Rendering text-justify:distribute for 8 bit characters.

Source/platform/fonts/Character.cpp

Index: Source/platform/fonts/Character.cpp
diff --git a/Source/platform/fonts/Character.cpp b/Source/platform/fonts/Character.cpp
index 40ccd3ee22fecd4196832e4db6ffed5b7cd1903f..8848ba04d59d3716704a3f65c5cbbabe0dee3f1a 100644
--- a/Source/platform/fonts/Character.cpp
+++ b/Source/platform/fonts/Character.cpp
@@ -272,32 +272,32 @@ bool Character::isCJKIdeographOrSymbol(UChar32 c)
     return valueInIntervalList(cjkSymbolRanges, c);
 }
 
-unsigned Character::expansionOpportunityCount(const LChar* characters, size_t length, TextDirection direction, bool& isAfterExpansion)
+unsigned Character::expansionOpportunityCount(const LChar* characters, size_t length, TextDirection direction, bool& isAfterExpansion, const bool distributeJustification)
 {
     unsigned count = 0;
     if (direction == LTR) {

[leviw_travelin_and_unemployed, 2014/07/28 23:59:58]

This codepath can be simplified now. We only need one iteration, and just need
to change the index we use to check "isAfterExpansion"

[dw.im, 2014/07/29 01:54:54]

If the value of text-justify is distribute, then, yes, we can simplify it.
We only need to know how many characters we have, which we already know before
starting the iteration.
If we do, then we can have simple algorithm, and also some performance gain as
well.

I will try to do it.

         for (size_t i = 0; i < length; ++i) {
-            if (treatAsSpace(characters[i])) {
+            if (treatAsSpace(characters[i]) || distributeJustification)
                 count++;
-                isAfterExpansion = true;
-            } else {
-                isAfterExpansion = false;
-            }
         }
+        if (treatAsSpace(characters[length - 1]))
+            isAfterExpansion = true;
+        else
+            isAfterExpansion = false;
     } else {
         for (size_t i = length; i > 0; --i) {
-            if (treatAsSpace(characters[i - 1])) {
+            if (treatAsSpace(characters[i - 1]) || distributeJustification)
                 count++;
-                isAfterExpansion = true;
-            } else {
-                isAfterExpansion = false;
-            }
         }
+        if (treatAsSpace(characters[0]))
+            isAfterExpansion = true;
+        else
+            isAfterExpansion = false;
     }
     return count;
 }
 
-unsigned Character::expansionOpportunityCount(const UChar* characters, size_t length, TextDirection direction, bool& isAfterExpansion)
+unsigned Character::expansionOpportunityCount(const UChar* characters, size_t length, TextDirection direction, bool& isAfterExpansion, const bool distributeJustification)
 {
     static bool expandAroundIdeographs = FontPlatformFeatures::canExpandAroundIdeographsInComplexText();
     unsigned count = 0;