datalowe
commented
8 months ago Hi, thanks for putting together the project/examples :) I don't know how active this project is, but in case it's helpful for anyone else then here's a quick emscripten version of the "linear memory" example for Rust.
// linmem.cpp
#include <iostream>
const int WASM_MEMORY_BUFFER_SIZE {2};
uint8_t buffer[WASM_MEMORY_BUFFER_SIZE] {0};
extern "C" {
void put_buffer_index_zero(uint8_t val) {
buffer[0] = val;
}
uint8_t* get_buffer_ptr() {
return buffer;
}
uint8_t get_buffer_index_one() {
return buffer[1];
}
}// use_wasm.js
(async () => {
const resp = await fetch("linmem.wasm");
const fileBuf = await resp.arrayBuffer();
const linMemModule = await WebAssembly.instantiate(fileBuf);
const {
memory,
put_buffer_index_zero,
get_buffer_ptr,
get_buffer_index_one,
} = linMemModule.instance.exports;
const p1 = document.createElement("p");
p1.appendChild(
document.createTextNode(
`Initial value at buffer index 1: ${get_buffer_index_one()}`
)
);
document.body.appendChild(p1);
const ptr = get_buffer_ptr();
const memBuffer = new Uint8Array(memory.buffer);
put_buffer_index_zero(200);
const p2 = document.createElement("p");
p2.appendChild(
document.createTextNode(
`Inserted value at buffer index 0: ${memBuffer[ptr + 0]}`
)
);
document.body.appendChild(p2);
memBuffer[ptr + 1] = 15;
const p3 = document.createElement("p");
p3.appendChild(
document.createTextNode(
`Directly updated value at buffer index 1: ${get_buffer_index_one()}`
)
);
document.body.appendChild(p3);
})();<!-- index.html -->
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Linear Memory - Emscripten</title>
<script type="module" src="./use_wasm.js"></script>
</head>
<body></body>
</html>emcc -O3 -s STANDALONE_WASM -s EXPORTED_FUNCTIONS="['_put_buffer_index_zero', '_get_buffer_ptr', '_get_buffer_index_one']" -Wl,--no-entry linmem.cpp -o "linmem.wasm"
# serving files in the current dir with Python, but any other HTTP server will do
python -m http.server --bind 127.0.0.1 8080
Was going to do this in the MVP. But honestly, I know nothing about Emscripten :joy:
Thus, I think I will go ahead, launch, and get the hype going, and then teach myself emscripten to make the demos :+1: