全屏HTML画布

我正在使用HTML画布处理以下应用程序：http : //driz.co.uk/particles/

目前将其设置为640x480像素，但我想使其全屏显示，因为它将显示为投影仪。但是据我所知，我不能将画布大小设置为100％，因为变量只能是数字而不是％。使用CSS只会拉伸它，而不是使其变成全屏显示。

有任何想法吗？

编辑：试图使用jQuery找到高度和宽度，但它打破了画布的任何想法，为什么？

var $j = jQuery.noConflict();


var canvas;
var ctx;
var canvasDiv;
var outerDiv;

var canvasW = $j('body').width();
var canvasH = $j('body').height();

//var canvasW     = 640;
//var canvasH     = 480;

var numMovers   = 550;
var movers      = [];
var friction    = .96;
var radCirc     = Math.PI * 2;

var mouseX, mouseY, mouseVX, mouseVY, prevMouseX = 0, prevMouseY = 0;   
var isMouseDown = true;



function init()
{
    canvas = document.getElementById("mainCanvas");

    if( canvas.getContext )
    {
        setup();
        setInterval( run , 33 );
    }
}

function setup()
{
    outerDiv = document.getElementById("outer");
    canvasDiv = document.getElementById("canvasContainer");
    ctx = canvas.getContext("2d");

    var i = numMovers;
    while( i-- )
    {
        var m = new Mover();
        m.x  = canvasW * .5;
        m.y  = canvasH * .5;
        m.vX = Math.cos(i) * Math.random() * 25;
        m.vY = Math.sin(i) * Math.random() * 25;
        m.size = 2;
        movers[i] = m;
    }

    document.onmousedown = onDocMouseDown;
    document.onmouseup   = onDocMouseUp;
    document.onmousemove = onDocMouseMove;
}

function run()
{
    ctx.globalCompositeOperation = "source-over";
    ctx.fillStyle = "rgba(8,8,12,.65)";
    ctx.fillRect( 0 , 0 , canvasW , canvasH );
    ctx.globalCompositeOperation = "lighter";

    mouseVX    = mouseX - prevMouseX;
    mouseVY    = mouseY - prevMouseY;
    prevMouseX = mouseX;
    prevMouseY = mouseY;

    var toDist   = canvasW / 1.15;
    var stirDist = canvasW / 8;
    var blowDist = canvasW / 2;

    var Mrnd   = Math.random;
    var Mabs   = Math.abs;
    var Msqrt  = Math.sqrt;
    var Mcos   = Math.cos;
    var Msin   = Math.sin;
    var Matan2 = Math.atan2;
    var Mmax   = Math.max;
    var Mmin   = Math.min;

    var i = numMovers;
    while( i-- )
    {
        var m  = movers[i];
        var x  = m.x;
        var y  = m.y;
        var vX = m.vX;
        var vY = m.vY;

        var dX = x - mouseX;
        var dY = y - mouseY; 
        var d = Msqrt( dX * dX + dY * dY );
        var a = Matan2( dY , dX );
        var cosA = Mcos( a );
        var sinA = Msin( a );

        if( isMouseDown )
        {
            if( d < blowDist )
            {
                var blowAcc = ( 1 - ( d / blowDist ) ) * 2;
                vX += cosA * blowAcc + .5 - Mrnd();
                vY += sinA * blowAcc + .5 - Mrnd();
            }
        }

        if( d < toDist )
        {
            var toAcc = ( 1 - ( d / toDist ) ) * canvasW * .0014;
            vX -= cosA * toAcc;
            vY -= sinA * toAcc;
        }

        if( d < stirDist )
        {
            var mAcc = ( 1 - ( d / stirDist ) ) * canvasW * .00022;
            vX += mouseVX * mAcc;
            vY += mouseVY * mAcc;           
        }


        vX *= friction;
        vY *= friction;

        var avgVX = Mabs( vX );
        var avgVY = Mabs( vY );
        var avgV = ( avgVX + avgVY ) * .5;

        if( avgVX < .1 ) vX *= Mrnd() * 3;
        if( avgVY < .1 ) vY *= Mrnd() * 3;

        var sc = avgV * .45;
        sc = Mmax( Mmin( sc , 3.5 ) , .4 );


        var nextX = x + vX;
        var nextY = y + vY;

        if( nextX > canvasW )
        {
            nextX = canvasW;
            vX *= -1;
        }
        else if( nextX < 0 )
        {
            nextX = 0;
            vX *= -1;
        }

        if( nextY > canvasH )
        {
            nextY = canvasH;
            vY *= -1;
        }
        else if( nextY < 0 )
        {
            nextY = 0;
            vY *= -1;
        }


        m.vX = vX;
        m.vY = vY;
        m.x  = nextX;
        m.y  = nextY;

        ctx.fillStyle = m.color;
        ctx.beginPath();
        ctx.arc( nextX , nextY , sc , 0 , radCirc , true );
        ctx.closePath();
        ctx.fill();     
    }

    //rect( ctx , mouseX - 3 , mouseY - 3 , 6 , 6 );
}


function onDocMouseMove( e )
{
    var ev = e ? e : window.event;
    mouseX = ev.clientX - outerDiv.offsetLeft - canvasDiv.offsetLeft;
    mouseY = ev.clientY - outerDiv.offsetTop  - canvasDiv.offsetTop;
}

function onDocMouseDown( e )
{
    isMouseDown = true;
    return false;
}

function onDocMouseUp( e )
{
    isMouseDown = true;
    return false;
}



// ==========================================================================================


function Mover()
{
    this.color = "rgb(" + Math.floor( Math.random()*255 ) + "," + Math.floor( Math.random()*255 ) + "," + Math.floor( Math.random()*255 ) + ")";
    this.y     = 0;
    this.x     = 0;
    this.vX    = 0;
    this.vY    = 0;
    this.size  = 0; 
}


// ==========================================================================================


function rect( context , x , y , w , h ) 
{
    context.beginPath();
    context.rect( x , y , w , h );
    context.closePath();
    context.fill();
}


// ==========================================================================================

javascript有

var canvasW     = 640;
var canvasH     = 480;

在里面。尝试更改这些以及画布的CSS。

或者更好的是，让initialize函数从css确定画布的大小！

根据您的修改，更改您的init函数：

function init()
{
    canvas = document.getElementById("mainCanvas");
    canvas.width = document.body.clientWidth; //document.width is obsolete
    canvas.height = document.body.clientHeight; //document.height is obsolete
    canvasW = canvas.width;
    canvasH = canvas.height;

    if( canvas.getContext )
    {
        setup();
        setInterval( run , 33 );
    }
}

还要从包装器中删除所有的css，这只是垃圾。但是，您必须编辑js才能完全摆脱它们。但是我还是可以全屏显示它。

html, body {
    overflow: hidden;
}

编辑：document.width并且document.height 已过时。替换为document.body.clientWidth和document.body.clientHeight

您可以将以下内容插入到您的主要html页面或函数中：

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;

然后删除页面上的边距

html, body {
    margin: 0 !important;
    padding: 0 !important;
}

那应该做的

最新的Chrome和Firefox支持全屏API，但设置为全屏就像调整窗口大小。收听窗口对象的onresize-Event：

$(window).bind("resize", function(){
    var w = $(window).width();
    var h = $(window).height();

    $("#mycanvas").css("width", w + "px");
    $("#mycanvas").css("height", h + "px"); 
});

//using HTML5 for fullscreen (only newest Chrome + FF)
$("#mycanvas")[0].webkitRequestFullScreen(Element.ALLOW_KEYBOARD_INPUT); //Chrome
$("#mycanvas")[0].mozRequestFullScreen(); //Firefox

//...

//now i want to cancel fullscreen
document.webkitCancelFullScreen(); //Chrome
document.mozCancelFullScreen(); //Firefox

并非在所有浏览器中都有效。您应该检查函数是否存在，否则会引发js错误。

有关html5-全屏的更多信息，请检查以下内容：http : //updates.html5rocks.com/2011/10/Let-Your-Content-Do-the-Talking-Fullscreen-API

您需要做的就是动态地将width和height属性设置为画布的大小。因此，您可以使用CSS使其扩展到整个浏览器窗口，然后在javascript中有一个小功能可以测量宽度和高度，并为其分配值。我不是非常熟悉jQuery，因此请考虑以下伪代码：

window.onload = window.onresize = function() {
  theCanvas.width = theCanvas.offsetWidth;
  theCanvas.height = theCanvas.offsetHeight;
}

元素的width和height属性确定元素在内部渲染缓冲区中使用的像素数。将其更改为新的数字会导致画布使用大小不同的空白缓冲区重新初始化。仅当width和height属性与实际的实际像素宽度和高度不一致时，浏览器才会拉伸图形。

因为它尚未发布，并且是简单的CSS修复程序：

#canvas {
    position:fixed;
    left:0;
    top:0;
    width:100%;
    height:100%;
}

如果您想应用全屏画布背景（例如，使用Granim.js），则效果很好。

在文件加载时设置

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;

A-如何计算全屏宽度和高度

这里是功能；

canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;

检查了这出

B-如何通过调整大小使全屏稳定

这是resize事件的resize方法；

function resizeCanvas() {
    canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
    canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;

    WIDTH = canvas.width;
    HEIGHT = canvas.height;

    clearScreen();
}

C-如何摆脱滚动条

只是;

<style>
    html, body {
        overflow: hidden;
    }
</style>

D-演示代码

<html>
	<head>
		<title>Full Screen Canvas Example</title>
		<style>
			html, body {
				overflow: hidden;
			}
		</style>
	</head>
	<body onresize="resizeCanvas()">
		<canvas id="mainCanvas">
		</canvas>
		<script>
			(function () {
				canvas = document.getElementById('mainCanvas');
				ctx = canvas.getContext("2d");
				
				canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
				canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
				WIDTH	= canvas.width;
				HEIGHT	= canvas.height;
				
				clearScreen();
			})();
			
			function resizeCanvas() {
				canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
				canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
				
				WIDTH = canvas.width;
				HEIGHT = canvas.height;
				
				clearScreen();
			}
			
			function clearScreen() {
				var grd = ctx.createLinearGradient(0,0,0,180);
				grd.addColorStop(0,"#6666ff");
				grd.addColorStop(1,"#aaaacc");

				ctx.fillStyle = grd;
				ctx.fillRect(  0, 0, WIDTH, HEIGHT );
			}
		</script>
	</body>
</html>

我希望它会有用。

// Get the canvas element
var canvas = document.getElementById('canvas');

var isInFullScreen = (document.fullscreenElement && document.fullscreenElement !== null) ||
    (document.webkitFullscreenElement && document.webkitFullscreenElement !== null) ||
    (document.mozFullScreenElement && document.mozFullScreenElement !== null) ||
    (document.msFullscreenElement && document.msFullscreenElement !== null);

// Enter fullscreen
function fullscreen(){
    if(canvas.RequestFullScreen){
        canvas.RequestFullScreen();
    }else if(canvas.webkitRequestFullScreen){
        canvas.webkitRequestFullScreen();
    }else if(canvas.mozRequestFullScreen){
        canvas.mozRequestFullScreen();
    }else if(canvas.msRequestFullscreen){
        canvas.msRequestFullscreen();
    }else{
        alert("This browser doesn't supporter fullscreen");
    }
}

// Exit fullscreen
function exitfullscreen(){
    if (document.exitFullscreen) {
        document.exitFullscreen();
    } else if (document.webkitExitFullscreen) {
        document.webkitExitFullscreen();
    } else if (document.mozCancelFullScreen) {
        document.mozCancelFullScreen();
    } else if (document.msExitFullscreen) {
        document.msExitFullscreen();
    }else{
        alert("Exit fullscreen doesn't work");
    }
}

function resize() {
    canvas.width = window.innerWidth;
    canvas.height = window.innerHeight;
    render();
}
window.addEventListener('resize', resize, false); resize();
function render() { // draw to screen here
}

https://jsfiddle.net/jy8k6hfd/2/

很简单，将画布的宽度和高度设置为screen.width和screen.height。然后按F11！认为F11应该在大多数浏览器中使FFox和IE中的全屏显示。

AFAIK，HTML5不提供支持全屏的API。

这个问题对使html5视频全屏显示有一些观点，例如webkitEnterFullscreen在webkit中使用。
有没有办法使全屏html5视频

您可以捕获窗口调整大小事件，并将画布的大小设置为浏览器的视口。

获取屏幕的完整宽度和高度，并创建一个新窗口，将其设置为适当的宽度和高度，并禁用所有功能。在该新窗口内创建一个画布，将画布的宽度和高度设置为宽度-10px和高度-20px（以允许窗口的条和边缘）。然后在那块画布上工作。

好吧，我也希望将画布全屏显示，这就是我的方法。我将发布整个index.html，因为我还不是CSS专家：（基本上只是使用position：fixed，宽度和高度为100％，顶部和左侧为0％，并且我为每个标签嵌套了此CSS代码。也将min-height和min-width设为100％。当我尝试使用1px边框时，随着我放大和缩小边框的大小发生了变化，但是画布仍保持全屏显示。）

<!DOCTYPE html>
<html style="position:fixed;min-height:100%;min-width:100%;height:100%;width:100%;top:0%;left:0%;resize:none;">
<head>
<title>MOUSEOVER</title>
<script "text/javascript" src="main.js"></script>

</head>


<body id="BODY_CONTAINER" style="position:fixed;min-height:100%;min-width:100%;height:100%;width:100%;top:0%;left:0%;resize:none;">



<div id="DIV_GUI_CONTAINER" style="position:fixed;min-height:100%;min-width:100%;height:100%;width:100%;top:0%;left:0%;resize:none;">

<canvas id="myCanvas"  style="position:fixed;min-height:100%;min-width:100%;height:100%;width:100%;top:0%;left:0%;resize:none;">

</canvas>

</div>


</body>


</html>

编辑：将其添加到canvas元素：

<canvas id="myCanvas" width="" height="" style="position:fixed;min-height:100%;min-width:100%;height:100%;width:100%;top:0%;left:0%;resize:none;">

</canvas>

将此添加到JavaScript

canvas.width = window.screen.width;

canvas.height = window.screen.height;

我发现这使绘图比我的原始注释要平滑得多。

谢谢。

如果要在演示文稿中显示它，请考虑使用requestFullscreen（）方法

let canvas = document.getElementById("canvas_id");
canvas.requestFullscreen();

无论当前情况如何，都应使其全屏显示。

还要检查支持表https://caniuse.com/?search=requestFullscreen