Implement proper font handling

1 files changed, 463 insertions, 0 deletions

diff --git a/src/fontengine.cpp b/src/fontengine.cpp
new file mode 100644
index 000000000..c1e36d6c8
--- /dev/null
+++ b/src/fontengine.cpp
@@ -0,0 +1,463 @@
+/*
+Minetest
+Copyright (C) 2010-2014 sapier <sapier at gmx dot net>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+#include "fontengine.h"
+#include "log.h"
+#include "main.h"
+#include "config.h"
+#include "porting.h"
+#include "constants.h"
+#include "filesys.h"
+
+#if USE_FREETYPE
+#include "gettext.h"
+#include "xCGUITTFont.h"
+#endif
+
+/** maximum size distance for getting a "similar" font size */
+#define MAX_FONT_SIZE_OFFSET 10
+
+/** reference to access font engine, has to be initialized by main */
+FontEngine* glb_fontengine = NULL;
+
+/** callback to be used on change of font size setting */
+static void font_setting_changed(const std::string) {
+	glb_fontengine->readSettings();
+}
+
+/******************************************************************************/
+FontEngine::FontEngine(Settings* main_settings, gui::IGUIEnvironment* env) :
+	m_settings(main_settings),
+	m_env(env),
+	m_font_cache(),
+	m_default_size(),
+	m_currentMode(FM_Standard),
+	m_lastMode(),
+	m_lastSize(0),
+	m_lastFont(NULL)
+{
+
+	for ( unsigned int i = 0; i < FM_MaxMode; i++) {
+		m_default_size[i] = (FontMode) FONT_SIZE_UNSPECIFIED;
+	}
+
+	assert(m_settings != NULL);
+	assert(m_env != NULL);
+	assert(m_env->getSkin() != NULL);
+
+	m_currentMode = FM_Simple;
+
+#if USE_FREETYPE
+	if (g_settings->getBool("freetype")) {
+		m_default_size[FM_Standard] = m_settings->getU16("font_size");
+		m_default_size[FM_Fallback] = m_settings->getU16("fallback_font_size");
+		m_default_size[FM_Mono]     = m_settings->getU16("mono_font_size");
+
+		if (is_yes(gettext("needs_fallback_font"))) {
+			m_currentMode = FM_Fallback;
+		}
+		else {
+			m_currentMode = FM_Standard;
+		}
+	}
+
+	// having freetype but not using it is quite a strange case so we need to do
+	// special handling for it
+	if (m_currentMode == FM_Simple) {
+		std::stringstream fontsize;
+		fontsize << DEFAULT_FONT_SIZE;
+		m_settings->setDefault("font_size", fontsize.str());
+		m_settings->setDefault("mono_font_size", fontsize.str());
+	}
+#endif
+
+	m_default_size[FM_Simple]       = m_settings->getU16("font_size");
+	m_default_size[FM_SimpleMono]   = m_settings->getU16("mono_font_size");
+
+	updateSkin();
+
+	if (m_currentMode == FM_Standard) {
+		m_settings->registerChangedCallback("font_size", font_setting_changed);
+		m_settings->registerChangedCallback("font_path", font_setting_changed);
+		m_settings->registerChangedCallback("font_shadow", font_setting_changed);
+		m_settings->registerChangedCallback("font_shadow_alpha", font_setting_changed);
+	}
+	else if (m_currentMode == FM_Fallback) {
+		m_settings->registerChangedCallback("fallback_font_size", font_setting_changed);
+		m_settings->registerChangedCallback("fallback_font_path", font_setting_changed);
+		m_settings->registerChangedCallback("fallback_font_shadow", font_setting_changed);
+		m_settings->registerChangedCallback("fallback_font_shadow_alpha", font_setting_changed);
+	}
+
+	m_settings->registerChangedCallback("mono_font_path", font_setting_changed);
+	m_settings->registerChangedCallback("mono_font_size", font_setting_changed);
+	m_settings->registerChangedCallback("screen_dpi", font_setting_changed);
+	m_settings->registerChangedCallback("gui_scaling", font_setting_changed);
+}
+
+/******************************************************************************/
+FontEngine::~FontEngine()
+{
+	cleanCache();
+}
+
+/******************************************************************************/
+void FontEngine::cleanCache()
+{
+	for ( unsigned int i = 0; i < FM_MaxMode; i++) {
+
+		for (std::map<unsigned int, irr::gui::IGUIFont*>::iterator iter
+				= m_font_cache[i].begin();
+				iter != m_font_cache[i].end(); iter++) {
+			iter->second->drop();
+			iter->second = NULL;
+		}
+		m_font_cache[i].clear();
+	}
+}
+
+/******************************************************************************/
+irr::gui::IGUIFont* FontEngine::getFont(unsigned int font_size, FontMode mode)
+{
+	if (mode == FM_Unspecified) {
+		mode = m_currentMode;
+	}
+	else if ((mode == FM_Mono) && (m_currentMode == FM_Simple)) {
+		mode = FM_SimpleMono;
+	}
+
+	if (font_size == FONT_SIZE_UNSPECIFIED) {
+		font_size = m_default_size[mode];
+	}
+
+	if ((font_size == m_lastSize) && (mode == m_lastMode)) {
+		return m_lastFont;
+	}
+
+	if (m_font_cache[mode].find(font_size) == m_font_cache[mode].end()) {
+		initFont(font_size, mode);
+	}
+
+	if (m_font_cache[mode].find(font_size) == m_font_cache[mode].end()) {
+		return NULL;
+	}
+
+	m_lastSize = font_size;
+	m_lastMode = mode;
+	m_lastFont = m_font_cache[mode][font_size];
+
+	return m_font_cache[mode][font_size];
+}
+
+/******************************************************************************/
+unsigned int FontEngine::getTextHeight(unsigned int font_size, FontMode mode)
+{
+	irr::gui::IGUIFont* font = getFont(font_size, mode);
+
+	// use current skin font as fallback
+	if (font == NULL) {
+		font = m_env->getSkin()->getFont();
+	}
+	assert(font != NULL);
+
+	return font->getDimension(L"Some unimportant example String").Height;
+}
+
+/******************************************************************************/
+unsigned int FontEngine::getTextWidth(const std::wstring& text,
+		unsigned int font_size, FontMode mode)
+{
+	irr::gui::IGUIFont* font = getFont(font_size, mode);
+
+	// use current skin font as fallback
+	if (font == NULL) {
+		font = m_env->getSkin()->getFont();
+	}
+	assert(font != NULL);
+
+	return font->getDimension(text.c_str()).Width;
+}
+
+
+/** get line height for a specific font (including empty room between lines) */
+unsigned int FontEngine::getLineHeight(unsigned int font_size, FontMode mode)
+{
+	irr::gui::IGUIFont* font = getFont(font_size, mode);
+
+	// use current skin font as fallback
+	if (font == NULL) {
+		font = m_env->getSkin()->getFont();
+	}
+	assert(font != NULL);
+
+	return font->getDimension(L"Some unimportant example String").Height
+			+ font->getKerningHeight();
+}
+
+/******************************************************************************/
+unsigned int FontEngine::getDefaultFontSize()
+{
+	return m_default_size[m_currentMode];
+}
+
+/******************************************************************************/
+void FontEngine::readSettings()
+{
+#if USE_FREETYPE
+	if (g_settings->getBool("freetype")) {
+		m_default_size[FM_Standard] = m_settings->getU16("font_size");
+		m_default_size[FM_Fallback] = m_settings->getU16("fallback_font_size");
+		m_default_size[FM_Mono]     = m_settings->getU16("mono_font_size");
+
+		if (is_yes(gettext("needs_fallback_font"))) {
+			m_currentMode = FM_Fallback;
+		}
+		else {
+			m_currentMode = FM_Standard;
+		}
+	}
+#endif
+	m_default_size[FM_Simple]       = m_settings->getU16("font_size");
+	m_default_size[FM_SimpleMono]   = m_settings->getU16("mono_font_size");
+
+	cleanCache();
+	updateFontCache();
+	updateSkin();
+}
+
+/******************************************************************************/
+void FontEngine::updateSkin()
+{
+	gui::IGUIFont *font = getFont();
+
+	if (font)
+		m_env->getSkin()->setFont(font);
+	else
+		errorstream << "FontEngine: Default font file: " <<
+				"\n\t\"" << m_settings->get("font_path") << "\"" <<
+				"\n\trequired for current screen configuration was not found" <<
+				" or was invalid file format." <<
+				"\n\tUsing irrlicht default font." << std::endl;
+
+	// If we did fail to create a font our own make irrlicht find a default one
+	font = m_env->getSkin()->getFont();
+	assert(font);
+
+	u32 text_height = font->getDimension(L"Hello, world!").Height;
+	infostream << "text_height=" << text_height << std::endl;
+}
+
+/******************************************************************************/
+void FontEngine::updateFontCache()
+{
+	/* the only font to be initialized is default one,
+	 * all others are re-initialized on demand */
+	initFont(m_default_size[m_currentMode], m_currentMode);
+
+	/* reset font quick access */
+	m_lastMode = FM_Unspecified;
+	m_lastSize = 0;
+	m_lastFont = NULL;
+}
+
+/******************************************************************************/
+void FontEngine::initFont(unsigned int basesize, FontMode mode)
+{
+
+	std::string font_config_prefix;
+
+	if (mode == FM_Unspecified) {
+		mode = m_currentMode;
+	}
+
+	switch (mode) {
+
+		case FM_Standard:
+			font_config_prefix = "";
+			break;
+
+		case FM_Fallback:
+			font_config_prefix = "fallback_";
+			break;
+
+		case FM_Mono:
+			font_config_prefix = "mono_";
+			if (m_currentMode == FM_Simple)
+				mode = FM_SimpleMono;
+			break;
+
+		case FM_Simple: /* Fallthrough */
+		case FM_SimpleMono: /* Fallthrough */
+		default:
+			font_config_prefix = "";
+
+	}
+
+	if (m_font_cache[mode].find(basesize) != m_font_cache[mode].end())
+		return;
+
+	if ((mode == FM_Simple) || (mode == FM_SimpleMono)) {
+		initSimpleFont(basesize, mode);
+		return;
+	}
+#if USE_FREETYPE
+	else {
+		if (! is_yes(m_settings->get("freetype"))) {
+			return;
+		}
+		unsigned int size = floor(
+				porting::getDisplayDensity() *
+				m_settings->getFloat("gui_scaling") *
+				basesize);
+		u32 font_shadow       = 0;
+		u32 font_shadow_alpha = 0;
+
+		try {
+			font_shadow =
+					g_settings->getU16(font_config_prefix + "font_shadow");
+		} catch (SettingNotFoundException&) {}
+		try {
+			font_shadow_alpha =
+					g_settings->getU16(font_config_prefix + "font_shadow_alpha");
+		} catch (SettingNotFoundException&) {}
+
+		std::string font_path = g_settings->get(font_config_prefix + "font_path");
+
+		if (font_path.substr(font_path.length() -4) != ".ttf") {
+			errorstream << "FontEngine: \"" << font_path
+					<< "\" doesn't seem to be a ttf File." << std::endl;
+			return;
+		}
+
+		irr::gui::IGUIFont* font = gui::CGUITTFont::createTTFont(m_env,
+				font_path.c_str(), size, true, true, font_shadow,
+				font_shadow_alpha);
+
+		if (font != NULL) {
+			font->grab();
+			m_font_cache[mode][basesize] = font;
+		}
+		else {
+			errorstream << "FontEngine: failed to load freetype font: "
+					<< font_path << std::endl;
+		}
+	}
+#endif
+}
+
+/** initialize a font without freetype */
+void FontEngine::initSimpleFont(unsigned int basesize, FontMode mode)
+{
+	assert((mode == FM_Simple) || (mode == FM_SimpleMono));
+
+	std::string font_path = "";
+	if (mode == FM_Simple) {
+		font_path = m_settings->get("font_path");
+	} else {
+		font_path = m_settings->get("mono_font_path");
+	}
+	std::string basename = font_path;
+	std::string ending = font_path.substr(font_path.length() -4);
+
+	if (ending == ".ttf") {
+		errorstream << "FontEngine: Not trying to open \"" << font_path
+				<< "\" which seems to be a truetype font." << std::endl;
+		return;
+	}
+
+	if ((ending == ".xml") || ( ending == ".png")) {
+		basename = font_path.substr(0,font_path.length()-4);
+	}
+
+	if (basesize == FONT_SIZE_UNSPECIFIED)
+		basesize = DEFAULT_FONT_SIZE;
+
+	unsigned int size = floor(
+			porting::getDisplayDensity() *
+			m_settings->getFloat("gui_scaling") *
+			basesize);
+
+	irr::gui::IGUIFont* font = NULL;
+
+	for(unsigned int offset = 0; offset < MAX_FONT_SIZE_OFFSET; offset++) {
+
+		// try opening positive offset
+		std::stringstream fontsize_plus_png;
+		fontsize_plus_png << basename << "_" << (size + offset) << ".png";
+
+		if (fs::PathExists(fontsize_plus_png.str())) {
+			font = m_env->getFont(fontsize_plus_png.str().c_str());
+
+			if (font) {
+				verbosestream << "FontEngine: found font: " << fontsize_plus_png.str() << std::endl;
+				break;
+			}
+		}
+
+		std::stringstream fontsize_plus_xml;
+		fontsize_plus_xml << basename << "_" << (size + offset) << ".xml";
+
+		if (fs::PathExists(fontsize_plus_xml.str())) {
+			font = m_env->getFont(fontsize_plus_xml.str().c_str());
+
+			if (font) {
+				verbosestream << "FontEngine: found font: " << fontsize_plus_xml.str() << std::endl;
+				break;
+			}
+		}
+
+		// try negative offset
+		std::stringstream fontsize_minus_png;
+		fontsize_minus_png << basename << "_" << (size - offset) << ".png";
+
+		if (fs::PathExists(fontsize_minus_png.str())) {
+			font = m_env->getFont(fontsize_minus_png.str().c_str());
+
+			if (font) {
+				verbosestream << "FontEngine: found font: " << fontsize_minus_png.str() << std::endl;
+				break;
+			}
+		}
+
+		std::stringstream fontsize_minus_xml;
+		fontsize_minus_xml << basename << "_" << (size - offset) << ".xml";
+
+		if (fs::PathExists(fontsize_minus_xml.str())) {
+			font = m_env->getFont(fontsize_minus_xml.str().c_str());
+
+			if (font) {
+				verbosestream << "FontEngine: found font: " << fontsize_minus_xml.str() << std::endl;
+				break;
+			}
+		}
+	}
+
+	// try name direct
+	if (font == NULL) {
+		if (fs::PathExists(font_path)) {
+			font = m_env->getFont(font_path.c_str());
+			if (font)
+				verbosestream << "FontEngine: found font: " << font_path << std::endl;
+		}
+	}
+
+	if (font != NULL) {
+		font->grab();
+		m_font_cache[mode][basesize] = font;
+	}
+}