Rendering text-justify:distribute for 8 bit characters.

Source/platform/fonts/Character.cpp

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
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  *     * Redistributions in binary form must reproduce the above
@@ skipping 254 matching lines @@
         0x1F110, 0x1F129,
         0x1F130, 0x1F149,
         0x1F150, 0x1F169,
         0x1F170, 0x1F189,
         0x1F200, 0x1F6FF
     };
 
     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;
     if (direction == LTR) {
         for (size_t i = 0; i < length; ++i) {
             UChar32 character = characters[i];
             if (treatAsSpace(character)) {
                 count++;
                 isAfterExpansion = true;
                 continue;
@@ skipping 66 matching lines @@
 {
     return normalizeSpacesInternal(characters, length);
 }
 
 String Character::normalizeSpaces(const UChar* characters, unsigned length)
 {
     return normalizeSpacesInternal(characters, length);
 }
 
 }