1 const canvas = document.querySelector('canvas')
4 const width = canvas.width, height = canvas.height
5 canvas.style.width = width + 'px'
6 canvas.style.height = height + 'px'
7 canvas.width = width * window.devicePixelRatio
8 canvas.height = height * window.devicePixelRatio
10 const gl = canvas.getContext('webgl')
12 const shaderMap = new Map()
13 var currentShaderId = 0
14 function createShaderId() {
15 const id = currentShaderId
20 const programMap = new Map()
21 var currentProgramId = 0
22 function createProgramId() {
23 const id = currentProgramId
28 const bufferMap = new Map()
29 var currentBufferId = 0
30 function createBufferId() {
31 const id = currentBufferId
38 var decoder = new TextDecoder('utf-8')
40 function getUint32(addr) {
41 const view = new DataView(memory.buffer)
42 return view.getUint32(addr, true)
45 function setUint32(addr, val) {
46 const view = new DataView(memory.buffer)
47 view.setUint32(addr, val, true)
50 function getString(addr) {
51 const view = new DataView(memory.buffer)
53 while (view.getUint8(addr + len) != 0) len++
54 return decoder.decode(memory.buffer.slice(addr, addr + len))
59 glCreateShader: shaderType => {
60 const id = createShaderId()
61 const shader = gl.createShader(shaderType)
62 shaderMap.set(id, shader)
65 glShaderSource: (id, numSrcs, srcs, lens) => {
66 const shader = shaderMap.get(id)
68 for (let i = 0; i < numSrcs; i++) {
69 const addr = srcs + i * 4
70 const src = getUint32(addr)
71 const len = getUint32(lens + i * 4)
72 totalSource += decoder.decode(memory.buffer.slice(src, src + len))
74 gl.shaderSource(shader, totalSource)
76 glCompileShader: id => gl.compileShader(shaderMap.get(id)),
77 glCreateProgram: () => {
78 const id = createProgramId()
79 const prog = gl.createProgram()
80 programMap.set(id, prog)
83 glAttachShader: (progId, shaderId) => {
84 gl.attachShader(programMap.get(progId), shaderMap.get(shaderId))
86 glLinkProgram: (progId) => gl.linkProgram(programMap.get(progId)),
87 glUseProgram: (progId) => gl.useProgram(programMap.get(progId)),
88 glGetAttribLocation: (progId, name) => {
89 const prog = programMap.get(progId)
90 return gl.getAttribLocation(prog, getString(name))
92 glEnableVertexAttribArray: (loc) => gl.enableVertexAttribArray(loc),
93 glVertexAttribPointer: (loc, size, type, normalized, stride, offset) => {
94 gl.vertexAttribPointer(loc, size, type, normalized, stride, offset)
96 glGenBuffers: (num, addr) => {
97 for (let i = 0; i < num; i++) {
98 const id = createBufferId()
99 const buffer = gl.createBuffer()
100 bufferMap.set(id, buffer)
101 setUint32(addr + i * 4, id)
104 glBindBuffer: (target, bufferId) => gl.bindBuffer(target, bufferMap.get(bufferId)),
105 glBufferData: (target, size, addr, usage) => {
106 const data = new Float32Array(memory.buffer.slice(addr, addr + size * 4))
107 gl.bufferData(target, data, usage)
112 const sock = new WebSocket('ws://localhost:8889')
113 sock.onmessage = function (e) {
117 function instantiate(bytes) {
118 return WebAssembly.compile(bytes).
120 const inst = new WebAssembly.Instance(m, imports)
121 memory = inst.exports.memory
127 .then(response => response.arrayBuffer())
128 .then(bytes => instantiate(bytes))
130 instance.exports.setup()
131 gl.drawArrays(gl.TRIANGLES, 0, 3)