A relative rotation in an animation
I have a problem with Raphael.js. I want to rotate the "compassScale" - set in the following code - in a relative manner.
This works for the paths, but all the texts "animate" to the absolute rotation of 30 degree. I want them to rotate to the 30 degrees relative from their actual positions.
var compassScale = paper.set();
var centerX = 200;
var centerY = 200;
var radius = 195;
var compasCircle = paper.circle(centerX, centerY, radius);
for(var i = 0; i < 360; i++) {
var winkelRad = i * (Math.PI/180)
var xStart = centerX + Math.sin(winkelRad) * radius;
var yStart = centerY + Math.cos(winkelRad) * radius;
var 开发者_开发技巧diff = 6;
if(i % 10 === 0){
compassScale.push(paper.text(centerX, centerY - radius + 18, i).rotate(i, centerX, centerY, true));
diff = 12;
} else if(i % 5 === 0) {
diff = 8;
}
var xEnd = centerX + Math.sin(winkelRad) * (radius - diff);
var yEnd = centerY + Math.cos(winkelRad) * (radius - diff);
compassScale.push(paper.path("M" + xStart + " " + yStart + " L" + xEnd + " " + yEnd));
}
compassScale.animate({rotation:"30 " + centerX + " " + centerY}, 5000);
Like you said, the problem is that you're animating all elements to 30 degrees, not their current rotation + 30 degrees. It's actually quite simple once you think of it that way. Here is your revised code that works:
var compassScale = paper.set();
var texts = []; // array to hold the text elements
var centerX = 200;
var centerY = 200;
var radius = 195;
var compasCircle = paper.circle(centerX, centerY, radius);
for(var i = 0; i < 360; i++) {
var winkelRad = i * (Math.PI/180)
var xStart = centerX + Math.sin(winkelRad) * radius;
var yStart = centerY + Math.cos(winkelRad) * radius;
var diff = 6;
if(i % 10 === 0){
texts.push(paper.text(centerX, centerY - radius + 18, i).rotate(i, centerX, centerY, true));
diff = 12;
} else if(i % 5 === 0) {
diff = 8;
}
var xEnd = centerX + Math.sin(winkelRad) * (radius - diff);
var yEnd = centerY + Math.cos(winkelRad) * (radius - diff);
compassScale.push(paper.path("M" + xStart + " " + yStart + " L" + xEnd + " " + yEnd));
}
compassScale.animate({rotation:"30 " + centerX + " " + centerY}, 5000);
// loop through the text elements, adjusting their rotation by adding 30 to their individual rotation
for (var i = 0, l = texts.length; i < l; i += 1) {
// node.attr("rotation") returns something like 50 200 200, so we have to split the string and grab the first number with shift
texts[i].animate({rotation: (30 + +texts[i].attr("rotation").split(" ").shift()) + " " + centerX + " " + centerY}, 5000);
}
Just a quick observation:
Looks like "Rotation" isn't part of the Atrr anymore since ver 2, so you can't use it in "animate", but you can replace that with "transform: "r" + (some degree)"..
eg:
element.animate( {transform: "r" + (-90)}, 2000, 'bounce');
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