Build hello_world.c using
emcc hello_world.c -Os -s WASM=1 -s SIDE_MODULE=1 -o hello_world.wasmCommand creates a WebAssembly dynamic library hello_world.wasm. You can then run hello_world.html in your browser.
Last active
January 6, 2022 12:02
-
-
Save jessenich/fbfb8f2e57119fc6cfc0fe40f0dc49c5 to your computer and use it in GitHub Desktop.
Standalone WebAssembly Example
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| int doubler(int x) { | |
| return 2 * x; | |
| } |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <html> | |
| <head> | |
| <script> | |
| // Check for wasm support. | |
| if (!('WebAssembly' in window)) { | |
| alert('you need a browser with wasm support enabled :('); | |
| } | |
| // Loads a WebAssembly dynamic library, returns a promise. | |
| // imports is an optional imports object | |
| function loadWebAssembly(filename, imports) { | |
| // Fetch the file and compile it | |
| return fetch(filename) | |
| .then(response => response.arrayBuffer()) | |
| .then(buffer => WebAssembly.compile(buffer)) | |
| .then(module => { | |
| // Create the imports for the module, including the | |
| // standard dynamic library imports | |
| imports = imports || {}; | |
| imports.env = imports.env || {}; | |
| imports.env.memoryBase = imports.env.memoryBase || 0; | |
| imports.env.tableBase = imports.env.tableBase || 0; | |
| if (!imports.env.memory) { | |
| imports.env.memory = new WebAssembly.Memory({ initial: 256 }); | |
| } | |
| if (!imports.env.table) { | |
| imports.env.table = new WebAssembly.Table({ initial: 0, element: 'anyfunc' }); | |
| } | |
| // Create the instance. | |
| return new WebAssembly.Instance(module, imports); | |
| }); | |
| } | |
| // Main part of this example, loads the module and uses it. | |
| loadWebAssembly('hello_world.wasm') | |
| .then(instance => { | |
| var exports = instance.exports; // the exports of that instance | |
| var doubler = exports._doubler; // the "doubler" function (note "_" prefix) | |
| // now we are ready, set up the button so the user can run the code | |
| var button = document.getElementById('run'); | |
| button.value = 'Call a method in the WebAssembly module'; | |
| button.addEventListener('click', function() { | |
| var input = 21; | |
| alert(input + ' doubled is ' + doubler(input)); | |
| }, false); | |
| } | |
| ) | |
| </script> | |
| </head> | |
| <body> | |
| <input type="button" id="run" value="(waiting for WebAssembly)"/> | |
| </body> | |
| </html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment