Introduce helper functions for parsing /Matrix and /BBox arrays

mozilla · May 3, 2024 · 14707f9 · 14707f9
1 parent 0c08809
commit 14707f9
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Showing 5 changed files with 55 additions and 65 deletions.
diff --git a/src/core/annotation.js b/src/core/annotation.js
@@ -44,6 +44,8 @@ import {
   getRotationMatrix,
   isAscii,
   isNumberArray,
+  lookupMatrix,
+  lookupRect,
   numberToString,
   stringToUTF16String,
 } from "./core_utils.js";
@@ -915,9 +917,7 @@ class Annotation {
    * @param {Array} rectangle - The rectangle array with exactly four entries
    */
   setRectangle(rectangle) {
-    this.rectangle = isNumberArray(rectangle, 4)
-      ? Util.normalizeRect(rectangle)
-      : [0, 0, 0, 0];
+    this.rectangle = lookupRect(rectangle, [0, 0, 0, 0]);
   }
 
   /**
@@ -1150,14 +1150,11 @@ class Annotation {
       ["ExtGState", "ColorSpace", "Pattern", "Shading", "XObject", "Font"],
       appearance
     );
-    let bbox = appearanceDict.getArray("BBox");
-    if (!isNumberArray(bbox, 4)) {
-      bbox = [0, 0, 1, 1];
-    }
-    let matrix = appearanceDict.getArray("Matrix");
-    if (!isNumberArray(matrix, 6)) {
-      matrix = [1, 0, 0, 1, 0, 0];
-    }
+    const bbox = lookupRect(appearanceDict.getArray("BBox"), [0, 0, 1, 1]);
+    const matrix = lookupMatrix(
+      appearanceDict.getArray("Matrix"),
+      IDENTITY_MATRIX
+    );
     const transform = getTransformMatrix(rect, bbox, matrix);
 
     const opList = new OperatorList();
@@ -1254,14 +1251,8 @@ class Annotation {
 
     if (text.length > 1 || text[0]) {
       const appearanceDict = this.appearance.dict;
-      let bbox = appearanceDict.getArray("BBox");
-      if (!isNumberArray(bbox, 4)) {
-        bbox = null;
-      }
-      let matrix = appearanceDict.getArray("Matrix");
-      if (!isNumberArray(matrix, 6)) {
-        matrix = null;
-      }
+      const bbox = lookupRect(appearanceDict.getArray("BBox"), null);
+      const matrix = lookupMatrix(appearanceDict.getArray("Matrix"), null);
 
       this.data.textPosition = this._transformPoint(
         firstPosition,
@@ -2987,8 +2978,10 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
       : this.uncheckedAppearance;
     if (appearance) {
       const savedAppearance = this.appearance;
-      const matrix = appearance.dict.getArray("Matrix");
-      const savedMatrix = isNumberArray(matrix, 6) ? matrix : IDENTITY_MATRIX;
+      const savedMatrix = lookupMatrix(
+        appearance.dict.getArray("Matrix"),
+        IDENTITY_MATRIX
+      );
 
       if (rotation) {
         appearance.dict.set(
@@ -3753,11 +3746,7 @@ class PopupAnnotation extends Annotation {
       warn("Popup annotation has a missing or invalid parent annotation.");
       return;
     }
-
-    const parentRect = parentItem.getArray("Rect");
-    this.data.parentRect = isNumberArray(parentRect, 4)
-      ? Util.normalizeRect(parentRect)
-      : null;
+    this.data.parentRect = lookupRect(parentItem.getArray("Rect"), null);
 
     const rt = parentItem.get("RT");
     if (isName(rt, AnnotationReplyType.GROUP)) {

diff --git a/src/core/core_utils.js b/src/core/core_utils.js
@@ -19,6 +19,7 @@ import {
   BaseException,
   objectSize,
   stringToPDFString,
+  Util,
   warn,
 } from "../shared/util.js";
 import { Dict, isName, Ref, RefSet } from "./primitives.js";
@@ -248,6 +249,16 @@ function isNumberArray(arr, len) {
   );
 }
 
+// Returns the matrix, or the fallback value if it's invalid.
+function lookupMatrix(arr, fallback) {
+  return isNumberArray(arr, 6) ? arr : fallback;
+}
+
+// Returns the normalized rectangle, or the fallback value if it's invalid.
+function lookupRect(arr, fallback) {
+  return isNumberArray(arr, 4) ? Util.normalizeRect(arr) : fallback;
+}
+
 /**
  * AcroForm field names use an array like notation to refer to
  * repeated XFA elements e.g. foo.bar[nnn].
@@ -671,6 +682,8 @@ export {
   isNumberArray,
   isWhiteSpace,
   log2,
+  lookupMatrix,
+  lookupRect,
   MissingDataException,
   numberToString,
   ParserEOFException,

diff --git a/src/core/document.js b/src/core/document.js
@@ -39,8 +39,8 @@ import {
   collectActions,
   getInheritableProperty,
   getNewAnnotationsMap,
-  isNumberArray,
   isWhiteSpace,
+  lookupRect,
   MissingDataException,
   PDF_VERSION_REGEXP,
   validateCSSFont,
@@ -161,10 +161,12 @@ class Page {
     if (this.xfaData) {
       return this.xfaData.bbox;
     }
-    let box = this._getInheritableProperty(name, /* getArray = */ true);
+    const box = lookupRect(
+      this._getInheritableProperty(name, /* getArray = */ true),
+      null
+    );
 
-    if (isNumberArray(box, 4)) {
-      box = Util.normalizeRect(box);
+    if (box) {
       if (box[2] - box[0] > 0 && box[3] - box[1] > 0) {
         return box;
       }

diff --git a/src/core/evaluator.js b/src/core/evaluator.js
@@ -53,6 +53,7 @@ import {
 import { getTilingPatternIR, Pattern } from "./pattern.js";
 import { getXfaFontDict, getXfaFontName } from "./xfa_fonts.js";
 import { IdentityToUnicodeMap, ToUnicodeMap } from "./to_unicode_map.js";
+import { isNumberArray, lookupMatrix, lookupRect } from "./core_utils.js";
 import { isPDFFunction, PDFFunctionFactory } from "./function.js";
 import { Lexer, Parser } from "./parser.js";
 import {
@@ -73,7 +74,6 @@ import { getGlyphsUnicode } from "./glyphlist.js";
 import { getMetrics } from "./metrics.js";
 import { getUnicodeForGlyph } from "./unicode.js";
 import { ImageResizer } from "./image_resizer.js";
-import { isNumberArray } from "./core_utils.js";
 import { MurmurHash3_64 } from "../shared/murmurhash3.js";
 import { OperatorList } from "./operator_list.js";
 import { PDFImage } from "./image.js";
@@ -460,12 +460,8 @@ class PartialEvaluator {
     localColorSpaceCache
   ) {
     const dict = xobj.dict;
-    let matrix = dict.getArray("Matrix");
-    if (!isNumberArray(matrix, 6)) {
-      matrix = null;
-    }
-    let bbox = dict.getArray("BBox");
-    bbox = isNumberArray(bbox, 4) ? Util.normalizeRect(bbox) : null;
+    const matrix = lookupMatrix(dict.getArray("Matrix"), null);
+    const bbox = lookupRect(dict.getArray("BBox"), null);
 
     let optionalContent, groupOptions;
     if (dict.has("OC")) {
@@ -1578,10 +1574,7 @@ class PartialEvaluator {
             localShadingPatternCache,
           });
           if (objId) {
-            let matrix = dict.getArray("Matrix");
-            if (!isNumberArray(matrix, 6)) {
-              matrix = null;
-            }
+            const matrix = lookupMatrix(dict.getArray("Matrix"), null);
             operatorList.addOp(fn, ["Shading", objId, matrix]);
           }
           return undefined;
@@ -3268,8 +3261,8 @@ class PartialEvaluator {
                 const currentState = stateManager.state.clone();
                 const xObjStateManager = new StateManager(currentState);
 
-                const matrix = xobj.dict.getArray("Matrix");
-                if (isNumberArray(matrix, 6)) {
+                const matrix = lookupMatrix(xobj.dict.getArray("Matrix"), null);
+                if (matrix) {
                   xObjStateManager.transform(matrix);
                 }
 
@@ -4247,10 +4240,7 @@ class PartialEvaluator {
 
     if (!descriptor) {
       if (isType3Font) {
-        let bbox = dict.getArray("FontBBox");
-        if (!isNumberArray(bbox, 4)) {
-          bbox = [0, 0, 0, 0];
-        }
+        const bbox = lookupRect(dict.getArray("FontBBox"), [0, 0, 0, 0]);
         // FontDescriptor is only required for Type3 fonts when the document
         // is a tagged pdf. Create a barbebones one to get by.
         descriptor = new Dict(null);
@@ -4440,14 +4430,14 @@ class PartialEvaluator {
       }
     }
 
-    let fontMatrix = dict.getArray("FontMatrix");
-    if (!isNumberArray(fontMatrix, 6)) {
-      fontMatrix = FONT_IDENTITY_MATRIX;
-    }
-    let bbox = descriptor.getArray("FontBBox") || dict.getArray("FontBBox");
-    if (!isNumberArray(bbox, 4)) {
-      bbox = undefined;
-    }
+    const fontMatrix = lookupMatrix(
+      dict.getArray("FontMatrix"),
+      FONT_IDENTITY_MATRIX
+    );
+    const bbox = lookupRect(
+      descriptor.getArray("FontBBox") || dict.getArray("FontBBox"),
+      undefined
+    );
     let ascent = descriptor.get("Ascent");
     if (typeof ascent !== "number") {
       ascent = undefined;

diff --git a/src/core/pattern.js b/src/core/pattern.js
@@ -24,6 +24,8 @@ import {
 import {
   isBooleanArray,
   isNumberArray,
+  lookupMatrix,
+  lookupRect,
   MissingDataException,
 } from "./core_utils.js";
 import { BaseStream } from "./base_stream.js";
@@ -128,8 +130,7 @@ class RadialAxialShading extends BaseShading {
       pdfFunctionFactory,
       localColorSpaceCache,
     });
-    const bbox = dict.getArray("BBox");
-    this.bbox = isNumberArray(bbox, 4) ? Util.normalizeRect(bbox) : null;
+    this.bbox = lookupRect(dict.getArray("BBox"), null);
 
     let t0 = 0.0,
       t1 = 1.0;
@@ -460,8 +461,7 @@ class MeshShading extends BaseShading {
     }
     const dict = stream.dict;
     this.shadingType = dict.get("ShadingType");
-    const bbox = dict.getArray("BBox");
-    this.bbox = isNumberArray(bbox, 4) ? Util.normalizeRect(bbox) : null;
+    this.bbox = lookupRect(dict.getArray("BBox"), null);
     const cs = ColorSpace.parse({
       cs: dict.getRaw("CS") || dict.getRaw("ColorSpace"),
       xref,
@@ -987,12 +987,8 @@ class DummyShading extends BaseShading {
 }
 
 function getTilingPatternIR(operatorList, dict, color) {
-  let matrix = dict.getArray("Matrix");
-  if (!isNumberArray(matrix, 6)) {
-    matrix = null;
-  }
-  let bbox = dict.getArray("BBox");
-  bbox = isNumberArray(bbox, 4) ? Util.normalizeRect(bbox) : null;
+  const matrix = lookupMatrix(dict.getArray("Matrix"), null);
+  const bbox = lookupRect(dict.getArray("BBox"), null);
   // Ensure that the pattern has a non-zero width and height, to prevent errors
   // in `pattern_helper.js` (fixes issue8330.pdf).
   if (!bbox || bbox[2] - bbox[0] === 0 || bbox[3] - bbox[1] === 0) {