[CODE]Keep Gameobject position exactly at mouse cursor when cast float position to int

Question

Hey everyone! I'm creating a 2d top-down game and currently im working on a script which should keep the Gameobject position exactly at the same position of the mouse, but it doesn't work. Maybe it's because I'm casting a float to an int, but I have seen other games where it works very well.

Problem: When I move the mouse very fast the object glitches from it's position

I hope anyone can help me!

 void Update ()
     {
         mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
 
         yMin = (int)playerRectAncor.transform.position.y - 1;
         yMax = (int)playerRectAncor.transform.position.y + 1;
         xMin = (int)playerRectAncor.transform.position.x - 1;
         xMax = (int)playerRectAncor.transform.position.x + 1;
 
         if (true) //Its just temporary true, for testing
         {
             pos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
             pos.z = transform.position.z;
             pos.x = Mathf.Clamp(pos.x, xMin, xMax);
             pos.y = Mathf.Clamp(pos.y, yMin, yMax);
            // put Object position to mousePosition
             rectObj.transform.position = new Vector3((int)pos.x, (int)pos.y, (int)pos.z);
         }

Answer 1

Answer by Neoletum · Jan 14, 2018 at 12:59 PM

Hey, thank you for your answer, it's difficult for me to describe my problem in english, maybe I described it bad, the point is that the game is tiled-base, and I'm casting it to an int because the whiteRect should only move in integers so the player can only build in a certain range around him.

In a nutshell, player should only be able to move the whiteRect in a 3x3 Range around his character otherwise he would be able to dig a hole out of his range^^ And moving the rect without casting it to an int seems not suitable to the kind of game im trying to create.

Here is a picture, it's like building in Stardew Valley:

alt text

@Bunny83 @RocketFriday @Orokon

problem2.png (121.0 kB)

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Neoletum · Jan 14, 2018 at 02:48 PM 1

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So, I found the answer, the Problem was that a cast doesnt round up like I expected it. When the number becomes negativ it rounds in an other way, like this:

(int)2.5 = 2 (int)(-2.5) = -2 but it has to become -3!

Solution: Using Mathf.Floor(-2.5) rounds up to -3 and everything works fine.

Thank you all!

Orokon · Jan 14, 2018 at 03:14 PM 0

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Thats what I tried to tell you. You are not rounding but casting so it cuts off the numbers after the dot. 2.1 becomes 2, -2.1 becomes -2. With the usage of floor you will run into other Problems. Look at how Mathf.Floor behaves:

 Debug.Log(Mathf.Floor(10.0F)); // returns 10
 Debug.Log(Mathf.Floor(10.2F)); // returns 10
 Debug.Log(Mathf.Floor(10.7F)); // returns 10
 Debug.Log(Mathf.Floor(-10.0F)); // returns -10
 Debug.Log(Mathf.Floor(-10.2F)); // returns -11
 Debug.Log(Mathf.Floor(-10.7F)); // returns -11

If that is what you want thats great, otherwise you should look at the rounding functions.

Also you should use FloorToInt instead of Floor so you dont have to cast, because it returns an int

Neoletum Orokon · Jan 14, 2018 at 10:24 PM 0

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Yes, but it works now like I expected it, thank you for your hints, when you answer not as a comment I can accept your answer =)

@Orokon

[CODE]Keep Gameobject position exactly at mouse cursor when cast float position to int

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