1 files changed, 154 insertions, 0 deletions
diff --git a/client/faceSearch/upload.js b/client/faceSearch/upload.js
new file mode 100644
index 00000000..f18bdce6
--- /dev/null
+++ b/client/faceSearch/upload.js
@@ -0,0 +1,154 @@
+const MAX_SIDE = 300
+
+function render(img){
+  var resized = renderToCanvas(img, { correctOrientation: true })
+  var canvas = document.createElement('canvas') // document.querySelector('#user_photo_canvas')
+  ctx = canvas.getContext('2d')
+  ctx.fillStyle = 'black'
+  ctx.fillRect(0, 0, MAX_SIDE, MAX_SIDE)
+  var x_offset = (MAX_SIDE - resized.width) / 2
+  var y_offset = (MAX_SIDE - resized.height) / 2
+  ctx.drawImage(resized, x_offset, y_offset)
+  return canvas
+}
+function renderToCanvas(img, options) {
+  if (!img) return
+  options = options || {}
+
+  // Canvas max size for any side
+  var maxSize = MAX_SIDE
+  var canvas = document.createElement('canvas')
+  var ctx = canvas.getContext('2d')
+  var initialScale = options.scale || 1
+  // Scale to needed to constrain canvas to max size
+  var scale = getScale(img.width * initialScale, img.height * initialScale, maxSize, maxSize, true)
+  // Still need to apply the user defined scale
+  scale *= initialScale
+  var width = canvas.width = Math.round(img.width * scale)
+  var height = canvas.height = Math.round(img.height * scale)
+  var correctOrientation = options.correctOrientation
+  var jpeg = !!img.src.match(/data:image\/jpeg|\.jpeg$|\.jpg$/i)
+  var hasDataURI = !!img.src.match(/^data:/)
+
+  ctx.save()
+
+  // Can only correct orientation on JPEGs represented as dataURIs
+  // for the time being
+  if (correctOrientation && jpeg && hasDataURI) {
+    applyOrientationCorrection(canvas, ctx, img.src)
+  }
+  // Resize image if too large
+  if (scale !== 1) {
+    ctx.scale(scale, scale)
+  }
+
+  ctx.drawImage(img, 0, 0)
+  ctx.restore()
+
+  return canvas
+}
+
+function getScale(width, height, viewportWidth, viewportHeight, fillViewport) {
+  fillViewport = !!fillViewport
+  var landscape = (width / height) > (viewportWidth / viewportHeight)
+  if (landscape) {
+    if (fillViewport) {
+      return fitVertical()
+    } else if (width > viewportWidth) {
+      return fitHorizontal()
+    }
+  } else {
+    if (fillViewport) {
+      return fitHorizontal()
+    } else if (height > viewportHeight) {
+      return fitVertical()
+    }
+  }
+  return 1
+
+  function fitHorizontal() {
+    return viewportWidth / width
+  }
+
+  function fitVertical() {
+    return viewportHeight / height
+  }
+}
+
+function applyOrientationCorrection(canvas, ctx, uri) {
+  var orientation = getOrientation(uri)
+  // Only apply transform if there is some non-normal orientation
+  if (orientation && orientation !== 1) {
+    var transform = orientationToTransform[orientation]
+    var rotation = transform.rotation
+    var mirror = transform.mirror
+    var flipAspect = rotation === 90 || rotation === 270
+    if (flipAspect) {
+      // Fancy schmancy swap algo
+      canvas.width = canvas.height + canvas.width
+      canvas.height = canvas.width - canvas.height
+      canvas.width -= canvas.height
+    }
+    if (rotation > 0) {
+      applyRotation(canvas, ctx, rotation)
+    }
+  }
+}
+
+function applyRotation(canvas, ctx, deg) {
+  var radians = deg * (Math.PI / 180)
+  if (deg === 90) {
+    ctx.translate(canvas.width, 0)
+  } else if (deg === 180) {
+    ctx.translate(canvas.width, canvas.height)
+  } else if (deg == 270) {
+    ctx.translate(0, canvas.height)
+  }
+  ctx.rotate(radians)
+}
+
+function getOrientation (uri) {
+  var exif = new ExifReader
+  // Split off the base64 data
+  var base64String = uri.split(',')[1]
+  // Read off first 128KB, which is all we need to
+  // get the EXIF data
+  var arr = base64ToUint8Array(base64String, 0, Math.pow(2, 17))
+  try {
+    exif.load(arr.buffer)
+    return exif.getTagValue('Orientation')
+  } catch (err) {
+    return 1
+  }
+}
+
+function base64ToUint8Array(string, start, finish) {
+  var start = start || 0
+  var finish = finish || string.length
+  // atob that shit
+  var binary = atob(string)
+  var buffer = new Uint8Array(binary.length)
+  for (var i = start; i < finish; i++) {
+    buffer[i] = binary.charCodeAt(i)
+  }
+  return buffer
+}
+
+/**
+ * Mapping from EXIF orientation values to data
+ * regarding the rotation and mirroring necessary to
+ * render the canvas correctly
+ * Derived from:
+ * http://www.daveperrett.com/articles/2012/07/28/exif-orientation-handling-is-a-ghetto/
+ */
+var orientationToTransform = {
+  1: { rotation: 0, mirror: false },
+  2: { rotation: 0, mirror: true },
+  3: { rotation: 180, mirror: false },
+  4: { rotation: 180, mirror: true },
+  5: { rotation: 90, mirror: true },
+  6: { rotation: 90, mirror: false },
+  7: { rotation: 270, mirror: true },
+  8: { rotation: 270, mirror: false }
+}
+