使用C ++在OpenGL中填充形状

Question

如何使用任何颜色的C ++在OpenGL中将形状填充为矩形，但不改变边框颜色（边框是形成矩形的线条）？

因为当我使用glBegin(GL_POLYGON)函数填充矩形时，边框也被填充但我不想改变边框的颜色。

我使用的代码如下：

 void display( )
   {
      glClear(GL_COLOR_BUFFER_BIT);
      glColor3f(1.0,0.0,0.0);
      glBegin(GL_POLYGON);
         glVertex2i(50,90);
         glVertex2i(100,90);
         glVertex2i(100,150);
         glVertex2i(50,150);
      glEnd();
      glFlush();       

    }

Answer 1

void display( )
{
  glClear(GL_COLOR_BUFFER_BIT);

  // Draw the Polygon First
  glColor3f(1.0,0.0,0.0);
  glBegin(GL_POLYGON);
     glVertex2i(50,90);
     glVertex2i(100,90);
     glVertex2i(100,150);
     glVertex2i(50,150);
  glEnd();

  // Draw the border next
  glColor3f(0.0,1.0,0.0);
  glBegin(GL_LINES);
     glVertex2i(50,90);
     glVertex2i(100,90);
     glVertex2i(100,150);
     glVertex2i(50,150);
  glEnd();
  glFlush();       

}