ANTIALIASED_QUALITY has no effect

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C++

Windows

GDI

OpenGL

Hello!

I am trying to draw text string to string with openGL.
I generate string to texture and then I draw the texture. Despite the fact that I setting ANTIALIASED_QUALITY fonts still pixelate and ugly.

Example

Here is the code I use:

HFONT m_font = ::CreateFont(m_description->m_fontSize, // nHeight,
     0, // nWidth,
     0, // nEscapement,
     0, // nOrientation,
     true,  // fnWeight,
     false,  //fdwItalic,
     false,  //fdwUnderline,
     false, //fdwStrikeOut,
     ANSI_CHARSET, //fdwCharSet,
     OUT_DEFAULT_PRECIS, // fdwOutputPrecision,
     CLIP_DEFAULT_PRECIS, // fdwClipPrecision,
     ANTIALIASED_QUALITY, // fdwQuality,
     DEFAULT_PITCH, // fdwPitchAndFamily,
     "Compress");

 m_hdc = ::CreateCompatibleDC(0);

 HFONT prevFont      = (HFONT)::SelectObject(m_hdc, m_font);
 int imode           = ::SetBkMode(m_hdc, TRANSPARENT);
 COLORREF colorref   = ::SetTextColor(m_hdc,0x00ff0000);
 SIZE stringSize     = {0,0};
 SIZE stringRoundedToPowerOf2Size = {0,0};

 stringRoundedToPowerOf2Size.cx = RoundUpToPowerOf2(stringSize.cx);
 stringRoundedToPowerOf2Size.cy = RoundUpToPowerOf2(stringSize.cy);

 BITMAPINFOHEADER bih =
 {
     sizeof (BITMAPINFOHEADER),  // biSize;
     (int)stringRoundedToPowerOf2Size.cx,            // biWidth;
     (int)stringRoundedToPowerOf2Size.cy,        // biWidth;
     1,                          // biPlanes;
     32,                         // biBitCount;
 };

 void* pPixels       = NULL;
 HBITMAP hBitMap     = ::CreateDIBSection(m_hdc, (BITMAPINFO*)&bih, DIB_RGB_COLORS, &pPixels, NULL, 0);
 HBITMAP prevBitMap  = (HBITMAP)::SelectObject (m_hdc, hBitMap);

 LOGFONT mFontDesc;  // To check if all the parameters are correct - they are !!!
 ::GetObject(m_font, sizeof(LOGFONT), &mFontDesc);

 RECT area   = {0, 0, stringSize.cx,stringSize.cy};
 int drawRet = ::DrawText(m_hdc,
              m_string.c_str(),
              -1, // null terminated string
              &area,
              DT_CENTER | DT_SINGLELINE | DT_VCENTER);

 if (0 != drawRet) // If DrawText fails, the return value is zero.
 {
     m_stringSize.Width() = stringRoundedToPowerOf2Size.cx;
     m_stringSize.Height() = stringRoundedToPowerOf2Size.cy;

     BITMAPINFOHEADER   bi;
     bi.biSize = sizeof(BITMAPINFOHEADER);
     bi.biWidth = stringRoundedToPowerOf2Size.cx;
     bi.biHeight = stringRoundedToPowerOf2Size.cy;
     bi.biPlanes = 1;
     bi.biBitCount = 32;
     bi.biCompression = BI_RGB;
     bi.biSizeImage = 0;
     bi.biXPelsPerMeter = 0;
     bi.biYPelsPerMeter = 0;
     bi.biClrUsed = 0;
     bi.biClrImportant = 0;

     DWORD dwBmpSize = stringRoundedToPowerOf2Size.cx * bi.biBitCount * stringRoundedToPowerOf2Size.cy;
     long* imageBuff = (LONG*)::HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, dwBmpSize);
     ::GetDIBits(m_hdc, hBitMap, 0, stringRoundedToPowerOf2Size.cy, imageBuff, (BITMAPINFO *)&bi, DIB_RGB_COLORS);

     WTRects tempRect(0,0,stringRoundedToPowerOf2Size.cy, stringRoundedToPowerOf2Size.cx);
     WTRects tempStringSize(0,0,stringRoundedToPowerOf2Size.cy, stringRoundedToPowerOf2Size.cx);
     ColorBuffer(m_textColor, (uint32_t*)imageBuff, tempRect, tempStringSize); //(unsigned long)lpbi->bmiHeader.biSizeImage

     glEnable (GL_TEXTURE_2D);

     //glDirect does not seem to like resizing the textures, so we delete and create new, if size has changed.
     if (0 != m_texture_name)
     {
        if ((stringRoundedToPowerOf2Size.cx != m_LastRoundedToPowerOf2Size.cx) ||
            (stringRoundedToPowerOf2Size.cy != m_LastRoundedToPowerOf2Size.cy))
        {
             glDeleteTextures(1, &m_texture_name);
             m_texture_name = 0;
        }
     }

     if (0 == m_texture_name)
         glGenTextures(1, &m_texture_name);

     glBindTexture(GL_TEXTURE_2D, m_texture_name);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);  // we use nearest to avoid corrupt alpha
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);  // TT 11717
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, stringRoundedToPowerOf2Size.cx,  stringRoundedToPowerOf2Size.cy, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageBuff);
     m_LastRoundedToPowerOf2Size = stringRoundedToPowerOf2Size; //for use to decide if we need to regenerate a texture.
     glDisable(GL_TEXTURE_2D);
     ::HeapFree(GetProcessHeap(), 0, imageBuff);
 }

 ::SelectObject(m_hdc, prevBitMap);
 ::DeleteObject(hBitMap);
 ::SelectObject(m_hdc, prevFont);

Anyone can help with that?
Maybe it is because my background is transparent so there is nothing to anti alias with?

Thanks!