bug 617905 pt 2 - remove code to split long runs from the uniscribe shaper now that gfxFont code handles this earlier. r=karlt a=joe

gfx/thebes/gfxUniscribeShaper.cpp

@@ -85,7 +85,9 @@ public:
         mNumGlyphs(0), mMaxGlyphs(ESTIMATE_MAX_GLYPHS(aLength)),
         mFontSelected(PR_FALSE), mIVS(aIVS)
     {
-        NS_ASSERTION(mMaxGlyphs < 65535, "UniscribeItem is too big, ScriptShape() will fail!");
+        // See bug 394751 for details.
+        NS_ASSERTION(mMaxGlyphs < 65535,
+                     "UniscribeItem is too big, ScriptShape() will fail!");
     }
 
     ~UniscribeItem() {
@@ -399,8 +401,6 @@ private:
     PRPackedBool mFontSelected;
 };
 
-#define MAX_ITEM_LENGTH 16384
-
 class Uniscribe
 {
 public:
@@ -410,8 +410,6 @@ public:
         mString(aString), mLength(aLength), mTextRun(aTextRun)
     {
     }
-    ~Uniscribe() {
-    }
 
     void Init() {
         memset(&mControl, 0, sizeof(SCRIPT_CONTROL));
@@ -422,77 +420,7 @@ public:
         mState.fOverrideDirection = PR_TRUE;
     }
 
-private:
-
-// We try to avoid calling Uniscribe with text runs that may generate
-// more than this many glyphs, because of the possibility of arithmetic
-// overflow of 16-bit variables. If long runs need to be split because
-// of this, we'll look for whitespace to break on so that shaping needed
-// (e.g. for complex scripts) should be unaffected.
-#define MAX_UNISCRIBE_GLYPHS 32767
-
-    // Append mItems[aIndex] to aDest, adding extra items to aDest to ensure
-    // that no item is too long for ScriptShape() to handle. See bug 366643.
-    nsresult CopyItemSplitOversize(int aIndex, nsTArray<SCRIPT_ITEM> &aDest) {
-        aDest.AppendElement(mItems[aIndex]);
-        const int itemLength =
-            mItems[aIndex+1].iCharPos - mItems[aIndex].iCharPos;
-        if (ESTIMATE_MAX_GLYPHS(itemLength) > MAX_UNISCRIBE_GLYPHS) {
-            // This item's length would cause ScriptShape() to fail.
-            // We need to add extra items here so that no item's length
-            // could cause the fail.
-
-            // We break on whitespace or cluster boundaries if possible.
-            const int nextItemStart = mItems[aIndex+1].iCharPos;
-            int start = FindNextItemStart(mItems[aIndex].iCharPos,
-                                          nextItemStart);
-
-            while (start < nextItemStart) {
-                SCRIPT_ITEM item = mItems[aIndex];
-                item.iCharPos = start;
-                aDest.AppendElement(item);
-                start = FindNextItemStart(start, nextItemStart);
-            }
-        } 
-        return NS_OK;
-    }
-
-    PRUint32 FindNextItemStart(int aOffset, int aLimit) {
-        if (aOffset + MAX_ITEM_LENGTH >= aLimit) {
-            // The item starting at aOffset can't be longer than max length,
-            // so starting the next item at aLimit won't cause ScriptShape()
-            // to fail.
-            return aLimit;
-        }
-        // Try to start the next item before or after a space, since spaces
-        // don't kern or ligate.
-        PRInt32 off;
-        int boundary = -1;
-        for (off = MAX_ITEM_LENGTH; off > 1; --off) {
-            if (mTextRun->IsClusterStart(off)) {
-                if (off > boundary) {
-                    boundary = off;
-                }
-                if (mString[aOffset+off] == ' ' ||
-                    mString[aOffset+off - 1] == ' ') {
-                    return aOffset+off;
-                }
-            }
-        }
-
-        // Try to start the next item at last cluster boundary in the range.
-        if (boundary > 0) {
-            return aOffset+boundary;
-        }
-
-        // No nice cluster boundaries inside MAX_ITEM_LENGTH characters, break
-        // on the size limit. It won't be visually pleasing, but at least it
-        // won't cause ScriptShape() to fail.
-        return aOffset + MAX_ITEM_LENGTH;
-    }
-
 public:
-
     int Itemize() {
         HRESULT rv;
 
@@ -514,25 +442,6 @@ public:
             Init();
         }
 
-        if (ESTIMATE_MAX_GLYPHS(mLength) > 65535) {
-            // Any item of length > 43680 will cause ScriptShape() to fail, as its
-            // mMaxGlyphs value will be greater than 65535 (43680*1.5+16>65535). So we
-            // need to break up items which are longer than that upon cluster boundaries.
-            // See bug 394751 for details.
-            nsTArray<SCRIPT_ITEM> items;
-            for (int i=0; i<mNumItems; i++) {
-                nsresult nrs = CopyItemSplitOversize(i, items);
-                NS_ASSERTION(NS_SUCCEEDED(nrs), "CopyItemSplitOversize() failed");
-            }
-            items.AppendElement(mItems[mNumItems]); // copy terminator.
-
-            mItems = items;
-            mNumItems = items.Length() - 1; // Don't count the terminator.
-        }
-        return mNumItems;
-    }
-
-    PRUint32 ItemsLength() {
         return mNumItems;
     }
 
@@ -640,7 +549,7 @@ gfxUniscribeShaper::InitTextRun(gfxContext *aContext,
         if (FAILED(rv)) {
             // Uniscribe doesn't like this font for some reason.
             // Returning FALSE will make the gfxGDIFont retry with the
-            // "dumb" GDI one, unless useUniscribeOnly was set.
+            // "dumb" GDI shaper, unless useUniscribeOnly was set.
             result = PR_FALSE;
             break;
         }