image rotation following the mouse

datandre

hi, i’ve searched online but i couldn’t find anything good for me.

There’s a PImage which has to follow the coordinates of the mouse, without moving. This gif is pretty much what i’d like to do

Chrisir

look at help for command rotate

Chrisir

float angle; 

void setup() {
  size (600, 600);
  background(0);
}

void draw() {
  background(0);
  translate (333, 333);
  rotate(angle);
  rect(-20, -20, 40, 40);
  angle+=.07;
}

Chrisir

to use mouse look at mouseX and use map() to map the value of mouseX to the angle you need (which is in radians)

see

https://processing.org/reference/map_.html

https://processing.org/reference/rotate_.html

https://processing.org/tutorials/transform2d/

quark

I assume that you want the image to face the mouse position in which case you can calculate the rotation angle with

float angle = atan2(mouseY - imgY, mouseX - imgX);

Where imgX and `imgY' is the position of the centre of the image on the screen.

In draw() you can then use rotate(angle); followed by image(img, imgX, imgY); where img is the PImage you want to rotate.