These main methods attach themselves to window.requestAnimationFrame(), which asks the browser for control over the upcoming frame. The above sections describe main loops which try not to wrestle away control from the browser. Ultimately, in JavaScript, the browser is running its own main loop and your code exists in some of its stages. Building a better main loop in JavaScript There are a lot of them and they will make your life easier. Simple animations can be easily performed, even GPU-accelerated, with CSS animations and other tools included in the browser. You cannot really get more smooth and responsive than that.īut do not immediately assume animations require frame-by-frame control. A First-Person Shooter (or a similar game) presents a new scene once every frame. It is also very simple because main() is the only function getting looped. You are given control over each frame of animation. Timing the main loop to when the browser paints to the display allows you to run your loop as frequently as the browser wants to paint. Before we discuss ways to change it, let us discuss what it already does well. Because main() is called once in the second statement and every call of it places itself in the queue of things to do next frame, main() is synchronized to your frame rate. The second statement calls the main() function, defined in the first statement. This function does some work and also tells the browser to call itself next frame with window.requestAnimationFrame(). The first statement creates a function as a global variable called main(). The above chunk of code has two statements. Calling the next requestAnimationFrame early ensures the browser receives it on time to plan accordingly even if your current frame misses its VSync window. That is not by accident and it is considered best practice. Note: In each of the main() methods discussed here, we schedule a new requestAnimationFrame before performing our loop contents. If something looks like it should be attached to a more infrequent event then it is often a good idea to break it out of the main loop (but not always). Of course, your game will only be as optimized as you make it. Modern JavaScript - as described in the next sections - thankfully makes it easy to develop an efficient, execute-once-per-frame main loop. It might even loop based on something else entirely. It might require both input and simulated time. Your game loop might be similar to the find the differences example and base itself on input events. If your game loops based on time then this will be its authority that your simulations will adhere to.īut it might not need per-frame control. This once-per-frame model is implemented in something called a main loop. The same principles as above apply with a slight twist: each frame of animation progresses the cycle and any change in user input is caught at the first available turn. Other games demand control over each of the smallest possible individual timeslices. This is more of a turn-based approach that doesn't demand a constant update every frame, only when the player reacts. The game loop is advanced by the user's input and sleeps until they provide it. finally, they calculate an updated scene resulting from that input. These games present two images to the user they accept their click (or touch) they interpret the input as a success, failure, pause, menu interaction, etc. Imagine that you are developing a "find the differences between these two similar pictures"-type game. Some games drive this cycle by user input. Not surprisingly, this pattern corresponds to how a game engine is programmed. Games are constantly looping through these stages, over and over, until some end condition occurs (such as winning, losing, or exiting to go to bed). The goal of every video game is to present the user(s) with a situation, accept their input, interpret those signals into actions, and calculate a new situation resulting from those acts.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |