doublebuffering

Double buffering is a graphics technique used to produce smooth imagery by using two buffers to hold image data during rendering. The front buffer is the image currently being displayed, while the back buffer is used to render the next frame. When the back buffer is ready, the two buffers are swapped so the new frame becomes the visible image. In many systems the swap is synchronized with the vertical retrace of the display (vsync) to avoid tearing, which can occur if a frame is updated while the monitor is drawing.

There are two common swap methods. In page flipping, the display switches to the back buffer by changing the pointer to the front buffer, making the swap almost instantaneous. In blitting, the back buffer is copied into the front buffer, which can introduce extra rendering latency.

The technique eliminates the partial updates that cause flicker and enables consistent, per-frame animation. It does, however, require extra memory for the back buffer and can add input latency if waits for a frame boundary. If rendering time surpasses the frame interval, animation may still appear choppy. To reduce latency while preserving smoothness, some systems use triple buffering or rely on graphics APIs with larger swap chains.

Applications include video games, graphical user interfaces, and media playback. Historically, double buffering helped mitigate flicker on CRT displays and remains a staple in many modern rendering pipelines, though it is often implemented as part of a broader buffering strategy.