OPENGL ES显示字符串（Windows Mobile）

当然国外有POWERVR提供基于OPENGL ES的SDK封装的APPPRINT3D类来处理字符串显示和GLFONT for windows ce等。

但是我们这里只整理了一个函数：

void  glTextShow(WCHAR *fontname, int fontsize, int style, int x, int y, const WCHAR *string)     
{     
      int len, xx = 0, yy = 0, nbpoints = 0, i;     
      GLshort *points;     
      GLushort *indices;     
      HFONT font;     
      LOGFONTW    lf;         
      RECT rect;     
      static HBITMAP bmp;     
      static BYTE *img;     
      static HDC hdc = NULL;     
      static BITMAPINFO bi;     
      SIZE sz;     
      static EGLint width, height;     
       
      if(!fontname || !string)     
          return;     
      if(!string[0])     
          return;     
       
      if(!hdc)     
      {             
          hdc = CreateCompatibleDC(GetDC(hWnd));         
               
          eglQuerySurface(eglDisplay, eglSurface, EGL_WIDTH, &width);     
          eglQuerySurface(eglDisplay, eglSurface, EGL_HEIGHT, &height);     
       
              
          ZeroMemory(&bi, sizeof(BITMAPINFO));     
          bi.bmiHeader.biSize=sizeof(BITMAPINFOHEADER);     
          bi.bmiHeader.biWidth = width;     
          bi.bmiHeader.biHeight = height;      
          bi.bmiHeader.biBitCount = 8;     
          bi.bmiHeader.biPlanes = 1;     
          bi.bmiHeader.biCompression = BI_RGB;     
               
          bmp = CreateDIBSection(hdc, &bi, DIB_RGB_COLORS, &img, NULL, 0);     
           
          SelectObject(hdc, bmp);     
               
          SelectObject(hdc, GetStockObject(BLACK_BRUSH));     
       
          SetBkMode(hdc, TRANSPARENT);     
          SetTextColor(hdc, RGB(255, 255, 255));                 
      }     
       
      Rectangle(hdc, 0, 0, width, height);     
      ZeroMemory(img, width * height);     
       
      lf.lfCharSet = DEFAULT_CHARSET;     
      lf.lfClipPrecision = CLIP_DEFAULT_PRECIS;     
      lf.lfEscapement = 0;     
      wcscpy(lf.lfFaceName, fontname);     
      lf.lfHeight = -(fontsize * GetDeviceCaps(GetDC(hWnd), LOGPIXELSY) / 72);     
      lf.lfItalic = (style & 1) ? TRUE : FALSE;     
      lf.lfOrientation = 0;     
      lf.lfOutPrecision = OUT_DEFAULT_PRECIS;     
      lf.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;     
      lf.lfQuality = DEFAULT_QUALITY;     
      lf.lfStrikeOut = FALSE;     
      lf.lfUnderline = (style & 4) ? TRUE : FALSE;     
      lf.lfWidth = 0;     
      lf.lfWeight = (style & 2) ? FW_BOLD : FW_NORMAL;     
           
      font = CreateFontIndirectW(&lf);     
       
      SelectObject(hdc, font);     
       
      len = wcslen(string);     
       
      GetTextExtentPointW(hdc, string, len, &sz);     
       
      rect.left = max(0, min(x, width));     
      rect.top = max(0, min(y, height));     
      rect.right = min(rect.left + sz.cx, width);     
      rect.bottom = min(rect.top + sz.cy, height);     
       
      DrawTextW(hdc, string, len, &rect, DT_LEFT | DT_BOTTOM);     
           
      points = (GLshort*)malloc(sz.cx * sz.cy * 2 * sizeof(short));     
       
      for(yy = rect.top; yy < rect.bottom; yy++)     
      {     
          for(xx = rect.left; xx < rect.right; xx++)     
          {     
              if(img[xx + (height - yy) * width] != 0)     
              {     
                  points[nbpoints * 2 + 0] = xx - x;     
                  points[nbpoints * 2 + 1] = (short)(rect.top + sz.cy - (yy - rect.top)) - y;     
                  nbpoints++;     
              }     
          }     
      }     
      DeleteObject(font);     
           
      indices = (GLushort*)malloc(nbpoints * sizeof(GLushort));     
      for(i = 0; i < nbpoints; i++)     
          indices[i] = i;     
       
      glMatrixMode(GL_PROJECTION);     
      glPushMatrix();     
      glLoadIdentity();      
       
      glOrthox(0, _INT2FIXED(width),      
              0, _INT2FIXED(height),      
              0, _INT2FIXED(1));     
       
       
      glMatrixMode(GL_MODELVIEW);     
      glPushMatrix();     
      glLoadIdentity();      
       
      glDisable(GL_DEPTH_TEST);     
           
      glTranslatex(_INT2FIXED(x), _INT2FIXED(y), 0);         
           
      glEnable(GL_ALPHA_TEST);     
      glAlphaFuncx(GL_NOTEQUAL, 0);     
      glDisableClientState(GL_TEXTURE_COORD_ARRAY);     
      glDisableClientState(GL_COLOR_ARRAY);     
      glDisableClientState(GL_NORMAL_ARRAY);     
      glEnableClientState (GL_VERTEX_ARRAY);     
      glVertexPointer(2, GL_SHORT, 0, points);     
       
      glDrawElements(GL_POINTS,     
                          nbpoints,     
                          GL_UNSIGNED_SHORT,     
                          indices);     
           
      glDisable(GL_ALPHA_TEST);     
       
      glEnable(GL_DEPTH_TEST);     
       
      glPopMatrix();     
      glMatrixMode(GL_PROJECTION);     
      glPopMatrix();     
      glMatrixMode(GL_MODELVIEW);     
       
      free(indices);     
      free(points);     
}