1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
<!doctype html>
<html>
<head>
<title>canvas.js | paths</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript" src="../../pattern/canvas.js"></script>
</head>
<body>
<script type="text/canvas">
function setup(canvas) {
canvas.size(500, 500);
}
function draw(canvas) {
canvas.clear();
// A Bézier path can be used to draw complex shapes (e.g., curve, star, ...)
// The BezierPath object has moveto(), lineto(), curveto() and close() methods.
// moveto() and lineto() take two parameters: x, y.
// curveto() takes six parameters: x1, y1, x2, y2, x3, y3,
// where (x1,y1) describes the direction in which the curve starts,
// and (x2,y2) describes the direction in which it ends in point (x3,y3).
var x = canvas.mouse.x;
var y = canvas.mouse.y;
var p = new BezierPath();
p.moveto(0, 0);
p.curveto(100, 100, x, y, 200, 200);
// drawpath() draws the given BezierPath.
// Notice how we set fill and stroke as optional parameters.
// You can do this with line(), rect(), ellipse() and text() too.
drawpath(p, {fill:null, stroke:[0,0,0,1]});
line(0, 0, 100, 100, {stroke:[0,0,0,0.5]}); // show handle (x1,y1)
line(200, 200, x, y, {stroke:[0,0,0,0.5]}); // show handle (x2,y2)
// Create a leaf shape.
var leaf = new BezierPath();
leaf.moveto(0, 0);
leaf.curveto(50, 50, 0, 150, 0, 200);
leaf.curveto(0, 150, -50, 50, 0, 0);
// Actually, we should have done this in setup().
// This way the path is calculated only once, instead of every frame.
// Draw copies of the leaf to create a flower-shape.
translate(250, 250);
fill(0.25, 0.15, 0.75, 0.25) // transparent purple-blue
stroke(0); // black
strokewidth(0.25);
// The Array.range() command generates an array of numbers.
// This is handy to use in a loop:
for (var i in Array.range(40)) {
rotate(9);
drawpath(leaf);
}
}
</script>
</body>
</html>
|
