geometry collisions and functions for math/p5js

math_collisions.js

function collisionPointCircle(pointX, pointY, circleX, circleY, circleR) {
  return p5.prototype.dist(pointX, pointY, circleX, circleY) <= circleR;
}

function collisionCirclePoint(circleX, circleY, circleR, pointX, pointY) {
  return collisionPointCircle(pointX, pointY, circleX, circleY, circleR);
}

function collisionPointLine(pointX, pointY, lineX1, lineY1, lineX2, lineY2) {
  var d1 = dist(pointX, pointY, lineX1, lineY1);
  var d2 = dist(pointX, pointY, lineX2, lineY2);
  var d = dist(lineX1, lineY1, lineX2, lineY2);

  return (d1 + d2) - d <= 0.01;
}

function collisionLinePoint(lineX1, lineY1, lineX2, lineY2, pointX, pointY) {
  return collisionPointLine(pointX, pointY, lineX1, lineY1, lineX2, lineY2);
}

function collisionCircleCircle(circle1X, circle1Y, circle1R, circle2X, circle2Y, circle2R) {
  return p5.prototype.dist(circle1X, circle1Y, circle2X, circle2Y) <= circle1R + circle2R;
}

function collisionCircleRect(circleX, circleY, circleR, rectX, rectY, rectWidth, rectHeight) {
  var px = max(rectX, min(circleX, rectX + rectWidth));
  var py = max(rectY, min(circleY, rectY + rectHeight));

  return p5.prototype.dist(px, py, circleX, circleY) < circleR;
}

function collisionRectCircle(rectX, rectY, rectWidth, rectHeight, circleX, circleY, circleR) {
  return collisionCircleRect(circleX, circleY, circleR, rectX, rectY, rectWidth, rectHeight);
}

function collisionPointRect(pointX, pointY, rectX, rectY, rectWidth, rectHeight) {
  return pointX > rectX && pointX < rectX + rectWidth &&
    pointY > rectY && pointY < rectY + rectHeight;
}

function collisionRectPoint(rectX, rectY, rectWidth, rectHeight, pointX, pointY) {
  return collisionPointRect(pointX, pointY, rectX, rectY, rectWidth, rectHeight);
}

function collisionRectRect(rect1X, rect1Y, rect1Width, rect1Height, rect2X, rect2Y, rect2Width, rect2Height) {
  return (rect1X < rect2X + rect2Width &&
    rect1X + rect1Width > rect2X &&
    rect1Y < rect2Y + rect2Height &&
    rect1Y + rect1Height > rect2Y);
}

 /**
  * Conserve aspect ratio of the original region. Useful when shrinking/enlarging
  * images to fit into a certain area.
  *
  * @param {Number} srcWidth width of source image
  * @param {Number} srcHeight height of source image
  * @param {Number} maxWidth maximum available width
  * @param {Number} maxHeight maximum available height
  * @return {Object} { width, height }
  */
function calculateAspectRatioFit(srcWidth, srcHeight, maxWidth, maxHeight) {

    var ratio = Math.min(maxWidth / srcWidth, maxHeight / srcHeight);

    return { width: srcWidth*ratio, height: srcHeight*ratio };
 }