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svgアニメーションを使用して楕円軌跡上で円を回転しようとしていますが、私が作った楕円上の円形軌跡上で回転させようとしています。このPLZで私を助けて??楕円軌跡上の円のsvgアニメーション
<!DOCTYPE html>
<html>
<head>
<title>JavaScript SVG Animation</title>
<style>
/* CSS here. */
</style>
<script>
/* CONSTANTS */
var initialTheta = 0; // The initial rotation angle, in degrees.
var thetaDelta = 0.3; // The amount to rotate the square every "delay" milliseconds, in degrees.
var delay = 10; // The delay between animation stills, in milliseconds. Affects animation smoothness.
var angularLimit = 360; // The maximum number of degrees to rotate the square.
var cx = 200; // circle center
var cy = 150; //circle center
/* GLOBALS */
var theCircle; // Will contain a reference to the square element, as well as other things.
var timer; // Contains the setInterval() object, used to stop the animation.
var pauseEvent = false;
function init()
{
theCircle = document.getElementById("s1"); // Set this custom property after the page loads.
theCircle.currentTheta = initialTheta; // The initial rotation angle to use when the animation starts, stored in
timer = setInterval(doAnim, delay); // Call the doAnim() function every "delay" milliseconds until "timer" is cleared.
}
function doAnim()
{
if (theCircle.currentTheta > angularLimit)
{
clearInterval(timer); // The square has rotated enough, instruct the browser to stop calling the doAnim() function.
return; // No point in continuing; stop now.
}
theCircle.setAttribute("transform", "rotate(" + theCircle.currentTheta + "," + cx + "," + cy +")"); // Rotate the square by a small amount. around given circle point
theCircle.currentTheta += thetaDelta; // Increase the angle that the square will be rotated to, by a small amount.
}
window.onload = function(){
var elplay = document.getElementById("play");
elplay.addEventListener("click", function(){
if(!pauseEvent){
init();
doAnim();
} else{
init();
doAnim();
pauseEvent = false;
}
}, false);
var elstop = document.getElementById("stop");
elstop.addEventListener("click", function(){
theCircle.currentTheta = 0 //initialTheta; // The initial rotation angle to use when the animation starts, stored in
theCircle.setAttribute("transform", "rotate(" + theCircle.currentTheta + "," + cx + "," + cy +")"); // Rotate the square by a small amount. around given circle point
clearInterval(timer); // The square has rotated enough, instruct the browser to stop calling the doAnim() function.
return; // No point in continuing; stop now.
}, false);
var elpause = document.getElementById("pause");
elpause.addEventListener("click", function(){
initialTheta = theCircle.currentTheta;
pauseEvent = true;
clearInterval(timer); // The square has rotated enough, instruct the browser to stop calling the doAnim() function.
return; // No point in continuing; stop now.
}, false);
}
</script>
</head>
<body>
<button id = "play" style="position: absolute;">Play</button>
<button id = "pause" style="position: absolute;left: 65px;">Pause</button>
<button id = "stop" style="position: absolute;left: 135px;">Stop</button>
<svg width="800px" height="800px" viewBox="0 0 800 800">
<g transform="translate(200, 150)">
<ellipse id = "s2" cx = "200" cy = "150" rx = "200" ry = "150" fill = "salmon" stroke = "black" stroke-width = "3"/>
<circle id = "s1" cx = "250" cy = "10" r = "20" fill = "yellow" stroke = "black" stroke-width = "3"/>
</g>
</svg>
</html>
組み込みのSMIL [パスに沿ったアニメーション]（http://www.w3.org/TR/SVG/animate.html#AnimateMotionElement）を使用するだけでは問題ありませんか？ – Phrogz