MuditaOS/module-gui/gui/core/Font.hpp

/*
 * Font.hpp
 *
 *  Created on: 25 kwi 2019
 *      Author: robert
 */

#ifndef GUI_CORE_FONT_HPP_
#define GUI_CORE_FONT_HPP_

#include <string>
#include <vector>
#include <map>
#include <cstdint>
#include <fstream>

#include "utf8/UTF8.hpp"
#include "../Common.hpp"

namespace gui {

class FontGlyph {
public:
	virtual ~FontGlyph();
	gui::Status load( uint8_t* data, uint32_t& offset );
	gui::Status loadImage( uint8_t* data, uint32_t offset );
	//character id
	uint16_t id;
	//offset in glyph data field
	uint32_t glyph_offset;
	//width of the character image in the texture
	uint16_t width;
	//height of the character image in the texture
	uint16_t height;
	//how much the current position should be offset when copying the image from the texture to the screen
	int16_t xoffset;
	//how much the current position should be offset when copying the image from the texture to the screen
	int16_t yoffset;
	//how much the current position should be advanced after drawing the character
	uint16_t xadvance;
	//image data of the glyph
	uint8_t* data;
};

class FontKerning {
public:
	gui::Status load( uint8_t* data, uint32_t& offset );
	//utf16 id of the first character
	uint16_t first;
	//utf16 id of the following character
	uint16_t second;
	//distance in pixels between beginning of first character and beginning of second character
	int16_t amount;
};

class FontInfo {
public:

	gui::Status load( uint8_t* data, uint32_t& offset );
	//name of the true type font. max 63 characters
	std::string face;
	//size of the true type font
	uint16_t size;
	//flag that informs if font is bold
	uint16_t bold;
	//flag that informs if font is italic
	uint16_t italic;
	//flag that informs if smoothing was turned on. 1 - smoothing was turned on.
	uint16_t smooth;
	//TODO additional space between characters????
	uint16_t char_spacing;
	//TODO additional space between lines
	uint16_t line_spacing;
	//distance in pixels between each line of text
	uint16_t line_height;
	//number of pixels from the absolute top of the line to the base of the characters
	uint16_t base;
	//width of the texture, normally used to scale the x pos of the character image
	uint16_t scale_w;
	//height of the texture, normally used to scale the y pos of the character image
	uint16_t scale_h;
};

class Font {
public:
	virtual ~Font();

	gui::Status load( uint8_t* data );

	//structure holding detailed information about font
	FontInfo info;
	//number of glyphs in the fontno
	uint32_t glyph_count;
	//offset to the beginning of the glyph data
	uint32_t glyph_data_offset;
	//number of kerning pairs
	uint32_t kern_count;
	//array of glyphs structures
	uint32_t kern_data_offset;
	//offset to the beginning of the image data
	uint32_t image_data_offset;
	//id of the font asigned by the font manager
	uint32_t id;
	std::map< uint32_t, FontGlyph* > glyphs;
	std::map< uint32_t, std::map< uint32_t, FontKerning* >* > kerning;

	/**
	 * @brief Returns kerning value for pair of the two characters.
	 * @param id1 Code of the first character.
	 * @param id2 Code of the second character.
	 * @return Value of the kerning or 0 if pair was not found.
	 */
	int32_t getKerning( uint32_t id1, uint32_t id2 );
	/**
	 * @brief Method calculates how many chars will fit specified width using current font.
	 * @param str UTF8 string that will be used to calculate how many chars can fit provided space.
	 * @param space Number of pixels in width availabale to calculate how many chars will fit.
	 * @param spaceConsumed Space actually consumed by characters.
	 * @return number of chars that can fit provided space;
	 */
	uint32_t getCharCountInSpace( const UTF8& str, const uint32_t space, uint32_t& spaceConsumed );
	/**
	 * @brief Calculates how many pixels will occupy selected part of the string.
	 * @param str String used as a source of text.
	 * @param start Starting index used to calculate number of occupied pixels in width.
	 * @param count Number of characters that should be used during calculating pixels width.
	 * @return Number of pixels in width occupied by selected part of the text.
	 */
	uint32_t getPixelWidth( const UTF8& str, const uint32_t start, const uint32_t count );
};

class FontManager {
protected:
	std::string fontFolder;
	std::vector<Font*> fonts;
	std::vector<std::string> getFontsList();

	Font* loadFont( std::string filename );
	void loadFonts( std::string baseDirectory );

	FontManager();
public:
	FontManager( const FontManager& ) = delete;
	void operator= (const FontManager& ) = delete;

	bool init( std::string baseDirectory );
	static FontManager& getInstance();

	virtual ~FontManager();

	Font* getFont( uint32_t id );
	uint32_t getFontID( const std::string& name );
};

} /* namespace gui */

#endif /* GUI_CORE_FONT_HPP_ */