source: orxonox.OLD/orxonox/branches/textEngine/src/lib/graphics/font/text_engine.h @ 3766

/*! 
    \file text_engine.h
    \brief Definition of textEngine, the Font and the Text

    Text is the text outputed.
    Font is a class that loads a certain ttf-file with a specific height into memory
    TextEngine is used to manage the all the different Fonts that might be included

    for more information see the specific classes.
*/

#ifndef _TEXT_ENGINE_H
#define _TEXT_ENGINE_H


#include "glincl.h"
#include "SDL_ttf.h"

#include "vector.h"
#include "base_object.h"

// FORWARD DECLARATION
class PNode;
template<class T> class tList;


/* some default values */
#define FONT_DEFAULT_SIZE       50                   //!< default size of the Text
#define FONT_DEFAULT_TEXT       "orxonox 1234567890" //!< some default text to display
#define FONT_DEFAULT_COLOR_R    256                  //!< the default red part (color) of the text
#define FONT_DEFAULT_COLOR_G    256                  //!< the default red green (color) of the text
#define FONT_DEFAULT_COLOR_B    256                  //!< the default red blue (color) of the text
#define FONT_NUM_COLORS         256                  //!< The number of colors.

#define FONT_HIGHEST_KNOWN_CHAR 128                  //!< The highest character known to the textEngine.

#define TEXT_STATIC             0                    //!< Static Text
#define TEXT_DYNAMIC            1                    //!< Dynamic Text
/**
 * STATIC means: a font, that is only one GL-face.
 ** it is very fast, and can be used for all text
 ** that does not have to be changed anymore, or if
 ** the the text should look very nice
 * DYNAMIC means: a very fast font, that will is build
 ** from multiple quads.
 ** Use this type, if you want to create fast changing
 ** text like a counter.
 */


//! A Struct to handel Texture Coordinates for quads
struct TexCoord
{
  float minU;                      //!< The minimum U-Coordinate
  float maxU;                      //!< The maximum U-Coordinate
  float minV;                      //!< The minimum V-Coordinate
  float maxV;                      //!< The maximum V-Coordinate
};

//! A struct for handling glyphs
/**
   a Glyph is one letter of a certain font
*/
struct Glyph
{
  // Glyph-specific (size and so on)
  Uint16 character;              //!< The character
  int minX;                      //!< The minimum distance from the origin in X
  int maxX;                      //!< The maximum distance from the origin in X
  int minY;                      //!< The minimum distance from the origin in Y
  int maxY;                      //!< The maximum distance from the origin in Y
  int width;                     //!< The width of the Glyph
  int height;                    //!< The height of the Glyph
  int bearingX;                  //!< How much is right of the Origin
  int bearingY;                  //!< How much is above the Origin
  int advance;                   //!< How big a Glyph would be in monospace-mode
  
  // OpenGL-specific
  //  TexCoord texCoord;             //!< A Texture Coordinate for this glyph.
  GLuint displayList;            //!< DiplayList to render this Glyph.
};

//! A class to handle a Font
class Font
{
 public:
  Font(const char* fontFile);
  virtual ~Font();

  // font
  bool setFont(const char* fontFile);
  void setSize(unsigned int fontSize);
  void setColor(Uint8 r, Uint8 g, Uint8 b);

  // text
  void setBindNode(PNode* bindNode);
  void setType(int type);
  void setText(const char* text);
  void setStyle(char* renderStyle);
  void setPosition(int x, int y);
  void createTexture(void);
  
  virtual void draw(void);

 private:
  // general purpose
  GLdouble projMat[16];             //!< The Projection Matrix

  // information about the Font
  TTF_Font* font;                   //!< The font we use for this.
  char* fontFile;                   //!< The fontfile from whitch the font was loaded.
  unsigned int fontSize;            //!< The size of the font in pixels. each Font has one size.
  
  Glyph** glyphArray;               //!< An Array of all the Glyphs stored in the Array of Glyphs.
  GLuint fastTextureID;             //!< The fast textureID.

  //! Represents one textElement.
  struct Text
  {
    int type;                   //!< The type of this Font.
    char* text;                      //!< The text to display
    SDL_Color color;                 //!< The color of the font.
    // placement in openGL
    GLuint texture;                  //!< A GL-texture to hold the text
    TexCoord texCoord;               //!< Texture-coordinates \todo fix this to have a struct
    SDL_Rect textPosSize;            //!< An SDL-Rectangle representing the position and size of the Text on the screen.
    int renderStyle;                 //!< The Renderstyle

    PNode* bindNode;                 //!< A node the Text is bind to. (if NULL thr node will not be bound to anything.)
  };
  tList<Text>* textList;
  Text* currentText;

  bool init(const char* fontFile, unsigned int fontSize = FONT_DEFAULT_SIZE);
  int getMaxHeight(void);
  int getMaxAscent(void);
  int getMaxDescent(void);
  Glyph* getGlyphMetrics(Uint16 character);

  void enter2DMode(void);
  void leave2DMode(void);


  GLuint createFastTexture();
  GLuint loadTexture(SDL_Surface* surface, TexCoord* texCoord);

  void initGlyphs(Uint16 from, Uint16 count);
  int findOptimalFastTextureSize(void);
  static int powerOfTwo(int input);

  void debug(void);

};

void m_inverse(const float *m, float *out);
Vector mvMult(const float *mat, const Vector* vec);


///////////////////
/// TEXT-ENGINE ///
///////////////////
//! A singleton Class that operates as a Handler for generating and rendering Text in 2D
class TextEngine : public BaseObject {

 public:
  static TextEngine* getInstance(void);
  virtual ~TextEngine(void);

  // general
  static void enableFonts(void);
  static void disableFonts(void);
  static bool checkVersion(void);

 private:
  TextEngine(void);
  static TextEngine* singletonRef;

};

#endif /* _TEXT_ENGINE_H */