SVG <feFuncA>用法及代码示例

SVG 代表可缩放矢量图形。它可以用来制作图形和动画，就像在 HTML 画布中一样。 SVG 自 1999 年起由万维网联盟 (W3C) 开发。

SVG <feFunA> 元素：这些元素通常是<feComponentTransfer>元素并指定传递函数，其中其父 <feComponentTransfer> 元素的输入图形的 alpha 分量(定义颜色的透明度)。

用法:

<feComponentTransfer>      
    <feFuncA type="" tableValues=""/>
</feComponentTransfer>

属性：它没有任何指定的属性，但它接受全局属性。

示例 1：以下代码演示了类型为 “table” 的 <feFuncA> 元素。

HTML


<!DOCTYPE html> 
<html> 
  
<head> 
    <title>SVG feFuncA Element</title> 
</head> 
  
<body> 
    <svg width="640" height="550" 
        viewBox="0 0 640 550"> 
        <defs> 
            <filter id="new" 
                filterUnits="objectBoundingBox" 
                x="0%" y="0%" width="100%" 
                height="100%"> 
  
                <feComponentTransfer> 
                    <feFuncA type="table" 
                        tableValues="1 0 1 1" /> 
                </feComponentTransfer> 
            </filter> 
        </defs> 
  
        <image x="10" y="10" width="280" 
            height="350" 
            preserveAspectRatio="true"
            xlink:href= 
"https://media.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-19.png" /> 
        <image x="310" y="10" width="280" 
            height="350" preserveAspectRatio="true" 
            filter="url(#new)"
            xlink:href= 
"https://media.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-19.png" /> 
    </svg> 
</body> 
  
</html>

输出：

示例 2：以下代码演示了类型为 “gamma” 的 <feFuncA> 元素。

HTML


<!DOCTYPE html> 
<html> 
  
<head> 
    <title>SVG feFuncA Element</title> 
</head> 
  
<body> 
    <svg width="640" height="550" 
        viewBox="0 0 640 550"> 
        <defs> 
            <filter id="new" 
                filterUnits="objectBoundingBox" 
                x="0%" y="0%" width="100%" 
                height="100%"> 
  
                <feComponentTransfer 
                    in="BackgroundImage" 
                    result="A"> 
  
                    <feFuncA type="gamma" 
                        amplitude="0" 
                        eponent="1" offset="0.5" /> 
                </feComponentTransfer> 
            </filter> 
        </defs> 
  
        <image x="10" y="10" width="280" 
            height="350" 
            preserveAspectRatio="true"
            xlink:href= 
"https://media.geeksforgeeks.org/wp-content/cdn-uploads/20200817185016/gfg_complete_logo_2x-min.png" /> 
        <image x="310" y="10" width="280" 
            height="350" 
            preserveAspectRatio="true" 
            filter="url(#new)"
            xlink:href= 
"https://media.geeksforgeeks.org/wp-content/cdn-uploads/20200817185016/gfg_complete_logo_2x-min.png" /> 
    </svg> 
</body> 
  
</html>

输出：

示例 3：以下代码演示了类型为 “discrete” 的 <feFuncA> 元素，并且使用值设置了诸如 “amplitude”,”exponent”,”offset” 之类的属性。

HTML


<!DOCTYPE html> 
<html> 
  
<head> 
    <title>SVG feFuncA Element</title> 
</head> 
  
<body> 
    <svg width="640" height="550" 
        viewBox="0 0 640 550"> 
          
        <defs> 
            <filter id="new" 
                filterUnits="objectBoundingBox" 
                x="0%" y="0%" width="100%" 
                height="100%"> 
  
                <feComponentTransfer 
                    in="BackgroundImage" result="A"> 
                    <feFuncA type="discrete" 
                        tableValues="1 1 0 1" /> 
                </feComponentTransfer> 
            </filter> 
        </defs> 
  
        <image x="10" y="10" width="280" 
            height="350" 
            preserveAspectRatio="true"
            xlink:href= 
"https://media.geeksforgeeks.org/wp-content/uploads/20210915115837/gfg3.png" /> 
        <image x="310" y="10" width="280" 
            height="350" 
            preserveAspectRatio="true" 
            filter="url(#new)"
            xlink:href= 
"https://media.geeksforgeeks.org/wp-content/uploads/20210915115837/gfg3.png" /> 
    </svg> 
</body> 
  
</html>

输出：

相关用法

注：本文由纯净天空筛选整理自rudrakshladdha大神的英文原创作品 SVG <feFuncA> Element。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。