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draw.js
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draw.js
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window.onload = function() {
document.ontouchmove = function(e){ e.preventDefault(); }
var canvas = document.getElementById('main');
var canvastop = canvas.offsetTop
var context = canvas.getContext("2d");
var lastx;
var lasty;
context.strokeStyle = "#000000";
context.lineCap = 'round';
context.lineJoin = 'round';
context.lineWidth = 5;
function clear() {
context.fillStyle = "#ffffff";
context.rect(0, 0, 300, 300);
context.fill();
}
function dot(x,y) {
context.beginPath();
context.fillStyle = "#000000";
context.arc(x,y,1,0,Math.PI*2,true);
context.fill();
context.stroke();
context.closePath();
}
function line(fromx,fromy, tox,toy) {
context.beginPath();
context.moveTo(fromx, fromy);
context.lineTo(tox, toy);
context.stroke();
context.closePath();
}
canvas.ontouchstart = function(event){
event.preventDefault();
lastx = event.touches[0].clientX;
lasty = event.touches[0].clientY - canvastop;
dot(lastx,lasty);
}
canvas.ontouchmove = function(event){
event.preventDefault();
var newx = event.touches[0].clientX;
var newy = event.touches[0].clientY - canvastop;
line(lastx,lasty, newx,newy);
lastx = newx;
lasty = newy;
}
var clearButton = document.getElementById('clear');
clearButton.onclick = clear;
clear();
}