image rotation following the mouse

Answers

• Chrisir

  October 2017

  look at help for command rotate
• Chrisir

  October 2017

  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

  October 2017 edited October 2017

  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

  October 2017

  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.