1 files changed, 139 insertions, 0 deletions
diff --git a/app/client/audio/lib/_draw.js b/app/client/audio/lib/_draw.js
new file mode 100644
index 0000000..974fa62
--- /dev/null
+++ b/app/client/audio/lib/_draw.js
@@ -0,0 +1,139 @@
+import {
+  browser, requestAudioContext,
+  randint, randrange, clamp, mod,
+} from './lib/util'
+
+import './lib/vendor/hidpi-canvas'
+
+import mouse from './lib/mouse'
+import color from './lib/color'
+
+let w, h
+let rx, ry
+
+const pixels_per_second = 512 // 1024
+
+const canvas = document.createElement('canvas')
+// document.body.appendChild(canvas)
+// document.body.addEventListener('resize', resize)
+resize()
+recenter()
+requestAnimationFrame(animate)
+
+// must request context after resizing
+const ctx = canvas.getContext('2d')
+
+const scratch = document.createElement('canvas')
+const scratchCtx = scratch.getContext('2d-lodpi')
+
+function resize(ww, hh){
+  w = canvas.width = ww || window.innerWidth
+  h = canvas.height = hh || window.innerHeight
+  canvas.style.width = w + 'px'
+  canvas.style.height = h + 'px'
+}
+function recenter(){
+  rx = randint(w), ry = randint(h)
+}
+let frame = null
+function onFrame(fn){
+  frame = fn
+}
+function animate(t){
+  requestAnimationFrame(animate)
+  if (frame) {
+    frame(t)
+    frame = null
+  }
+  // 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 || 0.9) + ')'
+  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.color((px+py)/(w+h), 0, 1, 0.2)
+  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 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()
+}
+
+export default {
+  canvas, ctx, onFrame, resize,
+  triangle, clear, line, dot,
+  waveform, spectrum, raw_spectrum,
+}
+\ No newline at end of file