javascript 玫瑰花漸現效果

antzone發表於2017-04-13
JavaScript

本章節分享一段程式碼例項，它實現了利用javascript的canvas實現漸現的玫瑰花效果。

程式碼例項如下:

[HTML] 純文字檢視 複製程式碼
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta name="author" content="http://www.softwhy.com/" />
<title>螞蟻部落</title>
</head>
<body style="margin-left:350px">
<canvas id="c"></canvas>
<script>
var b = document.body;
var c = document.getElementsByTagName('canvas')[0];
var a = c.getContext('2d');
document.body.clientWidth;
</script>
<script>
with (m = Math) C = cos, S = sin, P = pow, R = random;
c.width = c.height = f = 600;
h = -250;
function p(a, b, c) {
  if (c > 60) return [S(a * 7) * (13 + 5 / (.2 + P(b * 4, 4))) - S(b) * 50, b * f + 50, 625 + C(a * 7) * (13 + 5 / (.2 + P(b * 4, 4))) + b * 400, a * 1 - b / 2, a];
  A = a * 2 - 1;
  B = b * 2 - 1;
  if (A * A + B * B < 1) {
    if (c > 37) {
      n = (j = c & 1) ? 6 : 4;
      o = .5 / (a + .01) + C(b * 125) * 3 - a * 300;
      w = b * h;
      return [o * C(n) + w * S(n) + j * 610 - 390, o * S(n) - w * C(n) + 550 - j * 350, 1180 + C(B + A) * 99 - j * 300, .4 - a * .1 + P(1 - B * B, -h * 6) * .15 - a * b * .4 + C(a + b) / 5 + P(C((o * (a + 1) + (B > 0 ? w : -w)) / 25), 30) * .1 * (1 - B * B), o / 1e3 + .7 - o * w * 3e-6]
    }
    if (c > 32) {
      c = c * 1.16 - .15;
      o = a * 45 - 20;
      w = b * b * h;
      z = o * S(c) + w * C(c) + 620;
      return [o * C(c) - w * S(c), 28 + C(B * .5) * 99 - b * b * b * 60 - z / 2 - h, z, (b * b * .3 + P((1 - (A * A)), 7) * .15 + .3) * b, b * .7]
    }
    o = A * (2 - b) * (80 - c * 2);
    w = 99 - C(A) * 120 - C(b) * (-h - c * 4.9) + C(P(1 - b, 7)) * 50 + c * 2; z = o * S(c) + w * C(c) + 700;
    return [o * C(c) - w * S(c), B * 99 - C(P(b, 7)) * 50 - c / 3 - z / 1.35 + 450, z, (1 - b / 1.2) * .9 + a * .1, P((1 - b), 20) / 4 + .05]
  }
}
setInterval('for(i=0;i<1e4;i++)if(s=p(R(),R(),i%46/.74)){z=s[2];x=~~(s[0]*f/z-h);y=~~(s[1]*f/z-h);if(!m[q=y*f+x]|m[q]>z)m[q]=z,a.fillStyle="rgb("+~(s[3]*h)+","+~(s[4]*h)+","+~(s[3]*s[3]*-80)+")",a.fillRect(x,y,1,1)}', 0)
</script>
</body>
</html>

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