直線選擇

GLint selBufferSize = 512;
 GLuint selBuffer[512];
 glSelectBuffer(selBufferSize,selBuffer);
 glPushAttrib(GL_VIEWPORT_BIT);
 glPushMatrix();
 glViewport(x-2,y-2,4,4);
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 glOrtho(x-2,x+2,y-2,y+2,0.0f,1.0f);
 glMatrixMode(GL_MODELVIEW);
 glLoadIdentity();
 glRenderMode(GL_SELECT);
 glInitNames();
 glPushName(0);
 map<int,SelLine>::iterator line_iterator;
 line_iterator = lines.begin();

 for (;line_iterator != lines.end();line_iterator++)
 {
  (*line_iterator).second.Name();
 }
 glFlush();

 GLint hit = glRenderMode(GL_RENDER);
 printf("hit=%d/n",hit);
 GLuint names,*ptr;
 ptr = (GLuint*)selBuffer;
 for (int i = 0 ; i < hit;i++)
 {
  names = *ptr;
  printf(" number of names for hit = %d/n",names);ptr++;
  printf(" z1 is %g;",(float)*ptr/0x7fffffff);ptr++;
  printf(" z2 is%g/n",(float)*ptr/0x7fffffff);ptr++;
  printf(" the name is ");
  for(int j = 0;j < names;j++)
  {
   id = *ptr;
   printf(" %d ",*ptr);ptr++;

  }

  printf("/n");
 }
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 printf("glWindowWidth=%d  glWindowHeight=%d  magnification=%f",glWindowWidth,glWindowHeight,magnification);
 glOrtho(0,glWindowWidth/magnification,0,glWindowHeight/magnification,0.0f,1.0f);
 glMatrixMode(GL_MODELVIEW);
 glLoadIdentity();
 glPopMatrix();
 //glViewport(0,glWindowWidth,0,glWindowHeight);
 glPopAttrib();
 return hit>0;
 return true;