我使用Javascript & SVG圖形制作了一個非常簡單的餅圖生成器。你只需輸入你想要的餅圖的角度,然後點擊按鈕。餅圖生成器:僅爲某些值生成不正確的大小/角度
我的問題:它產生的圖形太大,角度100度,180度&許多其他人。它確實爲角度277生成正確的餅圖。對於諸如180的角度應該是半個圓圈,由於某種原因,它顯示出270度的餅圖。
我的簡單算法導致錯誤的餅形狀/值有什麼問題?
的的jsfiddle在這裏(出於某種原因的jsfiddle不會更新,但如果你複製它下面的HTML所有作品):http://jsfiddle.net/mabg3/1/
<html>
<head>
<script type="text/javascript">
<!--
function createPieGraph()
{
var angle = parseInt(document.getElementById("angleVal").value, 10);
var path = document.getElementById("pie"); //document.createElement("path");
var diameter = 200
var rad = diameter/2;
var point = resolveToPoint(angle, diameter);
var d = "M"+diameter+","+diameter+" L"+point.mX+","+point.mY+" A"+rad+","+rad+" "+determineDisplayType(angle)+" "+determineArcEnd(angle, diameter, rad)+" z";
path.setAttribute("d", d);
}
function resolveToPoint(/*int*/ deg, /*int*/ diameter)
{
var rad = Math.PI * deg/180;
var r = diameter/2;
var x = r * Math.cos(rad);
var y = r * Math.sin(rad);
var midX = diameter;
var midY = diameter;
if (deg <= 90)
{
console.log("1");
x = midX + x;
y = midY - y;
}
else if (deg <= 180)
{
console.log("2");
x = midX + x;
y = midY + y;
}
else if (deg <= 270)
{
console.log("3");
x = midX - x;
y = midY + y;
}
else if (deg <= 360)
{
console.log("4");
x = midX - x;
y = Math.abs(y);
}
return {mX: x, mY: y};
}
function determineDisplayType(/*int*/ deg)
{
if (deg <= 90)
return "0 0,0";
else if (deg <= 180)
return "0 1,0";
else if (deg <= 270)
return "0 1,0";
else if (deg <= 360)
return "1 1,1";
return "0 0,0";
}
function determineArcEnd(/*int*/ deg, /*int*/ diameter, /*int*/ rad)
{
if (deg >= 270)
return ""+rad+","+diameter;
return ""+diameter+","+rad;
}
-->
</script>
</head>
<body>
<svg id="main" width="400" height="400" style="background-color: red;">
<path id="pie" fill="blue" stroke="white"></path>
</svg>
<input type="text" id="angleVal" value="Enter angle"></input>
<input type="button" onclick="createPieGraph();" value="Show Pie Graph"></input>
</body></html>