[FOray-commit] SF.net SVN: foray:[13080] trunk/foray/foray-font/src/main/java/org/foray/ font

[<vic...@us...>]

Revision: 13080
          http://sourceforge.net/p/foray/code/13080
Author:   victormote
Date:     2023-01-22 22:21:20 +0000 (Sun, 22 Jan 2023)
Log Message:
-----------
Clean up parsing/computation of units-per-em.

Modified Paths:
--------------
    trunk/foray/foray-font/src/main/java/org/foray/font/Font4a.java
    trunk/foray/foray-font/src/main/java/org/foray/font/FsTrueTypeFont.java
    trunk/foray/foray-font/src/main/java/org/foray/font/FsType1Font.java
    trunk/foray/foray-font/src/main/java/org/foray/font/SystemFont.java
    trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1Metrics.java
    trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1MetricsParserPfm.java

Modified: trunk/foray/foray-font/src/main/java/org/foray/font/Font4a.java
===================================================================
--- trunk/foray/foray-font/src/main/java/org/foray/font/Font4a.java	2023-01-22 17:28:41 UTC (rev 13079)
+++ trunk/foray/foray-font/src/main/java/org/foray/font/Font4a.java	2023-01-22 22:21:20 UTC (rev 13080)
@@ -224,12 +224,11 @@
         final int metricIndex1 = this.metricIndex(codePoint1);
         final int metricIndex2 = this.metricIndex(codePoint2);
         final int rawKerning = getKerning().kern(metricIndex1, metricIndex2);
-        if (TypographicConstants.MILLIPOINTS_PER_POINT == this.getUnitsPerTextSpaceUnit()) {
+        if (TypographicConstants.MILLIPOINTS_PER_POINT == this.getUnitsPerEm()) {
             /* Avoid the potential loss of precision. */
             return rawKerning;
         }
-        return Math.round(rawKerning * TypographicConstants.MILLIPOINTS_PER_POINT
-                / this.getUnitsPerTextSpaceUnit());
+        return Math.round(rawKerning * TypographicConstants.MILLIPOINTS_PER_POINT / getUnitsPerEm());
     }
 
 
@@ -442,13 +441,12 @@
     }
 
     /**
-     * Returns the units per text-space unit that is used in this font for internal font
-     * measurements.
-     * For PostScript Type 1 fonts, this is 1000.
+     * Returns the number of units per em that is used in this font for internal font measurements.
+     * For PostScript Type 1 fonts, this is usually 1000.
      * For TrueType fonts, it is usually 2048, but can be specified in the font itself.
      * @return The units per text-space unit used by this font.
      */
-    public abstract int getUnitsPerTextSpaceUnit();
+    public abstract int getUnitsPerEm();
 
     /**
      * Indicates whether this font has the ability to map Unicode characters to font glyphs.

Modified: trunk/foray/foray-font/src/main/java/org/foray/font/FsTrueTypeFont.java
===================================================================
--- trunk/foray/foray-font/src/main/java/org/foray/font/FsTrueTypeFont.java	2023-01-22 17:28:41 UTC (rev 13079)
+++ trunk/foray/foray-font/src/main/java/org/foray/font/FsTrueTypeFont.java	2023-01-22 22:21:20 UTC (rev 13080)
@@ -242,9 +242,8 @@
     }
 
     @Override
-    public int getUnitsPerTextSpaceUnit() {
-        /* TODO: Add logic to get the actual value out of the font. */
-        return FsTrueTypeFont.DEFAULT_UNITS_PER_TEXT_SPACE;
+    public int getUnitsPerEm() {
+        return this.ttf.getHeadTable().unitsPerEm();
     }
 
     @Override

Modified: trunk/foray/foray-font/src/main/java/org/foray/font/FsType1Font.java
===================================================================
--- trunk/foray/foray-font/src/main/java/org/foray/font/FsType1Font.java	2023-01-22 17:28:41 UTC (rev 13079)
+++ trunk/foray/foray-font/src/main/java/org/foray/font/FsType1Font.java	2023-01-22 22:21:20 UTC (rev 13080)
@@ -398,9 +398,8 @@
     }
 
     @Override
-    public int getUnitsPerTextSpaceUnit() {
-        /* Type 1 fonts always use 1000 units per text-space unit. */
-        return TypographicConstants.MILLIPOINTS_PER_POINT;
+    public int getUnitsPerEm() {
+        return this.metricsFile.getMasterUnits();
     }
 
     @Override

Modified: trunk/foray/foray-font/src/main/java/org/foray/font/SystemFont.java
===================================================================
--- trunk/foray/foray-font/src/main/java/org/foray/font/SystemFont.java	2023-01-22 17:28:41 UTC (rev 13079)
+++ trunk/foray/foray-font/src/main/java/org/foray/font/SystemFont.java	2023-01-22 22:21:20 UTC (rev 13080)
@@ -543,13 +543,13 @@
     }
 
     @Override
-    public int getUnitsPerTextSpaceUnit() {
+    public int getUnitsPerEm() {
         final FreeStandingFont relatedFSFont = this.freeStandingFontManifestation();
         if (relatedFSFont == null) {
             /* SystemFont is usually created from a TrueType font, so use its default. */
             return FsTrueTypeFont.DEFAULT_UNITS_PER_TEXT_SPACE;
         }
-        return relatedFSFont.getUnitsPerTextSpaceUnit();
+        return relatedFSFont.getUnitsPerEm();
     }
 
     @Override

Modified: trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1Metrics.java
===================================================================
--- trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1Metrics.java	2023-01-22 17:28:41 UTC (rev 13079)
+++ trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1Metrics.java	2023-01-22 22:21:20 UTC (rev 13080)
@@ -33,6 +33,7 @@
 import org.foray.font.output.FontPdfUtilities;
 import org.foray.primitive.BitUtils;
 
+import org.axsl.constants.TypographicConstants;
 import org.axsl.primitive.sequence.ShortSequence;
 import org.axsl.ps.BoundingBox;
 import org.axsl.ps.CharSet;
@@ -137,6 +138,10 @@
     /** The parsed bounding box. */
     private BoundingBox fontBBox = BoundingBoxUtils.ZEROES;
 
+    /** The parsed master units (units per em) value for this font. This is only used for PFM metrics files, because
+     * AFM files are always a constant. */
+    private int etmMasterUnits;
+
     /** The parsed cap height. */
     private int etmCapHeight;
 
@@ -291,6 +296,28 @@
     }
 
     /**
+     * Sets the master units (unts per em).
+     * @param masterUnits The master units to set.
+     */
+    public void setMasterUnits(final int masterUnits) {
+        this.etmMasterUnits = masterUnits;
+    }
+
+    /**
+     * Returns the master units (units per em).
+     * @return The master units value.
+     */
+    public int getMasterUnits() {
+        if (this.format == Format.AFM) {
+            /* See "Adobe Font Metrics File Format Specification," Section 3.2 "Units of Measurement," which states "All
+             * measurements in AFM, AMFM, and ACFM files are given in terms of units equal to 1/1000 of the scale factor
+             * (point size) of the font being used." */
+            return TypographicConstants.MILLIPOINTS_PER_POINT;
+        }
+        return this.etmMasterUnits;
+    }
+
+    /**
      * Sets the cap height.
      * @param capHeight The capHeight to set.
      */

Modified: trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1MetricsParserPfm.java
===================================================================
--- trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1MetricsParserPfm.java	2023-01-22 17:28:41 UTC (rev 13079)
+++ trunk/foray/foray-font/src/main/java/org/foray/font/format/type1/Type1MetricsParserPfm.java	2023-01-22 22:21:20 UTC (rev 13080)
@@ -296,8 +296,11 @@
         this.input.skipBytes(PrimitiveConstants.BYTES_PER_SHORT);
         /* Skip the etmMaxScale field. */
         this.input.skipBytes(PrimitiveConstants.BYTES_PER_SHORT);
-        /* Skip the etmMasterUnits field. */
-        this.input.skipBytes(PrimitiveConstants.BYTES_PER_SHORT);
+
+        /* Adobe Technical Note #5178 "Building PFM Files for PostScript-Language CJK Fonts," Section 5, indicates that
+         * the master units value is always 1000. Some other sources seem to indicate that this is "usually" true. We
+         * read it anyway to be sure. */
+        this.metrics.setMasterUnits(this.input.readShortLoHi());
         this.metrics.setCapHeight(this.input.readUnsignedShortLoHi());
         this.metrics.setXHeight(this.input.readUnsignedShortLoHi());
         this.metrics.setLowerCaseAscent(this.input.readUnsignedShortLoHi());

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