Project-04: String Art-Section B

/*
* Evan Stuhlfire
* estuhlfi@andrew.cmu.edu
* Section B
*
* Project-04: String Art
* This program uses geometric shapes to create
* string art.
*/

function setup() {
    createCanvas(400, 300);
    background(73, 80, 87); //davys grey from coolors.com

}

function draw() {   
    // draw the string lines for the frame in light blue
    stringLeftLower(204, 255, 255, 55);
    stringLeftUpper(204, 255, 255, 55);
    stringRightUpper(204, 255, 255, 55);
    stringRightLower(204, 255, 255, 55);

    // move origin of canvas to center
    translate(width/2, height/2);

    // draw the circle design with light blue
    stringCircle(204, 255, 255); 
    noLoop();
}

/* draw the string pattern at the lower left */
function stringLeftLower(r, g, b, t) {
    var numLines = 40;
    var x1 = 0; // start at top right
    var y1 = 0; // top right
    var y2 = height;
    var x2 = xInc = (width/numLines);
    var yInc = (height/numLines);

    stroke(r, g, b, t);
    // iterate over each line to draw
    for (index = 0; index < numLines; index ++) {
        line(x1, y1, x2, y2);
        y1 += yInc;
        x2 += xInc;
    }
}

/* draw the string pattern at the upper left */
function stringLeftUpper(r, g, b, t) {
    // set vars to start at lower left and draw up
    var numLines = 40;
    var x1 = 0;
    var y1 = height; // lower left
    var y2 = 0;
    var x2 = xInc = width/numLines;
    var yInc = height/ numLines;

    stroke(r, g, b, t);
    // iterate over each line to draw
    for (index = 0; index < numLines; index ++) {
        line(x1, y1, x2, y2);
        y1 -= yInc; // move up the canvas
        x2 += xInc; // move across the canvas
    }
}

/* draw the string pattern at the upper right */
function stringRightUpper(r, g, b, t) {
    var numLines = 40;
    var x1 = xInc = width/numLines;
    var x2 = width;
    var y1 = 0;
    var y2 = 0;
    var yInc = height/ numLines;

    stroke(r, g, b, t);
    // iterate over each line to draw
    for (index = 0; index < numLines; index ++) {
        line(x1, y1, x2, y2);
        y2 += yInc; // move down the canvas
        x1 += xInc; // move right across the canvas
    }
}

/* draw the string pattern at the lower right */
function stringRightLower(r, g, b, t) {
    // set variable
    var numLines = 40;
    var x1 = width; // right side
    var x2 = 0;
    var xInc = width/numLines;;
    var yInc = height/numLines;
    var y1 = height - yInc; // bottom right
    var y2 = height;

    stroke(r, g, b, t); // set color and transparency
    // iterate over each line to draw
    for (index = 0; index < numLines; index ++) {
        line(x1, y1, x2, y2); 
        y1 -= yInc; // move up the canvas
        x2 += xInc; // move right across the canvase
    }
}

/* draw the center string circle */
function stringCircle(r, g, b) {
    // 36 spokes on the circle design
    var circlePoints = 36;
    var angle = 0;
    var rotDeg = 0;

    // iterate over each spoke
    for (index = 0; index < circlePoints; index++) {
        // save settings
        push();

        // map the angle to the perimeter of the circle
        angle = map(index, 0, circlePoints, 0, TWO_PI);

        // convert angle to x y coordinates
        var radius = 90;
        var circleX = radius * cos(angle);
        var circleY = radius * sin(angle);

        // move origin to the starting point of the circle
        translate(circleX, circleY);

        // rotate each spoke to the origin
        rotate(radians(rotDeg));

        // variables for drawing string design
        var circleX2 = -radius * 2;
        var circleY2 = 0;
        var smallCircleDiam = 10;
        var offset = 15;

        // draw small circles at end of spokes
        stroke(r, g, b, 255);
        circle(0, 0, smallCircleDiam * .2);
        noFill();
        circle(0, 0, smallCircleDiam); // outline

        // set stroke color and decrease transparency to
        // see more detail.
        stroke(r, g, b, 125); 

        // draw three lines from each perimeter point to
        // create spokes
        line(0, 0, circleX2, circleY2);
        line(0, 0, circleX2, circleY2 + offset);
        line(0, 0, circleX2, circleY2 -offset);

        // extend lines off of spokes
        stroke(r, g, b, 50);
        line(0, 0, offset * 8, circleY2);
        line(0, 0, offset * 8, circleY2 + offset);
        line(0, 0, offset * 8, circleY2 -offset);

        // call function to draw the background circles with
        // transparancey
        backgroundCircles(index, offset, r, g, b, 80);

        pop(); // restore settings 
        rotDeg += 10; // rotate 10 degrees 36/360
    }
}

/* draw the background circles with design */
function backgroundCircles(index, offset, r, g, b, t) {
    // save settings
    push();
    stroke(r, g, b, t); // light blue with transparency
    // rest origin, space circles out
    translate(25, 0);

    // draw small inner circle on even spoke
    if (index % 2 == 0) {           
        circle(0, 0, 20);
        circle(110, 0, 70);
    } else {
        var diam = offset * 4; // set diameter
        // draw bigger circle on odd spoke
        circle(offset * 3, 0, diam);

        // string design of four circles inside each 
        // bigger circle
        var shiftValue = 10;
        circle(offset * 3, -shiftValue, diam/2);
        circle(offset * 3, shiftValue, diam/2);
        circle(offset * 3 + shiftValue, 0, diam/2);
        circle(offset * 3 - shiftValue, 0, diam/2);
    }
    pop();// restores settings
}