CODEWITHSUNDEEP
coordinatestrigonometrygame-makergame-maker-studio-2game-maker-language
Joseph
Joseph

Reputation: 863

Get x and y 'coordinates' from object speed and direction

I have a player object that controls like the ship in Asteroids, using speed and direction. This object is fixed in the middle of the screen, but can rotate. Movement of this object is a visual illusion as other objects move past it.

I need to get x and y coordinates of this player object, from an origin of (0, 0) at room start. x and y do not provide this info as the object does not move. Does anyone know how I can get 'fake coordinates', based on the speed and direction?

Upvotes: 0

Views: 837

Answers (3)

willm127
willm127

Reputation: 39

One thing to make sure is that you're not just getting x and y on their own, as that will get the current object's x and y position. Instead, make sure to reference the object you're trying to get. For example:

var objectX = myShip.x;
var objectY = myShip.y;
show_debug_message("x: " + string(objectX));
show_debug_message("y: " + string(objectY));

Upvotes: 1

Steven
Steven

Reputation: 2123

You'll need to think what you'll use to move the ship around, but then use that code on different variables.

Normally, you'll update the x or y if you want to move the ship, but since you're not going to do that, simply use a custom variable that replaces the x and y value (like posx or posy), and use them on the code that would otherwise be used to move the ship around.

Upvotes: 0

jwezorek
jwezorek

Reputation: 9525

I think you are thinking about it wrong. You do not need "fake coordinates". Real coordinates are fine. Give the ship and asteroids/enemies whatever coordinates and velocity vectors you want; randomly generate them if the game is like Asteroids.

The coordinates do not have to be fake; it is just that when you render in your game loop, you render a particular frame of reference. If the origin is the center of the screen, when you paint an object at (x,y) paint it as though it were at (x - ship_x, y - ship_y) -- including the ship, which will be at (0,0). If you wanted to make rotation relative to the ship too, you could do the same thing with rotation.

Now, you have your question tagged as game-maker. I have no idea if game-maker lets you control how sprites are painted like this. If not then you need to maintain the real coordinates as separate properties of objects and let the official (x,y) coordinates be relative to the ship. The trouble with this is that you will have to update all of the objects everytime the ship moves. But like I said I don't know how GameMaker works -- if it is a problem maybe ask a question more specific to GameMaker.

Upvotes: 0

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