text: /*
   * FTGL - OpenGL font library
   *
   * Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz>
   * Copyright (c) 2008 Sam Hocevar <sam@zoy.org>
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
   * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  #include "config.h"
  
  #include <cassert>
  #include <string> // For memset
  
  #include "FTGL/ftgl.h"
  
  #include "FTInternals.h"
  
  #include "../FTGlyph/FTTextureGlyphImpl.h"
  #include "./FTTextureFontImpl.h"
  
  
  //
  //  FTTextureFont
  //
  
  
  FTTextureFont::FTTextureFont(char const *fontFilePath) :
      FTFont(new FTTextureFontImpl(this, fontFilePath))
  {}
  
  
  FTTextureFont::FTTextureFont(const unsigned char *pBufferBytes,
                               size_t bufferSizeInBytes) :
      FTFont(new FTTextureFontImpl(this, pBufferBytes, bufferSizeInBytes))
  {}
  
  
  FTTextureFont::~FTTextureFont()
  {}
  
  
  FTGlyph* FTTextureFont::MakeGlyph(FT_GlyphSlot ftGlyph)
  {
      FTTextureFontImpl *myimpl = dynamic_cast<FTTextureFontImpl *>(impl);
      if(!myimpl)
      {
          return NULL;
      }
  
      return myimpl->MakeGlyphImpl(ftGlyph);
  }
  
  
  //
  //  FTTextureFontImpl
  //
  
  
  static inline GLuint NextPowerOf2(GLuint in)
  {
       in -= 1;
  
       in |= in >> 16;
       in |= in >> 8;
       in |= in >> 4;
       in |= in >> 2;
       in |= in >> 1;
  
       return in + 1;
  }
  
  
  FTTextureFontImpl::FTTextureFontImpl(FTFont *ftFont, const char* fontFilePath)
  :   FTFontImpl(ftFont, fontFilePath),
      maximumGLTextureSize(0),
      textureWidth(0),
      textureHeight(0),
      glyphHeight(0),
      glyphWidth(0),
      padding(3),
      xOffset(0),
      yOffset(0)
  {
      load_flags = FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP;
      remGlyphs = numGlyphs = face.GlyphCount();
  }
  
  
  FTTextureFontImpl::FTTextureFontImpl(FTFont *ftFont,
                                       const unsigned char *pBufferBytes,
                                       size_t bufferSizeInBytes)
  :   FTFontImpl(ftFont, pBufferBytes, bufferSizeInBytes),
      maximumGLTextureSize(0),
      textureWidth(0),
      textureHeight(0),
      glyphHeight(0),
      glyphWidth(0),
      padding(3),
      xOffset(0),
      yOffset(0)
  {
      load_flags = FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP;
      remGlyphs = numGlyphs = face.GlyphCount();
  }
  
  
  FTTextureFontImpl::~FTTextureFontImpl()
  {
      if(textureIDList.size())
      {
          glDeleteTextures((GLsizei)textureIDList.size(),
                           (const GLuint*)&textureIDList[0]);
      }
  }
  
  
  FTGlyph* FTTextureFontImpl::MakeGlyphImpl(FT_GlyphSlot ftGlyph)
  {
      glyphHeight = static_cast<int>(charSize.Height() + 0.5);
      glyphWidth = static_cast<int>(charSize.Width() + 0.5);
  
      if(glyphHeight < 1) glyphHeight = 1;
      if(glyphWidth < 1) glyphWidth = 1;
  
      if(textureIDList.empty())
      {
          textureIDList.push_back(CreateTexture());
          xOffset = yOffset = padding;
      }
  
      if(xOffset > (textureWidth - glyphWidth))
      {
          xOffset = padding;
          yOffset += glyphHeight;
  
          if(yOffset > (textureHeight - glyphHeight))
          {
              textureIDList.push_back(CreateTexture());
              yOffset = padding;
          }
      }
  
      FTTextureGlyph* tempGlyph = new FTTextureGlyph(ftGlyph, textureIDList[textureIDList.size() - 1],
                                                      xOffset, yOffset, textureWidth, textureHeight);
      xOffset += static_cast<int>(tempGlyph->BBox().Upper().X() - tempGlyph->BBox().Lower().X() + padding + 0.5);
  
      --remGlyphs;
  
      return tempGlyph;
  }
  
  
  void FTTextureFontImpl::CalculateTextureSize()
  {
      if(!maximumGLTextureSize)
      {
          maximumGLTextureSize = 1024;
          glGetIntegerv(GL_MAX_TEXTURE_SIZE, (GLint*)&maximumGLTextureSize);
          assert(maximumGLTextureSize); // If you hit this then you have an invalid OpenGL context.
      }
  
      textureWidth = NextPowerOf2((remGlyphs * glyphWidth) + (padding * 2));
      textureWidth = textureWidth > maximumGLTextureSize ? maximumGLTextureSize : textureWidth;
  
      int h = static_cast<int>((textureWidth - (padding * 2)) / glyphWidth + 0.5);
  
      textureHeight = NextPowerOf2(((numGlyphs / h) + 1) * glyphHeight);
      textureHeight = textureHeight > maximumGLTextureSize ? maximumGLTextureSize : textureHeight;
  }
  
  
  GLuint FTTextureFontImpl::CreateTexture()
  {
  	CalculateTextureSize();
  
      int totalMemory = textureWidth * textureHeight;
      unsigned char* textureMemory = new unsigned char[totalMemory];
      memset(textureMemory, 0, totalMemory);
  
      GLuint textID;
      glGenTextures(1, (GLuint*)&textID);
  
      glBindTexture(GL_TEXTURE_2D, textID);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); //GL_CLAMP);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); //GL_CLAMP);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); // GL_LINEAR
  
      glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, textureWidth, textureHeight,
                   0, GL_ALPHA, GL_UNSIGNED_BYTE, textureMemory);
  
      delete [] textureMemory;
  
      return textID;
  }
  
  
  bool FTTextureFontImpl::FaceSize(const unsigned int size, const unsigned int res)
  {
      if(!textureIDList.empty())
      {
          glDeleteTextures((GLsizei)textureIDList.size(), (const GLuint*)&textureIDList[0]);
          textureIDList.clear();
          remGlyphs = numGlyphs = face.GlyphCount();
      }
  
      return FTFontImpl::FaceSize(size, res);
  }
  
  
  template <typename T>
  inline FTPoint FTTextureFontImpl::RenderI(const T* string, const int len,
                                            FTPoint position, FTPoint spacing,
                                            int renderMode)
  {
      // Protect GL_TEXTURE_2D, GL_BLEND and blending functions
     // glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT);
  
      //glEnable(GL_BLEND);
      //glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // GL_ONE
  
      glEnable(GL_TEXTURE_2D);
  
      FTTextureGlyphImpl::ResetActiveTexture();
  
      FTPoint tmp = FTFontImpl::Render(string, len,
                                       position, spacing, renderMode);
  
    //  glPopAttrib();
  
      return tmp;
  }
  
  
  FTPoint FTTextureFontImpl::Render(const char * string, const int len,
                                    FTPoint position, FTPoint spacing,
                                    int renderMode)
  {
      return RenderI(string, len, position, spacing, renderMode);
  }
  
  
  FTPoint FTTextureFontImpl::Render(const wchar_t * string, const int len,
                                    FTPoint position, FTPoint spacing,
                                    int renderMode)
  {
      return RenderI(string, len, position, spacing, renderMode);
  }
  
  