// static
BOOL LLFontGL::initDefaultFonts(F32 screen_dpi, F32 x_scale, F32 y_scale,
								const std::string& app_dir,
								const std::vector<std::string>& xui_paths)
{
	bool succ = true;
	sVertDPI = (F32)llfloor(screen_dpi * y_scale);
	sHorizDPI = (F32)llfloor(screen_dpi * x_scale);
	sScaleX = x_scale;
	sScaleY = y_scale;
	sAppDir = app_dir;

	// Font registry init
	if (!sFontRegistry)
	{
		sFontRegistry = new LLFontRegistry(xui_paths);
		sFontRegistry->parseFontInfo("fonts.xml");
	}
	else
	{
		sFontRegistry->reset();
	}

	// Force standard fonts to get generated up front.
	// This is primarily for error detection purposes.
 	succ &= (NULL != getFontSansSerifSmall());
 	succ &= (NULL != getFontSansSerif());
 	succ &= (NULL != getFontSansSerifBig());
 	succ &= (NULL != getFontSansSerifHuge());
 	succ &= (NULL != getFontSansSerifBold());
 	succ &= (NULL != getFontMonospace());
	succ &= (NULL != getFontExtChar());
	
	return succ;
}
// Force standard fonts to get generated up front.
// This is primarily for error detection purposes.
// Don't do this during initClass because it can be slow and we want to get
// the viewer window on screen first. JC
// static
bool LLFontGL::loadDefaultFonts()
{
	bool succ = true;
	succ &= (NULL != getFontSansSerifSmall());
	succ &= (NULL != getFontSansSerif());
	succ &= (NULL != getFontSansSerifBig());
	succ &= (NULL != getFontSansSerifHuge());
	succ &= (NULL != getFontSansSerifBold());
	succ &= (NULL != getFontMonospace());
	succ &= (NULL != getFontExtChar());
	return succ;
}
F32 LLFontGL::getEmbeddedCharAdvance(const embedded_data_t* ext_data) const
{
	const LLWString& label = ext_data->mLabel;
	LLImageGL* ext_image = ext_data->mImage;

	F32 ext_width = (F32)ext_image->getWidth();
	if( !label.empty() )
	{
		ext_width += (EXT_X_BEARING + getFontExtChar()->getWidthF32(label.c_str())) * sScaleX;
	}

	return (EXT_X_BEARING * sScaleX) + ext_width;
}
S32 LLFontGL::render(const LLWString &wstr, 
					 const S32 begin_offset,
					 const F32 x, const F32 y,
					 const LLColor4 &color,
					 const HAlign halign, const VAlign valign,
					 U8 style,
					 const S32 max_chars, S32 max_pixels,
					 F32* right_x,
					 BOOL use_embedded,
					 BOOL use_ellipses) const
{
	if(!sDisplayFont) //do not display texts
	{
		return wstr.length() ;
	}

	if (wstr.empty())
	{
		return 0;
	} 

	gGL.getTexUnit(0)->enable(LLTexUnit::TT_TEXTURE);

	S32 scaled_max_pixels = max_pixels == S32_MAX ? S32_MAX : llceil((F32)max_pixels * sScaleX);

	// Strip off any style bits that are already accounted for by the font.
	style = style & (~getFontDesc().getStyle());

	F32 drop_shadow_strength = 0.f;
	if (style & (DROP_SHADOW | DROP_SHADOW_SOFT))
	{
		F32 luminance;
		color.calcHSL(NULL, NULL, &luminance);
		drop_shadow_strength = clamp_rescale(luminance, 0.35f, 0.6f, 0.f, 1.f);
		if (luminance < 0.35f)
		{
			style = style & ~(DROP_SHADOW | DROP_SHADOW_SOFT);
		}
	}

	gGL.pushMatrix();
	glLoadIdentity();
	gGL.translatef(floorf(sCurOrigin.mX*sScaleX), floorf(sCurOrigin.mY*sScaleY), sCurOrigin.mZ);

	// this code snaps the text origin to a pixel grid to start with
	F32 pixel_offset_x = llround((F32)sCurOrigin.mX) - (sCurOrigin.mX);
	F32 pixel_offset_y = llround((F32)sCurOrigin.mY) - (sCurOrigin.mY);
	gGL.translatef(-pixel_offset_x, -pixel_offset_y, 0.f);

	LLFastTimer t(LLFastTimer::FTM_RENDER_FONTS);

	gGL.color4fv( color.mV );

	S32 chars_drawn = 0;
	S32 i;
	S32 length;

	if (-1 == max_chars)
	{
		length = (S32)wstr.length() - begin_offset;
	}
	else
	{
		length = llmin((S32)wstr.length() - begin_offset, max_chars );
	}

	F32 cur_x, cur_y, cur_render_x, cur_render_y;

 	// Not guaranteed to be set correctly
	gGL.setSceneBlendType(LLRender::BT_ALPHA);
	
	cur_x = ((F32)x * sScaleX);
	cur_y = ((F32)y * sScaleY);

	// Offset y by vertical alignment.
	switch (valign)
	{
	case TOP:
		cur_y -= mAscender;
		break;
	case BOTTOM:
		cur_y += mDescender;
		break;
	case VCENTER:
		cur_y -= ((mAscender - mDescender)/2.f);
		break;
	case BASELINE:
		// Baseline, do nothing.
		break;
	default:
		break;
	}

	switch (halign)
	{
	case LEFT:
		break;
	case RIGHT:
	  	cur_x -= llmin(scaled_max_pixels, llround(getWidthF32(wstr.c_str(), 0, length) * sScaleX));
		break;
	case HCENTER:
	    cur_x -= llmin(scaled_max_pixels, llround(getWidthF32(wstr.c_str(), 0, length) * sScaleX)) / 2;
		break;
	default:
		break;
	}

	cur_render_y = cur_y;
	cur_render_x = cur_x;

	F32 start_x = cur_x;

	F32 inv_width = 1.f / mFontBitmapCachep->getBitmapWidth();
	F32 inv_height = 1.f / mFontBitmapCachep->getBitmapHeight();

	const S32 LAST_CHARACTER = LLFont::LAST_CHAR_FULL;


	BOOL draw_ellipses = FALSE;
	if (use_ellipses && halign == LEFT)
	{
		// check for too long of a string
		if (getWidthF32(wstr.c_str(), 0, max_chars) * sScaleX > scaled_max_pixels)
		{
			// use four dots for ellipsis width to generate padding
			const LLWString dots(utf8str_to_wstring(std::string("....")));
			scaled_max_pixels = llmax(0, scaled_max_pixels - llround(getWidthF32(dots.c_str())));
			draw_ellipses = TRUE;
		}
	}


	// Remember last-used texture to avoid unnecesssary bind calls.
	LLImageGL *last_bound_texture = NULL;

	for (i = begin_offset; i < begin_offset + length; i++)
	{
		llwchar wch = wstr[i];

		// Handle embedded characters first, if they're enabled.
		// Embedded characters are a hack for notecards
		const embedded_data_t* ext_data = use_embedded ? getEmbeddedCharData(wch) : NULL;
		if (ext_data)
		{
			LLImageGL* ext_image = ext_data->mImage;
			const LLWString& label = ext_data->mLabel;

			F32 ext_height = (F32)ext_image->getHeight() * sScaleY;

			F32 ext_width = (F32)ext_image->getWidth() * sScaleX;
			F32 ext_advance = (EXT_X_BEARING * sScaleX) + ext_width;

			if (!label.empty())
			{
				ext_advance += (EXT_X_BEARING + getFontExtChar()->getWidthF32( label.c_str() )) * sScaleX;
			}

			if (start_x + scaled_max_pixels < cur_x + ext_advance)
			{
				// Not enough room for this character.
				break;
			}

			if (last_bound_texture != ext_image)
			{
				gGL.getTexUnit(0)->bind(ext_image);
				last_bound_texture = ext_image;
			}

			// snap origin to whole screen pixel
			const F32 ext_x = (F32)llround(cur_render_x + (EXT_X_BEARING * sScaleX));
			const F32 ext_y = (F32)llround(cur_render_y + (EXT_Y_BEARING * sScaleY + mAscender - mLineHeight));

			LLRectf uv_rect(0.f, 1.f, 1.f, 0.f);
			LLRectf screen_rect(ext_x, ext_y + ext_height, ext_x + ext_width, ext_y);
			drawGlyph(screen_rect, uv_rect, LLColor4::white, style, drop_shadow_strength);

			if (!label.empty())
			{
				gGL.pushMatrix();
				//glLoadIdentity();
				//gGL.translatef(sCurOrigin.mX, sCurOrigin.mY, 0.0f);
				//glScalef(sScaleX, sScaleY, 1.f);
				getFontExtChar()->render(label, 0,
									 /*llfloor*/((ext_x + (F32)ext_image->getWidth() + EXT_X_BEARING) / sScaleX), 
									 /*llfloor*/(cur_y / sScaleY),
									 color,
									 halign, BASELINE, NORMAL, S32_MAX, S32_MAX, NULL,
									 TRUE );
				gGL.popMatrix();
			}

			gGL.color4fv(color.mV);

			chars_drawn++;
			cur_x += ext_advance;
			if (((i + 1) < length) && wstr[i+1])
			{
				cur_x += EXT_KERNING * sScaleX;
			}
			cur_render_x = cur_x;
		}
		else
		{
			if (!hasGlyph(wch))
			{
				addChar(wch);
			}

			const LLFontGlyphInfo* fgi= getGlyphInfo(wch);
			if (!fgi)
			{
				llerrs << "Missing Glyph Info" << llendl;
				break;
			}
			// Per-glyph bitmap texture.
			LLImageGL *image_gl = mFontBitmapCachep->getImageGL(fgi->mBitmapNum);
			if (last_bound_texture != image_gl)
			{
				gGL.getTexUnit(0)->bind(image_gl);
				last_bound_texture = image_gl;
			}

			if ((start_x + scaled_max_pixels) < (cur_x + fgi->mXBearing + fgi->mWidth))
			{
				// Not enough room for this character.
				break;
			}

			// Draw the text at the appropriate location
			//Specify vertices and texture coordinates
			LLRectf uv_rect((fgi->mXBitmapOffset) * inv_width,
					(fgi->mYBitmapOffset + fgi->mHeight + PAD_UVY) * inv_height,
					(fgi->mXBitmapOffset + fgi->mWidth) * inv_width,
					(fgi->mYBitmapOffset - PAD_UVY) * inv_height);
			// snap glyph origin to whole screen pixel
			LLRectf screen_rect(llround(cur_render_x + (F32)fgi->mXBearing),
					    llround(cur_render_y + (F32)fgi->mYBearing),
					    llround(cur_render_x + (F32)fgi->mXBearing) + (F32)fgi->mWidth,
					    llround(cur_render_y + (F32)fgi->mYBearing) - (F32)fgi->mHeight);
			
			drawGlyph(screen_rect, uv_rect, color, style, drop_shadow_strength);

			chars_drawn++;
			cur_x += fgi->mXAdvance;
			cur_y += fgi->mYAdvance;

			llwchar next_char = wstr[i+1];
			if (next_char && (next_char < LAST_CHARACTER))
			{
				// Kern this puppy.
				if (!hasGlyph(next_char))
				{
					addChar(next_char);
				}
				cur_x += getXKerning(wch, next_char);
			}

			// Round after kerning.
			// Must do this to cur_x, not just to cur_render_x, otherwise you
			// will squish sub-pixel kerned characters too close together.
			// For example, "CCCCC" looks bad.
			cur_x = (F32)llfloor(cur_x + 0.5f);
			//cur_y = (F32)llfloor(cur_y + 0.5f);

			cur_render_x = cur_x;
			cur_render_y = cur_y;
		}
	}

	if (right_x)
	{
		*right_x = cur_x / sScaleX;
	}

	if (style & UNDERLINE)
	{
		gGL.getTexUnit(0)->unbind(LLTexUnit::TT_TEXTURE);
		gGL.begin(LLRender::LINES);
		gGL.vertex2f(start_x, cur_y - (mDescender));
		gGL.vertex2f(cur_x, cur_y - (mDescender));
		gGL.end();
	}

	// *FIX: get this working in all alignment cases, etc.
	if (draw_ellipses)
	{
		// recursively render ellipses at end of string
		// we've already reserved enough room
		gGL.pushMatrix();
		//glLoadIdentity();
		//gGL.translatef(sCurOrigin.mX, sCurOrigin.mY, 0.0f);
		//glScalef(sScaleX, sScaleY, 1.f);
		renderUTF8(std::string("..."), 
				0,
				cur_x / sScaleX, (F32)y,
				color,
				LEFT, valign,
				style,
				S32_MAX, max_pixels,
				right_x,
				FALSE); 
		gGL.popMatrix();
	}

	gGL.popMatrix();

	return chars_drawn;
}
S32 LLFontGL::render(const LLWString &wstr, S32 begin_offset, F32 x, F32 y, const LLColor4 &color, HAlign halign, VAlign valign, U8 style, 
					 ShadowType shadow, S32 max_chars, S32 max_pixels, F32* right_x, BOOL use_embedded, BOOL use_ellipses) const
{
	LLFastTimer _(FTM_RENDER_FONTS);

	if(!sDisplayFont) //do not display texts
	{
		return wstr.length() ;
	}

	if (wstr.empty() || !max_pixels)
	{
		return 0;
	} 

	if (max_chars == -1)
		max_chars = S32_MAX;

	const S32 max_index = llmin(llmax(max_chars, begin_offset + max_chars), S32(wstr.length()));
	if (max_index <= 0 || begin_offset >= max_index || max_pixels <= 0)
		return 0;

	gGL.getTexUnit(0)->enable(LLTexUnit::TT_TEXTURE);

	S32 scaled_max_pixels = max_pixels == S32_MAX ? S32_MAX : llceil((F32)max_pixels * sScaleX);

	// Strip off any style bits that are already accounted for by the font.
	style = style & (~getFontDesc().getStyle());

	F32 drop_shadow_strength = 0.f;
	if (shadow != NO_SHADOW)
	{
		F32 luminance;
		color.calcHSL(NULL, NULL, &luminance);
		drop_shadow_strength = clamp_rescale(luminance, 0.35f, 0.6f, 0.f, 1.f);
		if (luminance < 0.35f)
		{
			shadow = NO_SHADOW;
		}
	}

	gGL.pushUIMatrix();

	gGL.loadUIIdentity();
	
	LLVector2 origin(floorf(sCurOrigin.mX*sScaleX), floorf(sCurOrigin.mY*sScaleY));

	// Depth translation, so that floating text appears 'in-world'
	// and is correctly occluded.
	gGL.translatef(0.f,0.f,sCurDepth);

	S32 chars_drawn = 0;
	S32 i;
	S32 length = max_index - begin_offset;

	F32 cur_x, cur_y, cur_render_x, cur_render_y;

 	// Not guaranteed to be set correctly
	gGL.setSceneBlendType(LLRender::BT_ALPHA);
	
	cur_x = ((F32)x * sScaleX) + origin.mV[VX];
	cur_y = ((F32)y * sScaleY) + origin.mV[VY];

	// Offset y by vertical alignment.
	// use unscaled font metrics here
	switch (valign)
	{
	case TOP:
		cur_y -= llceil(mFontFreetype->getAscenderHeight());
		break;
	case BOTTOM:
		cur_y += llceil(mFontFreetype->getDescenderHeight());
		break;
	case VCENTER:
		cur_y -= llceil((llceil(mFontFreetype->getAscenderHeight()) - llceil(mFontFreetype->getDescenderHeight())) / 2.f);
		break;
	case BASELINE:
		// Baseline, do nothing.
		break;
	default:
		break;
	}

	switch (halign)
	{
	case LEFT:
		break;
	case RIGHT:
	  	cur_x -= llmin(scaled_max_pixels, ll_round(getWidthF32(wstr.c_str(), begin_offset, length) * sScaleX));
		break;
	case HCENTER:
	    cur_x -= llmin(scaled_max_pixels, ll_round(getWidthF32(wstr.c_str(), begin_offset, length) * sScaleX)) / 2;
		break;
	default:
		break;
	}

	cur_render_y = cur_y;
	cur_render_x = cur_x;

	F32 start_x = (F32)ll_round(cur_x);

	const LLFontBitmapCache* font_bitmap_cache = mFontFreetype->getFontBitmapCache();

	F32 inv_width = 1.f / font_bitmap_cache->getBitmapWidth();
	F32 inv_height = 1.f / font_bitmap_cache->getBitmapHeight();

	const S32 LAST_CHARACTER = LLFontFreetype::LAST_CHAR_FULL;


	BOOL draw_ellipses = FALSE;
	if (use_ellipses && halign == LEFT)
	{
		// check for too long of a string
		S32 string_width = ll_round(getWidthF32(wstr, begin_offset, max_chars) * sScaleX);
		if (string_width > scaled_max_pixels)
		{
			// use four dots for ellipsis width to generate padding
			const LLWString dots(utf8str_to_wstring(std::string("....")));
			scaled_max_pixels = llmax(0, scaled_max_pixels - ll_round(getWidthF32(dots.c_str())));
			draw_ellipses = TRUE;
		}
	}

	const LLFontGlyphInfo* next_glyph = NULL;

	const S32 GLYPH_BATCH_SIZE = 30;
	static LL_ALIGN_16(LLVector4a vertices[GLYPH_BATCH_SIZE * 4]);
	static LLVector2 uvs[GLYPH_BATCH_SIZE * 4];
	static LLColor4U colors[GLYPH_BATCH_SIZE * 4];

	LLColor4U text_color(color);

	S32 bitmap_num = -1;
	S32 glyph_count = 0;
	for (i = begin_offset; i < begin_offset + length; i++)
	{
		llwchar wch = wstr[i];

		// Handle embedded characters first, if they're enabled.
		// Embedded characters are a hack for notecards
		const embedded_data_t* ext_data = use_embedded ? getEmbeddedCharData(wch) : NULL;
		if (ext_data)
		{
			LLImageGL* ext_image = ext_data->mImage;
			const LLWString& label = ext_data->mLabel;

			F32 ext_height = (F32)ext_image->getHeight() * sScaleY;

			F32 ext_width = (F32)ext_image->getWidth() * sScaleX;
			F32 ext_advance = (EXT_X_BEARING * sScaleX) + ext_width;

			if (!label.empty())
			{
				ext_advance += (EXT_X_BEARING + getFontExtChar()->getWidthF32( label.c_str() )) * sScaleX;
			}

			if (start_x + scaled_max_pixels < cur_x + ext_advance)
			{
				// Not enough room for this character.
				break;
			}

			gGL.getTexUnit(0)->bind(ext_image);

			// snap origin to whole screen pixel
			const F32 ext_x = (F32)ll_round(cur_render_x + (EXT_X_BEARING * sScaleX));
			const F32 ext_y = (F32)ll_round(cur_render_y + (EXT_Y_BEARING * sScaleY + mFontFreetype->getAscenderHeight() - mFontFreetype->getLineHeight()));

			LLRectf uv_rect(0.f, 1.f, 1.f, 0.f);
			LLRectf screen_rect(ext_x, ext_y + ext_height, ext_x + ext_width, ext_y);

			if (glyph_count > 0)
			{
				gGL.begin(LLRender::QUADS);
				{
					gGL.vertexBatchPreTransformed(vertices, uvs, colors, glyph_count * 4);
				}
				gGL.end();
				glyph_count = 0;
			}
			renderQuad(vertices, uvs, colors, screen_rect, uv_rect, LLColor4U::white, 0);
			//No batching here. It will never happen.
			gGL.begin(LLRender::QUADS);
			{
				gGL.vertexBatchPreTransformed(vertices, uvs, colors, 4);
			}
			gGL.end();

			if (!label.empty())
			{
				gGL.pushMatrix();
				getFontExtChar()->render(label, 0,
									 /*llfloor*/(ext_x / sScaleX) + ext_image->getWidth() + EXT_X_BEARING - sCurOrigin.mX, 
									 /*llfloor*/(cur_render_y / sScaleY) - sCurOrigin.mY,
									 color,
									 halign, BASELINE, UNDERLINE, NO_SHADOW, S32_MAX, S32_MAX, NULL,
									 TRUE );
				gGL.popMatrix();
			}

			chars_drawn++;
			cur_x += ext_advance;
			if (((i + 1) < length) && wstr[i+1])
			{
				cur_x += EXT_KERNING * sScaleX;
			}
			cur_render_x = cur_x;
		}
		else
		{
			const LLFontGlyphInfo* fgi = next_glyph;
			next_glyph = NULL;
			if(!fgi)
			{
				fgi = mFontFreetype->getGlyphInfo(wch);
			}
			if (!fgi)
			{
				LL_ERRS() << "Missing Glyph Info" << LL_ENDL;
				break;
			}
			// Per-glyph bitmap texture.
			S32 next_bitmap_num = fgi->mBitmapNum;
			if (next_bitmap_num != bitmap_num)
			{
				// Actually draw the queued glyphs before switching their texture;
				// otherwise the queued glyphs will be taken from wrong textures.
				if (glyph_count > 0)
				{
					gGL.begin(LLRender::QUADS);
					{
						gGL.vertexBatchPreTransformed(vertices, uvs, colors, glyph_count * 4);
					}
					gGL.end();
					glyph_count = 0;
				}

				bitmap_num = next_bitmap_num;
				LLImageGL *font_image = font_bitmap_cache->getImageGL(bitmap_num);
				gGL.getTexUnit(0)->bind(font_image);
			}

			if ((start_x + scaled_max_pixels) < (cur_x + fgi->mXBearing + fgi->mWidth))
			{
				// Not enough room for this character.
				break;
			}

			// Draw the text at the appropriate location
			//Specify vertices and texture coordinates
			LLRectf uv_rect((fgi->mXBitmapOffset) * inv_width,
					(fgi->mYBitmapOffset + fgi->mHeight + PAD_UVY) * inv_height,
					(fgi->mXBitmapOffset + fgi->mWidth) * inv_width,
				(fgi->mYBitmapOffset - PAD_UVY) * inv_height);
			// snap glyph origin to whole screen pixel
			LLRectf screen_rect((F32)ll_round(cur_render_x + (F32)fgi->mXBearing),
				    (F32)ll_round(cur_render_y + (F32)fgi->mYBearing),
				    (F32)ll_round(cur_render_x + (F32)fgi->mXBearing) + (F32)fgi->mWidth,
				    (F32)ll_round(cur_render_y + (F32)fgi->mYBearing) - (F32)fgi->mHeight);
			
			if (glyph_count >= GLYPH_BATCH_SIZE)
			{
				gGL.begin(LLRender::QUADS);
				{
					gGL.vertexBatchPreTransformed(vertices, uvs, colors, glyph_count * 4);
				}
				gGL.end();

				glyph_count = 0;
			}

			drawGlyph(glyph_count, vertices, uvs, colors, screen_rect, uv_rect, text_color, style, shadow, drop_shadow_strength);

			chars_drawn++;
			cur_x += fgi->mXAdvance;
			cur_y += fgi->mYAdvance;

			llwchar next_char = wstr[i+1];
			if (next_char && (next_char < LAST_CHARACTER))
			{
				// Kern this puppy.
				next_glyph = mFontFreetype->getGlyphInfo(next_char);
				cur_x += mFontFreetype->getXKerning(fgi, next_glyph);
			}

			// Round after kerning.
			// Must do this to cur_x, not just to cur_render_x, otherwise you
			// will squish sub-pixel kerned characters too close together.
			// For example, "CCCCC" looks bad.
			cur_x = (F32)ll_round(cur_x);
			//cur_y = (F32)ll_round(cur_y);

			cur_render_x = cur_x;
			cur_render_y = cur_y;
		}
	}

	if(glyph_count)
	{
		gGL.begin(LLRender::QUADS);
		{
			gGL.vertexBatchPreTransformed(vertices, uvs, colors, glyph_count * 4);
		}
		gGL.end();
	}


	if (right_x)
	{
		*right_x = (cur_x - origin.mV[VX]) / sScaleX;
	}

	if (style & UNDERLINE)
	{
		F32 descender = (F32)llfloor(mFontFreetype->getDescenderHeight());

		gGL.getTexUnit(0)->unbind(LLTexUnit::TT_TEXTURE);
		gGL.begin(LLRender::LINES);
		gGL.vertex2f(start_x, cur_y - descender);
		gGL.vertex2f(cur_x, cur_y - descender);
		gGL.end();
	}

	if (draw_ellipses)
	{

		// recursively render ellipses at end of string
		// we've already reserved enough room
		gGL.pushUIMatrix();
		renderUTF8(std::string("..."), 
				0,
				(cur_x - origin.mV[VX]) / sScaleX, (F32)y,
				color,
				LEFT, valign,
				style,
				shadow,
				S32_MAX, max_pixels,
				right_x,
				FALSE); 
		gGL.popUIMatrix();
	}

	gGL.popUIMatrix();

	return chars_drawn;
}