Dual-buffer decryption under VC

To understand the problem of dual buffering, first of all, we need to understand the principle of animation. Basically, animation is a continuous playback of multiple static images, the fast switching of consistent static images gives a dynamic "illusion ". You also need to refresh the image between two frames to eliminate unnecessary elements in the next frame. The simplest refresh is to "draw white" or "clear ", this is the root cause of the problem. If this refresh is visible to the audience, it will flash because the screen is blank at one time. For details, see the next ProgramDemo:
Jumpball1.exe
It can be seen that the key to eliminating "blinking" is to eliminate "blank", but "Clearing" is inevitable. Otherwise, the running character may become an octopus, that is, a shadow; the solution is "dual Buffering", that is, to open up a large unit such as memory and transfer the previously completed refresh work in the memory to the memory, the last one-time write to the video memory, thus avoiding the "blank" process visually.
An efficient bitblt function is provided in Win32 API to implement fast migration of the bitmap structure. Based on this function and the "Double Buffering" principle, this article implements continuous animation and eliminates the "blinking ":
Jumpball2.exe
Readers can compare jumpball1 ("flashing") and jumpball2 (without "flashing"), download the complete source code, and intuitively understand the implementation method of this mechanism.