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Help => General => Topic started by: MarbleXeno on January 24, 2021, 01:50:34 pm

Title: [fixed] Can't stop the sprite from moving
Post by: MarbleXeno on January 24, 2021, 01:50:34 pm

Hi. Im creating simple game and i implemented this move script. I want to stop my sprite from moving but it actually never stops. I printed the velocity.x in terminal and it shows random numbers.

How can i stop my sprite from moving in a correct smooth way? i'm struggling with this for a long time.

//code

(click to show/hide)

//VARIABLES
const float gravity = 9.81f;
const float force = 15.f;
bool isMoving = false;
sf::Vector2f velocity = { 0,0 };

//PLAYER.CPP
        if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) { //movement
                isMoving = true;
                velocity.x -= force;
        }
        else if(sf::Keyboard::isKeyPressed(sf::Keyboard::D)){
                isMoving = true;
                velocity.x += force;
        }
        else {
                isMoving = false; //yeah i know its dumb
        }

        if (isMoving == false) { //deceleration
                velocity.x *=0.9;
        }
       

        if (velocity.x > 400) //max x speed
                velocity.x = 400;
        if (velocity.x < -400)
                velocity.x = -400;

        player_sprite.getSprite("player").move(velocity*dt); //thats my sprite manager script

 

//what terminal prints when the sprite should stop moving

(click to show/hide)

3.22666e-12
2.90399e-12
2.61359e-12
2.35223e-12
2.11701e-12
1.90531e-12
1.71478e-12
1.5433e-12
1.38897e-12
1.25007e-12
1.12507e-12
1.01256e-12
 

Title: Re: Can't stop the sprite from moving
Post by: G. on January 24, 2021, 02:32:11 pm

Hey.
They are not random numbers, they are very tiny numbers written in scientific notation.
3.22666e-12 means 3.22666 * 10^-12 which means 0.00000000000322666...

Set your velocity to 0 when it is very close to 0 and isMoving is false.
Something like < to 0.01 and > to -0.01 or whatever feels good to your game.

Title: Re: Can't stop the sprite from moving
Post by: MarbleXeno on January 24, 2021, 03:00:00 pm

Thanks, it was so obvious and easy!  The final code:

(click to show/hide)

if (velocity.x < 0.01 && velocity.x > -0.01)
velocity.x = 0;