HTML and CSS Reference
In-Depth Information
<!doctype html>
<html
<html lang=
"en"
>
<head>
<head>
<meta
<meta charset=
"UTF-8"
>
<title>
<title>
CH5EX14: Simple Gravity
</title>
</title>
<
script src
=
"modernizr.js"
><
/script>
<
script type
=
"text/javascript"
>
window
.
addEventListener
(
'load'
,
eventWindowLoaded
,
false
false
);
function
function
eventWindowLoaded
() {
canvasApp
();
}
function
function
canvasSupport
() {
return
return
Modernizr
.
canvas
;
}
function
function
canvasApp
() {
iif
(
!
canvasSupport
()) {
return
return
;
}
function
function
drawScreen
() {
context
.
fillStyle
=
'#EEEEEE'
;
context
.
fillRect
(
0
,
0
,
theCanvas
.
width
,
theCanvas
.
height
);
//Box
context
.
strokeStyle
=
'#000000'
;
context
.
strokeRect
(
1
,
1
,
theCanvas
.
width
-
2
,
theCanvas
.
height
-
2
);
iif
(
ball
.
y
+
ball
.
radius
<=
theCanvas
.
height
) {
ball
.
velocityy
+=
gravity
;
}
else
else
{
ball
.
velocityx
=
0
;
ball
.
velocityy
=
0
;
ball
.
y
=
theCanvas
.
height
-
ball
.
radius
;
}
ball
.
y
+=
ball
.
velocityy
;
ball
.
x
+=
ball
.
velocityx
;
context
.
fillStyle
=
"#000000"
;
context
.
beginPath
();
context
.
arc
(
ball
.
x
,
ball
.
y
,
ball
.
radius
,
0
,
Math
.
PI
*
2
,
true
true
);
context
.
closePath
();
