Speed in relation to MouseY coordinate on a 2 point system

MauriceSchill

In need some help with controlling the speed of an object along a straight line. This is the basic outline of the code, and the setup i want for my simulation. I am trying create a simple environment to test some arduino prototypes with later on. All i need is a square that moves horizontally along a line and the speed can be adjusted depending on the state of an a external potentiometer input. For now I was just trying to use the relative MouseX coordinates to simulate a potentiometer. I have tried creating an object for the moving piece, which brought me a little closer, but still didn't allow me to have variable speeds, depending on the location on my finger on the trackpad. I would greatly appreciate any help on this. I have spend the last two days going through examples, tutorials, and anything i could find, without figuring out how this can be done.

Thank you-

 int dx = 1;
    float x = 100;
    float y = 100;
    float xspeed = 1;


    void setup () {
      size(1200, 300);
      smooth();
      background(#1E8FD3);
      fill(#1F8E27);
      ellipse(0, 150, 150, 150);
      ellipse(1200, 150, 150, 150);
      fill(50);
      ellipse(150, 150, 25, 25);
      ellipse(1050, 150, 25, 25);
      rect(150, 150, 900, 2);


    }

    void draw () {
      background(#1E8FD3);
      fill(#1F8E27);
      ellipse(0, 150, 150, 150);
      ellipse(1200, 150, 150, 150);
      fill(50);
      ellipse(150, 150, 25, 25);
      ellipse(1050, 150, 25, 25);
      rect(150, 149, 900, 2);
      fill (155);
      rect(x,145, 30, 10); 
      x = x + dx;
     if (x> 1000){
     dx = -1;
     }
     if(x <150) {
       dx = 1;
     }
     }
`

Any help is greatly appreciated!

PhiLho

You have a xspeed variable which you don't use. Make it dependent of an external factor (you can try mouse position for testing, then serial input). Then replace the formula

x = x + dx;

by

x += dx * xspeed;

ie. dx is just the direction, the xspeed is the amount of displacement on each frame.

MauriceSchill

It seems to simple now. Thank you very much for the tip, hopefully this will work.

MauriceSchill

I tried including the formula into my code, but it doesn't work. The square stops moving all together. I have tried several options to enter the mouse position, but none of them have worked. Any further suggestions? i think the equation should work, however the numbers coming in from mouseY are too large/small maybe. I tried mapping the mouseY which didnt work either.

PhiLho

You should show your last attempt (with mapping), so we can help you further. Sometime code fails because of simple things overlooked.