<style>
.video-x {
position: relative;
width: 640px;
margin: auto;
}
.canvas-barrage {
position: absolute;
width: 640px;
height: 360px;
}
.video-placeholder {
height: 360px;
background-color: #000;
animation: bgColor 10s infinite alternate;
}
@keyframes bgColor {
25% {
background-color: darkred;
}
50% {
background-color: darkgreen;
}
75% {
background-color: darkblue;
}
100% {
background-color: sliver;
}
}
</style>
<div class="video-x">
<canvas id="canvasBarrage" class="canvas-barrage"></canvas>
<div class="video-placeholder"></div>
</div>
<script>
// 彈幕數(shù)據(jù)
var dataBarrage = [{
value: '使用的是靜態(tài)死數(shù)據(jù)',
color: 'blue',
range: [0, 0.5]
}, {
value: '隨機循環(huán)播放',
color: 'blue',
range: [0, 0.6]
}, {
value: '可以控制區(qū)域和垂直分布范圍',
color: 'blue',
range: [0, 0.5]
}, {
value: '字體大小和速度在方法內設置',
color: 'black',
range: [0.1, 1]
}, {
value: '適合用在一些靜態(tài)頁面上',
color: 'black',
range: [0.2, 1]
}, {
value: '基于canvas實現(xiàn)',
color: 'black',
range: [0.2, 0.9]
}, {
value: '因此IE9+瀏覽器才支持',
color: 'black',
range: [0.2, 1]
}, {
value: '可以設置邊框顏色',
color: 'black',
range: [0.2, 1]
}, {
value: '文字顏色默認都是白色',
color: 'black',
range: [0.2, 0.9]
}, {
value: '若文字顏色不想白色',
color: 'black',
range: [0.2, 1]
}, {
value: '需要自己調整下JS',
color: 'black',
range: [0.6, 0.7]
}, {
value: '如果需要的是真實和視頻交互的彈幕',
color: 'black',
range: [0.2, 1]
}, {
value: '可以回到原文',
color: 'black',
range: [0, 0.9]
}, {
value: '查看另外一個demo',
color: 'black',
range: [0.7, 1]
}, {
value: '下面就是占位彈幕了',
color: 'black',
range: [0.7, 0.95]
}, {
value: '前方高能預警！??！',
color: 'orange',
range: [0.5, 0.8]
}, {
value: '前方高能預警?。?！',
color: 'orange',
range: [0.5, 0.9]
}, {
value: '前方高能預警?。?！',
color: 'orange',
range: [0, 1]
}, {
value: '前方高能預警?。?！',
color: 'orange',
range: [0, 1]
}];
// 彈幕方法
var canvasBarrage = function (canvas, data) {
if (!canvas || !data || !data.length) {
return;
}
if (typeof canvas == 'string') {
canvas = document.querySelector(canvas);
canvasBarrage(canvas, data);
return;
}
var context = canvas.getContext('2d');
canvas.width = canvas.clientWidth;
canvas.height = canvas.clientHeight;
// 存儲實例
var store = {};
// 字號大小
var fontSize = 28;
// 實例方法
var Barrage = function (obj, index) {
// 隨機x坐標也就是橫坐標，對于y縱坐標，以及變化量moveX
this.x = (1 + index * 0.1 / Math.random()) * canvas.width;
this.y = obj.range[0] * canvas.height + (obj.range[1] - obj.range[0]) * canvas.height * Math.random() + 36;
if (this.y < fontSize) {
this.y = fontSize;
} else if (this.y > canvas.height - fontSize) {
this.y = canvas.height - fontSize;
}
this.moveX = 1 + Math.random() * 3;
this.opacity = 0.8 + 0.2 * Math.random();
this.params = obj;
this.draw = function () {
var params = this.params;
// 根據(jù)此時x位置繪制文本
context.strokeStyle = params.color;
context.font = 'bold ' + fontSize + 'px "microsoft yahei", sans-serif';
context.fillStyle = 'rgba(255,255,255,' + this.opacity + ')';
context.fillText(params.value, this.x, this.y);
context.strokeText(params.value, this.x, this.y);
};
};
data.forEach(function (obj, index) {
store[index] = new Barrage(obj, index);
});
// 繪制彈幕文本
var draw = function () {
for (var index in store) {
var barrage = store[index];
// 位置變化
barrage.x -= barrage.moveX;
if (barrage.x < -1 * canvas.width * 1.5) {
// 移動到畫布外部時候從左側開始繼續(xù)位移
barrage.x = (1 + index * 0.1 / Math.random()) * canvas.width;
barrage.y = (barrage.params.range[0] + (barrage.params.range[1] - barrage.params.range[0]) * Math.random()) * canvas.height;
if (barrage.y < fontSize) {
barrage.y = fontSize;
} else if (barrage.y > canvas.height - fontSize) {
barrage.y = canvas.height - fontSize;
}
barrage.moveX = 1 + Math.random() * 3;
}
// 根據(jù)新位置繪制圓圈圈
store[index].draw();
}
};
// 畫布渲染
var render = function () {
// 清除畫布
context.clearRect(0, 0, canvas.width, canvas.height);
// 繪制畫布上所有的圓圈圈
draw();
// 繼續(xù)渲染
requestAnimationFrame(render);
};
render();
};
canvasBarrage('#canvasBarrage', dataBarrage);
</script>
到此這篇關于HTML5 canvas實現(xiàn)的靜態(tài)循環(huán)滾動播放彈幕的文章就介紹到這了,更多相關canvas靜態(tài)循環(huán)彈幕內容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關文章，希望大家以后多多支持腳本之家！
