akluk-Project-07-curves

sketch

//Alvin Luk
//Section A
//akluk@andrew.cmu.edu
//Project-07


var nPoints = 200;
var edges = 2;


function setup() {
    createCanvas(400, 400);
    frameRate(10);
}


function draw() {
    background(255);
    // draw the frame
    fill(0); 
    noStroke();
    stroke(0);
    noFill(); 
    rect(0, 0, width-1, height-1); 
    
    // draw the curve
    push();
    translate(width / 2, height / 2);
    drawCurve(edges);
    pop();
}

//--------------------------------------------------
function drawCurve() {
    // Hypotrochoid
    // http://mathworld.wolfram.com/Hypotrochoid.html
    // draws multiple hypotrochoid with differeing h's
    for (var j = 0; j < 30; j++){
    var x;
    var y;
    
    var a = map(mouseX,0,width,0,200);
    var b = a/edges;
    var h = map(mouseY,0,height,0,4*j);
    //changes color gradient depending on which hypotrochoid currently at
    //and also the position of mouseX and mouseY
    var red = map(j,0,30,0,255);
    var green = map(mouseX,0,width,0,255);
    var blue = map(mouseY,0,height,0,255);
    stroke(color(red,green,blue));

    //draws single hypotrochoid
 	noFill();
    beginShape();
    for (var i = 0; i < nPoints; i++) {
        var t = map(i, 0, nPoints, 0, TWO_PI);
        
        x = (a - b) * cos(t) + h* cos(t * (a - b) / b);
        y = (a - b) * sin(t) - h * sin(t * (a - b) / b);
        vertex(x, y);
    }
    endShape(CLOSE);
	}	


}

//adds number of edges/ corners each time the mouse is pressed
function mousePressed() {
    edges +=1
    if (edges > 7){
    	edges = 2;
    }
}
//--------------------------------------------------

For this project. I first followed the guidelines provided in the assignments and chose a graph from the mathworks curves section. I chose the Hypotrochoid, since there was a lot of variables in the parametric equations of the curves that I could play with that enabled me to create varying versions and variations of the curve. I also thought that just one hypotrochoid seems kind of static. So I decided to use a for loop to generate numerous hypotrochoid super imposed on each other with a changed parameters. I also made it so the color changes based on the position of x and y. Clicking also changes the ratio of a and b creating new different classes of hypotrochoid. Below are some screenshots of what my program creates.