Looping with canvas
Revision as of 15:56, 25 September 2012 by Michael Murtaugh (talk | contribs)
while CONDITION {
LOOP
LOOP
LOOP...
}
Examples
Here is a complete HTML page with a working canvas:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<script>
function draw(){
c = document.getElementById("canvas")
//console.log("c is",c)
p = c.getContext("2d")
x = 10
while (x<300) {
p.strokeRect(x,100,20,40)
x+=60
}
}
</script>
</head>
<body onload="draw()">
<h1>Hello canvas</h1>
<canvas id="canvas" width="640" height="640" style="border: 3px dotted red"></canvas>
</body>
</html>
Here's the output:
<canvas id="c1"> function draw(){
c = document.getElementById("c1")
//console.log("c is",c)
p = c.getContext("2d")
x = 10
while (x<250) {
p.strokeRect(x,100,20,40)
x+=60
}
} </canvas>
Variation: When the loop reaches the end of page it breaks the line. It redefines the "x" value to the begin of the line and adds 40px to "y".
<canvas id="c2" width="300" height="300" showsrc="true"> function draw() {
c = document.getElementById("c2");
p = c.getContext("2d");
hands = 1;
x = 20;
y = 20;
while (hands < 100) {
//console.log(hands);
p.strokeRect(x,y,20,20);
x = x + 50;
hands++;
if (x > 600) {
x = 20;
y = y + 40;
}
}
} </canvas>