requestAnimationFrame

requestAnimationFrame is a method provided by the browser's Window interface that allows developers to execute JavaScript code before the next repaint of the browser's window. It is designed to perform animations and other visual updates in a way that is optimized for the display's refresh rate, leading to smoother and more efficient animations.

When a function is passed to requestAnimationFrame, the browser schedules that function to be called just before the next screen repaint. This means that if the user's screen refreshes 60 times per second, the provided function will be called up to 60 times per second. This synchronization with the display's refresh rate prevents visual glitches like screen tearing and reduces unnecessary work when the animation is not visible, such as when the tab is in the background.

The function passed to requestAnimationFrame typically receives a single argument: a high-resolution timestamp. This timestamp indicates the time at which requestAnimationFrame began executing its callback. Developers can use this timestamp to accurately calculate the progress of an animation, ensuring consistent timing across different devices and frame rates.

To create a continuous animation loop, the function passed to requestAnimationFrame should itself call requestAnimationFrame with the same function, creating a recursive loop. This is the standard pattern for implementing animations in modern web development, offering significant performance benefits over older methods like setInterval or setTimeout for visual updates.