在 Double-Buffered OpenGL 窗口中绘制文本

通过在字体中为所选字符创建显示列表，然后为要绘制的每个字符执行相应的显示列表，在双缓冲的 OpenGL 窗口中绘制文本。 下面的代码示例创建一个呈现上下文，绘制一个红色三角形，然后使用文本标记它。 对于此示例代码，我们假设存在具有字体和像素格式的设备上下文。

// create an OpenGL rendering context  
hglrc = wglCreateContext(hdc); 
 
// make it this thread's current rendering context  
wglMakeCurrent(hdc, hglrc); 
 
// make the color a deep blue hue  
glClearColor(0.0F, 0.0F, 0.4F, 1.0F); 
 
// make the shading smooth 
glShadeModel(GL_SMOOTH); 
 
// clear the color buffers  
glClear(GL_COLOR_BUFFER_BIT); 
 
// specify a red triangle  
glBegin(GL_TRIANGLES); 
    glColor3f(1.0F, 0.0F, 0.0F); 
    glVertex2f(10.0F, 10.0F); 
    glVertex2f(250.0F, 50.0F); 
    glVertex2f(105.0F, 280.0F); 
glEnd(); 
 
// create bitmaps for the device context font's first 256 glyphs  
wglUseFontBitmaps(hdc, 0, 256, 1000); 
 
// move bottom left, southwest of the red triangle  
glRasterPos2f(30.0F, 300.0F); 
 
// set up for a string-drawing display list call  
glListBase(1000); 
 
// draw a string using font display lists  
glCallLists(12, GL_UNSIGNED_BYTE, "Red Triangle"); 
 
// get all those commands to execute  
glFlush(); 
 
// delete our 256 glyph display lists  
glDeleteLists(1000, 256) ; 
 
// make the rendering context not current  
wglMakeCurrent (NULL, NULL) ; 
 
// release the device context  
ReleaseDC(hdc) ; 
 
// delete the rendering context  
wglDeleteContext(hglrc);