lil sine wave

var c = document.getElementById("canvas");
var ctx = c.getContext("2d");
var imageData = ctx.createImageData(1, 1);
ctx.fillStyle = "#000";
ctx.fillRect(0, 0, 1, 1);
var imgData = ctx.getImageData(0, 0, 1, 1);

function colorPixel(ax, ay) {
    ctx.putImageData(imgData, ax, ay);
}

function bresenham(startX, startY, endX, endY) {
    var x;
    var y;
    var d;
    var count;
    var newX;
    var newY;
    var negative;
    var higrad;
    var nx;
    var ny;

    function define() {
        x = endX - startX;
        y = endY - startY;
        d = 2*y-x;
        count = 0;
        newX = startX;
        newY = startY;
    }

    define();

    if (y < 0) {
        var mem1 = startX;
        var mem2 = startY;
        startX = -endX;
        startY = endY;
        endX = -mem1;
        endY = mem2;
        negative = 1;
        define();
    }

    if (y > x) {
        higrad = 1;
        define();
        d = 2*x-y;
    }

    while(y != 0 || x != 0) {
        x = endX - newX;
        y = endY - newY;
        count++;
        if (negative == 1 & higrad == 1) {
            nx = -newX;
            ny = newY;
            colorPixel(nx, ny);
        } else if (higrad == 1) {
            nx = newX;
            ny = newY;
            colorPixel(nx, ny);
        } else if (negative == 1) {
            nx = -newX;
            ny = newY;
            colorPixel(nx, ny);
        } else {
            nx = newX;
            ny = newY;
            colorPixel(nx, ny);
        }
        if (higrad == 1) {
            if (d < 0) {
                d = d+x;
            } else {
                d = d+x-y;
                newX++;
            }
            newY++;
        } else {
            if (d < 0) {
                d = d+y;
            } else {
                d = d+y-x;
                newY++;
            }
            newX++;
        }
    }
}

var printX1 = 0;
var printY1 = 0;
var printX2 = 1;
var printY2 = 0;

while(printX2 < 3500) {
    printY1 = Math.round(1750 - 500 * (Math.sin(Math.pow(printX1 * 0.003, 2))));
    printX1++;
    printY2 = Math.round(1750 - 500 * (Math.sin(Math.pow(printX2 * 0.003, 2))));
    printX2++;
    bresenham(printX1, printY1, printX2, printY2);
}