Convert src/core/jpx.js to use standard classes

*Please note:* Ignoring whitespace-only changes is probably necessary in order to review this.

src/core/jpx.js

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { BaseException, info, warn } from "../shared/util.js";
+import { BaseException, info, unreachable, warn } from "../shared/util.js";
 import { log2, readUint16, readUint32 } from "./core_utils.js";
 import { ArithmeticDecoder } from "./arithmetic_decoder.js";
 
@@ -23,7 +23,6 @@ class JpxError extends BaseException {
   }
 }
 
-const JpxImage = (function JpxImageClosure() {
 // Table E.1
 const SubbandsGainLog2 = {
   LL: 0,
@@ -32,12 +31,12 @@ const JpxImage = (function JpxImageClosure() {
   HH: 2,
 };
 
-  // eslint-disable-next-line no-shadow
+class JpxImage {
-  function JpxImage() {
+  constructor() {
     this.failOnCorruptedImage = false;
   }
-  JpxImage.prototype = {
+
-    parse: function JpxImage_parse(data) {
+  parse(data) {
     const head = readUint16(data, 0);
     // No box header, immediate start of codestream (SOC)
     if (head === 0xff4f) {
@@ -114,15 +113,16 @@ const JpxImage = (function JpxImageClosure() {
             (tbox >> 8) & 0xff,
             tbox & 0xff
           );
-            warn("Unsupported header type " + tbox + " (" + headerType + ")");
+          warn(`Unsupported header type ${tbox} (${headerType}).`);
           break;
       }
       if (jumpDataLength) {
         position += dataLength;
       }
     }
-    },
+  }
-    parseImageProperties: function JpxImage_parseImageProperties(stream) {
+
+  parseImageProperties(stream) {
     let newByte = stream.getByte();
     while (newByte >= 0) {
       const oldByte = newByte;
@@ -146,8 +146,9 @@ const JpxImage = (function JpxImageClosure() {
       }
     }
     throw new JpxError("No size marker found in JPX stream");
-    },
+  }
-    parseCodestream: function JpxImage_parseCodestream(data, start, end) {
+
+  parseCodestream(data, start, end) {
     const context = {};
     let doNotRecover = false;
     try {
@@ -350,9 +351,7 @@ const JpxImage = (function JpxImageClosure() {
             }
             if (unsupported.length > 0) {
               doNotRecover = true;
-                warn(
+              warn(`JPX: Unsupported COD options (${unsupported.join(", ")}).`);
-                  `JPX: Unsupported COD options (${unsupported.join(", ")}).`
-                );
             }
             if (context.mainHeader) {
               context.COD = cod;
@@ -417,8 +416,9 @@ const JpxImage = (function JpxImageClosure() {
     this.width = context.SIZ.Xsiz - context.SIZ.XOsiz;
     this.height = context.SIZ.Ysiz - context.SIZ.YOsiz;
     this.componentsCount = context.SIZ.Csiz;
-    },
+  }
-  };
+}
+
 function calculateComponentDimensions(component, siz) {
   // Section B.2 Component mapping
   component.x0 = Math.ceil(siz.XOsiz / component.XRsiz);
@@ -507,8 +507,7 @@ const JpxImage = (function JpxImageClosure() {
   // coordinates of a point in the LL band and child subband, respectively.
   const isZeroRes = resolution.resLevel === 0;
   const precinctWidthInSubband = 1 << (dimensions.PPx + (isZeroRes ? 0 : -1));
-    const precinctHeightInSubband =
+  const precinctHeightInSubband = 1 << (dimensions.PPy + (isZeroRes ? 0 : -1));
-      1 << (dimensions.PPy + (isZeroRes ? 0 : -1));
   const numprecinctswide =
     resolution.trx1 > resolution.trx0
       ? Math.ceil(resolution.trx1 / precinctWidth) -
@@ -1584,9 +1583,8 @@ const JpxImage = (function JpxImageClosure() {
 }
 
 // Section B.10.2 Tag trees
-  const TagTree = (function TagTreeClosure() {
+class TagTree {
-    // eslint-disable-next-line no-shadow
+  constructor(width, height) {
-    function TagTree(width, height) {
     const levelsLength = log2(Math.max(width, height)) + 1;
     this.levels = [];
     for (let i = 0; i < levelsLength; i++) {
@@ -1600,8 +1598,8 @@ const JpxImage = (function JpxImageClosure() {
       height = Math.ceil(height / 2);
     }
   }
-    TagTree.prototype = {
+
-      reset: function TagTree_reset(i, j) {
+  reset(i, j) {
     let currentLevel = 0,
       value = 0,
       level;
@@ -1622,12 +1620,14 @@ const JpxImage = (function JpxImageClosure() {
     level.items[level.index] = value;
     this.currentLevel = currentLevel;
     delete this.value;
-      },
+  }
-      incrementValue: function TagTree_incrementValue() {
+
+  incrementValue() {
     const level = this.levels[this.currentLevel];
     level.items[level.index]++;
-      },
+  }
-      nextLevel: function TagTree_nextLevel() {
+
+  nextLevel() {
     let currentLevel = this.currentLevel;
     let level = this.levels[currentLevel];
     const value = level.items[level.index];
@@ -1641,14 +1641,11 @@ const JpxImage = (function JpxImageClosure() {
     level = this.levels[currentLevel];
     level.items[level.index] = value;
     return true;
-      },
+  }
-    };
+}
-    return TagTree;
-  })();
 
-  const InclusionTree = (function InclusionTreeClosure() {
+class InclusionTree {
-    // eslint-disable-next-line no-shadow
+  constructor(width, height, defaultValue) {
-    function InclusionTree(width, height, defaultValue) {
     const levelsLength = log2(Math.max(width, height)) + 1;
     this.levels = [];
     for (let i = 0; i < levelsLength; i++) {
@@ -1668,8 +1665,8 @@ const JpxImage = (function JpxImageClosure() {
       height = Math.ceil(height / 2);
     }
   }
-    InclusionTree.prototype = {
+
-      reset: function InclusionTree_reset(i, j, stopValue) {
+  reset(i, j, stopValue) {
     let currentLevel = 0;
     while (currentLevel < this.levels.length) {
       const level = this.levels[currentLevel];
@@ -1694,13 +1691,15 @@ const JpxImage = (function JpxImageClosure() {
     }
     this.currentLevel = currentLevel - 1;
     return true;
-      },
+  }
-      incrementValue: function InclusionTree_incrementValue(stopValue) {
+
+  incrementValue(stopValue) {
     const level = this.levels[this.currentLevel];
     level.items[level.index] = stopValue + 1;
     this.propagateValues();
-      },
+  }
-      propagateValues: function InclusionTree_propagateValues() {
+
+  propagateValues() {
     let levelIndex = this.currentLevel;
     let level = this.levels[levelIndex];
     const currentValue = level.items[level.index];
@@ -1708,8 +1707,9 @@ const JpxImage = (function JpxImageClosure() {
       level = this.levels[levelIndex];
       level.items[level.index] = currentValue;
     }
-      },
+  }
-      nextLevel: function InclusionTree_nextLevel() {
+
+  nextLevel() {
     let currentLevel = this.currentLevel;
     let level = this.levels[currentLevel];
     const value = level.items[level.index];
@@ -1723,10 +1723,8 @@ const JpxImage = (function JpxImageClosure() {
     level = this.levels[currentLevel];
     level.items[level.index] = value;
     return true;
-      },
+  }
-    };
+}
-    return InclusionTree;
-  })();
 
 // Section D. Coefficient bit modeling
 const BitModel = (function BitModelClosure() {
@@ -1755,7 +1753,8 @@ const JpxImage = (function JpxImageClosure() {
     ]);
 
   // eslint-disable-next-line no-shadow
-    function BitModel(width, height, subband, zeroBitPlanes, mb) {
+  class BitModel {
+    constructor(width, height, subband, zeroBitPlanes, mb) {
       this.width = width;
       this.height = height;
 
@@ -1797,11 +1796,11 @@ const JpxImage = (function JpxImageClosure() {
       this.reset();
     }
 
-    BitModel.prototype = {
+    setDecoder(decoder) {
-      setDecoder: function BitModel_setDecoder(decoder) {
       this.decoder = decoder;
-      },
+    }
-      reset: function BitModel_reset() {
+
+    reset() {
       // We have 17 contexts that are accessed via context labels,
       // plus the uniform and runlength context.
       this.contexts = new Int8Array(19);
@@ -1811,12 +1810,9 @@ const JpxImage = (function JpxImageClosure() {
       this.contexts[0] = (4 << 1) | 0;
       this.contexts[UNIFORM_CONTEXT] = (46 << 1) | 0;
       this.contexts[RUNLENGTH_CONTEXT] = (3 << 1) | 0;
-      },
+    }
-      setNeighborsSignificance: function BitModel_setNeighborsSignificance(
+
-        row,
+    setNeighborsSignificance(row, column, index) {
-        column,
-        index
-      ) {
       const neighborsSignificance = this.neighborsSignificance;
       const width = this.width,
         height = this.height;
@@ -1853,8 +1849,9 @@ const JpxImage = (function JpxImageClosure() {
         neighborsSignificance[index + 1] += 0x01;
       }
       neighborsSignificance[index] |= 0x80;
-      },
+    }
-      runSignificancePropagationPass: function BitModel_runSignificancePropagationPass() {
+
+    runSignificancePropagationPass() {
       const decoder = this.decoder;
       const width = this.width,
         height = this.height;
@@ -1880,10 +1877,7 @@ const JpxImage = (function JpxImageClosure() {
             // clear processed flag first
             processingFlags[index] &= processedInverseMask;
 
-              if (
+            if (coefficentsMagnitude[index] || !neighborsSignificance[index]) {
-                coefficentsMagnitude[index] ||
-                !neighborsSignificance[index]
-              ) {
               continue;
             }
 
@@ -1901,8 +1895,9 @@ const JpxImage = (function JpxImageClosure() {
           }
         }
       }
-      },
+    }
-      decodeSignBit: function BitModel_decodeSignBit(row, column, index) {
+
+    decodeSignBit(row, column, index) {
       const width = this.width,
         height = this.height;
       const coefficentsMagnitude = this.coefficentsMagnitude;
@@ -1953,8 +1948,9 @@ const JpxImage = (function JpxImageClosure() {
         decoded = this.decoder.readBit(this.contexts, contextLabel) ^ 1;
       }
       return decoded;
-      },
+    }
-      runMagnitudeRefinementPass: function BitModel_runMagnitudeRefinementPass() {
+
+    runMagnitudeRefinementPass() {
       const decoder = this.decoder;
       const width = this.width,
         height = this.height;
@@ -1996,8 +1992,9 @@ const JpxImage = (function JpxImageClosure() {
           }
         }
       }
-      },
+    }
-      runCleanupPass: function BitModel_runCleanupPass() {
+
+    runCleanupPass() {
       const decoder = this.decoder;
       const width = this.width,
         height = this.height;
@@ -2090,8 +2087,9 @@ const JpxImage = (function JpxImageClosure() {
           }
         }
       }
-      },
+    }
-      checkSegmentationSymbol: function BitModel_checkSegmentationSymbol() {
+
+    checkSegmentationSymbol() {
       const decoder = this.decoder;
       const contexts = this.contexts;
       const symbol =
@@ -2102,29 +2100,29 @@ const JpxImage = (function JpxImageClosure() {
       if (symbol !== 0xa) {
         throw new JpxError("Invalid segmentation symbol");
       }
-      },
+    }
-    };
+  }
 
   return BitModel;
 })();
 
 // Section F, Discrete wavelet transformation
-  const Transform = (function TransformClosure() {
+class Transform {
-    // eslint-disable-next-line no-shadow
+  constructor() {
-    function Transform() {}
+    if (this.constructor === Transform) {
+      unreachable("Cannot initialize Transform.");
+    }
+  }
 
-    Transform.prototype.calculate = function transformCalculate(
+  calculate(subbands, u0, v0) {
-      subbands,
-      u0,
-      v0
-    ) {
     let ll = subbands[0];
     for (let i = 1, ii = subbands.length; i < ii; i++) {
       ll = this.iterate(ll, subbands[i], u0, v0);
     }
     return ll;
-    };
+  }
-    Transform.prototype.extend = function extend(buffer, offset, size) {
+
+  extend(buffer, offset, size) {
     // Section F.3.7 extending... using max extension of 4
     let i1 = offset - 1,
       j1 = offset + 1;
@@ -2138,13 +2136,13 @@ const JpxImage = (function JpxImageClosure() {
     buffer[j2++] = buffer[i2--];
     buffer[i1] = buffer[j1];
     buffer[j2] = buffer[i2];
-    };
+  }
-    Transform.prototype.iterate = function Transform_iterate(
+
-      ll,
+  filter(x, offset, length) {
-      hl_lh_hh,
+    unreachable("Abstract method `filter` called");
-      u0,
+  }
-      v0
+
-    ) {
+  iterate(ll, hl_lh_hh, u0, v0) {
     const llWidth = ll.width,
       llHeight = ll.height;
     let llItems = ll.items;
@@ -2181,10 +2179,7 @@ const JpxImage = (function JpxImageClosure() {
         this.extend(rowBuffer, bufferPadding, width);
         this.filter(rowBuffer, bufferPadding, width);
 
-          items.set(
+        items.set(rowBuffer.subarray(bufferPadding, bufferPadding + width), k);
-            rowBuffer.subarray(bufferPadding, bufferPadding + width),
-            k
-          );
       }
     }
 
@@ -2241,28 +2236,13 @@ const JpxImage = (function JpxImageClosure() {
       }
     }
 
-      return {
+    return { width, height, items };
-        width,
+  }
-        height,
-        items,
-      };
-    };
-    return Transform;
-  })();
-
-  // Section 3.8.2 Irreversible 9-7 filter
-  const IrreversibleTransform = (function IrreversibleTransformClosure() {
-    // eslint-disable-next-line no-shadow
-    function IrreversibleTransform() {
-      Transform.call(this);
 }
 
-    IrreversibleTransform.prototype = Object.create(Transform.prototype);
+// Section 3.8.2 Irreversible 9-7 filter
-    IrreversibleTransform.prototype.filter = function irreversibleTransformFilter(
+class IrreversibleTransform extends Transform {
-      x,
+  filter(x, offset, length) {
-      offset,
-      length
-    ) {
     const len = length >> 1;
     offset = offset | 0;
     let j, n, current, next;
@@ -2343,24 +2323,12 @@ const JpxImage = (function JpxImageClosure() {
         }
       }
     }
-    };
+  }
-
-    return IrreversibleTransform;
-  })();
-
-  // Section 3.8.1 Reversible 5-3 filter
-  const ReversibleTransform = (function ReversibleTransformClosure() {
-    // eslint-disable-next-line no-shadow
-    function ReversibleTransform() {
-      Transform.call(this);
 }
 
-    ReversibleTransform.prototype = Object.create(Transform.prototype);
+// Section 3.8.1 Reversible 5-3 filter
-    ReversibleTransform.prototype.filter = function reversibleTransformFilter(
+class ReversibleTransform extends Transform {
-      x,
+  filter(x, offset, length) {
-      offset,
-      length
-    ) {
     const len = length >> 1;
     offset = offset | 0;
     let j, n;
@@ -2372,12 +2340,7 @@ const JpxImage = (function JpxImageClosure() {
     for (j = offset + 1, n = len; n--; j += 2) {
       x[j] += (x[j - 1] + x[j + 1]) >> 1;
     }
-    };
+  }
-
+}
-    return ReversibleTransform;
-  })();
-
-  return JpxImage;
-})();
 
 export { JpxImage };