欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  web前端

HTML5 Canvas 填充与描边(Fill And Stroke) 实现的实例代码

程序员文章站 2022-03-05 20:07:43
...
HTML5 Canvas 填充与描边(Fill And Stroke)

演示HTML5 Canvas Fill 与Stroke文字效果,基于Canvas如何实

现纹理填充与描边。

一:颜色填充与描边

颜色填充可以通过fillStyle来实现,描边颜色可以通过strokeStyle来实现。简单示例

如下:

// fill and stroke text
ctx.font = '60pt Calibri';
ctx.lineWidth = 3;
ctx.strokeStyle = 'green';
ctx.strokeText('Hello World!', 20, 100);
ctx.fillStyle = 'red';
ctx.fillText('Hello World!', 20, 100);

二:纹理填充与描边

HTML5 Canvas还支持纹理填充,通过加载一张纹理图像,然后创建画笔模式,创建

纹理模式的API为ctx.createPattern(imageTexture,"repeat");第二参数支持四个

值,分别为”repeat-x”, ”repeat-y”, ”repeat”,”no-repeat”意思是纹理分别沿着

X轴,Y轴,XY方向沿重复或者不重复。纹理描边与填充的代码如下:

var woodfill = ctx.createPattern(imageTexture,"repeat");
ctx.strokeStyle = woodfill;
ctx.strokeText('Hello World!', 20, 200);
// fill rectangle
ctx.fillStyle = woodfill;
ctx.fillRect(60, 240, 260, 440);


纹理图片:

HTML5 Canvas 填充与描边(Fill And Stroke) 实现的实例代码

三:运行效果

HTML5 Canvas 填充与描边(Fill And Stroke) 实现的实例代码

代码:

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="X-UA-Compatible" content="chrome=IE8">
<meta http-equiv="Content-type" content="text/html;charset=UTF-8">
<title>Canvas Fill And Stroke Text Demo</title>
<link href="default.css" rel="stylesheet" />
	<script>
		var ctx = null; // global variable 2d context
		var imageTexture = null;
		window.onload = function() {
			var canvas = document.getElementById("text_canvas");
			console.log(canvas.parentNode.clientWidth);
			canvas.width = canvas.parentNode.clientWidth;
			canvas.height = canvas.parentNode.clientHeight;
			
			if (!canvas.getContext) {
			    console.log("Canvas not supported. Please install a HTML5 compatible browser.");
			    return;
			}
			
			// get 2D context of canvas and draw rectangel
			ctx = canvas.getContext("2d");
			ctx.fillStyle="black";
			ctx.fillRect(0, 0, canvas.width, canvas.height);
			
			// fill and stroke text
			ctx.font = '60pt Calibri';
			ctx.lineWidth = 3;
			ctx.strokeStyle = 'green';
			ctx.strokeText('Hello World!', 20, 100);
			ctx.fillStyle = 'red';
			ctx.fillText('Hello World!', 20, 100);
			
			// fill and stroke by pattern
			imageTexture = document.createElement('img');
			imageTexture.src = "../pattern.png";
			imageTexture.onload = loaded();
		}
		
		function loaded() {
			// delay to image loaded
			setTimeout(textureFill, 1000/30);
		}
		
		function textureFill() {
			// var woodfill = ctx.createPattern(imageTexture, "repeat-x");
			// var woodfill = ctx.createPattern(imageTexture, "repeat-y");
			// var woodfill = ctx.createPattern(imageTexture, "no-repeat");
			var woodfill = ctx.createPattern(imageTexture, "repeat");
			ctx.strokeStyle = woodfill;
			ctx.strokeText('Hello World!', 20, 200);
			
			// fill rectangle
			ctx.fillStyle = woodfill;
			ctx.fillRect(60, 240, 260, 440);
		}
		
	</script>
</head>
<body>
	<h1>HTML5 Canvas Text Demo - By Gloomy Fish</h1>
	<pre>Fill And Stroke</pre>
	<p id="my_painter">
		<canvas id="text_canvas"></canvas>
	</p>
</body>
</html>

以上就是HTML5 Canvas 填充与描边(Fill And Stroke) 实现的实例代码的内容,更多相关内容请关注PHP中文网(www.php.cn)!