Add Freetype support

1 files changed, 1146 insertions, 0 deletions

diff --git a/src/cguittfont/CGUITTFont.cpp b/src/cguittfont/CGUITTFont.cpp
new file mode 100644
index 000000000..fb8199e21
--- /dev/null
+++ b/src/cguittfont/CGUITTFont.cpp
@@ -0,0 +1,1146 @@
+/*
+   CGUITTFont FreeType class for Irrlicht
+   Copyright (c) 2009-2010 John Norman
+
+   This software is provided 'as-is', without any express or implied
+   warranty. In no event will the authors be held liable for any
+   damages arising from the use of this software.
+
+   Permission is granted to anyone to use this software for any
+   purpose, including commercial applications, and to alter it and
+   redistribute it freely, subject to the following restrictions:
+
+   1. The origin of this software must not be misrepresented; you
+      must not claim that you wrote the original software. If you use
+      this software in a product, an acknowledgment in the product
+      documentation would be appreciated but is not required.
+
+   2. Altered source versions must be plainly marked as such, and
+      must not be misrepresented as being the original software.
+
+   3. This notice may not be removed or altered from any source
+      distribution.
+
+   The original version of this class can be located at:
+   http://irrlicht.suckerfreegames.com/
+
+   John Norman
+   john@suckerfreegames.com
+*/
+
+#include <irrlicht.h>
+#include "CGUITTFont.h"
+
+namespace irr
+{
+namespace gui
+{
+
+// Manages the FT_Face cache.
+struct SGUITTFace : public virtual irr::IReferenceCounted
+{
+	SGUITTFace() : face_buffer(0), face_buffer_size(0)
+	{
+		memset((void*)&face, 0, sizeof(FT_Face));
+	}
+
+	~SGUITTFace()
+	{
+		FT_Done_Face(face);
+		delete[] face_buffer;
+	}
+
+	FT_Face face;
+	FT_Byte* face_buffer;
+	FT_Long face_buffer_size;
+};
+
+// Static variables.
+FT_Library CGUITTFont::c_library;
+core::map<io::path, SGUITTFace*> CGUITTFont::c_faces;
+bool CGUITTFont::c_libraryLoaded = false;
+scene::IMesh* CGUITTFont::shared_plane_ptr_ = 0;
+scene::SMesh CGUITTFont::shared_plane_;
+
+//
+
+video::IImage* SGUITTGlyph::createGlyphImage(const FT_Bitmap& bits, video::IVideoDriver* driver) const
+{
+	// Determine what our texture size should be.
+	// Add 1 because textures are inclusive-exclusive.
+	core::dimension2du d(bits.width + 1, bits.rows + 1);
+	core::dimension2du texture_size;
+	//core::dimension2du texture_size(bits.width + 1, bits.rows + 1);
+
+	// Create and load our image now.
+	video::IImage* image = 0;
+	switch (bits.pixel_mode)
+	{
+		case FT_PIXEL_MODE_MONO:
+		{
+			// Create a blank image and fill it with transparent pixels.
+			texture_size = d.getOptimalSize(true, true);
+			image = driver->createImage(video::ECF_A1R5G5B5, texture_size);
+			image->fill(video::SColor(0, 255, 255, 255));
+
+			// Load the monochrome data in.
+			const u32 image_pitch = image->getPitch() / sizeof(u16);
+			u16* image_data = (u16*)image->lock();
+			u8* glyph_data = bits.buffer;
+			for (s32 y = 0; y < bits.rows; ++y)
+			{
+				u16* row = image_data;
+				for (s32 x = 0; x < bits.width; ++x)
+				{
+					// Monochrome bitmaps store 8 pixels per byte.  The left-most pixel is the bit 0x80.
+					// So, we go through the data each bit at a time.
+					if ((glyph_data[y * bits.pitch + (x / 8)] & (0x80 >> (x % 8))) != 0)
+						*row = 0xFFFF;
+					++row;
+				}
+				image_data += image_pitch;
+			}
+			image->unlock();
+			break;
+		}
+
+		case FT_PIXEL_MODE_GRAY:
+		{
+			// Create our blank image.
+			texture_size = d.getOptimalSize(!driver->queryFeature(video::EVDF_TEXTURE_NPOT), !driver->queryFeature(video::EVDF_TEXTURE_NSQUARE), true, 0);
+			image = driver->createImage(video::ECF_A8R8G8B8, texture_size);
+			image->fill(video::SColor(0, 255, 255, 255));
+
+			// Load the grayscale data in.
+			const float gray_count = static_cast<float>(bits.num_grays);
+			const u32 image_pitch = image->getPitch() / sizeof(u32);
+			u32* image_data = (u32*)image->lock();
+			u8* glyph_data = bits.buffer;
+			for (s32 y = 0; y < bits.rows; ++y)
+			{
+				u8* row = glyph_data;
+				for (s32 x = 0; x < bits.width; ++x)
+				{
+					image_data[y * image_pitch + x] |= static_cast<u32>(255.0f * (static_cast<float>(*row++) / gray_count)) << 24;
+					//data[y * image_pitch + x] |= ((u32)(*bitsdata++) << 24);
+				}
+				glyph_data += bits.pitch;
+			}
+			image->unlock();
+			break;
+		}
+		default:
+			// TODO: error message?
+			return 0;
+	}
+	return image;
+}
+
+void SGUITTGlyph::preload(u32 char_index, FT_Face face, video::IVideoDriver* driver, u32 font_size, const FT_Int32 loadFlags)
+{
+	if (isLoaded) return;
+
+	// Set the size of the glyph.
+	FT_Set_Pixel_Sizes(face, 0, font_size);
+
+	// Attempt to load the glyph.
+	if (FT_Load_Glyph(face, char_index, loadFlags) != FT_Err_Ok)
+		// TODO: error message?
+		return;
+
+	FT_GlyphSlot glyph = face->glyph;
+	FT_Bitmap bits = glyph->bitmap;
+
+	// Setup the glyph information here:
+	advance = glyph->advance;
+	offset = core::vector2di(glyph->bitmap_left, glyph->bitmap_top);
+
+	// Try to get the last page with available slots.
+	CGUITTGlyphPage* page = parent->getLastGlyphPage();
+
+	// If we need to make a new page, do that now.
+	if (!page)
+	{
+		page = parent->createGlyphPage(bits.pixel_mode);
+		if (!page)
+			// TODO: add error message?
+			return;
+	}
+
+	glyph_page = parent->getLastGlyphPageIndex();
+	u32 texture_side_length = page->texture->getOriginalSize().Width;
+	core::vector2di page_position(
+		(page->used_slots % (texture_side_length / font_size)) * font_size,
+		(page->used_slots / (texture_side_length / font_size)) * font_size
+		);
+	source_rect.UpperLeftCorner = page_position;
+	source_rect.LowerRightCorner = core::vector2di(page_position.X + bits.width, page_position.Y + bits.rows);
+
+	page->dirty = true;
+	++page->used_slots;
+	--page->available_slots;
+
+	// We grab the glyph bitmap here so the data won't be removed when the next glyph is loaded.
+	surface = createGlyphImage(bits, driver);
+
+	// Set our glyph as loaded.
+	isLoaded = true;
+}
+
+void SGUITTGlyph::unload()
+{
+	if (surface)
+	{
+		surface->drop();
+		surface = 0;
+	}
+	isLoaded = false;
+}
+
+//////////////////////
+
+CGUITTFont* CGUITTFont::createTTFont(IGUIEnvironment *env, const io::path& filename, const u32 size, const bool antialias, const bool transparency)
+{
+	if (!c_libraryLoaded)
+	{
+		if (FT_Init_FreeType(&c_library))
+			return 0;
+		c_libraryLoaded = true;
+	}
+
+	CGUITTFont* font = new CGUITTFont(env);
+	bool ret = font->load(filename, size, antialias, transparency);
+	if (!ret)
+	{
+		font->drop();
+		return 0;
+	}
+
+	return font;
+}
+
+CGUITTFont* CGUITTFont::createTTFont(IrrlichtDevice *device, const io::path& filename, const u32 size, const bool antialias, const bool transparency)
+{
+	if (!c_libraryLoaded)
+	{
+		if (FT_Init_FreeType(&c_library))
+			return 0;
+		c_libraryLoaded = true;
+	}
+
+	CGUITTFont* font = new CGUITTFont(device->getGUIEnvironment());
+	font->Device = device;
+	bool ret = font->load(filename, size, antialias, transparency);
+	if (!ret)
+	{
+		font->drop();
+		return 0;
+	}
+
+	return font;
+}
+
+CGUITTFont* CGUITTFont::create(IGUIEnvironment *env, const io::path& filename, const u32 size, const bool antialias, const bool transparency)
+{
+	return CGUITTFont::createTTFont(env, filename, size, antialias, transparency);
+}
+
+CGUITTFont* CGUITTFont::create(IrrlichtDevice *device, const io::path& filename, const u32 size, const bool antialias, const bool transparency)
+{
+	return CGUITTFont::createTTFont(device, filename, size, antialias, transparency);
+}
+
+//////////////////////
+
+//! Constructor.
+CGUITTFont::CGUITTFont(IGUIEnvironment *env)
+: use_monochrome(false), use_transparency(true), use_hinting(true), use_auto_hinting(true),
+batch_load_size(1), Device(0), Environment(env), Driver(0), GlobalKerningWidth(0), GlobalKerningHeight(0)
+{
+	#ifdef _DEBUG
+	setDebugName("CGUITTFont");
+	#endif
+
+	if (Environment)
+	{
+		// don't grab environment, to avoid circular references
+		Driver = Environment->getVideoDriver();
+	}
+
+	if (Driver)
+		Driver->grab();
+
+	setInvisibleCharacters(L" ");
+
+	// Glyphs aren't reference counted, so don't try to delete them when we free the array.
+	Glyphs.set_free_when_destroyed(false);
+}
+
+bool CGUITTFont::load(const io::path& filename, const u32 size, const bool antialias, const bool transparency)
+{
+	// Some sanity checks.
+	if (Environment == 0 || Driver == 0) return false;
+	if (size == 0) return false;
+	if (filename.size() == 0) return false;
+
+	io::IFileSystem* filesystem = Environment->getFileSystem();
+	irr::ILogger* logger = (Device != 0 ? Device->getLogger() : 0);
+	this->size = size;
+	this->filename = filename;
+
+	// Update the font loading flags when the font is first loaded.
+	this->use_monochrome = !antialias;
+	this->use_transparency = transparency;
+	update_load_flags();
+
+	// Log.
+	if (logger)
+		logger->log(L"CGUITTFont", core::stringw(core::stringw(L"Creating new font: ") + core::ustring(filename).toWCHAR_s() + L" " + core::stringc(size) + L"pt " + (antialias ? L"+antialias " : L"-antialias ") + (transparency ? L"+transparency" : L"-transparency")).c_str(), irr::ELL_INFORMATION);
+
+	// Grab the face.
+	SGUITTFace* face = 0;
+	core::map<io::path, SGUITTFace*>::Node* node = c_faces.find(filename);
+	if (node == 0)
+	{
+		face = new SGUITTFace();
+		c_faces.set(filename, face);
+
+		if (filesystem)
+		{
+			// Read in the file data.
+			io::IReadFile* file = filesystem->createAndOpenFile(filename);
+			if (file == 0)
+			{
+				if (logger) logger->log(L"CGUITTFont", L"Failed to open the file.", irr::ELL_INFORMATION);
+
+				c_faces.remove(filename);
+				delete face;
+				face = 0;
+				return false;
+			}
+			face->face_buffer = new FT_Byte[file->getSize()];
+			file->read(face->face_buffer, file->getSize());
+			face->face_buffer_size = file->getSize();
+			file->drop();
+
+			// Create the face.
+			if (FT_New_Memory_Face(c_library, face->face_buffer, face->face_buffer_size, 0, &face->face))
+			{
+				if (logger) logger->log(L"CGUITTFont", L"FT_New_Memory_Face failed.", irr::ELL_INFORMATION);
+
+				c_faces.remove(filename);
+				delete face;
+				face = 0;
+				return false;
+			}
+		}
+		else
+		{
+			core::ustring converter(filename);
+			if (FT_New_Face(c_library, reinterpret_cast<const char*>(converter.toUTF8_s().c_str()), 0, &face->face))
+			{
+				if (logger) logger->log(L"CGUITTFont", L"FT_New_Face failed.", irr::ELL_INFORMATION);
+
+				c_faces.remove(filename);
+				delete face;
+				face = 0;
+				return false;
+			}
+		}
+	}
+	else
+	{
+		// Using another instance of this face.
+		face = node->getValue();
+		face->grab();
+	}
+
+	// Store our face.
+	tt_face = face->face;
+
+	// Store font metrics.
+	FT_Set_Pixel_Sizes(tt_face, size, 0);
+	font_metrics = tt_face->size->metrics;
+
+	// Allocate our glyphs.
+	Glyphs.clear();
+	Glyphs.reallocate(tt_face->num_glyphs);
+	Glyphs.set_used(tt_face->num_glyphs);
+	for (FT_Long i = 0; i < tt_face->num_glyphs; ++i)
+	{
+		Glyphs[i].isLoaded = false;
+		Glyphs[i].glyph_page = 0;
+		Glyphs[i].source_rect = core::recti();
+		Glyphs[i].offset = core::vector2di();
+		Glyphs[i].advance = FT_Vector();
+		Glyphs[i].surface = 0;
+		Glyphs[i].parent = this;
+	}
+
+	// Cache the first 127 ascii characters.
+	u32 old_size = batch_load_size;
+	batch_load_size = 127;
+	getGlyphIndexByChar((uchar32_t)0);
+	batch_load_size = old_size;
+
+	return true;
+}
+
+CGUITTFont::~CGUITTFont()
+{
+	// Delete the glyphs and glyph pages.
+	reset_images();
+	CGUITTAssistDelete::Delete(Glyphs);
+	//Glyphs.clear();
+
+	// We aren't using this face anymore.
+	core::map<io::path, SGUITTFace*>::Node* n = c_faces.find(filename);
+	if (n)
+	{
+		SGUITTFace* f = n->getValue();
+
+		// Drop our face.  If this was the last face, the destructor will clean up.
+		if (f->drop())
+			c_faces.remove(filename);
+
+		// If there are no more faces referenced by FreeType, clean up.
+		if (c_faces.size() == 0)
+		{
+			FT_Done_FreeType(c_library);
+			c_libraryLoaded = false;
+		}
+	}
+
+	// Drop our driver now.
+	if (Driver)
+		Driver->drop();
+}
+
+void CGUITTFont::reset_images()
+{
+	// Delete the glyphs.
+	for (u32 i = 0; i != Glyphs.size(); ++i)
+		Glyphs[i].unload();
+
+	// Unload the glyph pages from video memory.
+	for (u32 i = 0; i != Glyph_Pages.size(); ++i)
+		delete Glyph_Pages[i];
+	Glyph_Pages.clear();
+
+	// Always update the internal FreeType loading flags after resetting.
+	update_load_flags();
+}
+
+void CGUITTFont::update_glyph_pages() const
+{
+	for (u32 i = 0; i != Glyph_Pages.size(); ++i)
+	{
+		if (Glyph_Pages[i]->dirty)
+			Glyph_Pages[i]->updateTexture();
+	}
+}
+
+CGUITTGlyphPage* CGUITTFont::getLastGlyphPage() const
+{
+	CGUITTGlyphPage* page = 0;
+	if (Glyph_Pages.empty())
+		return 0;
+	else
+	{
+		page = Glyph_Pages[getLastGlyphPageIndex()];
+		if (page->available_slots == 0)
+			page = 0;
+	}
+	return page;
+}
+
+CGUITTGlyphPage* CGUITTFont::createGlyphPage(const u8& pixel_mode)
+{
+	CGUITTGlyphPage* page = 0;
+	
+	// Name of our page.
+	io::path name("TTFontGlyphPage_");
+	name += tt_face->family_name;
+	name += ".";
+	name += tt_face->style_name;
+	name += ".";
+	name += size;
+	name += "_";
+	name += Glyph_Pages.size(); // The newly created page will be at the end of the collection.
+
+	// Create the new page.
+	page = new CGUITTGlyphPage(Driver, name);
+
+	// Determine our maximum texture size.
+	// If we keep getting 0, set it to 1024x1024, as that number is pretty safe.
+	core::dimension2du max_texture_size = max_page_texture_size;
+	if (max_texture_size.Width == 0 || max_texture_size.Height == 0)
+		max_texture_size = Driver->getMaxTextureSize();
+	if (max_texture_size.Width == 0 || max_texture_size.Height == 0)
+		max_texture_size = core::dimension2du(1024, 1024);
+
+	// We want to try to put at least 144 glyphs on a single texture.
+	core::dimension2du page_texture_size;
+	if (size <= 21) page_texture_size = core::dimension2du(256, 256);
+	else if (size <= 42) page_texture_size = core::dimension2du(512, 512);
+	else if (size <= 84) page_texture_size = core::dimension2du(1024, 1024);
+	else if (size <= 168) page_texture_size = core::dimension2du(2048, 2048);
+	else page_texture_size = core::dimension2du(4096, 4096);
+
+	if (page_texture_size.Width > max_texture_size.Width || page_texture_size.Height > max_texture_size.Height)
+		page_texture_size = max_texture_size;
+
+	if (!page->createPageTexture(pixel_mode, page_texture_size))
+		// TODO: add error message?
+		return 0;
+
+	if (page)
+	{
+		// Determine the number of glyph slots on the page and add it to the list of pages.
+		page->available_slots = (page_texture_size.Width / size) * (page_texture_size.Height / size);
+		Glyph_Pages.push_back(page);
+	}
+	return page;
+}
+
+void CGUITTFont::setTransparency(const bool flag)
+{
+	use_transparency = flag;
+	reset_images();
+}
+
+void CGUITTFont::setMonochrome(const bool flag)
+{
+	use_monochrome = flag;
+	reset_images();
+}
+
+void CGUITTFont::setFontHinting(const bool enable, const bool enable_auto_hinting)
+{
+	use_hinting = enable;
+	use_auto_hinting = enable_auto_hinting;
+	reset_images();
+}
+
+void CGUITTFont::draw(const core::stringw& text, const core::rect<s32>& position, video::SColor color, bool hcenter, bool vcenter, const core::rect<s32>* clip)
+{
+	if (!Driver)
+		return;
+
+	// Clear the glyph pages of their render information.
+	for (u32 i = 0; i < Glyph_Pages.size(); ++i)
+	{
+		Glyph_Pages[i]->render_positions.clear();
+		Glyph_Pages[i]->render_source_rects.clear();
+	}
+
+	// Set up some variables.
+	core::dimension2d<s32> textDimension;
+	core::position2d<s32> offset = position.UpperLeftCorner;
+
+	// Determine offset positions.
+	if (hcenter || vcenter)
+	{
+		textDimension = getDimension(text.c_str());
+
+		if (hcenter)
+			offset.X = ((position.getWidth() - textDimension.Width) >> 1) + offset.X;
+
+		if (vcenter)
+			offset.Y = ((position.getHeight() - textDimension.Height) >> 1) + offset.Y;
+	}
+
+	// Convert to a unicode string.
+	core::ustring utext(text);
+
+	// Set up our render map.
+	core::map<u32, CGUITTGlyphPage*> Render_Map;
+
+	// Start parsing characters.
+	u32 n;
+	uchar32_t previousChar = 0;
+	core::ustring::const_iterator iter(utext);
+	while (!iter.atEnd())
+	{
+		uchar32_t currentChar = *iter;
+		n = getGlyphIndexByChar(currentChar);
+		bool visible = (Invisible.findFirst(currentChar) == -1);
+		if (n > 0 && visible)
+		{
+			bool lineBreak=false;
+			if (currentChar == L'\r') // Mac or Windows breaks
+			{
+				lineBreak = true;
+				if (*(iter + 1) == (uchar32_t)'\n')	// Windows line breaks.
+					currentChar = *(++iter);
+			}
+			else if (currentChar == (uchar32_t)'\n') // Unix breaks
+			{
+				lineBreak = true;
+			}
+
+			if (lineBreak)
+			{
+				previousChar = 0;
+				offset.Y += font_metrics.ascender / 64;
+				offset.X = position.UpperLeftCorner.X;
+
+				if (hcenter)
+					offset.X += (position.getWidth() - textDimension.Width) >> 1;
+				++iter;
+				continue;
+			}
+
+			// Calculate the glyph offset.
+			s32 offx = Glyphs[n-1].offset.X;
+			s32 offy = (font_metrics.ascender / 64) - Glyphs[n-1].offset.Y;
+
+			// Apply kerning.
+			core::vector2di k = getKerning(currentChar, previousChar);
+			offset.X += k.X;
+			offset.Y += k.Y;
+
+			// Determine rendering information.
+			SGUITTGlyph& glyph = Glyphs[n-1];
+			CGUITTGlyphPage* const page = Glyph_Pages[glyph.glyph_page];
+			page->render_positions.push_back(core::position2di(offset.X + offx, offset.Y + offy));
+			page->render_source_rects.push_back(glyph.source_rect);
+			Render_Map.set(glyph.glyph_page, page);
+		}
+		offset.X += getWidthFromCharacter(currentChar);
+
+		previousChar = currentChar;
+		++iter;
+	}
+
+	// Draw now.
+	update_glyph_pages();
+	core::map<u32, CGUITTGlyphPage*>::Iterator j = Render_Map.getIterator();
+	while (!j.atEnd())
+	{
+		core::map<u32, CGUITTGlyphPage*>::Node* n = j.getNode();
+		j++;
+		if (n == 0) continue;
+
+		CGUITTGlyphPage* page = n->getValue();
+
+		if (!use_transparency) color.color |= 0xff000000;
+		Driver->draw2DImageBatch(page->texture, page->render_positions, page->render_source_rects, clip, color, true);
+	}
+}
+
+core::dimension2d<u32> CGUITTFont::getCharDimension(const wchar_t ch) const
+{
+	return core::dimension2d<u32>(getWidthFromCharacter(ch), getHeightFromCharacter(ch));
+}
+
+core::dimension2d<u32> CGUITTFont::getDimension(const wchar_t* text) const
+{
+	return getDimension(core::ustring(text));
+}
+
+core::dimension2d<u32> CGUITTFont::getDimension(const core::ustring& text) const
+{
+	// Get the maximum font height.  Unfortunately, we have to do this hack as
+	// Irrlicht will draw things wrong.  In FreeType, the font size is the
+	// maximum size for a single glyph, but that glyph may hang "under" the
+	// draw line, increasing the total font height to beyond the set size.
+	// Irrlicht does not understand this concept when drawing fonts.  Also, I
+	// add +1 to give it a 1 pixel blank border.  This makes things like
+	// tooltips look nicer.
+	s32 test1 = getHeightFromCharacter((uchar32_t)'g') + 1;
+	s32 test2 = getHeightFromCharacter((uchar32_t)'j') + 1;
+	s32 test3 = getHeightFromCharacter((uchar32_t)'_') + 1;
+	s32 max_font_height = core::max_(test1, core::max_(test2, test3));
+
+	core::dimension2d<u32> text_dimension(0, max_font_height);
+	core::dimension2d<u32> line(0, max_font_height);
+
+	uchar32_t previousChar = 0;
+	core::ustring::const_iterator iter = text.begin();
+	for (; !iter.atEnd(); ++iter)
+	{
+		uchar32_t p = *iter;
+		bool lineBreak = false;
+		if (p == '\r')	// Mac or Windows line breaks.
+		{
+			lineBreak = true;
+			if (*(iter + 1) == '\n')
+			{
+				++iter;
+				p = *iter;
+			}
+		}
+		else if (p == '\n')	// Unix line breaks.
+		{
+			lineBreak = true;
+		}
+
+		// Kerning.
+		core::vector2di k = getKerning(p, previousChar);
+		line.Width += k.X;
+		previousChar = p;
+
+		// Check for linebreak.
+		if (lineBreak)
+		{
+			previousChar = 0;
+			text_dimension.Height += line.Height;
+			if (text_dimension.Width < line.Width)
+				text_dimension.Width = line.Width;
+			line.Width = 0;
+			line.Height = max_font_height;
+			continue;
+		}
+		line.Width += getWidthFromCharacter(p);
+	}
+	if (text_dimension.Width < line.Width)
+		text_dimension.Width = line.Width;
+
+	return text_dimension;
+}
+
+inline u32 CGUITTFont::getWidthFromCharacter(wchar_t c) const
+{
+	return getWidthFromCharacter((uchar32_t)c);
+}
+
+inline u32 CGUITTFont::getWidthFromCharacter(uchar32_t c) const
+{
+	// Set the size of the face.
+	// This is because we cache faces and the face may have been set to a different size.
+	//FT_Set_Pixel_Sizes(tt_face, 0, size);
+
+	u32 n = getGlyphIndexByChar(c);
+	if (n > 0)
+	{
+		int w = Glyphs[n-1].advance.x / 64;
+		return w;
+	}
+	if (c >= 0x2000)
+		return (font_metrics.ascender / 64);
+	else return (font_metrics.ascender / 64) / 2;
+}
+
+inline u32 CGUITTFont::getHeightFromCharacter(wchar_t c) const
+{
+	return getHeightFromCharacter((uchar32_t)c);
+}
+
+inline u32 CGUITTFont::getHeightFromCharacter(uchar32_t c) const
+{
+	// Set the size of the face.
+	// This is because we cache faces and the face may have been set to a different size.
+	//FT_Set_Pixel_Sizes(tt_face, 0, size);
+
+	u32 n = getGlyphIndexByChar(c);
+	if (n > 0)
+	{
+		// Grab the true height of the character, taking into account underhanging glyphs.
+		s32 height = (font_metrics.ascender / 64) - Glyphs[n-1].offset.Y + Glyphs[n-1].source_rect.getHeight();
+		return height;
+	}
+	if (c >= 0x2000)
+		return (font_metrics.ascender / 64);
+	else return (font_metrics.ascender / 64) / 2;
+}
+
+u32 CGUITTFont::getGlyphIndexByChar(wchar_t c) const
+{
+	return getGlyphIndexByChar((uchar32_t)c);
+}
+
+u32 CGUITTFont::getGlyphIndexByChar(uchar32_t c) const
+{
+	// Get the glyph.
+	u32 glyph = FT_Get_Char_Index(tt_face, c);
+
+	// Check for a valid glyph.  If it is invalid, attempt to use the replacement character.
+	if (glyph == 0)
+		glyph = FT_Get_Char_Index(tt_face, core::unicode::UTF_REPLACEMENT_CHARACTER);
+
+	// If our glyph is already loaded, don't bother doing any batch loading code.
+	if (glyph != 0 && Glyphs[glyph - 1].isLoaded)
+		return glyph;
+
+	// Determine our batch loading positions.
+	u32 half_size = (batch_load_size / 2);
+	u32 start_pos = 0;
+	if (c > half_size) start_pos = c - half_size;
+	u32 end_pos = start_pos + batch_load_size;
+
+	// Load all our characters.
+	do
+	{
+		// Get the character we are going to load.
+		u32 char_index = FT_Get_Char_Index(tt_face, start_pos);
+
+		// If the glyph hasn't been loaded yet, do it now.
+		if (char_index)
+		{
+			SGUITTGlyph& glyph = Glyphs[char_index - 1];
+			if (!glyph.isLoaded)
+			{
+				glyph.preload(char_index, tt_face, Driver, size, load_flags);
+				Glyph_Pages[glyph.glyph_page]->pushGlyphToBePaged(&glyph);
+			}
+		}
+	}
+	while (++start_pos < end_pos);
+
+	// Return our original character.
+	return glyph;
+}
+
+s32 CGUITTFont::getCharacterFromPos(const wchar_t* text, s32 pixel_x) const
+{
+	return getCharacterFromPos(core::ustring(text), pixel_x);
+}
+
+s32 CGUITTFont::getCharacterFromPos(const core::ustring& text, s32 pixel_x) const
+{
+	s32 x = 0;
+	//s32 idx = 0;
+
+	u32 character = 0;
+	uchar32_t previousChar = 0;
+	core::ustring::const_iterator iter = text.begin();
+	while (!iter.atEnd())
+	{
+		uchar32_t c = *iter;
+		x += getWidthFromCharacter(c);
+
+		// Kerning.
+		core::vector2di k = getKerning(c, previousChar);
+		x += k.X;
+
+		if (x >= pixel_x)
+			return character;
+
+		previousChar = c;
+		++iter;
+		++character;
+	}
+
+	return -1;
+}
+
+void CGUITTFont::setKerningWidth(s32 kerning)
+{
+	GlobalKerningWidth = kerning;
+}
+
+void CGUITTFont::setKerningHeight(s32 kerning)
+{
+	GlobalKerningHeight = kerning;
+}
+
+s32 CGUITTFont::getKerningWidth(const wchar_t* thisLetter, const wchar_t* previousLetter) const
+{
+	if (tt_face == 0)
+		return GlobalKerningWidth;
+	if (thisLetter == 0 || previousLetter == 0)
+		return 0;
+
+	return getKerningWidth((uchar32_t)*thisLetter, (uchar32_t)*previousLetter);
+}
+
+s32 CGUITTFont::getKerningWidth(const uchar32_t thisLetter, const uchar32_t previousLetter) const
+{
+	// Return only the kerning width.
+	return getKerning(thisLetter, previousLetter).X;
+}
+
+s32 CGUITTFont::getKerningHeight() const
+{
+	// FreeType 2 currently doesn't return any height kerning information.
+	return GlobalKerningHeight;
+}
+
+core::vector2di CGUITTFont::getKerning(const wchar_t thisLetter, const wchar_t previousLetter) const
+{
+	return getKerning((uchar32_t)thisLetter, (uchar32_t)previousLetter);
+}
+
+core::vector2di CGUITTFont::getKerning(const uchar32_t thisLetter, const uchar32_t previousLetter) const
+{
+	if (tt_face == 0 || thisLetter == 0 || previousLetter == 0)
+		return core::vector2di();
+
+	// Set the size of the face.
+	// This is because we cache faces and the face may have been set to a different size.
+	FT_Set_Pixel_Sizes(tt_face, 0, size);
+
+	core::vector2di ret(GlobalKerningWidth, GlobalKerningHeight);
+
+	// If we don't have kerning, no point in continuing.
+	if (!FT_HAS_KERNING(tt_face))
+		return ret;
+
+	// Get the kerning information.
+	FT_Vector v;
+	FT_Get_Kerning(tt_face, getGlyphIndexByChar(previousLetter), getGlyphIndexByChar(thisLetter), FT_KERNING_DEFAULT, &v);
+
+	// If we have a scalable font, the return value will be in font points.
+	if (FT_IS_SCALABLE(tt_face))
+	{
+		// Font points, so divide by 64.
+		ret.X += (v.x / 64);
+		ret.Y += (v.y / 64);
+	}
+	else
+	{
+		// Pixel units.
+		ret.X += v.x;
+		ret.Y += v.y;
+	}
+	return ret;
+}
+
+void CGUITTFont::setInvisibleCharacters(const wchar_t *s)
+{
+	core::ustring us(s);
+	Invisible = us;
+}
+
+void CGUITTFont::setInvisibleCharacters(const core::ustring& s)
+{
+	Invisible = s;
+}
+
+video::IImage* CGUITTFont::createTextureFromChar(const uchar32_t& ch)
+{
+	u32 n = getGlyphIndexByChar(ch);
+	const SGUITTGlyph& glyph = Glyphs[n-1];
+	CGUITTGlyphPage* page = Glyph_Pages[glyph.glyph_page];
+
+	if (page->dirty)
+		page->updateTexture();
+
+	video::ITexture* tex = page->texture;
+
+	// Acquire a read-only lock of the corresponding page texture.
+	#if IRRLICHT_VERSION_MAJOR==1 && IRRLICHT_VERSION_MINOR>=8
+	void* ptr = tex->lock(video::ETLM_READ_ONLY);
+	#else
+	void* ptr = tex->lock(true);
+	#endif
+
+	video::ECOLOR_FORMAT format = tex->getColorFormat();
+	core::dimension2du tex_size = tex->getOriginalSize();
+	video::IImage* pageholder = Driver->createImageFromData(format, tex_size, ptr, true, false);
+
+	// Copy the image data out of the page texture.
+	core::dimension2du glyph_size(glyph.source_rect.getSize());
+	video::IImage* image = Driver->createImage(format, glyph_size);
+	pageholder->copyTo(image, core::position2di(0, 0), glyph.source_rect);
+
+	tex->unlock();
+	return image;
+}
+
+video::ITexture* CGUITTFont::getPageTextureByIndex(const u32& page_index) const
+{
+	if (page_index < Glyph_Pages.size())
+		return Glyph_Pages[page_index]->texture;
+	else
+		return 0;
+}
+
+void CGUITTFont::createSharedPlane()
+{
+	/*
+		2___3
+		|  /|
+		| / |	<-- plane mesh is like this, point 2 is (0,0), point 0 is (0, -1)
+		|/  |	<-- the texture coords of point 2 is (0,0, point 0 is (0, 1)
+		0---1
+	*/
+
+	using namespace core;
+	using namespace video;
+	using namespace scene;
+	S3DVertex vertices[4];
+	u16 indices[6] = {0,2,3,3,1,0};
+	vertices[0] = S3DVertex(vector3df(0,-1,0), vector3df(0,0,-1), SColor(255,255,255,255), vector2df(0,1));
+	vertices[1] = S3DVertex(vector3df(1,-1,0), vector3df(0,0,-1), SColor(255,255,255,255), vector2df(1,1));
+	vertices[2] = S3DVertex(vector3df(0, 0,0), vector3df(0,0,-1), SColor(255,255,255,255), vector2df(0,0));
+	vertices[3] = S3DVertex(vector3df(1, 0,0), vector3df(0,0,-1), SColor(255,255,255,255), vector2df(1,0));
+
+	SMeshBuffer* buf = new SMeshBuffer();
+	buf->append(vertices, 4, indices, 6);
+
+	shared_plane_.addMeshBuffer( buf );
+
+	shared_plane_ptr_ = &shared_plane_;
+	buf->drop(); //the addMeshBuffer method will grab it, so we can drop this ptr.
+}
+
+core::dimension2d<u32> CGUITTFont::getDimensionUntilEndOfLine(const wchar_t* p) const
+{
+	core::stringw s;
+	for (const wchar_t* temp = p; temp && *temp != '\0' && *temp != L'\r' && *temp != L'\n'; ++temp )
+		s.append(*temp);
+
+	return getDimension(s.c_str());
+}
+
+core::array<scene::ISceneNode*> CGUITTFont::addTextSceneNode(const wchar_t* text, scene::ISceneManager* smgr, scene::ISceneNode* parent, const video::SColor& color, bool center)
+{
+	using namespace core;
+	using namespace video;
+	using namespace scene;
+
+	array<scene::ISceneNode*> container;
+
+	if (!Driver || !smgr) return container;
+	if (!parent)
+		parent = smgr->addEmptySceneNode(smgr->getRootSceneNode(), -1);
+	// if you don't specify parent, then we add a empty node attached to the root node
+	// this is generally undesirable.
+
+	if (!shared_plane_ptr_) //this points to a static mesh that contains the plane
+		createSharedPlane(); //if it's not initialized, we create one.
+
+	dimension2d<s32> text_size(getDimension(text)); //convert from unsigned to signed.
+	vector3df start_point(0, 0, 0), offset;
+
+	/** NOTICE:
+		Because we are considering adding texts into 3D world, all Y axis vectors are inverted.
+	**/
+
+	// There's currently no "vertical center" concept when you apply text scene node to the 3D world.
+	if (center)
+	{
+		offset.X = start_point.X = -text_size.Width / 2.f;
+		offset.Y = start_point.Y = +text_size.Height/ 2.f;
+		offset.X += (text_size.Width - getDimensionUntilEndOfLine(text).Width) >> 1;
+	}
+
+	// the default font material
+	SMaterial mat;
+	mat.setFlag(video::EMF_LIGHTING, true);
+	mat.setFlag(video::EMF_ZWRITE_ENABLE, false);
+	mat.setFlag(video::EMF_NORMALIZE_NORMALS, true);
+	mat.ColorMaterial = video::ECM_NONE;
+	mat.MaterialType = use_transparency ? video::EMT_TRANSPARENT_ALPHA_CHANNEL : video::EMT_SOLID;
+	mat.MaterialTypeParam = 0.01f;
+	mat.DiffuseColor = color;
+
+	wchar_t current_char = 0, previous_char = 0;
+	u32 n = 0;
+
+	array<u32> glyph_indices;
+
+	while (*text)
+	{
+		current_char = *text;
+		bool line_break=false;
+		if (current_char == L'\r') // Mac or Windows breaks
+		{
+			line_break = true;
+			if (*(text + 1) == L'\n') // Windows line breaks.
+				current_char = *(++text);
+		}
+		else if (current_char == L'\n') // Unix breaks
+		{
+			line_break = true;
+		}
+
+		if (line_break)
+		{
+			previous_char = 0;
+			offset.Y -= tt_face->size->metrics.ascender / 64;
+			offset.X = start_point.X;
+			if (center)
+				offset.X += (text_size.Width - getDimensionUntilEndOfLine(text+1).Width) >> 1;
+			++text;
+		}
+		else
+		{
+			n = getGlyphIndexByChar(current_char);
+			if (n > 0)
+			{
+				glyph_indices.push_back( n );
+
+				// Store glyph size and offset informations.
+				SGUITTGlyph const& glyph = Glyphs[n-1];
+				u32 texw = glyph.source_rect.getWidth();
+				u32 texh = glyph.source_rect.getHeight();
+				s32 offx = glyph.offset.X;
+				s32 offy = (font_metrics.ascender / 64) - glyph.offset.Y;
+
+				// Apply kerning.
+				vector2di k = getKerning(current_char, previous_char);
+				offset.X += k.X;
+				offset.Y += k.Y;
+
+				vector3df current_pos(offset.X + offx, offset.Y - offy, 0);
+				dimension2d<u32> letter_size = dimension2d<u32>(texw, texh);
+
+				// Now we copy planes corresponding to the letter size.
+				IMeshManipulator* mani = smgr->getMeshManipulator();
+				IMesh* meshcopy = mani->createMeshCopy(shared_plane_ptr_);
+				#if IRRLICHT_VERSION_MAJOR==1 && IRRLICHT_VERSION_MINOR>=8
+				mani->scale(meshcopy, vector3df((f32)letter_size.Width, (f32)letter_size.Height, 1));
+				#else
+				mani->scaleMesh(meshcopy, vector3df((f32)letter_size.Width, (f32)letter_size.Height, 1));
+				#endif
+
+				ISceneNode* current_node = smgr->addMeshSceneNode(meshcopy, parent, -1, current_pos);
+				meshcopy->drop();
+
+				current_node->getMaterial(0) = mat;
+				current_node->setAutomaticCulling(EAC_OFF);
+				current_node->setIsDebugObject(true);  //so the picking won't have any effect on individual letter
+				//current_node->setDebugDataVisible(EDS_BBOX); //de-comment this when debugging
+
+				container.push_back(current_node);
+			}
+			offset.X += getWidthFromCharacter(current_char);
+			previous_char = current_char;
+			++text;
+		}
+	}
+
+	update_glyph_pages();
+	//only after we update the textures can we use the glyph page textures.
+
+	for (u32 i = 0; i < glyph_indices.size(); ++i)
+	{
+		u32 n = glyph_indices[i];
+		SGUITTGlyph const& glyph = Glyphs[n-1];
+		ITexture* current_tex = Glyph_Pages[glyph.glyph_page]->texture;
+		f32 page_texture_size = (f32)current_tex->getSize().Width;
+		//Now we calculate the UV position according to the texture size and the source rect.
+		//
+		//  2___3
+		//  |  /|
+		//  | / |	<-- plane mesh is like this, point 2 is (0,0), point 0 is (0, -1)
+		//  |/  |	<-- the texture coords of point 2 is (0,0, point 0 is (0, 1)
+		//  0---1
+		//
+		f32 u1 = glyph.source_rect.UpperLeftCorner.X / page_texture_size;
+		f32 u2 = u1 + (glyph.source_rect.getWidth() / page_texture_size);
+		f32 v1 = glyph.source_rect.UpperLeftCorner.Y / page_texture_size;
+		f32 v2 = v1 + (glyph.source_rect.getHeight() / page_texture_size);
+
+		//we can be quite sure that this is IMeshSceneNode, because we just added them in the above loop.
+		IMeshSceneNode* node = static_cast<IMeshSceneNode*>(container[i]);
+
+		S3DVertex* pv = static_cast<S3DVertex*>(node->getMesh()->getMeshBuffer(0)->getVertices());
+		//pv[0].TCoords.Y = pv[1].TCoords.Y = (letter_size.Height - 1) / static_cast<f32>(letter_size.Height);
+		//pv[1].TCoords.X = pv[3].TCoords.X = (letter_size.Width - 1)  / static_cast<f32>(letter_size.Width);
+		pv[0].TCoords = vector2df(u1, v2);
+		pv[1].TCoords = vector2df(u2, v2);
+		pv[2].TCoords = vector2df(u1, v1);
+		pv[3].TCoords = vector2df(u2, v1);
+
+		container[i]->getMaterial(0).setTexture(0, current_tex);
+	}
+
+	return container;
+}
+
+} // end namespace gui
+} // end namespace irr