GlutPostRedisplay

GlutPostRedisplay is a function in the OpenGL Utility Toolkit (GLUT), a library used for creating graphical user interfaces and handling input in OpenGL applications. The function is used to mark the current window as needing to be redisplayed. When called, it schedules a redraw of the window, causing the display callback function to be triggered. This is particularly useful in animations or interactive applications where the scene needs to be updated frequently.

The glutPostRedisplay function does not immediately redraw the window; instead, it sets a flag indicating that the window needs to be redrawn. The actual redraw occurs when the event loop processes the redisplay request. This approach helps in optimizing performance by reducing the number of redraws and ensuring that the window is updated only when necessary.

The function is typically used in conjunction with other GLUT functions, such as glutDisplayFunc, which sets the display callback function. The display callback function is responsible for rendering the scene and is called whenever the window needs to be redrawn. By using glutPostRedisplay, developers can efficiently manage the rendering process, ensuring that the window is updated smoothly and responsively.

In summary, glutPostRedisplay is a key function in GLUT for managing window redraws in OpenGL applications. It helps in optimizing performance by scheduling redraws only when necessary, ensuring smooth and responsive rendering.