From 31e0f0321057a7612ed5a7fa890dad09e6a53ee6 Mon Sep 17 00:00:00 2001
From: David Turner <david@freetype.org>
Date: Thu, 7 Sep 2006 14:29:35 -0700
Subject: [PATCH] Replace character discovery loop with simpler, faster
 version.

The existing loop for discovering which characters map to glyphs is ugly and
inefficient. The replacement is functionally identical, but far cleaner and
faster.
---
 src/fcfreetype.c | 83 +++++++++++++++++-------------------------------
 1 file changed, 30 insertions(+), 53 deletions(-)

diff --git a/src/fcfreetype.c b/src/fcfreetype.c
index 96f70c3..83c58d6 100644
--- a/src/fcfreetype.c
+++ b/src/fcfreetype.c
@@ -2584,71 +2584,48 @@ FcFreeTypeCharSetAndSpacing (FT_Face face, FcBlanks *blanks, int *spacing)
 	}
 	else
 	{
-	    FT_UInt gindex;
-	  
-	    /*
-	     * Find the first encoded character in the font
-	     */
-	    if (FT_Get_Char_Index (face, 0))
-	    {
-		ucs4 = 0;
-		gindex = 1;
-	    }
-	    else
-	    {
-		ucs4 = FT_Get_Next_Char (face, 0, &gindex);
-		if (!ucs4)
-		    gindex = 0;
-	    }
-
-	    while (gindex)
+            page = ~0;
+            leaf = NULL;
+            ucs4 = FT_Get_First_Char (face, &glyph);
+            while (glyph != 0)
 	    {
-		page = ucs4 >> 8;
-		leaf = 0;
-		while ((ucs4 >> 8) == page)
+		if (FcFreeTypeCheckGlyph (face, ucs4, glyph, blanks, &advance))
 		{
-		    glyph = FT_Get_Char_Index (face, ucs4);
-		    if (glyph && FcFreeTypeCheckGlyph (face, ucs4, 
-						       glyph, blanks, &advance))
+		    if (advance)
 		    {
-			if (advance)
+			if (!has_advance)
 			{
-			    if (!has_advance)
-			    {
-				has_advance = FcTrue;
-				advance_one = advance;
-			    }
-			    else if (!APPROXIMATELY_EQUAL (advance, advance_one))
+			    has_advance = FcTrue;
+			    advance_one = advance;
+			}
+			else if (!APPROXIMATELY_EQUAL (advance, advance_one))
+			{
+			    if (fixed_advance)
 			    {
-				if (fixed_advance)
-				{
-				    dual_advance = FcTrue;
-				    fixed_advance = FcFalse;
-				    advance_two = advance;
-				}
-				else if (!APPROXIMATELY_EQUAL (advance, advance_two))
-				    dual_advance = FcFalse;
+				dual_advance = FcTrue;
+				fixed_advance = FcFalse;
+				advance_two = advance;
 			    }
+			    else if (!APPROXIMATELY_EQUAL (advance, advance_two))
+				dual_advance = FcFalse;
 			}
+		    }
 
+		    if ((ucs4 >> 8) != page)
+		    {
+			page = (ucs4 >> 8);
+			leaf = FcCharSetFindLeafCreate (fcs, ucs4);
 			if (!leaf)
-			{
-			    leaf = FcCharSetFindLeafCreate (fcs, ucs4);
-			    if (!leaf)
-				goto bail1;
-			}
-			off = ucs4 & 0xff;
-			leaf->map[off >> 5] |= (1 << (off & 0x1f));
+			    goto bail1;
+		    }
+		    off = ucs4 & 0xff;
+		    leaf->map[off >> 5] |= (1 << (off & 0x1f));
 #ifdef CHECK
-			if (ucs4 > font_max)
-			    font_max = ucs4;
+		    if (ucs4 > font_max)
+			font_max = ucs4;
 #endif
-		    }
-		    ucs4++;
 		}
-		ucs4 = FT_Get_Next_Char (face, ucs4 - 1, &gindex);
-		if (!ucs4)
-		    gindex = 0;
+		ucs4 = FT_Get_Next_Char (face, ucs4, &glyph);
 	    }
 #ifdef CHECK
 	    for (ucs4 = 0; ucs4 < 0x10000; ucs4++)
-- 
2.39.2