ES-DE/es-core/src/resources/Font.cpp

#include "resources/Font.h"
#include <iostream>
#include <algorithm>
#include <vector>
#include <boost/filesystem.hpp>
#include "Renderer.h"
#include "Log.h"
#include "Util.h"

FT_Library Font::sLibrary = NULL;

int Font::getSize() const { return mSize; }

std::map< std::pair<std::string, int>, std::weak_ptr<Font> > Font::sFontMap;


// utf8 stuff
size_t Font::getNextCursor(const std::string& str, size_t cursor)
{
	// compare to character at the cursor
	const char& c = str[cursor];

	size_t result = cursor;
	if((c & 0x80) == 0) // 0xxxxxxx, one byte character
	{
		result += 1;
	}
	else if((c & 0xE0) == 0xC0) // 110xxxxx, two bytes left in character
	{
		result += 2;
	}
	else if((c & 0xF0) == 0xE0) // 1110xxxx, three bytes left in character
	{
		result += 3;
	}
	else if((c & 0xF8) == 0xF0) // 11110xxx, four bytes left in character
	{
		result += 4;
	}
	else
	{
		// error, invalid utf8 string
		
		// if this assert is tripped, the cursor is in the middle of a utf8 code point
		assert((c & 0xC0) != 0x80); // character is 10xxxxxx

		// if that wasn't it, something crazy happened
		assert(false);
	}

	if(str.length() < result || result < cursor) // don't go beyond the very end of the string, try and catch overflow
		return cursor;
	return result;
}

// note: will happily accept malformed utf8
size_t Font::getPrevCursor(const std::string& str, size_t cursor)
{
	if(cursor == 0)
		return 0;

	do
	{
		cursor--;
	} while(cursor > 0 &&
		(str[cursor] & 0xC0) == 0x80); // character is 10xxxxxx

	return cursor;
}

size_t Font::moveCursor(const std::string& str, size_t cursor, int amt)
{
	if(amt > 0)
	{
		for(int i = 0; i < amt; i++)
			cursor = Font::getNextCursor(str, cursor);
	}
	else if(amt < 0)
	{
		for(int i = amt; i < 0; i++)
			cursor = Font::getPrevCursor(str, cursor);
	}

	return cursor;
}

UnicodeChar Font::readUnicodeChar(const std::string& str, size_t& cursor)
{
	const char& c = str[cursor];

	if((c & 0x80) == 0) // 0xxxxxxx, one byte character
	{
		// 0xxxxxxx
		cursor++;
		return (UnicodeChar)c;
	}
	else if((c & 0xE0) == 0xC0) // 110xxxxx, two bytes left in character
	{
		// 110xxxxx 10xxxxxx
		UnicodeChar val = ((str[cursor] & 0x1F) << 6) |
			(str[cursor + 1] & 0x3F);
		cursor += 2;
		return val;
	}
	else if((c & 0xF0) == 0xE0) // 1110xxxx, three bytes left in character
	{
		// 1110xxxx 10xxxxxx 10xxxxxx
		UnicodeChar val = ((str[cursor] & 0x0F) << 12) |
			((str[cursor + 1] & 0x3F) << 6) |
			 (str[cursor + 2] & 0x3F);
		cursor += 3;
		return val;
	}
	else if((c & 0xF8) == 0xF0) // 11110xxx, four bytes left in character
	{
		// 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
		UnicodeChar val = ((str[cursor] & 0x07) << 18) |
			((str[cursor + 1] & 0x3F) << 12) |
			((str[cursor + 2] & 0x3F) << 6) |
			 (str[cursor + 3] & 0x3F);
		cursor += 4;
		return val;
	}
	else
	{
		// error, invalid utf8 string

		// if this assert is tripped, the cursor is in the middle of a utf8 code point
		assert((c & 0xC0) != 0x80); // character is 10xxxxxx

		// if that wasn't it, something crazy happened
		assert(false);
	}

	// error
	return 0;
}


void Font::initLibrary()
{
	assert(sLibrary == NULL);
	if(FT_Init_FreeType(&sLibrary))
	{
		sLibrary = NULL;
		LOG(LogError) << "Error initializing FreeType!";
	}
}

size_t Font::getMemUsage() const
{
	size_t memUsage = 0;
	for(auto it = mTextures.begin(); it != mTextures.end(); it++)
		memUsage += it->textureSize.x() * it->textureSize.y() * 4;

	return memUsage;
}

size_t Font::getTotalMemUsage()
{
	size_t total = 0;

	auto it = sFontMap.begin();
	while(it != sFontMap.end())
	{
		if(it->second.expired())
		{
			it = sFontMap.erase(it);
			continue;
		}

		total += it->second.lock()->getMemUsage();
		it++;
	}

	return total;
}

Font::Font(int size, const std::string& path) : mSize(size), mPath(path)
{
	assert(mSize > 0);
	
	if(!sLibrary)
		initLibrary();

	// always initialize ASCII characters
	for(UnicodeChar i = 32; i < 128; i++)
		getGlyph(i);
}

Font::~Font()
{
	unload(ResourceManager::getInstance());
}

void Font::reload(std::shared_ptr<ResourceManager>& rm)
{
	rebuildTextures();
}

void Font::unload(std::shared_ptr<ResourceManager>& rm)
{
	unloadTextures();
}

std::shared_ptr<Font> Font::get(int size, const std::string& path)
{
	const std::string canonicalPath = getCanonicalPath(path);

	std::pair<std::string, int> def(canonicalPath.empty() ? getDefaultPath() : canonicalPath, size);
	auto foundFont = sFontMap.find(def);
	if(foundFont != sFontMap.end())
	{
		if(!foundFont->second.expired())
			return foundFont->second.lock();
	}

	std::shared_ptr<Font> font = std::shared_ptr<Font>(new Font(def.second, def.first));
	sFontMap[def] = std::weak_ptr<Font>(font);
	ResourceManager::getInstance()->addReloadable(font);
	return font;
}

void Font::unloadTextures()
{
	for(auto it = mTextures.begin(); it != mTextures.end(); it++)
	{
		it->deinitTexture();
	}
}

Font::FontTexture::FontTexture()
{
	textureId = 0;
	textureSize << 2048, 512;
	writePos = Eigen::Vector2i::Zero();
	rowHeight = 0;
}

Font::FontTexture::~FontTexture()
{
	deinitTexture();
}

bool Font::FontTexture::findEmpty(const Eigen::Vector2i& size, Eigen::Vector2i& cursor_out)
{
	if(size.x() >= textureSize.x() || size.y() >= textureSize.y())
		return false;

	if(writePos.x() + size.x() >= textureSize.x() &&
		writePos.y() + rowHeight + size.y() + 1 < textureSize.y())
	{
		// row full, but it should fit on the next row
		// move cursor to next row
		writePos << 0, writePos.y() + rowHeight + 1; // leave 1px of space between glyphs
		rowHeight = 0;
	}

	if(writePos.x() + size.x() >= textureSize.x() ||
		writePos.y() + size.y() >= textureSize.y())
	{
		// nope, still won't fit
		return false;
	}

	cursor_out = writePos;
	writePos[0] += size.x() + 1; // leave 1px of space between glyphs

	if(size.y() > rowHeight)
		rowHeight = size.y();

	return true;
}

void Font::FontTexture::initTexture()
{
	assert(textureId == 0);

	glGenTextures(1, &textureId);
	glBindTexture(GL_TEXTURE_2D, textureId);

	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

	glPixelStorei(GL_PACK_ALIGNMENT, 1);
	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, textureSize.x(), textureSize.y(), 0, GL_ALPHA, GL_UNSIGNED_BYTE, NULL);
}

void Font::FontTexture::deinitTexture()
{
	if(textureId != 0)
	{
		glDeleteTextures(1, &textureId);
		textureId = 0;
	}
}

void Font::getTextureForNewGlyph(const Eigen::Vector2i& glyphSize, FontTexture*& tex_out, Eigen::Vector2i& cursor_out)
{
	if(mTextures.size())
	{
		// check if the most recent texture has space
		tex_out = &mTextures.back();

		// will this one work?
		if(tex_out->findEmpty(glyphSize, cursor_out))
			return; // yes
	}

	// current textures are full,
	// make a new one
	mTextures.push_back(FontTexture());
	tex_out = &mTextures.back();
	tex_out->initTexture();
	
	bool ok = tex_out->findEmpty(glyphSize, cursor_out);
	if(!ok)
	{
		LOG(LogError) << "Glyph too big to fit on a new texture (glyph size > " << tex_out->textureSize.x() << ", " << tex_out->textureSize.y() << ")!";
		tex_out = NULL;
	}
}

Font::Glyph* Font::getGlyph(UnicodeChar id)
{
	// is it already loaded?
	auto it = mGlyphMap.find(id);
	if(it != mGlyphMap.end())
		return &it->second;

	// nope, need to make a glyph
	// get the font data
	ResourceData data = ResourceManager::getInstance()->getFileData(mPath);

	FT_Face face;
	if(FT_New_Memory_Face(sLibrary, data.ptr.get(), data.length, 0, &face))
	{
		LOG(LogError) << "Error creating font face! (mPath: " << mPath << ", data.length: " << data.length << ")";
		return NULL;
	}

	FT_Set_Pixel_Sizes(face, 0, mSize);

	FT_GlyphSlot g = face->glyph;

	if(FT_Load_Char(face, id, FT_LOAD_RENDER))
	{
		LOG(LogError) << "Could not find glyph for character " << id << " for font " << mPath << ", size " << mSize << "!";
		return NULL;
	}

	Eigen::Vector2i glyphSize(g->bitmap.width, g->bitmap.rows);

	FontTexture* tex = NULL;
	Eigen::Vector2i cursor;
	getTextureForNewGlyph(glyphSize, tex, cursor);

	// getTextureForNewGlyph can fail if the glyph is bigger than the max texture size (absurdly large font size)
	if(tex == NULL)
	{
		LOG(LogError) << "Could not create glyph for character " << id << " for font " << mPath << ", size " << mSize << " (no suitable texture found)!";
		return NULL;
	}

	// create glyph
	Glyph& glyph = mGlyphMap[id];
	
	glyph.texture = tex;
	glyph.texPos << cursor.x() / (float)tex->textureSize.x(), cursor.y() / (float)tex->textureSize.y();
	glyph.texSize << glyphSize.x() / (float)tex->textureSize.x(), glyphSize.y() / (float)tex->textureSize.y();

	glyph.advance << (float)g->metrics.horiAdvance / 64.0f, (float)g->metrics.vertAdvance / 64.0f;
	glyph.bearing << (float)g->metrics.horiBearingX / 64.0f, (float)g->metrics.horiBearingY / 64.0f;

	// upload glyph bitmap to texture
	glBindTexture(GL_TEXTURE_2D, tex->textureId);
	glTexSubImage2D(GL_TEXTURE_2D, 0, cursor.x(), cursor.y(), glyphSize.x(), glyphSize.y(), GL_ALPHA, GL_UNSIGNED_BYTE, g->bitmap.buffer);
	glBindTexture(GL_TEXTURE_2D, 0);

	// free the FT face
	FT_Done_Face(face);

	// update max glyph height
	if(glyphSize.y() > mMaxGlyphHeight)
		mMaxGlyphHeight = glyphSize.y();

	// done
	return &glyph;
}

// completely recreate the texture data for all textures based on mGlyphs information
void Font::rebuildTextures()
{
	// recreate OpenGL textures
	for(auto it = mTextures.begin(); it != mTextures.end(); it++)
	{
		it->initTexture();
	}

	// open the font file
	ResourceData data = ResourceManager::getInstance()->getFileData(mPath);

	// load the font with FT
	FT_Face face;
	FT_New_Memory_Face(sLibrary, data.ptr.get(), data.length, 0, &face);

	// set the size
	FT_Set_Pixel_Sizes(face, 0, mSize);

	FT_GlyphSlot glyphSlot = face->glyph;
	
	// reupload the texture data
	for(auto it = mGlyphMap.begin(); it != mGlyphMap.end(); it++)
	{
		// load the glyph bitmap through FT
		FT_Load_Char(face, it->first, FT_LOAD_RENDER);

		FontTexture* tex = it->second.texture;
		
		// find the position/size
		Eigen::Vector2i cursor(it->second.texPos.x() * tex->textureSize.x(), it->second.texPos.y() * tex->textureSize.y());
		Eigen::Vector2i glyphSize(it->second.texSize.x() * tex->textureSize.x(), it->second.texSize.y() * tex->textureSize.y());
		
		// upload to texture
		glBindTexture(GL_TEXTURE_2D, tex->textureId);
		glTexSubImage2D(GL_TEXTURE_2D, 0, cursor.x(), cursor.y(), glyphSize.x(), glyphSize.y(), GL_ALPHA, GL_UNSIGNED_BYTE, glyphSlot->bitmap.buffer);
	}

	glBindTexture(GL_TEXTURE_2D, 0);

	// free the FT face
	FT_Done_Face(face);
}

void Font::renderTextCache(TextCache* cache)
{
	if(cache == NULL)
	{
		LOG(LogError) << "Attempted to draw NULL TextCache!";
		return;
	}

	for(auto it = cache->vertexLists.begin(); it != cache->vertexLists.end(); it++)
	{
		assert(*it->textureIdPtr != 0);

		auto vertexList = *it;

		glBindTexture(GL_TEXTURE_2D, *it->textureIdPtr);
		glEnable(GL_TEXTURE_2D);
		glEnable(GL_BLEND);
		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

		glEnableClientState(GL_VERTEX_ARRAY);
		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
		glEnableClientState(GL_COLOR_ARRAY);

		glVertexPointer(2, GL_FLOAT, sizeof(TextCache::Vertex), it->verts[0].pos.data());
		glTexCoordPointer(2, GL_FLOAT, sizeof(TextCache::Vertex), it->verts[0].tex.data());
		glColorPointer(4, GL_UNSIGNED_BYTE, 0, it->colors.data());

		glDrawArrays(GL_TRIANGLES, 0, it->verts.size());

		glDisableClientState(GL_VERTEX_ARRAY);
		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
		glDisableClientState(GL_COLOR_ARRAY);

		glDisable(GL_TEXTURE_2D);
		glDisable(GL_BLEND);
	}
}

Eigen::Vector2f Font::sizeText(std::string text, float lineSpacing)
{
	float lineWidth = 0.0f;
	float highestWidth = 0.0f;

	const float lineHeight = getHeight(lineSpacing);

	float y = lineHeight;

	size_t i = 0;
	while(i < text.length())
	{
		UnicodeChar character = readUnicodeChar(text, i); // advances i

		if(character == (UnicodeChar)'\n')
		{
			if(lineWidth > highestWidth)
				highestWidth = lineWidth;

			lineWidth = 0.0f;
			y += lineHeight;
		}

		lineWidth += getGlyph(character)->advance.x();
	}

	if(lineWidth > highestWidth)
		highestWidth = lineWidth;

	return Eigen::Vector2f(highestWidth, y);
}

float Font::getHeight(float lineSpacing) const
{
	return mMaxGlyphHeight * lineSpacing;
}

float Font::getLetterHeight()
{
	Glyph* glyph = getGlyph((UnicodeChar)'S');
	return glyph->texSize.y() * glyph->texture->textureSize.y();
}

//the worst algorithm ever written
//breaks up a normal string with newlines to make it fit xLen
std::string Font::wrapText(std::string text, float xLen)
{
	std::string out;

	std::string line, word, temp;
	size_t space;

	Eigen::Vector2f textSize;

	while(text.length() > 0) //while there's text or we still have text to render
	{
		space = text.find_first_of(" \t\n");
		if(space == std::string::npos)
			space = text.length() - 1;

		word = text.substr(0, space + 1);
		text.erase(0, space + 1);

		temp = line + word;

		textSize = sizeText(temp);

		// if the word will fit on the line, add it to our line, and continue
		if(textSize.x() <= xLen)
		{
			line = temp;
			continue;
		}else{
			// the next word won't fit, so break here
			out += line + '\n';
			line = word;
		}
	}

	// whatever's left should fit
	out += line;

	return out;
}

Eigen::Vector2f Font::sizeWrappedText(std::string text, float xLen, float lineSpacing)
{
	text = wrapText(text, xLen);
	return sizeText(text, lineSpacing);
}

Eigen::Vector2f Font::getWrappedTextCursorOffset(std::string text, float xLen, size_t stop, float lineSpacing)
{
	std::string wrappedText = wrapText(text, xLen);

	float lineWidth = 0.0f;
	float y = 0.0f;

	size_t wrapCursor = 0;
	size_t cursor = 0;
	while(cursor < stop)
	{
		UnicodeChar wrappedCharacter = readUnicodeChar(wrappedText, wrapCursor);
		UnicodeChar character = readUnicodeChar(text, cursor);

		if(wrappedCharacter == (UnicodeChar)'\n' && character != (UnicodeChar)'\n')
		{
			//this is where the wordwrap inserted a newline
			//reset lineWidth and increment y, but don't consume a cursor character
			lineWidth = 0.0f;
			y += getHeight(lineSpacing);

			cursor = getPrevCursor(text, cursor); // unconsume
			continue;
		}

		if(character == (UnicodeChar)'\n')
		{
			lineWidth = 0.0f;
			y += getHeight(lineSpacing);
			wrapCursor = getPrevCursor(wrappedText, wrapCursor); // unconsume
			continue;
		}

		lineWidth += getGlyph(character)->advance.x();
	}

	return Eigen::Vector2f(lineWidth, y);
}

//=============================================================================================================
//TextCache
//=============================================================================================================

float Font::getNewlineStartOffset(const std::string& text, const unsigned int& charStart, const float& xLen, const Alignment& alignment)
{
	switch(alignment)
	{
	case ALIGN_LEFT:
		return 0;
	case ALIGN_CENTER:
		{
			unsigned int endChar = text.find('\n', charStart);
			return (xLen - sizeText(text.substr(charStart, endChar != std::string::npos ? endChar - charStart : endChar)).x()) / 2.0f;
		}
	case ALIGN_RIGHT:
		{
			unsigned int endChar = text.find('\n', charStart);
			return xLen - (sizeText(text.substr(charStart, endChar != std::string::npos ? endChar - charStart : endChar)).x());
		}
	default:
		return 0;
	}
}

inline float font_round(float v)
{
	return round(v);
}

TextCache* Font::buildTextCache(const std::string& text, Eigen::Vector2f offset, unsigned int color, float xLen, Alignment alignment, float lineSpacing)
{
	float x = offset[0] + (xLen != 0 ? getNewlineStartOffset(text, 0, xLen, alignment) : 0);
	
	float yTop = getGlyph((UnicodeChar)'S')->bearing.y();
	float yBot = getHeight(lineSpacing);
	float y = offset[1] + (yBot + yTop)/2.0f;

	// vertices by texture
	std::map< FontTexture*, std::vector<TextCache::Vertex> > vertMap;

	size_t cursor = 0;
	UnicodeChar character;
	Glyph* glyph;
	while(cursor < text.length())
	{
		character = readUnicodeChar(text, cursor); // also advances cursor

		// invalid character
		if(character == 0)
			continue;

		if(character == (UnicodeChar)'\n')
		{
			y += getHeight(lineSpacing);
			x = offset[0] + (xLen != 0 ? getNewlineStartOffset(text, cursor /* cursor is already advanced */, xLen, alignment) : 0);
			continue;
		}

		glyph = getGlyph(character);
		if(glyph == NULL)
			continue;

		std::vector<TextCache::Vertex>& verts = vertMap[glyph->texture];
		size_t oldVertSize = verts.size();
		verts.resize(oldVertSize + 6);
		TextCache::Vertex* tri = verts.data() + oldVertSize;

		const float glyphStartX = x + glyph->bearing.x();

		const Eigen::Vector2i& textureSize = glyph->texture->textureSize;

		// triangle 1
		// round to fix some weird "cut off" text bugs
		tri[0].pos << font_round(glyphStartX), font_round(y + (glyph->texSize.y() * textureSize.y() - glyph->bearing.y()));
		tri[1].pos << font_round(glyphStartX + glyph->texSize.x() * textureSize.x()), font_round(y - glyph->bearing.y());
		tri[2].pos << tri[0].pos.x(), tri[1].pos.y();

		//tri[0].tex << 0, 0;
		//tri[0].tex << 1, 1;
		//tri[0].tex << 0, 1;

		tri[0].tex << glyph->texPos.x(), glyph->texPos.y() + glyph->texSize.y();
		tri[1].tex << glyph->texPos.x() + glyph->texSize.x(), glyph->texPos.y();
		tri[2].tex << tri[0].tex.x(), tri[1].tex.y();

		// triangle 2
		tri[3].pos = tri[0].pos;
		tri[4].pos = tri[1].pos;
		tri[5].pos << tri[1].pos.x(), tri[0].pos.y();

		tri[3].tex = tri[0].tex;
		tri[4].tex = tri[1].tex;
		tri[5].tex << tri[1].tex.x(), tri[0].tex.y();

		// advance
		x += glyph->advance.x();
	}

	//TextCache::CacheMetrics metrics = { sizeText(text, lineSpacing) };

	TextCache* cache = new TextCache();
	cache->vertexLists.resize(vertMap.size());
	cache->metrics = { sizeText(text, lineSpacing) };

	unsigned int i = 0;
	for(auto it = vertMap.begin(); it != vertMap.end(); it++)
	{
		TextCache::VertexList& vertList = cache->vertexLists.at(i);

		vertList.textureIdPtr = &it->first->textureId;
		vertList.verts = it->second;

		vertList.colors.resize(4 * it->second.size());
		Renderer::buildGLColorArray(vertList.colors.data(), color, it->second.size());
	}

	return cache;
}

TextCache* Font::buildTextCache(const std::string& text, float offsetX, float offsetY, unsigned int color)
{
	return buildTextCache(text, Eigen::Vector2f(offsetX, offsetY), color, 0.0f);
}

void TextCache::setColor(unsigned int color)
{
	for(auto it = vertexLists.begin(); it != vertexLists.end(); it++)
		Renderer::buildGLColorArray(it->colors.data(), color, it->verts.size());
}

std::shared_ptr<Font> Font::getFromTheme(const ThemeData::ThemeElement* elem, unsigned int properties, const std::shared_ptr<Font>& orig)
{
	using namespace ThemeFlags;
	if(!(properties & FONT_PATH) && !(properties & FONT_SIZE))
		return orig;
	
	std::shared_ptr<Font> font;
	int size = (orig ? orig->mSize : FONT_SIZE_MEDIUM);
	std::string path = (orig ? orig->mPath : getDefaultPath());

	float sh = (float)Renderer::getScreenHeight();
	if(properties & FONT_SIZE && elem->has("fontSize")) 
		size = (int)(sh * elem->get<float>("fontSize"));
	if(properties & FONT_PATH && elem->has("fontPath"))
		path = elem->get<std::string>("fontPath");

	return get(size, path);
}