캔버스에 특수 효과 잔해 불꽃놀이를 사용하여 검정색 배경을 만드는 방법
- php中世界最好的语言원래의
- 2018-03-13 16:12:172332검색
이번에는 캔버스를 활용한 검정색 배경과 특수효과로 빵 부스러기 불꽃놀이를 만드는 방법을 보여드리겠습니다. 봐. <canvas id="cas" style="
background-color
:rgba(0,5,24,1)" width="1235" height="680">浏览器不支持canvas</canvas><div class="city">
<img src="city.png" alt=""></div><img src="moon.png" alt="" id="moon" style="
visibility
: hidden;"><div style="display:none">
<div class="shape">新年快乐</div>
<div class="shape">阖家欢乐</div>
<div class="shape">万事如意</div>
<div class="shape">心想事成</div>
</div>css
body { 여백: 0; 오버플로: 숨김;
}.city { 너비: 100%; z-index: 100;}.city img width: 100%;
}
js
var canvas = document.getElementById("cas");var ocas = document.createElement("canvas");var octx = ocas.getContext("2d");var ctx = canvas.getContext("2d");
ocas.width = canvas.width = window.innerWidth;
ocas.height = canvas.height = window.innerHeight;var bigbooms = [];window.onload = function () {
initAnimate()
}function initAnimate() {
drawBg();
lastTime = new Date();
animate();
}var lastTime;function animate() {
ctx.save();
ctx.fillStyle = "rgba(0,5,24,0.1)";
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.restore(); var newTime = new Date(); if (newTime - lastTime > 500 + (window.innerHeight - 767) / 2) { var random = Math.random() * 100 > 2 ? true : false; var x = getRandom(canvas.width / 5, canvas.width * 4 / 5); var y = getRandom(50, 200); if (random) { var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", { x: x, y: y
});
bigbooms.push(bigboom)
} else { var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", { x: canvas.width / 2, y: 200
}, document.querySelectorAll(".shape")[parseInt(getRandom(0, document.querySelectorAll( ".shape").length))]);
bigbooms.push(bigboom)
}
lastTime = newTime;
}
stars.foreach(function () { this.paint();
})
drawMoon();
bigbooms.foreach(function (index) { var that = this; if (!this.dead) { this._move(); this._drawLight();
} else { this.booms.foreach(function (index) { if (!this.dead) { this.moveTo(index);
} else if (index === that.booms.length - 1) {
bigbooms[bigbooms.indexOf(that)] = null;
}
})
}
});
raf(animate);
}function drawMoon() { var moon = document.getElementById("moon"); var centerX = canvas.width - 200,
centerY = 100,
width = 80; if (moon.complete) {
ctx.drawImage(moon, centerX, centerY, width, width)
} else {
moon.onload = function () {
ctx.drawImage(moon, centerX, centerY, width, width)
}
} var index = 0; for (var i = 0; i < 10; i++) {
ctx.save();
ctx.beginPath();
ctx.arc(centerX + width / 2, centerY + width / 2, width / 2 + index, 0, 2 * Math.PI);
ctx.fillStyle = "rgba(240,219,120,0.005)";
index += 2;
ctx.fill();
ctx.restore();
}
}Array.prototype.foreach = function (callback) { for (var i = 0; i < this.length; i++) { if (this[i] !== null) callback.apply(this[i], [i])
}
}var raf = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function (callback) { window.setTimeout(callback, 1000 / 60);
};
canvas.onclick = function () { var x = event.clientX; var y = event.clientY; var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", { x: x, y: y
});
bigbooms.push(bigboom)
}var Boom = function (x, r, c, boomArea, shape) { this.booms = []; this.x = x; this.y = (canvas.height + r); this.r = r; this.c = c; this.shape = shape || false; this.boomArea = boomArea; this.theta = 0; this.dead = false; this.ba = parseInt(getRandom(80, 200));
}
Boom.prototype = { _paint: function () {
ctx.save();
ctx.beginPath();
ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);
ctx.fillStyle = this.c;
ctx.fill();
ctx.restore();
}, _move: function () { var dx = this.boomArea.x - this.x,
dy = this.boomArea.y - this.y; this.x = this.x + dx * 0.01; this.y = this.y + dy * 0.01; if (Math.abs(dx) <= this.ba && Math.abs(dy) <= this.ba) { if (this.shape) { this._shapBoom();
} else this._boom(); this.dead = true;
} else { this._paint();
}
}, _drawLight: function () {
ctx.save();
ctx.fillStyle = "rgba(255,228,150,0.3)";
ctx.beginPath();
ctx.arc(this.x, this.y, this.r + 3 * Math.random() + 1, 0, 2 * Math.PI);
ctx.fill();
ctx.restore();
}, _boom: function () { var fragNum = getRandom(30, 200); var style = getRandom(0, 10) >= 5 ? 1 : 2; var color; if (style === 1) {
color = { a: parseInt(getRandom(128, 255)), b: parseInt(getRandom(128, 255)), c: parseInt(getRandom(128, 255))
}
} var fanwei = parseInt(getRandom(300, 400)); for (var i = 0; i < fragNum; i++) { if (style === 2) {
color = { a: parseInt(getRandom(128, 255)), b: parseInt(getRandom(128, 255)), c: parseInt(getRandom(128, 255))
}
} var a = getRandom(-Math.PI, Math.PI); var x = getRandom(0, fanwei) * Math.cos(a) + this.x; var y = getRandom(0, fanwei) * Math.sin(a) + this.y; var radius = getRandom(0, 2) var frag = new Frag(this.x, this.y, radius, color, x, y); this.booms.push(frag);
}
}, _shapBoom: function () { var that = this;
putValue(ocas, octx, this.shape, 5, function (dots) { var dx = canvas.width / 2 - that.x; var dy = canvas.height / 2 - that.y; for (var i = 0; i < dots.length; i++) {
color = { a: dots[i].a, b: dots[i].b, c: dots[i].c
} var x = dots[i].x; var y = dots[i].y; var radius = 1; var frag = new Frag(that.x, that.y, radius, color, x - dx, y - dy);
that.booms.push(frag);
}
})
}
}function putValue(canvas, context, ele, dr, callback) {
context.clearRect(0, 0, canvas.width, canvas.height); var img = new Image(); if (ele.innerHTML.indexOf("img") >= 0) {
img.src = ele.
getElementsByTagName
("img")[0].src;
imgload(img, function () {
context.drawImage(img, canvas.width / 2 - img.width / 2, canvas.height / 2 - img.width / 2);
dots = getimgData(canvas, context, dr);
callback(dots);
})
} else { var text = ele.innerHTML;
context.save(); var fontSize = 200;
context.font = fontSize + "px 宋体 bold";
context.textAlign = "center";
context.textBaseline = "middle";
context.fillStyle = "rgba(" + parseInt(getRandom(128, 255)) + "," + parseInt(getRandom(128, 255)) + "," + parseInt(getRandom(128, 255)) + " , 1)";
context.fillText(text, canvas.width / 2, canvas.height / 2);
context.restore();
dots = getimgData(canvas, context, dr);
callback(dots);
}
}function imgload(img, callback) { if (img.complete) {
callback.call(img);
} else {
img.onload = function () {
callback.call(this);
}
}
}function getimgData(canvas, context, dr) { var imgData = context.getImageData(0, 0, canvas.width, canvas.height);
context.clearRect(0, 0, canvas.width, canvas.height); var dots = []; for (var x = 0; x < imgData.width; x += dr) { for (var y = 0; y < imgData.height; y += dr) { var i = (y * imgData.width + x) * 4; if (imgData.data[i + 3] > 128) { var dot = { x: x, y: y, a: imgData.data[i], b: imgData.data[i + 1], c: imgData.data[i + 2]
};
dots.push(dot);
}
}
} return dots;
}function getRandom(a, b) { return Math.random() * (b - a) + a;
}var maxRadius = 1,
stars = [];function drawBg() { for (var i = 0; i < 100; i++) { var r = Math.random() * maxRadius; var x = Math.random() * canvas.width; var y = Math.random() * 2 * canvas.height - canvas.height; var star = new Star(x, y, r);
stars.push(star);
star.paint()
}
}var Star = function (x, y, r) { this.x = x; this.y = y; this.r = r;
}
Star.prototype = { paint: function () {
ctx.save();
ctx.beginPath();
ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);
ctx.fillStyle = "rgba(255,255,255," + this.r + ")";
ctx.fill();
ctx.restore();
}
}var focallength = 250;var Frag = function (centerX, centerY, radius, color, tx, ty) { this.tx = tx; this.ty = ty; this.x = centerX; this.y = centerY; this.dead = false; this.centerX = centerX; this.centerY = centerY; this.radius = radius; this.color = color;
}
Frag.prototype = { paint: function () {
ctx.save();
ctx.beginPath();
ctx.arc(this.x, this.y, this.radius, 0, 2 * Math.PI);
ctx.fillStyle = "rgba(" + this.color.a + "," + this.color.b + "," + this.color.c + ",1)";
ctx.fill()
ctx.restore();
}, moveTo: function (index) { this.ty = this.ty + 0.3; var dx = this.tx - this.x,
dy = this.ty - this.y; this.x = Math.abs(dx) < 0.1 ? this.tx : (this.x + dx * 0.1); this.y = Math.abs(dy) < 0.1 ? this.ty : (this.y + dy * 0.1); if (dx === 0 && Math.abs(dy) <= 80) { this.dead = true;
} this.paint();
}
}이 기사의 사례를 읽으신 후 방법을 마스터하셨다고 생각합니다. 더 흥미로운 정보를 보려면 PHP 중국어 웹사이트의 다른 관련 기사에 주목하세요!
추천 자료:
캔버스에서 검정색 배경에 청록색 불꽃놀이 만드는 방법캔버스에서 검정색 배경에 빨간색 불꽃놀이 만드는 방법위 내용은 캔버스에 특수 효과 잔해 불꽃놀이를 사용하여 검정색 배경을 만드는 방법의 상세 내용입니다. 자세한 내용은 PHP 중국어 웹사이트의 기타 관련 기사를 참조하세요!
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