Make glyphs independent in bidi-reordered line from pre-reordering

DEVSIX-5161

Author: yulian-gaponenko

layout/src/main/java/com/itextpdf/layout/renderer/TypographyUtils.java

@@ -222,16 +222,7 @@ static int[] reorderLine(List<LineRenderer.RendererGlyph> line, byte[] lineLevel
                 }
             }
 
-            // fix anchorDelta
-            for (int i = 0; i < reorderedLine.size(); i++) {
-                Glyph glyph = reorderedLine.get(i).glyph;
-                if (glyph.hasPlacement()) {
-                    int oldAnchor = reorder[i] + glyph.getAnchorDelta();
-                    int newPos = inverseReorder[oldAnchor];
-                    int newAnchorDelta = newPos - i;
-                    glyph.setAnchorDelta((short) newAnchorDelta);
-                }
-            }
+            updateAnchorDeltaForReorderedLineGlyphs(reorder, inverseReorder, reorderedLine);
 
             line.clear();
             line.addAll(reorderedLine);
@@ -262,6 +253,24 @@ static List<Integer> getPossibleBreaks(String str) {
         return (List<Integer>) callMethod(TYPOGRAPHY_PACKAGE + WORD_WRAPPER, GET_POSSIBLE_BREAKS, new Class[] {String.class}, str);
     }
 
+    static void updateAnchorDeltaForReorderedLineGlyphs(int[] reorder, int[] inverseReorder,
+            List<LineRenderer.RendererGlyph> reorderedLine) {
+        for (int i = 0; i < reorderedLine.size(); i++) {
+            Glyph glyph = reorderedLine.get(i).glyph;
+            if (glyph.hasPlacement()) {
+                int oldAnchor = reorder[i] + glyph.getAnchorDelta();
+                int newPos = inverseReorder[oldAnchor];
+                int newAnchorDelta = newPos - i;
+
+                if (glyph.getAnchorDelta() != newAnchorDelta) {
+                    glyph = new Glyph(glyph);
+                    reorderedLine.get(i).glyph = glyph;
+                    glyph.setAnchorDelta((short) newAnchorDelta);
+                }
+            }
+        }
+    }
+
     private static Object callMethod(String className, String methodName, Class[] parameterTypes, Object... args) {
         return callMethod(className, methodName, (Object) null, parameterTypes, args);
     }

layout/src/test/java/com/itextpdf/layout/renderer/TypographyUtilsTest.java

@@ -42,8 +42,13 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.layout.renderer;
 
+import com.itextpdf.io.font.otf.Glyph;
+import com.itextpdf.layout.renderer.LineRenderer.RendererGlyph;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.type.UnitTest;
+
+import java.util.Arrays;
+import java.util.List;
 import org.junit.Assert;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
@@ -56,4 +61,48 @@ public void verifyPdfCalligraphIsNotAvailable() {
         Assert.assertFalse(TypographyUtils.isPdfCalligraphAvailable());
     }
 
+    @Test
+    public void updateAnchorDeltaMarkNotReorderedTest() {
+        // original line 'abm', and 'm' is a mark based on 'b'
+        Glyph mGlyph = new Glyph(100, 'm');
+        mGlyph.setAnchorDelta((short) -1);
+        mGlyph.setXAdvance((short) 15);
+        mGlyph.setYAdvance((short) 25);
+
+        RendererGlyph b = new RendererGlyph(new Glyph(100, 'b'), null);
+        RendererGlyph m = new RendererGlyph(mGlyph, null);
+        RendererGlyph a = new RendererGlyph(new Glyph(100, 'a'), null);
+        List<RendererGlyph> reorderedLine = Arrays.asList(b, m, a);
+
+        int[] reorder = new int[] {1, 2, 0};
+        int[] inverseReorder = new int[] {2, 0, 1};
+
+        TypographyUtils.updateAnchorDeltaForReorderedLineGlyphs(reorder, inverseReorder, reorderedLine);
+
+        Assert.assertSame(mGlyph, m.glyph);
+        Assert.assertEquals(-1, m.glyph.getAnchorDelta());
+    }
+
+    @Test
+    public void updateAnchorDeltaMarkReorderedTest() {
+        // original line 'abm', and 'm' is a mark based on 'b'
+        Glyph mGlyph = new Glyph(100, 'm');
+        mGlyph.setAnchorDelta((short) -1);
+        mGlyph.setXAdvance((short) 15);
+        mGlyph.setYAdvance((short) 25);
+
+        RendererGlyph m = new RendererGlyph(mGlyph, null);
+        RendererGlyph b = new RendererGlyph(new Glyph(100, 'b'), null);
+        RendererGlyph a = new RendererGlyph(new Glyph(100, 'a'), null);
+        List<RendererGlyph> reorderedLine = Arrays.asList(m, b, a);
+
+        int[] reorder = new int[] {2, 1, 0};
+        int[] inverseReorder = new int[] {2, 1, 0};
+
+        TypographyUtils.updateAnchorDeltaForReorderedLineGlyphs(reorder, inverseReorder, reorderedLine);
+
+        Assert.assertNotSame(mGlyph, m.glyph);
+        Assert.assertEquals(1, m.glyph.getAnchorDelta());
+    }
+
 }