XFA - Fix font scale factors (bug 1720888)

- All the scale factors in for the substitution font were wrong because of different glyph positions between Liberation and the other ones:
    - regenerate all the factors
  - Text may have polish chars for example and in this case the glyph widths were wrong:
    - treat substitution font as a composite one
    - add a map glyphIndex to unicode for Liberation in order to generate width array for cid font

src/core/xfa_fonts.js

@@ -23,6 +23,7 @@ import {
   CalibriRegularFactors,
   CalibriRegularMetrics,
 } from "./calibri_factors.js";
+import { Dict, Name } from "./primitives.js";
 import {
   HelveticaBoldFactors,
   HelveticaBoldItalicFactors,
@@ -34,9 +35,13 @@ import {
   HelveticaRegularMetrics,
 } from "./helvetica_factors.js";
 import {
+  LiberationSansBoldItalicMapping,
   LiberationSansBoldItalicWidths,
+  LiberationSansBoldMapping,
   LiberationSansBoldWidths,
+  LiberationSansItalicMapping,
   LiberationSansItalicWidths,
+  LiberationSansRegularMapping,
   LiberationSansRegularWidths,
 } from "./liberationsans_widths.js";
 import {
@@ -67,12 +72,14 @@ const getXFAFontMap = getLookupTableFactory(function (t) {
     name: "LiberationSans-Regular",
     factors: MyriadProRegularFactors,
     baseWidths: LiberationSansRegularWidths,
+    baseMapping: LiberationSansRegularMapping,
     metrics: MyriadProRegularMetrics,
   };
   t["MyriadPro-Bold"] = t["PdfJS-Fallback-Bold"] = {
     name: "LiberationSans-Bold",
     factors: MyriadProBoldFactors,
     baseWidths: LiberationSansBoldWidths,
+    baseMapping: LiberationSansBoldMapping,
     metrics: MyriadProBoldMetrics,
   };
   t["MyriadPro-It"] =
@@ -82,6 +89,7 @@ const getXFAFontMap = getLookupTableFactory(function (t) {
         name: "LiberationSans-Italic",
         factors: MyriadProItalicFactors,
         baseWidths: LiberationSansItalicWidths,
+        baseMapping: LiberationSansItalicMapping,
         metrics: MyriadProItalicMetrics,
       };
   t["MyriadPro-BoldIt"] =
@@ -91,6 +99,7 @@ const getXFAFontMap = getLookupTableFactory(function (t) {
         name: "LiberationSans-BoldItalic",
         factors: MyriadProBoldItalicFactors,
         baseWidths: LiberationSansBoldItalicWidths,
+        baseMapping: LiberationSansBoldItalicMapping,
         metrics: MyriadProBoldItalicMetrics,
       };
   t.ArialMT =
@@ -99,89 +108,105 @@ const getXFAFontMap = getLookupTableFactory(function (t) {
       {
         name: "LiberationSans-Regular",
         baseWidths: LiberationSansRegularWidths,
+        baseMapping: LiberationSansRegularMapping,
       };
   t["Arial-BoldMT"] = t["Arial-Bold"] = {
     name: "LiberationSans-Bold",
     baseWidths: LiberationSansBoldWidths,
+    baseMapping: LiberationSansBoldMapping,
   };
   t["Arial-ItalicMT"] = t["Arial-Italic"] = {
     name: "LiberationSans-Italic",
     baseWidths: LiberationSansItalicWidths,
+    baseMapping: LiberationSansItalicMapping,
   };
   t["Arial-BoldItalicMT"] = t["Arial-BoldItalic"] = {
     name: "LiberationSans-BoldItalic",
     baseWidths: LiberationSansBoldItalicWidths,
+    baseMapping: LiberationSansBoldItalicMapping,
   };
   t["Calibri-Regular"] = {
     name: "LiberationSans-Regular",
     factors: CalibriRegularFactors,
     baseWidths: LiberationSansRegularWidths,
+    baseMapping: LiberationSansRegularMapping,
     metrics: CalibriRegularMetrics,
   };
   t["Calibri-Bold"] = {
     name: "LiberationSans-Bold",
     factors: CalibriBoldFactors,
     baseWidths: LiberationSansBoldWidths,
+    baseMapping: LiberationSansBoldMapping,
     metrics: CalibriBoldMetrics,
   };
   t["Calibri-Italic"] = {
     name: "LiberationSans-Italic",
     factors: CalibriItalicFactors,
     baseWidths: LiberationSansItalicWidths,
+    baseMapping: LiberationSansItalicMapping,
     metrics: CalibriItalicMetrics,
   };
   t["Calibri-BoldItalic"] = {
     name: "LiberationSans-BoldItalic",
     factors: CalibriBoldItalicFactors,
     baseWidths: LiberationSansBoldItalicWidths,
+    baseMapping: LiberationSansBoldItalicMapping,
     metrics: CalibriBoldItalicMetrics,
   };
   t["Segoeui-Regular"] = {
     name: "LiberationSans-Regular",
     factors: SegoeuiRegularFactors,
     baseWidths: LiberationSansRegularWidths,
+    baseMapping: LiberationSansRegularMapping,
     metrics: SegoeuiRegularMetrics,
   };
   t["Segoeui-Bold"] = {
     name: "LiberationSans-Bold",
     factors: SegoeuiBoldFactors,
     baseWidths: LiberationSansBoldWidths,
+    baseMapping: LiberationSansBoldMapping,
     metrics: SegoeuiBoldMetrics,
   };
   t["Segoeui-Italic"] = {
     name: "LiberationSans-Italic",
     factors: SegoeuiItalicFactors,
     baseWidths: LiberationSansItalicWidths,
+    baseMapping: LiberationSansItalicMapping,
     metrics: SegoeuiItalicMetrics,
   };
   t["Segoeui-BoldItalic"] = {
     name: "LiberationSans-BoldItalic",
     factors: SegoeuiBoldItalicFactors,
     baseWidths: LiberationSansBoldItalicWidths,
+    baseMapping: LiberationSansBoldItalicMapping,
     metrics: SegoeuiBoldItalicMetrics,
   };
   t["Helvetica-Regular"] = t.Helvetica = {
     name: "LiberationSans-Regular",
     factors: HelveticaRegularFactors,
     baseWidths: LiberationSansRegularWidths,
+    baseMapping: LiberationSansRegularMapping,
     metrics: HelveticaRegularMetrics,
   };
   t["Helvetica-Bold"] = {
     name: "LiberationSans-Bold",
     factors: HelveticaBoldFactors,
     baseWidths: LiberationSansBoldWidths,
+    baseMapping: LiberationSansBoldMapping,
     metrics: HelveticaBoldMetrics,
   };
   t["Helvetica-Italic"] = {
     name: "LiberationSans-Italic",
     factors: HelveticaItalicFactors,
     baseWidths: LiberationSansItalicWidths,
+    baseMapping: LiberationSansItalicMapping,
     metrics: HelveticaItalicMetrics,
   };
   t["Helvetica-BoldItalic"] = {
     name: "LiberationSans-BoldItalic",
     factors: HelveticaBoldItalicFactors,
     baseWidths: LiberationSansBoldItalicWidths,
+    baseMapping: LiberationSansBoldItalicMapping,
     metrics: HelveticaBoldItalicMetrics,
   };
 });
@@ -198,11 +223,80 @@ function getXfaFontWidths(name) {
     return null;
   }
 
-  const { baseWidths, factors } = info;
+  const { baseWidths, baseMapping, factors } = info;
+  let rescaledBaseWidths;
   if (!factors) {
-    return baseWidths;
+    rescaledBaseWidths = baseWidths;
+  } else {
+    rescaledBaseWidths = baseWidths.map((w, i) => w * factors[i]);
   }
-  return baseWidths.map((w, i) => w * factors[i]);
+
+  let currentCode = -2;
+  let currentArray;
+
+  // Widths array for composite font is:
+  // CharCode1 [10, 20, 30] ...
+  // which means:
+  //   - CharCode1 has a width equal to 10
+  //   - CharCode1+1 has a width equal to 20
+  //   - CharCode1+2 has a width equal to 30
+  //
+  // The baseMapping array contains a map for glyph index to unicode.
+  // So from baseMapping we'll get sorted unicodes and their positions
+  // (i.e. glyph indices) and then we put widths in an array for the
+  // the consecutive unicodes.
+  const newWidths = [];
+  for (const [unicode, glyphIndex] of baseMapping
+    .map(
+      (charUnicode, index) => [
+        charUnicode,
+        index,
+      ] /* collect unicode and glyph index */
+    )
+    .sort(
+      ([unicode1], [unicode2]) =>
+        unicode1 - unicode2 /* order by unicode only */
+    )) {
+    if (unicode === -1) {
+      continue;
+    }
+
+    if (unicode === currentCode + 1) {
+      currentArray.push(rescaledBaseWidths[glyphIndex]);
+      currentCode += 1;
+    } else {
+      currentCode = unicode;
+      currentArray = [rescaledBaseWidths[glyphIndex]];
+      newWidths.push(unicode, currentArray);
+    }
+  }
+
+  return newWidths;
 }
 
-export { getXfaFontName, getXfaFontWidths };
+function getXfaFontDict(name) {
+  const widths = getXfaFontWidths(name);
+  const dict = new Dict(null);
+  dict.set("BaseFont", Name.get(name));
+  dict.set("Type", Name.get("Font"));
+  dict.set("Subtype", Name.get("CIDFontType2"));
+  dict.set("Encoding", Name.get("Identity-H"));
+  dict.set("CIDToGIDMap", Name.get("Identity"));
+  dict.set("W", widths);
+  dict.set("FirstChar", widths[0]);
+  dict.set(
+    "LastChar",
+    widths[widths.length - 2] + widths[widths.length - 1].length - 1
+  );
+  const descriptor = new Dict(null);
+  dict.set("FontDescriptor", descriptor);
+  const systemInfo = new Dict(null);
+  systemInfo.set("Ordering", "Identity");
+  systemInfo.set("Registry", "Adobe");
+  systemInfo.set("Supplement", 0);
+  dict.set("CIDSystemInfo", systemInfo);
+
+  return dict;
+}
+
+export { getXfaFontDict, getXfaFontName };