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import {
browser, requestAudioContext,
randint, randrange, clamp,
} from './lib/util'
import mouse from './lib/mouse'
import color from './lib/color'
let w, h
let rx, ry
const canvas = document.createElement('canvas')
const ctx = canvas.getContext('2d')
document.body.appendChild(canvas)
document.body.addEventListener('resize', resize)
resize()
recenter()
requestAnimationFrame(animate)
function resize(){
w = canvas.width = window.innerWidth
h = canvas.height = window.innerHeight
clear()
}
function recenter(){
rx = randint(w), ry = randint(h)
}
function animate(t){
requestAnimationFrame(animate)
ctx.save()
ctx.globalAlpha = 0.0001
ctx.translate(w/2, h/2)
ctx.rotate(0.1)
ctx.translate(-rx, -ry)
ctx.drawImage(canvas, 0, 0)
ctx.restore()
}
function clear(n, x, y, ww, hh){
ctx.fillStyle = 'rgba(255,255,255,' + (n || 0.5) + ')'
ctx.fillRect(x || 0, y || 0, ww || w, hh || h)
recenter()
}
function triangle(px,py,r){
setTimeout( () => tri(px,py,r), Math.random()*10)
// setTimeout( () => tri(px,py,r), Math.random()*200)
// setTimeout( () => tri(px,py,r), Math.random()*300)
}
function tri(px, py, r) {
ctx.save()
ctx.globalCompositeOperation = 'multiply'
ctx.fillStyle = color((px+py)/(w+h), 0, 1, 1)
function p(){
let theta = randrange(0, Math.PI*2)
let x = px + Math.cos(theta) * r
let y = py + Math.sin(theta) * r
return { x, y }
}
ctx.beginPath()
const p0 = p(), p1 = p(), p2 = p()
ctx.moveTo(p0.x, p0.y)
ctx.lineTo(p1.x, p1.y)
ctx.lineTo(p2.x, p2.y)
ctx.lineTo(p0.x, p0.y)
ctx.fill()
ctx.restore()
}
function line(y){
ctx.beginPath()
ctx.moveTo(0, y)
ctx.lineTo(w, y)
ctx.strokeStyle = "#888"
ctx.strokeWidth = 1
ctx.stroke()
}
function dot(x, y, r){
ctx.fillStyle = "#f00"
ctx.beginPath()
ctx.moveTo(x, y)
ctx.arc(x, y, r, 0, 2*Math.PI)
ctx.fill()
}
function waveform(pcm, sr, pos, zoom){
sr = sr || 44100
pos = pos || 0
var width = w
var height = Math.floor(h/4)
var half_height = Math.floor(height/2)
var x0 = 0
var y0 = 20
var ymid = y0 + half_height
var pixels_per_second = 1024
var max_width_in_seconds = width / pixels_per_second
var max_width_in_samples = max_width_in_seconds * sr
var pcm_length = pcm.length
var len = Math.min(pcm_length, max_width_in_samples)
var pcm_step = sr / pixels_per_second
var i
ctx.save()
clear(1, x0, y0, width, height)
line(ymid)
ctx.beginPath()
for (i = 0; i < width; i += 0.5) {
var si = Math.floor(pcm_step * i + pos)
if (si > pcm_length) break
var val = pcm[si] // -1, 1
// ctx.moveTo(x0 + i, ymid)
ctx.lineTo(x0 + i, ymid + val * half_height)
}
ctx.strokeStyle = "rgba(250,20,0,0.9)"
ctx.strokeWidth = 1
ctx.stroke()
ctx.restore()
}
const signalWindows = require('signal-windows').windows
const FFTJS = require('fft.js')
const fft_size = 1024
const fft = new FFTJS(fft_size)
function toSpectrum(pcm){
const ham = signalWindows.construct('ham', fft_size)
const pcm_in = new Array(fft_size)
const pcm_length = pcm.length
const pcm_q_length = Math.ceil(pcm_length / fft_size) * fft_size
let i, j, fft_out, spec = [];
for (i = 0; i < pcm_q_length; i += fft_size/4) {
for (j = 0; j < fft_size; j++) {
pcm_in[j] = pcm[i+j] * ham[j] || 0
}
fft_out = fft.createComplexArray()
fft.realTransform(fft_out, pcm_in)
spec.push(fft_out)
}
return spec
}
function spectrum(pcm, sr){
sr = sr || 44100
const spec = toSpectrum(pcm)
ctx.save()
const scratch = document.createElement('canvas')
scratch.width = spec.length
scratch.height = fft_size
const scratchCtx = scratch.getContext('2d')
var imageData = ctx.createImageData(scratch.width, scratch.height)
var data = imageData.data
let i, j, u, v, _r, _i, col, spec_len = spec.length
for (i = 0; i < spec_len; i++) {
col = spec[i]
for (j = 0; j < fft_size; j++) {
u = (j * spec_len + i) * 4
v = j * 2
_r = col[v]
_i = col[v+1]
// red - real part
data[u] = _r * 127 + 127
// green - imag part
data[u+1] = _i * 127 + 127
// blue - magnitude
data[u+2] = Math.sqrt(Math.pow(_r, 2) + Math.pow(_i, 2)) * 128 + 127
// data[u] = 128
// data[u+1] = 128
data[u+2] = 128
data[u+3] = 255
}
}
scratchCtx.putImageData(imageData, 0, 0)
var pcm_length = pcm.length
var pixels_per_second = 1024
const width = Math.round(pcm_length / sr * pixels_per_second) // ok not really this
const height = Math.floor(h*3/4)
const x0 = 0
const y0 = Math.floor(h/4) + 20
clear(1, x0, y0, w, height)
ctx.drawImage(scratch, x0, y0, width, height)
ctx.restore()
}
export default {
canvas, ctx,
triangle, clear, line, dot,
waveform, spectrum
}
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