Move JpegStream and JpxStream to their own files

src/core/jpx_stream.js

@@ -0,0 +1,92 @@
+/* Copyright 2012 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { DecodeStream } from './stream';
+import { JpxImage } from './jpx';
+import { shadow } from '../shared/util';
+
+/**
+ * For JPEG 2000's we use a library to decode these images and
+ * the stream behaves like all the other DecodeStreams.
+ */
+var JpxStream = (function JpxStreamClosure() {
+  function JpxStream(stream, maybeLength, dict, params) {
+    this.stream = stream;
+    this.maybeLength = maybeLength;
+    this.dict = dict;
+    this.params = params;
+
+    DecodeStream.call(this, maybeLength);
+  }
+
+  JpxStream.prototype = Object.create(DecodeStream.prototype);
+
+  Object.defineProperty(JpxStream.prototype, 'bytes', {
+    get: function JpxStream_bytes() {
+      // If this.maybeLength is null, we'll get the entire stream.
+      return shadow(this, 'bytes', this.stream.getBytes(this.maybeLength));
+    },
+    configurable: true,
+  });
+
+  JpxStream.prototype.ensureBuffer = function JpxStream_ensureBuffer(req) {
+    if (this.bufferLength) {
+      return;
+    }
+
+    var jpxImage = new JpxImage();
+    jpxImage.parse(this.bytes);
+
+    var width = jpxImage.width;
+    var height = jpxImage.height;
+    var componentsCount = jpxImage.componentsCount;
+    var tileCount = jpxImage.tiles.length;
+    if (tileCount === 1) {
+      this.buffer = jpxImage.tiles[0].items;
+    } else {
+      var data = new Uint8ClampedArray(width * height * componentsCount);
+
+      for (var k = 0; k < tileCount; k++) {
+        var tileComponents = jpxImage.tiles[k];
+        var tileWidth = tileComponents.width;
+        var tileHeight = tileComponents.height;
+        var tileLeft = tileComponents.left;
+        var tileTop = tileComponents.top;
+
+        var src = tileComponents.items;
+        var srcPosition = 0;
+        var dataPosition = (width * tileTop + tileLeft) * componentsCount;
+        var imgRowSize = width * componentsCount;
+        var tileRowSize = tileWidth * componentsCount;
+
+        for (var j = 0; j < tileHeight; j++) {
+          var rowBytes = src.subarray(srcPosition, srcPosition + tileRowSize);
+          data.set(rowBytes, dataPosition);
+          srcPosition += tileRowSize;
+          dataPosition += imgRowSize;
+        }
+      }
+      this.buffer = data;
+    }
+    this.bufferLength = this.buffer.length;
+    this.eof = true;
+  };
+
+  return JpxStream;
+})();
+
+export {
+  JpxStream,
+};