特效描述：html5 粒子效果 文字特效。html5粒子效果文字特效

代码结构

1. HTML代码

BLUR = false;

PULSATION = true;

PULSATION_PERIOD = 600;

PARTICLE_RADIUS = 4;

/* disable blur before using blink */

BLINK = false;

GLOBAL_PULSATION = false;

QUALITY = 2; /* 0 - 5 */

/* set false if you prefer rectangles */

ARC = true;

/* trembling + blur = fun */

TREMBLING = 0; /* 0 - infinity */

FANCY_FONT = "Arial";

BACKGROUND = "#000";

BLENDING = true;

/* if empty the text will be a random number */

var TEXT;

num = 0;

TEXTArray = ["周磊", "深爱", "闫蒙", "直到", "永远"];

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(new particle(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;

/* randomize delta to make particles sparkling */

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';//文本水平对齐方式

//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];

/* in lower qualities there is not enough full pixels for all of them - dirty hack*/

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) { /* this would be 0 -> 1 */

var mod = ((GLOBAL_PULSATION ? 0 : p.deltaOffset) + now) % PULSATION_PERIOD / PULSATION_PERIOD;

/* lets make the value bouncing with sinus */

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();

};

body {

background: #000;

text-align: center;

font-family: "simhei"

}

canvas {

margin: auto;

position: absolute;

left: 0;

right:0;

top: 0;

bottom: 0;

}