My Sketch2

//Clair(sijing) Sun

//sijings@andrew.cmu.edu

//Assignment-5

​

var lineP=[];

var boolDoRefresh;

var numberofL=10;

​

function setup() {

    createCanvas(480, 480);

    boolDoRefresh = false;

    for (var i=0; i<numberofL; i++){

        var x1 = random(0,width);

        var x2 = random(0,width);

        var y1 = random(0,height);

        var y2 = random(9,height);

        lineP[i] = [x1,y1,x2,y2];

    }

}

​

function draw() {

    background(200);

​

    //regenerate if mousePressed

    if (boolDoRefresh) { 

        for (var i=0; i<numberofL; i++){

            var x1 = random(0,width);

            var x2 = random(0,width);

            var y1 = random(0,height);

            var y2 = random(9,height);

            lineP[i] = [x1,y1,x2,y2];

        }

    boolDoRefresh=false

    }

​

    //for drawing the lines

    for (var i = 0; i < numberofL; i += 1){

        line(lineP[i][0],lineP[i][1],lineP[i][2],lineP[i][3]);

    }

​

    //for drawing the intersections, spliting to two lines each time

    for (var j = 0; j < numberofL; j += 1){

            for (var i = 0; i < numberofL; i += 1){

                var x1 = lineP[j][0];

                var y1 = lineP[j][1];

                var x2 = lineP[j][2];

                var y2 = lineP[j][3];

                var x3 = lineP[i][0];

                var y3 = lineP[i][1];

                var x4 = lineP[i][2];

                var y4 = lineP[i][3];

                intersect(x1, y1, x2, y2, x3, y3, x4, y4);

            }

    }

}

​

// Modified from line intercept math by Paul Bourke http://paulbourke.net/geometry/pointlineplane/

// Determine the intersection point of two line segments

// Modified from http://paulbourke.net/geometry/pointlineplane/javascript.txt

function intersect(x1, y1, x2, y2, x3, y3, x4, y4) {

    if ((x1 == x2 && y1 == y2) || (x3 == x4 && y3 == y4)) {

        return false

    }

​

    var denom = ((y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1))

    if (denom === 0) {

        return false

    }

    var ua = ((x4 - x3) * (y1 - y3) - (y4 - y3) * (x1 - x3)) / denom

    var ub = ((x2 - x1) * (y1 - y3) - (y2 - y1) * (x1 - x3)) / denom

    // is the intersection along the segments

    if (ua < 0 || ua > 1 || ub < 0 || ub > 1) {

        return false

    }

​

    fill(0);

    ellipse (x1 + ua * (x2 - x1),y1 + ua * (y2 - y1),15);

}

​

​

function mousePressed() {

    boolDoRefresh = true;

}

​