atan2, follow mouse and rotating box from rested position?

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atan2, follow mouse and rotating box from rested position?

in Programming Questions • 2 years ago

My brain has gone into meltdown trying to work out how to do this seemingly simple code.

I'd like to get a box to rotate to the position of the mouse on mouseDragged (script below already does this), then on drag again start rotating the box from its rested position NOT where the mouse's current position is.

float angle;

void mouseDragged(){

angle - atan2(mouseY-height/2,mouseX-width/2)

}

void draw(){

background(150);

translate(width/2,height/2);

rotate(angle);

rectMode(CENTER);

rect(0,0,25,25);

}

help would be brilliant :L

Replies(1)

local_guru

Re: atan2, follow mouse and rotating box from rested position?

2 years ago

You could save the current angle if a mouseReleased event occures ( = dragging ends )
and add it to your current ange. When the user dragges the mouse for the first time oldAngle = 0 so the box gets rotated
to the current mouseposition on every following drag it gets rotated starting from where you left it.

              float angle, oldAngle = 0;
              
void mouseDragged(){
              
   angle = atan2(mouseY-height/2,mouseX-width/2) + oldAngle;
              
}
              
void mouseReleased() {
              
  oldAngle = angle;
              
}
              
void draw(){
              
      background(150);
              
      translate(width/2,height/2);
              
      rotate(angle);
              
      rectMode(CENTER);
              
      rect(0,0,25,25);
              
}

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