1 files changed, 108 insertions, 0 deletions
diff --git a/animism-align/frontend/views/align/components/waveform.component.js b/animism-align/frontend/views/align/components/waveform.component.js
new file mode 100644
index 0000000..d4ff913
--- /dev/null
+++ b/animism-align/frontend/views/align/components/waveform.component.js
@@ -0,0 +1,108 @@
+import React, { Component } from 'react'
+// import { Link } from 'react-router-dom'
+// import { bindActionCreators } from 'redux'
+import { connect } from 'react-redux'
+
+import actions from '../../../actions'
+// import * as uploadActions from './upload.actions'
+
+import { DEFAULT_HEIGHT, WAVEFORM_HEIGHT, ZOOM_STEPS, ZOOM_LABEL_STEPS, ZOOM_TICK_STEPS } from '../constants'
+
+class Waveform extends Component {
+  constructor(props){
+    super(props)
+    this.canvasRef = React.createRef()
+  }
+  componentDidMount() {
+    this.resize()
+    this.draw()
+  }
+  componentDidUpdate() {
+    this.draw()
+  }
+  resize() {
+    const canvas = this.canvasRef.current
+    canvas.width = window.innerWidth
+    canvas.height = DEFAULT_HEIGHT
+  }
+  draw() {
+    const canvas = this.canvasRef.current
+    const ctx = canvas.getContext('2d')
+    const w = window.innerWidth
+    this.clearCanvas(ctx, w)
+    this.drawCurve(ctx, w)
+  }
+  clearCanvas(ctx, w) {  
+    const h = WAVEFORM_HEIGHT
+    ctx.clearRect(0, 0, w, h)
+    ctx.fillStyle = 'rgba(0,0,0,0.5)'
+    ctx.fillRect(0, 0, w, h)
+    ctx.fillStyle = 'rgba(64,128,192,0.5)'
+  }
+  drawCurve(ctx, w) {
+    let { peaks, timeline } = this.props
+    let { start_ts, zoom, duration } = timeline
+
+    // console.log(start_ts)
+    // start_ts *= 10
+
+    let secondsPerPixel = ZOOM_STEPS[zoom] / 10 // 0.1 sec / step
+    let stepsPerPixel = ZOOM_STEPS[zoom] // 0.1 sec / step
+    let indexesPerPixel = stepsPerPixel * 2
+
+    let widthTimeDuration = window.innerWidth * secondsPerPixel // secs per pixel
+
+    let timeMin = start_ts
+    let timeMax = Math.min(start_ts + widthTimeDuration, duration)
+
+    let pixelMin = timeMin / secondsPerPixel
+    let pixelMax = timeMax / secondsPerPixel
+
+    // console.log('wf start_ts', pixelMin)
+
+    let stepMin = Math.floor(pixelMin * 2)
+    let stepMax = Math.floor(pixelMax * 2)
+    let stepWidth = stepMax - stepMin
+
+    let i = 0
+    let step = stepMin
+    let waveformPeak = WAVEFORM_HEIGHT / 2
+    let origin = (1 - peaks[step]) * waveformPeak
+    let y = origin
+    let peak
+
+    ctx.beginPath()
+    ctx.moveTo(0, y)
+    for (i = 0; i < stepWidth; i++) {
+      step = i * indexesPerPixel + stepMin
+      peak = peaks[step]
+      y = (1 - peak) * waveformPeak
+      ctx.lineTo(i, y)
+    }
+    for (i = stepWidth - 1; i > 0; i--) {
+      step = i * indexesPerPixel + stepMin
+      peak = peaks[step]
+      y = (1 + peak) * waveformPeak
+      ctx.lineTo(i, y)
+    }
+    ctx.lineTo(0, origin)
+    ctx.fillStyle = 'rgba(255,255,255,0.8)'
+    ctx.fill()
+  }
+  render() {
+    return (
+      <canvas ref={this.canvasRef} />
+    )
+  }
+}
+
+const mapStateToProps = state => ({
+  timeline: state.align.timeline,
+  peaks: state.site.peaks,
+})
+
+const mapDispatchToProps = dispatch => ({
+  // uploadActions: bindActionCreators({ ...uploadActions }, dispatch),
+})
+
+export default connect(mapStateToProps, mapDispatchToProps)(Waveform)