glSwapBuffers

glSwapBuffers is a function in OpenGL that is used to display the rendered image. When you draw to the screen in OpenGL, you are typically drawing to a hidden buffer called a back buffer. This is done to prevent flickering and to allow for smooth animation. Once you have finished drawing to the back buffer, you call glSwapBuffers to swap the back buffer with the front buffer, which is the buffer that is currently being displayed on the screen. This effectively makes your newly rendered image visible to the user.

The exact behavior of glSwapBuffers can vary depending on the operating system and the graphics driver. In most cases, it will wait for the vertical retrace of the monitor before swapping the buffers. This is known as vertical synchronization or vsync. Vsync helps to prevent screen tearing, which is a visual artifact that can occur when the graphics card renders frames at a different rate than the monitor's refresh rate. Some implementations of glSwapBuffers may also offer options to control vsync behavior.

This function is a crucial part of the rendering pipeline in OpenGL applications. Without it, the rendered content would remain in the back buffer and would not be displayed to the user. It is typically called once per frame, after all rendering commands for that frame have been issued. Understanding glSwapBuffers is essential for anyone developing graphical applications using OpenGL, as it directly controls when and how the rendered output becomes visible.