Additional optimizations to text reflow for EXT-5071.

Added versions of LLFontFreeType::getXAdvance() and LLFontFreeType::getXKerning() that take LLFontGlyphInfo* instead of llwchar.  This allows code in LLFontGL that already has the LLFontGlyphInfo* to pass them instead, saving calls to LLFontFreetype::getGlyphInfo.

Reviewed by Richard.

indra/llrender/llfontfreetype.cpp

@@ -270,6 +270,14 @@ F32 LLFontFreetype::getXAdvance(llwchar wch) const
 	return (F32)mFontBitmapCachep->getMaxCharWidth();
 }
 
+F32 LLFontFreetype::getXAdvance(const LLFontGlyphInfo* glyph) const
+{
+	if (mFTFace == NULL)
+		return 0.0;
+
+	return glyph->mXAdvance;
+}
+
 F32 LLFontFreetype::getXKerning(llwchar char_left, llwchar char_right) const
 {
 	if (mFTFace == NULL)
@@ -289,6 +297,21 @@ F32 LLFontFreetype::getXKerning(llwchar char_left, llwchar char_right) const
 	return delta.x*(1.f/64.f);
 }
 
+F32 LLFontFreetype::getXKerning(const LLFontGlyphInfo* left_glyph_info, const LLFontGlyphInfo* right_glyph_info) const
+{
+	if (mFTFace == NULL)
+		return 0.0;
+
+	U32 left_glyph = left_glyph_info ? left_glyph_info->mGlyphIndex : 0;
+	U32 right_glyph = right_glyph_info ? right_glyph_info->mGlyphIndex : 0;
+
+	FT_Vector  delta;
+
+	llverify(!FT_Get_Kerning(mFTFace, left_glyph, right_glyph, ft_kerning_unfitted, &delta));
+
+	return delta.x*(1.f/64.f);
+}
+
 BOOL LLFontFreetype::hasGlyph(llwchar wch) const
 {
 	llassert(!mIsFallback);

indra/llrender/llfontfreetype.h

@@ -128,7 +128,9 @@ class LLFontFreetype : public LLRefCount
 	};
 
 	F32 getXAdvance(llwchar wc) const;
+	F32 getXAdvance(const LLFontGlyphInfo* glyph) const;
 	F32 getXKerning(llwchar char_left, llwchar char_right) const; // Get the kerning between the two characters
+	F32 getXKerning(const LLFontGlyphInfo* left_glyph_info, const LLFontGlyphInfo* right_glyph_info) const; // Get the kerning between the two characters
 
 	LLFontGlyphInfo* getGlyphInfo(llwchar wch) const;
 

indra/llrender/llfontgl.cpp

@@ -249,11 +249,18 @@ S32 LLFontGL::render(const LLWString &wstr, S32 begin_offset, F32 x, F32 y, cons
 	// Remember last-used texture to avoid unnecesssary bind calls.
 	LLImageGL *last_bound_texture = NULL;
 
+	const LLFontGlyphInfo* next_glyph = NULL;
+
 	for (i = begin_offset; i < begin_offset + length; i++)
 	{
 		llwchar wch = wstr[i];
 
-		const LLFontGlyphInfo* fgi= mFontFreetype->getGlyphInfo(wch);
+		const LLFontGlyphInfo* fgi = next_glyph;
+		next_glyph = NULL;
+		if(!fgi)
+		{
+			fgi = mFontFreetype->getGlyphInfo(wch);
+		}
 		if (!fgi)
 		{
 			llerrs << "Missing Glyph Info" << llendl;
@@ -295,7 +302,8 @@ S32 LLFontGL::render(const LLWString &wstr, S32 begin_offset, F32 x, F32 y, cons
 		if (next_char && (next_char < LAST_CHARACTER))
 		{
 			// Kern this puppy.
-			cur_x += mFontFreetype->getXKerning(wch, next_char);
+			next_glyph = mFontFreetype->getGlyphInfo(next_char);
+			cur_x += mFontFreetype->getXKerning(fgi, next_glyph);
 		}
 
 		// Round after kerning.
@@ -435,14 +443,21 @@ F32 LLFontGL::getWidthF32(const llwchar* wchars, S32 begin_offset, S32 max_chars
 	F32 cur_x = 0;
 	const S32 max_index = begin_offset + max_chars;
 
+	const LLFontGlyphInfo* next_glyph = NULL;
+
 	F32 width_padding = 0.f;
 	for (S32 i = begin_offset; i < max_index && wchars[i] != 0; i++)
 	{
 		llwchar wch = wchars[i];
 
-		const LLFontGlyphInfo* fgi= mFontFreetype->getGlyphInfo(wch);
+		const LLFontGlyphInfo* fgi = next_glyph;
+		next_glyph = NULL;
+		if(!fgi)
+		{
+			fgi = mFontFreetype->getGlyphInfo(wch);
+		}
 
-		F32 advance = mFontFreetype->getXAdvance(wch);
+		F32 advance = mFontFreetype->getXAdvance(fgi);
 
 		// for the last character we want to measure the greater of its width and xadvance values
 		// so keep track of the difference between these values for the each character we measure
@@ -459,7 +474,8 @@ F32 LLFontGL::getWidthF32(const llwchar* wchars, S32 begin_offset, S32 max_chars
 			&& (next_char < LAST_CHARACTER))
 		{
 			// Kern this puppy.
-			cur_x += mFontFreetype->getXKerning(wch, next_char);
+			next_glyph = mFontFreetype->getGlyphInfo(next_char);
+			cur_x += mFontFreetype->getXKerning(fgi, next_glyph);
 		}
 		// Round after kerning.
 		cur_x = (F32)llround(cur_x);
@@ -492,6 +508,8 @@ S32 LLFontGL::maxDrawableChars(const llwchar* wchars, F32 max_pixels, S32 max_ch
 	// avoid S32 overflow when max_pixels == S32_MAX by staying in floating point
 	F32 scaled_max_pixels =	ceil(max_pixels * sScaleX);
 	F32 width_padding = 0.f;
+	
+	LLFontGlyphInfo* next_glyph = NULL;
 
 	S32 i;
 	for (i=0; (i < max_chars); i++)
@@ -534,8 +552,13 @@ S32 LLFontGL::maxDrawableChars(const llwchar* wchars, F32 max_pixels, S32 max_ch
 				in_word = TRUE;
 			}
 		}
-
-		LLFontGlyphInfo* fgi = mFontFreetype->getGlyphInfo(wch);
+		
+		LLFontGlyphInfo* fgi = next_glyph;
+		next_glyph = NULL;
+		if(!fgi)
+		{
+			fgi = mFontFreetype->getGlyphInfo(wch);
+		}
 
 		// account for glyphs that run beyond the starting point for the next glyphs
 		width_padding = llmax(	0.f,													// always use positive padding amount
@@ -554,7 +577,8 @@ S32 LLFontGL::maxDrawableChars(const llwchar* wchars, F32 max_pixels, S32 max_ch
 		if (((i+1) < max_chars) && wchars[i+1])
 		{
 			// Kern this puppy.
-			cur_x += mFontFreetype->getXKerning(wch, wchars[i+1]);
+			next_glyph = mFontFreetype->getGlyphInfo(wchars[i+1]);
+			cur_x += mFontFreetype->getXKerning(fgi, next_glyph);
 		}
 
 		// Round after kerning.
@@ -660,6 +684,8 @@ S32 LLFontGL::charFromPixelOffset(const llwchar* wchars, S32 begin_offset, F32 t
 	const S32 max_index = begin_offset + llmin(S32_MAX - begin_offset, max_chars);
 
 	F32 scaled_max_pixels =	max_pixels * sScaleX;
+	
+	const LLFontGlyphInfo* next_glyph = NULL;
 
 	S32 pos;
 	for (pos = begin_offset; pos < max_index; pos++)
@@ -669,7 +695,15 @@ S32 LLFontGL::charFromPixelOffset(const llwchar* wchars, S32 begin_offset, F32 t
 		{
 			break; // done
 		}
-		F32 char_width = mFontFreetype->getXAdvance(wch);
+		
+		const LLFontGlyphInfo* glyph = next_glyph;
+		next_glyph = NULL;
+		if(!glyph)
+		{
+			glyph = mFontFreetype->getGlyphInfo(wch);
+		}
+		
+		F32 char_width = mFontFreetype->getXAdvance(glyph);
 
 		if (round)
 		{
@@ -695,11 +729,12 @@ S32 LLFontGL::charFromPixelOffset(const llwchar* wchars, S32 begin_offset, F32 t
 		if (((pos + 1) < max_index)
 			&& (wchars[(pos + 1)]))
 		{
-			llwchar next_char = wchars[pos + 1];
 			// Kern this puppy.
-			cur_x += mFontFreetype->getXKerning(wch, next_char);
+			next_glyph = mFontFreetype->getGlyphInfo(wchars[pos + 1]);
+			cur_x += mFontFreetype->getXKerning(glyph, next_glyph);
 		}
 
+
 		// Round after kerning.
 		cur_x = llround(cur_x);
 	}