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

/* 
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Benjamin Grauer
   co-programmer: ...

   for some fonts and licenses visit: =http://www.dafont.com/en/font.php=

   !! IMPORTANT !! When using ttf fonts clear the license issues prior to
   adding them to orxonox. This is really important, because we do not 
   want to defend anyone.
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_FONT

#include "text_engine.h"

using namespace std;

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "graphics_engine.h"
#include "p_node.h"
#include "vector.h"
#include "debug.h"


////////////
/// FONT ///
////////////

/**
   \brief constructs a Font
   \param fontFile the File to load the font from
*/
Font::Font(const char* fontFile)
{
  this->init(fontFile);
}

/**
   \brief destructs a font
*/
Font::~Font(void)
{
  delete this->currentText;

  if (this->glyphArray)
    {
      for (int i = 0; i < FONT_HIGHEST_KNOWN_CHAR; i++)
        delete this->glyphArray[i];
      delete []this->glyphArray;
    }

  if (this->font)
    TTF_CloseFont(this->font);
}

/**
   \brief initializes a new Font
   \param fontFile The file to load a Font from
   \param fontSize the Size in pixels of the Font
*/
bool Font::init(const char* fontFile, unsigned int fontSize)
{
  if (!TTF_WasInit())
    TextEngine::enableFonts();

  // setting default values.
  this->font = NULL;
  this->fontFile = NULL;
  this->glyphArray = NULL;
  this->fastTextureID = 0;

  this->currentText = new Text;

  this->currentText->bindNode = NULL;
  this->currentText->text = NULL;
  this->currentText->texture = 0;
  
  this->setSize(fontSize);
  this->setType(TEXT_DYNAMIC);
  
  this->currentText->renderStyle = TTF_STYLE_NORMAL;

  this->setFont(fontFile);

  this->setColor(0, 255, 0);
  this->setPosition(0, 0);

  this->setText(FONT_DEFAULT_TEXT);
  
  this->setColor(0,255,0);

  this->createTexture();

  this->fastTextureID = this->createFastTexture();
}

/**
   \brief sets The Font.
   \param fontFile The file containing the font.
   \returns true if loaded, false if something went wrong, or if a font was loaded before.
*/
bool Font::setFont(const char* fontFile)
{
  if (!this->fontFile)
    {
      this->fontFile = new char[strlen(fontFile)+1];
      strcpy(this->fontFile, fontFile);
      
      this->font = TTF_OpenFont(this->fontFile, this->fontSize);
      if(!this->font) 
        {
          PRINTF(1)("TTF_OpenFont: %s\n", TTF_GetError());
          return false;
      }
      return true;
    }
  else
    {
      PRINTF(2)("Font already initialized, unable to change it now.\n");
      return false;
    }
}

void Font::setBindNode(PNode* bindNode)
{
  this->currentText->bindNode = bindNode;
}

/**
   \brief sets the Type of this Text
   \param type the type to set.
*/
void Font::setType(int type)
{
  this->currentText->type = type;
}


/**
   \brief Sets a new Text to the font
   \param text the new text to set
*/
void Font::setText(const char* text)
{
  if (this->currentText->text)
    delete []this->currentText->text;
  this->currentText->text = new char[strlen(text)+1];
  strcpy(this->currentText->text, text);
}

/**
   \brief sets a specific renderStyle
   \param renderStyle the Style to render: a char-array containing:
   i: italic, b: bold, u, underline
*/
void Font::setStyle(char* renderStyle)
{
  this->currentText->renderStyle = TTF_STYLE_NORMAL;
  
  for (int i = 0; i < strlen(renderStyle); i++)
    if (strncmp(renderStyle+i, "b", 1) == 0) 
      this->currentText->renderStyle |= TTF_STYLE_BOLD;
    else if (strncmp(renderStyle+i, "i", 1) == 0)
      this->currentText->renderStyle |= TTF_STYLE_ITALIC;
    else if (strncmp(renderStyle+i, "u", 1) == 0) 
      this->currentText->renderStyle |= TTF_STYLE_UNDERLINE;

  if (this->font)
    TTF_SetFontStyle(this->font, this->currentText->renderStyle);
  else
    PRINTF(2)("Font was not initialized, please do so before setting the Font-Style.\n");
}

/**
   \brief Sets a new Size to the font
   \param fontSize The new Size in pixels.
*/
void Font::setSize(unsigned int fontSize)
{
  this->fontSize = fontSize;
}

/**
   \brief sets a new color to the font
   \param r Red
   \param g Green
   \param b Blue
*/
void Font::setColor(Uint8 r, Uint8 g, Uint8 b)
{
  this->currentText->color.r = r;
  this->currentText->color.g = g;
  this->currentText->color.b = b;
}

/**
   \brief sets a Position.
   \param x the x-position in pixels from the left border
   \param y the y-position in pixels from the top border
*/
void Font::setPosition(int x, int y)
{
  this->currentText->textPosSize.x = x;
  this->currentText->textPosSize.y = y;
}

/**
   \brief draws the Font
   \todo FIX this is to slow/static
*/
void Font::draw(void)
{
  // storing all the Transformation Matrices.
  GLdouble modMat[16];
  GLint viewPort[4];
  glGetDoublev(GL_PROJECTION_MATRIX, this->projMat);
  glGetDoublev(GL_MODELVIEW_MATRIX, modMat);
  glGetIntegerv(GL_VIEWPORT, viewPort);
  this->enter2DMode();

  // setting the Position of this Text.
  Vector pos;
  if (this->currentText->bindNode)
    {
      GLdouble x = this->currentText->bindNode->getAbsCoor().x;
      GLdouble y = this->currentText->bindNode->getAbsCoor().y;
      GLdouble z = this->currentText->bindNode->getAbsCoor().z;
      GLdouble tmp[3];
      gluProject(x, y, z, modMat, projMat, viewPort, tmp, tmp+1, tmp+2);
      printf("test %f %f %f,\n", tmp[0], tmp[1], tmp[2]);
      pos.x = tmp[0] + this->currentText->textPosSize.x;
      pos.y = GraphicsEngine::getInstance()->getResolutionY() - tmp[1] + this->currentText->textPosSize.y;
      pos.z = tmp[2];
    }
  else 
    {
      pos.x = this->currentText->textPosSize.x;
      pos.y = this->currentText->textPosSize.y;
      pos.z = 0;
    }

  // drawing this Text.
  if(currentText->type == TEXT_STATIC)
    {
      glBindTexture(GL_TEXTURE_2D, this->currentText->texture);
      glEnable(GL_TEXTURE_2D);
      glBegin(GL_QUADS);
      
      glTexCoord2f(this->currentText->texCoord.minU, this->currentText->texCoord.minV);
      glVertex2i(pos.x,   pos.y  );
      
      glTexCoord2f(this->currentText->texCoord.maxU, this->currentText->texCoord.minV);
      glVertex2i(pos.x + this->currentText->textPosSize.w, pos.y  );
      
      glTexCoord2f(this->currentText->texCoord.maxU, this->currentText->texCoord.maxV);
      glVertex2i(pos.x + this->currentText->textPosSize.w, pos.y + this->currentText->textPosSize.h);
      
      glTexCoord2f(this->currentText->texCoord.minU, this->currentText->texCoord.maxV);
      glVertex2i(pos.x, pos.y + this->currentText->textPosSize.h);
      
      glEnd();
    }
  else //(if currentText->type & TEXT_DYNAMIC)
    {
      glBindTexture(GL_TEXTURE_2D, this->fastTextureID);
      //      glEnable(GL_TEXTURE_2D);
      glTranslatef(pos.x, pos.y, 0);

      printf("%d, %d\n", this->fastTextureID, glyphArray[65]->displayList);
      char* tmpText = this->currentText->text;
      while (*tmpText != '\0')
        {
          if(glyphArray[*tmpText])
            {
              glCallList(this->glyphArray[*tmpText]->displayList);
              glTranslatef(this->glyphArray[*tmpText]->width, 0, 0);
            }
          tmpText++;
        }
    }
  this->leave2DMode();
}

/**
   \brief creates a texture out of the given parameters

   this has to be called every time by the user, to if changes were made.
*/
void Font::createTexture(void)
{
  SDL_Surface* tmpSurf;
  if (this->currentText->texture)
    glDeleteTextures(1, &this->currentText->texture);
  tmpSurf = TTF_RenderText_Blended(this->font,
                                   this->currentText->text,
                                   this->currentText->color);
  if (tmpSurf)
    this->currentText->texture = loadTexture(tmpSurf, &this->currentText->texCoord);

  this->currentText->textPosSize.w = tmpSurf->w;
  this->currentText->textPosSize.h = tmpSurf->h;
  SDL_FreeSurface(tmpSurf);
}


/**
   \returns the maximum height of the Font, if the font was initialized, 0 otherwise
*/
int Font::getMaxHeight(void)
{
  if (this->font)
    return TTF_FontHeight(this->font);
  else
    return 0;
}

/**
   \returns the maximum ascent of the Font, if the font was initialized, 0 otherwise

   the ascent is the pixels of the font above the baseline
*/
int Font::getMaxAscent(void)
{
  if (this->font)
    return TTF_FontAscent(this->font);
  else
    return 0;
}

/**
   \returns the maximum descent of the Font, if the font was initialized, 0 otherwise

   the descent is the pixels of the font below the baseline
*/
int Font::getMaxDescent(void)
{
  if (this->font)
    return TTF_FontDescent(this->font);
  else
    return 0;
}

/**
   \param character The character to get info about.
   \returns a Glyph struct of a character. This Glyph is a pointer,
   and MUST be deleted by the user..

   This only works for horizontal fonts. see 
   http://freetype.sourceforge.net/freetype2/docs/tutorial/step2.html
   for more info about vertical Fonts
*/
Glyph* Font::getGlyphMetrics(Uint16 character)
{
  Glyph* rg = new Glyph;
  rg->character = character;
  TTF_GlyphMetrics(this->font, rg->character,
                   &rg->minX, &rg->maxX,
                   &rg->minY, &rg->maxY,
                   &rg->advance);
  rg->height = rg->maxY - rg->minY;
  rg->width = rg->maxX - rg->minX;
  rg->bearingX = (rg->advance - rg->width) / 2;
  rg->bearingY = rg->maxY;
  return rg;
}

/**
   \brief entering 2D Mode
   
   this is a GL-Projection-mode, that is orthogonal, for placing the font in fron of everything else
*/
void Font::enter2DMode(void)
{
  SDL_Surface *screen = SDL_GetVideoSurface();
  
  /* Note, there may be other things you need to change,
     depending on how you have your OpenGL state set up.
  */
  glPushAttrib(GL_ENABLE_BIT);
  glDisable(GL_DEPTH_TEST);
  glDisable(GL_CULL_FACE);
  glDisable(GL_LIGHTING);  // will be set back when leaving 2D-mode
  glEnable(GL_TEXTURE_2D);

  /* This allows alpha blending of 2D textures with the scene */
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  
  glViewport(0, 0, screen->w, screen->h);
  
  glMatrixMode(GL_PROJECTION);
  glPushMatrix();
  glLoadIdentity();
  
  glOrtho(0.0, (GLdouble)screen->w, (GLdouble)screen->h, 0.0, 0.0, 1.0);
  
  glMatrixMode(GL_MODELVIEW);
  glPushMatrix();
  glLoadIdentity();
  
  glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
}

/**
   \brief leaves the 2DMode again also \see Font::enter2DMode(void)
*/
void Font::leave2DMode(void)
{
        glMatrixMode(GL_MODELVIEW);
        glPopMatrix();

        glMatrixMode(GL_PROJECTION);
        glPopMatrix();

        glPopAttrib();
}


GLuint Font::createFastTexture(void)
{
  /* interesting GLYPHS: 
   *  33-47: Special Characters.
   *  48-57: 0-9
   *  58-63: some more special chars (minor)
   *  65-90: A-Z
   *  97-122: a-z
   */
  int numberOfGlyphs = 90;

  this->initGlyphs(33, numberOfGlyphs);

  int rectSize = this->findOptimalFastTextureSize();

  // setting default values. (maybe not needed afterwards)
  SDL_Color tmpColor;  tmpColor.r = tmpColor.g = tmpColor.b = 0;
  // Surface definition.
  SDL_Rect tmpRect; // this represents a Rectangle for blitting.
  SDL_Surface* tmpSurf =  SDL_CreateRGBSurface(SDL_SWSURFACE,
                                               rectSize, rectSize,
                                               32,
#if SDL_BYTEORDER == SDL_LIL_ENDIAN /* OpenGL RGBA masks */
                                               0x000000FF, 
                                               0x0000FF00, 
                                               0x00FF0000, 
                                               0xFF000000
#else
                                               0xFF000000,
                                               0x00FF0000, 
                                               0x0000FF00, 
                                               0x000000FF
#endif
                                               );
  tmpRect.x = 0; tmpRect.y = 0; tmpRect.w = tmpSurf->w; tmpRect.h = tmpSurf->h;
  SDL_SetClipRect(tmpSurf, &tmpRect);
  int maxLineHeight = 0;

  // all the interessting Glyphs
  for (int i = 33; i <= 122; i++)
    {
      SDL_Surface* glyphSurf = NULL;
      Glyph* tmpGlyph;

      if (tmpGlyph = this->glyphArray[i])
        {
          if (tmpGlyph->height > maxLineHeight)
            maxLineHeight = tmpGlyph->height;
          
          if (tmpRect.x+tmpGlyph->width > tmpSurf->w)
            {
              tmpRect.x = 0;
              tmpRect.y = tmpRect.y + maxLineHeight + 1;
              maxLineHeight = 0;
            }
          if (tmpRect.y + maxLineHeight > tmpSurf->h)
            {
              PRINTF(1)("Protection, so font cannot write over the boundraries error (this should not heappen\n");
              break;
            }
          // reading in the new Glyph
          //glyphSurf = TTF_RenderGlyph_Shaded(this->font, i, this->currentText->color, tmpColor);
          glyphSurf = TTF_RenderGlyph_Blended(this->font, i, this->currentText->color);
          if( glyphSurf ) 
            {

              SDL_SetAlpha(glyphSurf, 0, 0);

              SDL_BlitSurface(glyphSurf, NULL, tmpSurf, &tmpRect);
              TexCoord tmpTexCoord;
              tmpTexCoord.minU = (float)tmpRect.x/(float)tmpSurf->w;
              tmpTexCoord.maxU = (float)(tmpRect.x+tmpGlyph->width)/(float)tmpSurf->w;
              tmpTexCoord.minV = (float)tmpRect.y/(float)tmpSurf->w;
              tmpTexCoord.maxV = (float)(tmpRect.y+tmpGlyph->height)/(float)tmpSurf->w;
              tmpGlyph->displayList = glGenLists(1);

              glNewList(tmpGlyph->displayList, GL_COMPILE);
              glBegin(GL_QUADS);
              glTexCoord2f(tmpTexCoord.minU, tmpTexCoord.minV);
              glVertex2d(0, 0);
              glTexCoord2f(tmpTexCoord.minU, tmpTexCoord.maxV);
              glVertex2d(0, tmpGlyph->height);
              glTexCoord2f(tmpTexCoord.maxU, tmpTexCoord.maxV);
              glVertex2d(tmpGlyph->width, tmpGlyph->height);
              glTexCoord2f(tmpTexCoord.maxU, tmpTexCoord.minV);
              glVertex2d(tmpGlyph->width, 0);
              glEnd();
              glEndList();
              SDL_FreeSurface(glyphSurf);

              tmpRect.x += tmpGlyph->width + 1;

              // Outputting Glyphs to BMP-files.
              /*
                char outname[64];
                if (i < 10)
                sprintf( outname, "glyph-00%d.bmp", i );
                else if (i <100)
                sprintf( outname, "glyph-0%d.bmp", i );
                else
                sprintf( outname, "glyph-%d.bmp", i );
                SDL_SaveBMP(tmpSurf, outname);
              */
            }
        }
    }
  GLuint texture;
  glGenTextures(1, &texture);
  glBindTexture(GL_TEXTURE_2D, texture);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexImage2D(GL_TEXTURE_2D,
               0,
               GL_RGBA,
               tmpSurf->w, tmpSurf->h,
               0,
               GL_RGBA,
               GL_UNSIGNED_BYTE,
               tmpSurf->pixels);
  SDL_FreeSurface(tmpSurf);
  return texture;
}

/**
   \brief Loads a Font from an SDL_surface into a texture.
   \param surface The surface to make the texture of
   \param texCoord The texture coordinates of the 4 corners of the texture
   \returns the ID of the texture
*/
GLuint Font::loadTexture(SDL_Surface *surface, TexCoord* texCoord)
{
  GLuint texture;
  int w, h;
  SDL_Surface *image;
  SDL_Rect area;
  Uint32 saved_flags;
  Uint8  saved_alpha;
  
  /* Use the surface width and height expanded to powers of 2 */
  w = powerOfTwo(surface->w);
  h = powerOfTwo(surface->h);
  if (texCoord)
    {
      texCoord->minU = 0.0f;
      texCoord->minV = 0.0f;
      texCoord->maxU = (GLfloat)surface->w / w;
      texCoord->maxV = (GLfloat)surface->h / h;
    }
  image = SDL_CreateRGBSurface(SDL_SWSURFACE,
                               w, h,
                               32,
#if SDL_BYTEORDER == SDL_LIL_ENDIAN /* OpenGL RGBA masks */
                               0x000000FF, 
                               0x0000FF00, 
                               0x00FF0000, 
                               0xFF000000
#else
                               0xFF000000,
                               0x00FF0000, 
                               0x0000FF00, 
                               0x000000FF
#endif
                               );
  if ( image == NULL ) {
    return 0;
  }
  
  /* Save the alpha blending attributes */
  saved_flags = surface->flags&(SDL_SRCALPHA|SDL_RLEACCELOK);
  saved_alpha = surface->format->alpha;
  if ( (saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA ) {
    SDL_SetAlpha(surface, 0, 0);
  }
  
  /* Copy the surface into the GL texture image */
  area.x = 0;
  area.y = 0;
  area.w = surface->w;
  area.h = surface->h;
  SDL_BlitSurface(surface, &area, image, &area);
  
  /* Restore the alpha blending attributes */
  if ( (saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA ) {
    SDL_SetAlpha(surface, saved_flags, saved_alpha);
  }
  
  /* Create an OpenGL texture for the image */
  glGenTextures(1, &texture);
  glBindTexture(GL_TEXTURE_2D, texture);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexImage2D(GL_TEXTURE_2D,
               0,
               GL_RGBA,
               w, h,
               0,
               GL_RGBA,
               GL_UNSIGNED_BYTE,
               image->pixels);
  SDL_FreeSurface(image); /* No longer needed */
  
  return texture;
}

/**
   \brief stores Glyph Metrics in an Array.
   \param from The Glyph to start from.
   \param count The number of Glyphs to start From.
*/
void Font::initGlyphs(Uint16 from, Uint16 count)
{
  /* initialize the Array, and set all its entries to NULL
   *  only if the Glyph-array has not been initialized
   */
  if (!this->glyphArray)
    {
      this->glyphArray = new Glyph*[FONT_HIGHEST_KNOWN_CHAR];
      for (int i = 0; i < FONT_HIGHEST_KNOWN_CHAR; i++)
        this->glyphArray[i] = NULL;
    }
  
  Uint16 lastGlyph = from + count;
  
  for (int i = from; i <= lastGlyph; i++)
    {
      // setting up all the Glyphs we like.
      glyphArray[i] = getGlyphMetrics(i);
    }
  return;
}

/**
   \returns the optimal size to use as the texture size

   \todo: this algorithm can be a lot more faster, althought it does 
   not really matter within the init-context, and 128 glyphs.

   This function searches for a 2^n sizes texture-size, this is for 
   openGL-version < 1.2 compatibility. and because it is realy easy like this.
*/
int Font::findOptimalFastTextureSize(void)
{
  int i;
  int x,y; // the counters
  int maxLineHeight;
  int size = 32;      // starting Value, we have to start somewhere 32 seems reasonable.
  bool sizeOK = false;
  Glyph* tmpGlyph;

  while (!sizeOK)
    {
      x = 0; y = 0;
      maxLineHeight = 0;
      for (i = 0; i < FONT_HIGHEST_KNOWN_CHAR; i++)
        {
          if(tmpGlyph = this->glyphArray[i])
            {
              // getting the height of the highest Glyph in the Line.
              if (tmpGlyph->height > maxLineHeight)
                maxLineHeight = tmpGlyph->height;

              if (x + tmpGlyph->width > size)
                {
                  x = 0;
                  y = y + maxLineHeight;
                  maxLineHeight = 0;
                }
              if (y + maxLineHeight + 1 > size)
                break;
              x += tmpGlyph->width + 1;

            }
        }
      if (i == FONT_HIGHEST_KNOWN_CHAR)
        sizeOK = true;
      else
        size *= 2;
    }
  return size;
  
}

/**
   \brief Quick utility function for texture creation 
   \param input an integer
   \returns the next bigger 2^n-integer than input
*/
int Font::powerOfTwo(int input)
{
  int value = 1;
  
  while ( value < input ) {
    value <<= 1;
  }
  return value;
}



/**
   \brief a simple function to get some interesting information about this class
*/
void Font::debug(void)
{

  // print the loaded font's style
  int style;
  style=TTF_GetFontStyle(this->font);
  PRINTF(0)("The font style is:");
  if(style==TTF_STYLE_NORMAL)
    PRINTF(0)(" normal");
  else {
    if(style&TTF_STYLE_BOLD)
      PRINTF(0)(" bold");
    if(style&TTF_STYLE_ITALIC)
      PRINTF(0)(" italic");
    if(style&TTF_STYLE_UNDERLINE)
      PRINTF(0)(" underline");
  }
  PRINTF(0)("\n");


}


void m_inverse(const float *m, float *out)
{
    float det;
    det=  m[0]*m[5]*m[10];
    det+= m[4]*m[9]*m[2];
    det+= m[8]*m[1]*m[6];
    det-= m[8]*m[5]*m[2];
    det-= m[4]*m[1]*m[10];
    det-= m[0]*m[9]*m[6];
    
    if(det!= 0.0)
        det=1.0/det;
    out[0]=  (m[5]*m[10]-m[9]*m[6])*det;
    out[1]= -(m[1]*m[10]-m[9]*m[2])*det;
    out[2]=  (m[1]*m[6]-m[5]*m[2])*det;
    out[3]= 0.0;
    out[4]= -(m[4]*m[10]-m[8]*m[6])*det;
    out[5]=  (m[0]*m[10]-m[8]*m[2])*det;
    out[6]= -(m[0]*m[6]-m[4]*m[2])*det;
    out[7]= 0.0;
    out[8]=  (m[4]*m[9]-m[8]*m[5])*det;
    out[9]= -(m[0]*m[9]-m[8]*m[1])*det;
    out[10]= (m[0]*m[5]-m[4]*m[1])*det;
    out[11]= 0.0;
    out[12]=- (m[12]*out[0]+m[13]*out[4]+m[14]*out[8]);
    out[13]=- (m[12]*out[1]+m[13]*out[5]+m[14]*out[9]);
    out[14]=- (m[12]*out[2]+m[13]*out[6]+m[14]*out[10]);
    out[15]= 1.0;
}


Vector mvMult(const float *mat, const Vector* vec)
{
  Vector tmp;
  tmp.x = mat[0]*vec->x+mat[1]*vec->y+mat[2]*vec->z;
  tmp.y = mat[4]*vec->x+mat[5]*vec->y+mat[6]*vec->z;
  tmp.z = mat[8]*vec->x+mat[9]*vec->y+mat[10]*vec->z;
  return tmp;
}















/**
   \brief standard constructor
*/
TextEngine::TextEngine () 
{
   this->setClassName ("TextEngine");

}

/**
   \brief the singleton reference to this class
*/
TextEngine* TextEngine::singletonRef = NULL;

/**
   \returns a Pointer to this Class
*/
TextEngine* TextEngine::getInstance(void)
{
  if (!TextEngine::singletonRef)
    TextEngine::singletonRef = new TextEngine();
  return TextEngine::singletonRef;
}

/**
   \brief standard deconstructor

*/
TextEngine::~TextEngine () 
{
  TextEngine::singletonRef = NULL;

}

/**
   \brief function to enable TTF_Fonts
*/
void TextEngine::enableFonts(void)
{
  if (!TTF_WasInit())
    {
      if(TTF_Init()==-1)
        PRINTF(1)("TTF_Init: %s\n", TTF_GetError());

      TextEngine::checkVersion();
    }
  else
    PRINTF(4)("Fonts already initialized\n");
      
}

/**
   \brief function to disable TTF_fonts
*/
void TextEngine::disableFonts(void)
{
  if (TTF_WasInit())
    {
      TTF_Quit();
    }
  else
    PRINTF(4)("Fonts were not initialized.\n");
}

/**
   \brief checks if the compiled version and the local version of SDL_ttf match.
   \returns true if match, false otherwise
*/
bool TextEngine::checkVersion(void)
{
  SDL_version compile_version;
  SDL_version link_version;
  TTF_VERSION(&compile_version);
  link_version = *TTF_Linked_Version();

  if (compile_version.major == link_version.major &&
      compile_version.minor == link_version.minor &&
      compile_version.patch == link_version.patch)
    {
      return true;
    }
  else
    {
      PRINTF(2)("compiled with SDL_ttf version: %d.%d.%d\n", 
                compile_version.major,
                compile_version.minor,
                compile_version.patch);
      
      PRINTF(2)("running with SDL_ttf version: %d.%d.%d\n", 
                link_version.major,
                link_version.minor,
                link_version.patch);
      return false;
    }
}