||
this._pendingEvent = null;
|
||||
this._scheduledTimeouts = new Map();
|
||||
this._nextCallbackTimeoutID = 1;
|
||||
|
||||
const setInt64 = (addr, v) => {
|
||||
this.mem.setUint32(addr + 0, v, true);
|
||||
this.mem.setUint32(addr + 4, Math.floor(v / 4294967296), true);
|
||||
};
|
||||
|
||||
const getInt64 = (addr) => {
|
||||
const low = this.mem.getUint32(addr + 0, true);
|
||||
const high = this.mem.getInt32(addr + 4, true);
|
||||
return low + high * 4294967296;
|
||||
};
|
||||
|
||||
const loadValue = (addr) => {
|
||||
const f = this.mem.getFloat64(addr, true);
|
||||
if (f === 0) {
|
||||
return undefined;
|
||||
}
|
||||
if (!isNaN(f)) {
|
||||
return f;
|
||||
}
|
||||
|
||||
const id = this.mem.getUint32(addr, true);
|
||||
return this._values[id];
|
||||
};
|
||||
|
||||
const storeValue = (addr, v) => {
|
||||
const nanHead = 0x7ff80000;
|
||||
|
||||
if (typeof v === "number" && v !== 0) {
|
||||
if (isNaN(v)) {
|
||||
this.mem.setUint32(addr + 4, nanHead, true);
|
||||
this.mem.setUint32(addr, 0, true);
|
||||
return;
|
||||
}
|
||||
this.mem.setFloat64(addr, v, true);
|
||||
return;
|
||||
}
|
||||
|
||||
if (v === undefined) {
|
||||
this.mem.setFloat64(addr, 0, true);
|
||||
return;
|
||||
}
|
||||
|
||||
let id = this._ids.get(v);
|
||||
if (id === undefined) {
|
||||
id = this._idPool.pop();
|
||||
if (id === undefined) {
|
||||
id = this._values.length;
|
||||
}
|
||||
this._values[id] = v;
|
||||
this._goRefCounts[id] = 0;
|
||||
this._ids.set(v, id);
|
||||
}
|
||||
this._goRefCounts[id]++;
|
||||
let typeFlag = 0;
|
||||
switch (typeof v) {
|
||||
case "object":
|
||||
if (v !== null) {
|
||||
typeFlag = 1;
|
||||
}
|
||||
break;
|
||||
case "string":
|
||||
typeFlag = 2;
|
||||
break;
|
||||
case "symbol":
|
||||
typeFlag = 3;
|
||||
break;
|
||||
case "function":
|
||||
typeFlag = 4;
|
||||
break;
|
||||
}
|
||||
this.mem.setUint32(addr + 4, nanHead | typeFlag, true);
|
||||
this.mem.setUint32(addr, id, true);
|
||||
};
|
||||
|
||||
const loadSlice = (addr) => {
|
||||
const array = getInt64(addr + 0);
|
||||
const len = getInt64(addr + 8);
|
||||
return new Uint8Array(this._inst.exports.mem.buffer, array, len);
|
||||
};
|
||||
|
||||
const loadSliceOfValues = (addr) => {
|
||||
const array = getInt64(addr + 0);
|
||||
const len = getInt64(addr + 8);
|
||||
const a = new Array(len);
|
||||
for (let i = 0; i < len; i++) {
|
||||
a[i] = loadValue(array + i * 8);
|
||||
}
|
||||
return a;
|
||||
};
|
||||
|
||||
const loadString = (addr) => {
|
||||
const saddr = getInt64(addr + 0);
|
||||
const len = getInt64(addr + 8);
|
||||
return decoder.decode(
|
||||
new DataView(this._inst.exports.mem.buffer, saddr, len)
|
||||
);
|
||||
};
|
||||
|
||||
const timeOrigin = Date.now() - performance.now();
|
||||
this.importObject = {
|
||||
go: {
|
||||
// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
|
||||
// may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported
|
||||
// function. A goroutine can switch to a new stack if the current stack is too small (see morestack function).
|
||||
// This changes the SP, thus we have to update the SP used by the imported function.
|
||||
|
||||
// func wasmExit(code int32)
|
||||
"runtime.wasmExit": (sp) => {
|
||||
sp >>>= 0;
|
||||
const code = this.mem.getInt32(sp + 8, true);
|
||||
this.exited = true;
|
||||
delete this._inst;
|
||||
delete this._values;
|
||||
delete this._goRefCounts;
|
||||
delete this._ids;
|
||||
delete this._idPool;
|
||||
this.exit(code);
|
||||
},
|
||||
|
||||
// func wasmWrite(fd uintptr, p unsafe.Pointer, n int32)
|
||||
"runtime.wasmWrite": (sp) => {
|
||||
sp >>>= 0;
|
||||
const fd = getInt64(sp + 8);
|
||||
const p = getInt64(sp + 16);
|
||||
const n = this.mem.getInt32(sp + 24, true);
|
||||
fs.writeSync(
|
||||
fd,
|
||||
new Uint8Array(this._inst.exports.mem.buffer, p, n)
|
||||
);
|
||||
},
|
||||
|
||||
// func resetMemoryDataView()
|
||||
"runtime.resetMemoryDataView": (sp) => {
|
||||
sp >>>= 0;
|
||||
this.mem = new DataView(this._inst.exports.mem.buffer);
|
||||
},
|
||||
|
||||
// func nanotime1() int64
|
||||
"runtime.nanotime1": (sp) => {
|
||||
sp >>>= 0;
|
||||
setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
|
||||
},
|
||||
|
||||
// func walltime() (sec int64, nsec int32)
|
||||
"runtime.walltime": (sp) => {
|
||||
sp >>>= 0;
|
||||
const msec = new Date().getTime();
|
||||
setInt64(sp + 8, msec / 1000);
|
||||
this.mem.setInt32(sp + 16, (msec % 1000) * 1000000, true);
|
||||
},
|
||||
|
||||
// func scheduleTimeoutEvent(delay int64) int32
|
||||
"runtime.scheduleTimeoutEvent": (sp) => {
|
||||
sp >>>= 0;
|
||||
const id = this._nextCallbackTimeoutID;
|
||||
this._nextCallbackTimeoutID++;
|
||||
this._scheduledTimeouts.set(
|
||||
id,
|
||||
setTimeout(
|
||||
() => {
|
||||
this._resume();
|
||||
while (this._scheduledTimeouts.has(id)) {
|
||||
// for some reason Go failed to register the timeout event, log and try again
|
||||
// (temporary workaround for https://github.com/golang/go/issues/28975)
|
||||
console.warn("scheduleTimeoutEvent: missed timeout event");
|
||||
this._resume();
|
||||
}
|
||||
},
|
||||
getInt64(sp + 8) + 1 // setTimeout has been seen to fire up to 1 millisecond early
|
||||
)
|
||||
);
|
||||
this.mem.setInt32(sp + 16, id, true);
|
||||
},
|
||||
|
||||
// func clearTimeoutEvent(id int32)
|
||||
"runtime.clearTimeoutEvent": (sp) => {
|
||||
sp >>>= 0;
|
||||
const id = this.mem.getInt32(sp + 8, true);
|
||||
clearTimeout(this._scheduledTimeouts.get(id));
|
||||
this._scheduledTimeouts.delete(id);
|
||||
},
|
||||
|
||||
// func getRandomData(r []byte)
|
||||
"runtime.getRandomData": (sp) => {
|
||||
sp >>>= 0;
|
||||
crypto.getRandomValues(loadSlice(sp + 8));
|
||||
},
|
||||
|
||||
// func finalizeRef(v ref)
|
||||
"syscall/js.finalizeRef": (sp) => {
|
||||
sp >>>= 0;
|
||||
const id = this.mem.getUint32(sp + 8, true);
|
||||
this._goRefCounts[id]--;
|
||||
if (this._goRefCounts[id] === 0) {
|
||||
const v = this._values[id];
|
||||
this._values[id] = null;
|
||||
this._ids.delete(v);
|
||||
this._idPool.push(id);
|
||||
}
|
||||
},
|
||||
|
||||
// func stringVal(value string) ref
|
||||
"syscall/js.stringVal": (sp) => {
|
||||
sp >>>= 0;
|
||||
storeValue(sp + 24, loadString(sp + 8));
|
||||
},
|
||||
|
||||
// func valueGet(v ref, p string) ref
|
||||
"syscall/js.valueGet": (sp) => {
|
||||
sp >>>= 0;
|
||||
const result = Reflect.get(loadValue(sp + 8), loadString(sp + 16));
|
||||
sp = this._inst.exports.getsp() >>> 0; // see comment above
|
||||
storeValue(sp + 32, result);
|
||||
},
|
||||
|
||||
// func valueSet(v ref, p string, x ref)
|
||||
"syscall/js.valueSet": (sp) => {
|
||||
sp >>>= 0;
|
||||
Reflect.set(
|
||||
loadValue(sp + 8),
|
||||
loadString(sp + 16),
|
||||
loadValue(sp + 32)
|
||||
);
|
||||
},
|
||||
|
||||
// func valueDelete(v ref, p string)
|
||||
"syscall/js.valueDelete": (sp) => {
|
||||
sp >>>= 0;
|
||||
Reflect.deleteProperty(loadValue(sp + 8), loadString(sp + 16));
|
||||
},
|
||||
|
||||
// func valueIndex(v ref, i int) ref
|
||||
"syscall/js.valueIndex": (sp) => {
|
||||
sp >>>= 0;
|
||||
storeValue(
|
||||
sp + 24,
|
||||
Reflect.get(loadValue(sp + 8), getInt64(sp + 16))
|
||||
);
|
||||
},
|
||||
|
||||
// valueSetIndex(v ref, i int, x ref)
|
||||
"syscall/js.valueSetIndex": (sp) => {
|
||||
sp >>>= 0;
|
||||
Reflect.set(
|
||||
loadValue(sp + 8),
|
||||
getInt64(sp + 16),
|
||||
loadValue(sp + 24)
|
||||
);
|
||||
},
|
||||
|
||||
// func valueCall(v ref, m string, args []ref) (ref, bool)
|
||||
"syscall/js.valueCall": (sp) => {
|
||||
sp >>>= 0;
|
||||
try {
|
||||
const v = loadValue(sp + 8);
|
||||
const m = Reflect.get(v, loadString(sp + 16));
|
||||
const args = loadSliceOfValues(sp + 32);
|
||||
const result = Reflect.apply(m, v, args);
|
||||
sp = this._inst.exports.getsp() >>> 0; // see comment above
|
||||
storeValue(sp + 56, result);
|
||||
this.mem.setUint8(sp + 64, 1);
|
||||
} catch (err) {
|
||||
sp = this._inst.exports.getsp() >>> 0; // see comment above
|
||||
storeValue(sp + 56, err);
|
||||
this.mem.setUint8(sp + 64, 0);
|
||||
}
|
||||
},
|
||||
|
||||
// func valueInvoke(v ref, args []ref) (ref, bool)
|
||||
"syscall/js.valueInvoke": (sp) => {
|
||||
sp >>>= 0;
|
||||
try {
|
||||
const v = loadValue(sp + 8);
|
||||
const args = loadSliceOfValues(sp + 16);
|
||||
const result = Reflect.apply(v, undefined, args);
|
||||
sp = this._inst.exports.getsp() >>> 0; // see comment above
|
||||
storeValue(sp + 40, result);
|
||||
this.mem.setUint8(sp + 48, 1);
|
||||
} catch (err) {
|
||||
sp = this._inst.exports.getsp() >>> 0; // see comment above
|
||||
storeValue(sp + 40, err);
|
||||
this.mem.setUint8(sp + 48, 0);
|
||||
}
|
||||
},
|
||||
|
||||
// func valueNew(v ref, args []ref) (ref, bool)
|
||||
"syscall/js.valueNew": (sp) => {
|
||||
sp >>>= 0;
|
||||
try {
|
||||
const v = loadValue(sp + 8);
|
||||
const args = loadSliceOfValues(sp + 16);
|
||||
const result = Reflect.construct(v, args);
|
||||
sp = this._inst.exports.getsp() >>> 0; // see comment above
|
||||
storeValue(sp + 40, result);
|
||||
this.mem.setUint8(sp + 48, 1);
|
||||
} catch (err) {
|
||||
sp = this._inst.exports.getsp() >>> 0; // see comment above
|
||||
storeValue(sp + 40, err);
|
||||
this.mem.setUint8(sp + 48, 0);
|
||||
}
|
||||
},
|
||||
|
||||
// func valueLength(v ref) int
|
||||
"syscall/js.valueLength": (sp) => {
|
||||
sp >>>= 0;
|
||||
setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
|
||||
},
|
||||
|
||||
// valuePrepareString(v ref) (ref, int)
|
||||
"syscall/js.valuePrepareString": (sp) => {
|
||||
sp >>>= 0;
|
||||
const str = encoder.encode(String(loadValue(sp + 8)));
|
||||
storeValue(sp + 16, str);
|
||||
setInt64(sp + 24, str.length);
|
||||
},
|
||||
|
||||
// valueLoadString(v ref, b []byte)
|
||||
"syscall/js.valueLoadString": (sp) => {
|
||||
sp >>>= 0;
|
||||
const str = loadValue(sp + 8);
|
||||
loadSlice(sp + 16).set(str);
|
||||
},
|
||||
|
||||
// func valueInstanceOf(v ref, t ref) bool
|
||||
"syscall/js.valueInstanceOf": (sp) => {
|
||||
sp >>>= 0;
|
||||
this.mem.setUint8(
|
||||
sp + 24,
|
||||
loadValue(sp + 8) instanceof loadValue(sp + 16) ? 1 : 0
|
||||
);
|
||||
},
|
||||
|
||||
// func copyBytesToGo(dst []byte, src ref) (int, bool)
|
||||
"syscall/js.copyBytesToGo": (sp) => {
|
||||
sp >>>= 0;
|
||||
const dst = loadSlice(sp + 8);
|
||||
const src = loadValue(sp + 32);
|
||||
if (
|
||||
!(src instanceof Uint8Array || src instanceof Uint8ClampedArray)
|
||||
) {
|
||||
this.mem.setUint8(sp + 48, 0);
|
||||
return;
|
||||
}
|
||||
const toCopy = src.subarray(0, dst.length);
|
||||
dst.set(toCopy);
|
||||
setInt64(sp + 40, toCopy.length);
|
||||
this.mem.setUint8(sp + 48, 1);
|
||||
},
|
||||
|
||||
// func copyBytesToJS(dst ref, src []byte) (int, bool)
|
||||
"syscall/js.copyBytesToJS": (sp) => {
|
||||
sp >>>= 0;
|
||||
const dst = loadValue(sp + 8);
|
||||
const src = loadSlice(sp + 16);
|
||||
if (
|
||||
!(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)
|
||||
) {
|
||||
this.mem.setUint8(sp + 48, 0);
|
||||
return;
|
||||
}
|
||||
const toCopy = src.subarray(0, dst.length);
|
||||
dst.set(toCopy);
|
||||
setInt64(sp + 40, toCopy.length);
|
||||
this.mem.setUint8(sp + 48, 1);
|
||||
},
|
||||
|
||||
debug: (value) => {
|
||||
console.log(value);
|
||||
},
|
||||
},
|
||||
};
|
||||
}
|
||||
|
||||
async run(instance) {
|
||||
if (!(instance instanceof WebAssembly.Instance)) {
|
||||
throw new Error("Go.run: WebAssembly.Instance expected");
|
||||
}
|
||||
this._inst = instance;
|
||||
this.mem = new DataView(this._inst.exports.mem.buffer);
|
||||
this._values = [
|
||||
// JS values that Go currently has references to, indexed by reference id
|
||||
NaN,
|
||||
0,
|
||||
null,
|
||||
true,
|
||||
false,
|
||||
global,
|
||||
this,
|
||||
];
|
||||
this._goRefCounts = new Array(this._values.length).fill(Infinity); // number of references that Go has to a JS value, indexed by reference id
|
||||
this._ids = new Map([
|
||||
// mapping from JS values to reference ids
|
||||
[0, 1],
|
||||
[null, 2],
|
||||
[true, 3],
|
||||
[false, 4],
|
||||
[global, 5],
|
||||
[this, 6],
|
||||
]);
|
||||
this._idPool = []; // unused ids that have been garbage collected
|
||||
this.exited = false; // whether the Go program has exited
|
||||
|
||||
// Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
|
||||
let offset = 4096;
|
||||
|
||||
const strPtr = (str) => {
|
||||
const ptr = offset;
|
||||
const bytes = encoder.encode(str + "\0");
|
||||
new Uint8Array(this.mem.buffer, offset, bytes.length).set(bytes);
|
||||
offset += bytes.length;
|
||||
if (offset % 8 !== 0) {
|
||||
offset += 8 - (offset % 8);
|
||||
}
|
||||
return ptr;
|
||||
};
|
||||
|
||||
const argc = this.argv.length;
|
||||
|
||||
const argvPtrs = [];
|
||||
this.argv.forEach((arg) => {
|
||||
argvPtrs.push(strPtr(arg));
|
||||
});
|
||||
argvPtrs.push(0);
|
||||
|
||||
const keys = Object.keys(this.env).sort();
|
||||
keys.forEach((key) => {
|
||||
argvPtrs.push(strPtr(`${key}=${this.env[key]}`));
|
||||
});
|
||||
argvPtrs.push(0);
|
||||
|
||||
const argv = offset;
|
||||
argvPtrs.forEach((ptr) => {
|
||||
this.mem.setUint32(offset, ptr, true);
|
||||
this.mem.setUint32(offset + 4, 0, true);
|
||||
offset += 8;
|
||||
});
|
||||
|
||||
// The linker guarantees global data starts from at least wasmMinDataAddr.
|
||||
// Keep in sync with cmd/link/internal/ld/data.go:wasmMinDataAddr.
|
||||
const wasmMinDataAddr = 4096 + 8192;
|
||||
if (offset >= wasmMinDataAddr) {
|
||||
throw new Error(
|
||||
"total length of command line and environment variables exceeds limit"
|
||||
);
|
||||
}
|
||||
|
||||
this._inst.exports.run(argc, argv);
|
||||
if (this.exited) {
|
||||
this._resolveExitPromise();
|
||||
}
|
||||
await this._exitPromise;
|
||||
}
|
||||
|
||||
_resume() {
|
||||
if (this.exited) {
|
||||
throw new Error("Go program has already exited");
|
||||
}
|
||||
this._inst.exports.resume();
|
||||
if (this.exited) {
|
||||
this._resolveExitPromise();
|
||||
}
|
||||
}
|
||||
|
||||
_makeFuncWrapper(id) {
|
||||
const go = this;
|
||||
return function () {
|
||||
const event = { id: id, this: this, args: arguments };
|
||||
go._pendingEvent = event;
|
||||
go._resume();
|
||||
return event.result;
|
||||
};
|
||||
}
|
||||
};
|
||||
|
||||
if (
|
||||
typeof module !== "undefined" &&
|
||||
global.require &&
|
||||
global.require.main === module &&
|
||||
global.process &&
|
||||
global.process.versions &&
|
||||
!global.process.versions.electron
|
||||
) {
|
||||
if (process.argv.length < 3) {
|
||||
console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
|
||||
process.exit(1);
|
||||
}
|
||||
|
||||
const go = new Go();
|
||||
go.argv = process.argv.slice(2);
|
||||
go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
|
||||
go.exit = process.exit;
|
||||
WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject)
|
||||
.then((result) => {
|
||||
process.on("exit", (code) => {
|
||||
// Node.js exits if no event handler is pending
|
||||
if (code === 0 && !go.exited) {
|
||||
// deadlock, make Go print error and stack traces
|
||||
go._pendingEvent = { id: 0 };
|
||||
go._resume();
|
||||
}
|
||||
});
|
||||
return go.run(result.instance);
|
||||
})
|
||||
.catch((err) => {
|
||||
console.error(err);
|
||||
process.exit(1);
|
||||
});
|
||||
}
|
||||
})();
|
||||
61
client/public/worker.js
Normal file
61
client/public/worker.js
Normal file
@ -0,0 +1,61 @@
|
||||
importScripts("./wasm_exec.js");
|
||||
|
||||
if (!WebAssembly.instantiateStreaming) {
|
||||
WebAssembly.instantiateStreaming = async (resp, importObject) => {
|
||||
const source = await (await resp).arrayBuffer();
|
||||
return await WebAssembly.instantiate(source, importObject);
|
||||
};
|
||||
}
|
||||
|
||||
// Create promise to handle Worker calls whilst
|
||||
// module is still initialising
|
||||
let wasmResolve;
|
||||
const wasmReady = new Promise((resolve) => {
|
||||
wasmResolve = resolve;
|
||||
});
|
||||
|
||||
const go = new self.Go();
|
||||
|
||||
addEventListener(
|
||||
"message",
|
||||
async (e) => {
|
||||
const { eventType, eventData, eventId } = e.data;
|
||||
|
||||
if (eventType === "INITIALISE") {
|
||||
const instantiatedSource = await WebAssembly.instantiateStreaming(
|
||||
fetch(eventData),
|
||||
go.importObject
|
||||
);
|
||||
go.run(instantiatedSource.instance);
|
||||
|
||||
// Go does nor exposes the exports in the instantiated module :(((
|
||||
const methods = ["DitherNord"];
|
||||
wasmResolve(methods);
|
||||
postMessage({
|
||||
eventType: "INITIALISED",
|
||||
eventData: methods,
|
||||
});
|
||||
} else if (eventType === "CALL") {
|
||||
await wasmReady;
|
||||
try {
|
||||
const method = self[eventData.method];
|
||||
const result = await method.apply(null, eventData.arguments);
|
||||
self.postMessage({
|
||||
eventType: "RESULT",
|
||||
eventData: result,
|
||||
eventId: eventId,
|
||||
});
|
||||
} catch (e) {
|
||||
console.error(e);
|
||||
self.postMessage({
|
||||
eventType: "ERROR",
|
||||
eventData:
|
||||
"An error occured executing WASM instance function: " +
|
||||
error.toString(),
|
||||
eventId: eventId,
|
||||
});
|
||||
}
|
||||
}
|
||||
},
|
||||
false
|
||||
);
|
||||
@ -1,41 +1,10 @@
|
||||
@media (prefers-color-scheme: dark) {
|
||||
body {
|
||||
color: #fff;
|
||||
background: #000;
|
||||
}
|
||||
a:link {
|
||||
color: #9cf;
|
||||
}
|
||||
a:hover,
|
||||
a:visited:hover {
|
||||
color: #cef;
|
||||
}
|
||||
a:visited {
|
||||
color: #c9f;
|
||||
}
|
||||
}
|
||||
body {
|
||||
margin: 1em auto;
|
||||
max-width: 40em;
|
||||
padding: 0 0.62em;
|
||||
font: 1.2em/1.62 sans-serif;
|
||||
}
|
||||
h1,
|
||||
h2,
|
||||
h3 {
|
||||
line-height: 1.2;
|
||||
}
|
||||
.container {
|
||||
display: flex;
|
||||
flex-direction: column;
|
||||
justify-content: center;
|
||||
}
|
||||
#output {
|
||||
max-width: 100%;
|
||||
align-self: center;
|
||||
}
|
||||
@media print {
|
||||
body {
|
||||
max-width: none;
|
||||
}
|
||||
image-rendering: optimizeSpeed; /* Legal fallback */
|
||||
image-rendering: -moz-crisp-edges; /* Firefox */
|
||||
image-rendering: -o-crisp-edges; /* Opera */
|
||||
image-rendering: -webkit-optimize-contrast; /* Safari */
|
||||
image-rendering: optimize-contrast; /* CSS3 Proposed */
|
||||
image-rendering: crisp-edges; /* CSS4 Proposed */
|
||||
image-rendering: pixelated; /* CSS4 Proposed */
|
||||
-ms-interpolation-mode: nearest-neighbor; /* IE8+ */
|
||||
}
|
||||
|
||||
@ -1,43 +1,117 @@
|
||||
import React from 'react';
|
||||
import './App.css';
|
||||
import React, { useEffect } from "react";
|
||||
import "./App.css";
|
||||
|
||||
function App() {
|
||||
const [imageSrc, setImageSrc] = React.useState("");
|
||||
const [displayOutput, setDisplayOutput] = React.useState(false);
|
||||
const fileInput = React.useRef<HTMLInputElement>(null);
|
||||
|
||||
const handleClick = async () => {
|
||||
if (!fileInput.current) {
|
||||
return;
|
||||
}
|
||||
const workerProxy: any = await wasmWorker("main.wasm");
|
||||
|
||||
setDisplayOutput(false);
|
||||
setImageSrc("");
|
||||
|
||||
// Check if a file was selected
|
||||
if (fileInput.current.files!.length === 0) {
|
||||
alert("No file selected");
|
||||
return;
|
||||
}
|
||||
const reader = new FileReader();
|
||||
reader.readAsArrayBuffer(fileInput.current.files![0]);
|
||||
reader.onloadend = async (evt) => {
|
||||
if (evt.target!.readyState === FileReader.DONE) {
|
||||
const imageData = new Uint8Array(evt.target!.result as ArrayBuffer);
|
||||
const ditheredImage = await workerProxy.DitherNord(imageData);
|
||||
const outputValue = `data:image/png;base64,${ditheredImage}`;
|
||||
setImageSrc(outputValue);
|
||||
setDisplayOutput(true);
|
||||
}
|
||||
};
|
||||
};
|
||||
|
||||
return (
|
||||
<article>
|
||||
<h1>Go+Wasm image dithering tool</h1>
|
||||
<aside>Featuring the Nord Color Palette</aside>
|
||||
<p>
|
||||
Load an image, click Go and wait (potentially for a while) for the image
|
||||
to be dithered using the Nord color palette and the Floyd-Steinberg
|
||||
algorithm.
|
||||
</p>
|
||||
<p>
|
||||
Running in the browser with Wasm causes a bit of a performance penalty.
|
||||
Multithreading is not available (not that it matters much since
|
||||
Floyd-Steinberg is single-threaded), and sending data back and forth
|
||||
between JS and Wasm can take a little while.
|
||||
</p>
|
||||
<p>
|
||||
I've re-used code from
|
||||
<a
|
||||
href="https://www.sitepen.com/blog/using-webassembly-with-web-workers"
|
||||
>this article</a
|
||||
>
|
||||
to make the Wasm code run in a web worker, with some adaptations for Go
|
||||
oddities.
|
||||
</p>
|
||||
<p>
|
||||
If you're into that sort of thing, source code is available on
|
||||
<a href="https://github.com/CrispyBaguette/wasm-palette-converter"
|
||||
>GitHub</a
|
||||
>.
|
||||
</p>
|
||||
<form>
|
||||
<input type="file" id="source-image" accept="image/png, image/jpeg" />
|
||||
<button id="go-btn" type="button" disabled>Go</button>
|
||||
</form>
|
||||
</article>
|
||||
<div className="App">
|
||||
<input
|
||||
type="file"
|
||||
id="source-image"
|
||||
ref={fileInput}
|
||||
accept="image/png, image/jpeg"
|
||||
/>
|
||||
<button id="go-btn" type="button" onClick={handleClick}>
|
||||
Go
|
||||
</button>
|
||||
<a id="output-wrapper" download="output.png" href={imageSrc}>
|
||||
<div className="container">
|
||||
<img
|
||||
id="output"
|
||||
alt="dithering output"
|
||||
src={imageSrc}
|
||||
style={{ display: displayOutput ? "block" : "none" }}
|
||||
/>
|
||||
</div>
|
||||
</a>
|
||||
</div>
|
||||
);
|
||||
}
|
||||
|
||||
function wasmWorker(modulePath: string) {
|
||||
// Create an object to later interact with
|
||||
const proxy: any = {};
|
||||
|
||||
// Keep track of the messages being sent
|
||||
// so we can resolve them correctly
|
||||
let id = 0;
|
||||
let idPromises: any = {};
|
||||
|
||||
return new Promise((resolve, reject) => {
|
||||
const worker = new Worker("./worker.js");
|
||||
worker.postMessage({ eventType: "INITIALISE", eventData: modulePath });
|
||||
worker.addEventListener("message", function (event: any) {
|
||||
const { eventType, eventData, eventId } = event.data;
|
||||
|
||||
if (eventType === "INITIALISED") {
|
||||
const methods = event.data.eventData;
|
||||
|
||||
methods.forEach((method: any) => {
|
||||
proxy[method] = (...args: any[]) => {
|
||||
return new Promise((resolve, reject) => {
|
||||
worker.postMessage({
|
||||
eventType: "CALL",
|
||||
eventData: {
|
||||
method: method,
|
||||
arguments: Array.from(args),
|
||||
},
|
||||
eventId: id,
|
||||
});
|
||||
|
||||
idPromises[id] = { resolve, reject };
|
||||
id++;
|
||||
});
|
||||
};
|
||||
});
|
||||
resolve(proxy);
|
||||
return;
|
||||
} else if (eventType === "RESULT") {
|
||||
if (eventId !== undefined && idPromises[eventId]) {
|
||||
idPromises[eventId].resolve(eventData);
|
||||
delete idPromises[eventId];
|
||||
}
|
||||
} else if (eventType === "ERROR") {
|
||||
if (eventId !== undefined && idPromises[eventId]) {
|
||||
idPromises[eventId].reject(event.data.eventData);
|
||||
delete idPromises[eventId];
|
||||
}
|
||||
}
|
||||
});
|
||||
|
||||
worker.addEventListener("error", function (error: any) {
|
||||
reject(error);
|
||||
});
|
||||
});
|
||||
}
|
||||
|
||||
export default App;
|
||||
|
||||
@ -1,13 +1,41 @@
|
||||
@media (prefers-color-scheme: dark) {
|
||||
body {
|
||||
color: #fff;
|
||||
background: #000;
|
||||
}
|
||||
a:link {
|
||||
color: #9cf;
|
||||
}
|
||||
a:hover,
|
||||
a:visited:hover {
|
||||
color: #cef;
|
||||
}
|
||||
a:visited {
|
||||
color: #c9f;
|
||||
}
|
||||
}
|
||||
body {
|
||||
margin: 0;
|
||||
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
|
||||
'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
|
||||
sans-serif;
|
||||
-webkit-font-smoothing: antialiased;
|
||||
-moz-osx-font-smoothing: grayscale;
|
||||
margin: 1em auto;
|
||||
max-width: 40em;
|
||||
padding: 0 0.62em;
|
||||
font: 1.2em/1.62 sans-serif;
|
||||
}
|
||||
|
||||
code {
|
||||
font-family: source-code-pro, Menlo, Monaco, Consolas, 'Courier New',
|
||||
monospace;
|
||||
h1,
|
||||
h2,
|
||||
h3 {
|
||||
line-height: 1.2;
|
||||
}
|
||||
.container {
|
||||
display: flex;
|
||||
flex-direction: column;
|
||||
justify-content: center;
|
||||
}
|
||||
#output {
|
||||
max-width: 100%;
|
||||
align-self: center;
|
||||
}
|
||||
@media print {
|
||||
body {
|
||||
max-width: none;
|
||||
}
|
||||
}
|
||||
|
||||
BIN
dist/main.wasm
vendored
BIN
dist/main.wasm
vendored
Binary file not shown.
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Reference in New Issue
Block a user