Created
November 3, 2012 03:50
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JavaScript look to mouse
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#box { | |
background-color: #cccccc; | |
left: 50%; | |
line-height: 3em; | |
height: 50px; | |
margin: -25px 0 0 -25px; | |
position: absolute; | |
text-align: center; | |
top: 50%; | |
width: 50px; | |
} |
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<div id="box"></div> | |
|
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var $box = $('#box'); | |
$(document).mousemove(function(event) { | |
var x, y, boxCenterX, boxCenterY, radians, angle; | |
// Helper to convert radians to degrees | |
function radToDeg(radians) { | |
return (radians * 180 / Math.PI); | |
} | |
// Calculate the center of the object | |
boxCenterX = $box.offset().left + $box.width() / 2; | |
boxCenterY = $box.offset().top + $box.height() / 2; | |
// Calulate the triangle dimensions | |
x = event.pageX - boxCenterX; | |
y = boxCenterY - event.pageY; | |
// Find the angle in radians | |
radians = Math.atan(y / x); | |
// Correct the angle by quadrant | |
if (event.pageX < boxCenterX && boxCenterY > event.pageY) radians += Math.PI; | |
if (event.pageX < boxCenterX && boxCenterY < event.pageY) radians += Math.PI; | |
if (event.pageX > boxCenterX && boxCenterY < event.pageY) radians += Math.PI * 2; | |
// Convert the angles to degress without precision | |
angle = radToDeg(radians).toFixed(0); | |
// Convert the given angle to a cardinal direction and their intermediates | |
function angleToCardinal(angle) { | |
if (angle > 345 || angle < 015) return "L"; | |
if (angle > 015 && angle < 075) return "NL"; | |
if (angle > 075 && angle < 105) return "N"; | |
if (angle > 105 && angle < 165) return "NO"; | |
if (angle > 165 && angle < 195) return "O"; | |
if (angle > 195 && angle < 255) return "SO"; | |
if (angle > 255 && angle < 285) return "S"; | |
if (angle > 285 && angle < 345) return "SL"; | |
} | |
// Show the cardinal direction | |
$box.html(angleToCardinal(angle)); | |
}); |
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Thank you !:)