Pen tool & Area Calculation

Answers

• Ater

  February 2015

  Hey. Try this to create a pen-like tool (sorry for the formatting). Getting the area of the shape is harder and out of my competence though.

  var prevPosX;
  var prevPosY;
  
  function setup() {
  createCanvas(500,500);
  background(0);
  stroke(255);
  }
  
  function draw() {
  }
  
  function mousePressed() {
    if (prevPosX !=0 && prevPosY !=0) {
       line(prevPosX, prevPosY, mouseX, mouseY);
  }
       prevPosX = mouseX;
       prevPosY = mouseY;
       return false;
      }
  
• knockout

  February 2015 edited February 2015

  I haven't tried coding but since processing can track the x and y coordinates, you can probably make a code base on the algorithms of finding the area irregular polygon :

  https://www.mathsisfun.com/geometry/area-irregular-polygons.html

  I am thinking you will probably need to set a counter with mouse pressed(for the vertices) and using a for loop that will go through the calculation and that should work