smartdown/docs/lib/gallery/VectorField.md

A library for translating, rendering and interacting with Smartdown documents. Smartdown is an extension of Markdown that provides richer media support and reactive programming capability.

## P5JS Vector Field


Vector Field Example Based upon https://github.com/winkerVSbecks/material-vector-field

```p5js/playable

var locs = [];
function calcVec(x, y) {
  return new P5.Vector(y - x, - x - y);
}

p5.windowResized = function() {
  p5.resizeCanvas(p5.windowWidth - 70, 500);
};

p5.setup = function() {
  p5.createCanvas(100, 100);
  p5.windowResized();

  var res = 20;
  var countX = p5.ceil(p5.width/res) + 1;
  var countY = p5.ceil(p5.height/res) + 1;

  for (var j = 0; j < countY; j++) {
    for (var i = 0; i < countX; i++) {
      locs.push( new P5.Vector(res*i, res*j) );
    }
  };

  p5.noFill();
  p5.stroke(249,78,128);

};
p5.draw = function() {
  p5.background(30,67,137);
  for (var i = locs.length - 1; i >= 0; i--) {
    var h = calcVec( locs[i].x - p5.mouseX, locs[i].y - p5.mouseY);
    p5.push();
      p5.translate(locs[i].x, locs[i].y);
      p5.rotate(h.heading());
      p5.line(0, 0, 0, - 15);
    p5.pop();
  };
};
```


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