Just got started with Godot. Read a few tutorials, made by own Pong, now I've got some questions

rivten

Hello everyone ! Just to give you a background of where I am. I have been programming for quite some time but I have never used engines. Godot is my first one. It's been two days of reading through tutorials and messing around and for the most part I have been enjoying it. As an exercise to myself, I decided to try and recreate a Pong-clone with Godot to learn all the basic. It took me most of my afternoon, I struggle with a lot of concepts but I ended up with something I am quite pleased with. Now that I am a little bit familiar with the most basic concepts of Godot, here the questions I have that I could not answer after working on my Pong-clone. 1. Basically, here's how my Pong project is architectured. There is three scenes : a TitleScreen, a PongScreen (where the game happens) and an EndScreen (to display who's the winner). Here a screenshot of the PongScreen tree. I think it is fairly straightforward. https://s18.postimg.org/nrhdmtpvd/godot_architecture.png  You might notice from this screenshot that, from my main node, I have two nodes : LeftPlayer and RightPlayer. I created LeftPlayer from scratch and, for the creation of RightPlayer, I re-did what I did for LeftPlayer. I just had to tweak a few variables here and there for the script of the RightPlayer (like the initial position of the paddle and the Input controlling the paddle). But apart from that, there were the same. Now, I think what I should have done is create another scene explaining what a Player is (a paddle, a goal area and a score) and instancing it twice. But then the script will be the same and I will not be able to tweak those small variables. So what is the solution here ? Is this possible to create a "generic player" and the modifying in the script a few variable for each instance ? 2. This genericity thing appeared to me another time. When I created my SamplePlayer, I wanted to create a function allowing me to pass a string to a Sample, and the function would set the Sample to LOOP_NONE mode. Basically, I would have like for all SamplePlayer to have this function available. I thought of deriving the SamplePlayer class, creating my MySamplePlayer object, implementing the NoLoop function, and then, all the other SamplePlayer I would have wanted to created would have derived from MySamplePlayer class. Is this possible in anyway other than creating the function in a global script (callable from anywhere) ? 3. And, is it even good practice to use a global script (since it is not good practice in programming to have global variables...) ? 4. For the paddles collisions with the screen, I had at first this idea : I will have an Arena which will be an Area2D or something, and the paddle (which are KinematicBody2D) will not be able to get out of this Area2D. I was excited at first to see that there was an on_body_exit signal on an Area2D but this does not do exactly what I want : I want a signal to be emitted as soon as a shape is no more included in another, whereas the given signal is emitted as soon as there is no intersection between the two shapes. I have overcome this by create wall around the screen, but I feel like this is hacky and lame. Any idea how to handle this collision more properly ? 5. One last problem was the following : when one player reach a given score (say MAX_SCORE), the game will end and there will be a title screen with the number of the winner (1 or 2). It is easy to load the scene but I have had hard times to pass to the to_be_loaded_scene a variable (here, the number of the winner). My hack was to store this in a global variable that the EndScene will load at _ready time, but I feel like I could have done a better jobs of passing an info to a scene that hasn't been loaded yet. Any idea ? Sorry if this is a long post. I have been pretty excited with Godot and I want to perform even better. If you have any other remarks on the way I could have done this better, I'd be very happy to hear about it :) Anyway, thanks a lot ! and Happy Programming. Rivten

Ross

Use export variables. They can be changed in the editor for each instance and are saved in the scene. For input, if you name your mappings something like "p1_up", you can set a player number var on the paddles, then in your process_input() do if event.is_action_pressed("p" + str(player_number) + "up"). I wouldn't think you'd have to set paddle starting position via script, just place the scene where it should be in the editor. 2 & 3: I don't know much about how "good" using global things is, but they seem pretty darn useful to me. Either use a global script or give every SamplePlayer a the same little helper script with that function. (I use the latter to give some AnimationPlayers better functions.) 4. Again I think your "hacky" solution is the right one. I mean that's basically what you want, right? Walls at the edges of the screen that neither the paddle nor the ball can escape. Just have four static bodies, or one body with four collision shapes. But I also don't understand why your area idea didn't work. When you say, "a shape is no more included in another", you mean, fully included inside the other? As in a signal when any part of the paddle is outside the area? There is no signal for that as you've seen, but couldn't you just make the Area smaller by about the width of the paddle? 5. See 2 & 3. But it also depends on how you're loading that scene. If you are instancing and adding it to the tree yourself when the game ends, you can set the winning player number on it then. The ready() function is fired when a scene enters the tree. So if you set variables in a scene before adding it to the tree, its ready function will have those new values to work with. So: var scenefile = preload("res://menu_scene.tscn") scene = scenefile.instance() scene.winner = 2 get_tree().get_root().add_child(scene) # scene's _ready() will then fire, with winner = 2.

rivten

Hey ! Thanks a lot for taking the time to help me. To answer of what you told me :  1. I just looked up export variables this is exactly what I was looking for indeed. But I don't think that I really want to set the paddles' starting position manually : if I want to place them at the center of the screen Y-wise and at a fixed margin X-wise from the border of the screen, it might be better for a script to place them (the position depending of the exported variable player_number obvisouly), or am I missing something ? 4. My main concern is robustness. Let's say I forgot a pixel while creating a body for my area, then it would be hard to detect (for it is just one pixel) and a ball might be able to get through. (ok, I am exaggerating but you get my point). Besides, conceptually, I just want to define one area (my arena), not the 4 margins of it. Now there's 3 solutions that comes to my mind :       A) Do just as I did, placing manually the 4 margin-bodies      B) Having a script placed on the Area2D, constructing the 4 margin-bodies for me at init-time      C) My Area2D could make use of the enclose function for Rect2. As soon as my Area2D does not enclose another body (here, my Paddles or the Ball), a signal is emitted. The Paddles and the Ball get that signal (which is a collision) and react to it. Any thoughts of which one is better than the other ? I'm thinking B might be the sweet spot here. Also, to finish on what you were saying, I cannot make the Area smaller by the width of the paddle, since then it won't work for the ball which have another with... So this quickly become unmaintainable I'd guess... Your answer have been very helpful and interesting ! I going back to test all this right now. Thanks !

Ross

Yeah, you're probably right, it makes little difference either way. If your screen size/proportion is going to change at all, then you would need to do it by script. Or if you want to adjust the margin. 4. Well, I would definitely overlap the bodies and make them fairly thick so there could be no issues like that. Do whatever seems easiest to you and works. It also may depend on how you're handling the ball bouncing.