情人節炫酷表白神器
<!DOCTYPE html PUBLIC "-//W3C//DTDXHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<htmlxmlns="http://www.w3.org/1999/xhtml">
<head>
<metahttp-equiv="Content-Type" content="text/html;charset=utf-8" />
<title>HTML5粒子效果動畫演示</title>
</head>
<body>
<scripttype="text/javascript">
BLUR = false;
PULSATION = true;
PULSATION_PERIOD = 600;
PARTICLE_RADIUS = 4;
BLINK = false;
GLOBAL_PULSATION = false;
QUALITY = 2;
ARC = true;
TREMBLING = 0;
FANCY_FONT = "Arial";
BACKGROUND = "#000";
BLENDING = true;
var TEXT;
num = 0;
TEXTArray = ["你說","你喜", "歡的", "是誰"];
QUALITY_TO_FONT_SIZE = [10, 12, 40, 50,100, 350];
QUALITY_TO_SCALE = [20, 6, 4, 2, 0.9, 0.5];
QUALITY_TO_TEXT_POS = [10, 20, 60, 100,370, 280];
window.onload = function () {
document.body.style.backgroundColor = BACKGROUND;
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var W = canvas.width;
var H = canvas.height;
var tcanvas = document.createElement("canvas");
var tctx = tcanvas.getContext("2d");
tcanvas.width = W;
tcanvas.height = H;
total_area = W * H;
total_particles = 928;
single_particle_area = total_area / total_particles;
area_length = Math.sqrt(single_particle_area);
var particles = [];
for (var i = 1; i <= total_particles; i++) {
particles.push(newparticle(i));
}
function particle(i) {
this.r =Math.round(Math.random() * 255 | 0);
this.g =Math.round(Math.random() * 255 | 0);
this.b =Math.round(Math.random() * 255 | 0);
this.alpha = 1;
this.x = (i * area_length) % W;
this.y = (i * area_length) / W* area_length;
this.deltaOffset =Math.random() * PULSATION_PERIOD | 0;
this.radius = 0.1 +Math.random() * 2;
}
var positions = [];
function new_positions() {
TEXT = TEXTArray[num];
if (num < TEXTArray.length -1) {
num++;
} else {
num = 0;
}
//alert(TEXT);
tctx.fillStyle ="white";
tctx.fillRect(0, 0, W, H)
//tctx.fill();
tctx.font = "bold " +QUALITY_TO_FONT_SIZE[QUALITY] + "px " + FANCY_FONT;
//tctx.textAlign='center';//文字水平對齊方式
//tctx.textBaseline='middle';
//tctx.strokeStyle ="black";
tctx.fillStyle ="#f00";
//tctx.strokeText(TEXT,30, 50);
tctx.fillText(TEXT, 20, 60);
image_data =tctx.getImageData(0, 0, W, H);
pixels = image_data.data;
positions = [];
for (var i = 0; i <pixels.length; i = i + 2) {
if (pixels[i] != 255) {
position = {
x: (i /2 % W | 0) * QUALITY_TO_SCALE[QUALITY] | 0,
y: (i /2 / W | 0) * QUALITY_TO_SCALE[QUALITY] | 0
}
positions.push(position);
}
}
get_destinations();
}
function draw() {
var now = Date.now();
ctx.globalCompositeOperation ="source-over";
if (BLUR) ctx.globalAlpha =0.1;
else if (!BLUR &&!BLINK) ctx.globalAlpha = 1.0;
ctx.fillStyle = BACKGROUND;
ctx.fillRect(0, 0, W, H)
if (BLENDING)ctx.globalCompositeOperation = "lighter";
for (var i = 0; i <particles.length; i++) {
p = particles[i];
if (isNaN(p.x))continue
ctx.beginPath();
ctx.fillStyle ="rgb(" + p.r + ", " + p.g + ", " + p.b +")";
ctx.fillStyle ="rgba(" + p.r + ", " + p.g + ", " + p.b + "," + p.alpha + ")";
if (BLINK)ctx.globalAlpha = Math.sin(Math.PI * mod * 1.0);
if (PULSATION) {
var mod =((GLOBAL_PULSATION ? 0 : p.deltaOffset) + now) % PULSATION_PERIOD /PULSATION_PERIOD;
mod =Math.sin(mod * Math.PI);
} else var mod = 1;
var offset = TREMBLING? TREMBLING * (-1 + Math.random() * 2) : 0;
var radius =PARTICLE_RADIUS * p.radius;
if (!ARC) {
ctx.fillRect(offset + p.x - mod * radius / 2 | 0, offset + p.y - mod *radius / 2 | 0, radius * mod,
radius * mod);
} else {
ctx.arc(offset+ p.x | 0, offset + p.y | 0, radius * mod, Math.PI * 2, false);
ctx.fill();
}
p.x += (p.dx - p.x) /10;
p.y += (p.dy - p.y) /10;
}
}
function get_destinations() {
for (var i = 0; i <particles.length; i++) {
pa = particles[i];
particles[i].alpha = 1;
var distance = [];
nearest_position = 0;
if (positions.length) {
for (var n = 0;n < positions.length; n++) {
po =positions[n];
distance[n] = Math.sqrt((pa.x - po.x) * (pa.x - po.x) + (pa.y - po.y) *(pa.y - po.y));
if (n> 0) {
if (distance[n] <= distance[nearest_position]) {
nearest_position = n;
}
}
}
particles[i].dx= positions[nearest_position].x;
particles[i].dy= positions[nearest_position].y;
particles[i].distance= distance[nearest_position];
var po1 =positions[nearest_position];
for (var n = 0;n < positions.length; n++) {
var po2= positions[n];
distance = Math.sqrt((po1.x - po2.x) * (po1.x - po2.x) + (po1.y - po2.y)* (po1.y - po2.y));
if(distance <= 5) {
positions.splice(n, 1);
}
}
} else {
//particles[i].alpha = 0;
}
}
}
function init() {
new_positions();
setInterval(draw, 30);
setInterval(new_positions,2000);
}
init();
};
</script>
<style type="text/css">
body {
background: #000;
text-align: center;
font-family: "simhei"
}
canvas {
margin: auto;
position: absolute;
left: 0;
right:0;
top: 0;
bottom: 0;
}
</style>
<canvas id="canvas"width="1000" height="800"></canvas>
</body>
</html>
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