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<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
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<head><script src='//production-assets.codepen.io/assets/editor/live/console_runner-079c09a0e3b9ff743e39ee2d5637b9216b3545af0de366d4b9aad9dc87e26bfd.js'></script><script src='//production-assets.codepen.io/assets/editor/live/events_runner-73716630c22bbc8cff4bd0f07b135f00a0bdc5d14629260c3ec49e5606f98fdd.js'></script><script src='//production-assets.codepen.io/assets/editor/live/css_live_reload_init-2c0dc5167d60a5af3ee189d570b1835129687ea2a61bee3513dee3a50c115a77.js'></script><meta charset='UTF-8'><meta name="robots" content="noindex"><link rel="shortcut icon" type="image/x-icon" href="//production-assets.codepen.io/assets/favicon/favicon-8ea04875e70c4b0bb41da869e81236e54394d63638a1ef12fa558a4a835f1164.ico" /><link rel="mask-icon" type="" href="//production-assets.codepen.io/assets/favicon/logo-pin-f2d2b6d2c61838f7e76325261b7195c27224080bc099486ddd6dccb469b8e8e6.svg" color="#111" /><link rel="canonical" href="https://codepen.io/13twelve/pen/xLoiH?q=gradient&limit=all&type=type-pens" />
<style class="cp-pen-styles">#gradient {
position: absolute;
left: 0;
top: 0;
right: 0;
bottom: 0;
background: #836997;
}</style></head><body>
<div id="gradient"></div>
<!-- Updated Jan 2017 to use requestAnimationFrame -->
<script src='//production-assets.codepen.io/assets/common/stopExecutionOnTimeout-b2a7b3fe212eaa732349046d8416e00a9dec26eb7fd347590fbced3ab38af52e.js'></script>
<script >
// target to give background to
var $div = document.getElementById("gradient");
// rgb vals of the gradients
var gradients = [
{ start: [128,179,171], stop: [30,41,58] },
{ start: [255,207,160], stop: [234,92,68] },
{ start: [212,121,121], stop: [130,105,151] }
];
// how long for each transition
var transition_time = 4;
// internal type vars
var currentIndex = 0; // where we are in the gradients array
var nextIndex = 1; // what index of the gradients array is next
var steps_count = 0; // steps counter
var steps_total = Math.round(transition_time*60); // total amount of steps
var rgb_steps = {
start: [0,0,0],
stop: [0,0,0]
}; // how much to alter each rgb value
var rgb_values = {
start: [0,0,0],
stop: [0,0,0]
}; // the current rgb values, gets altered by rgb steps on each interval
var prefixes = ["-webkit-","-moz-","-o-","-ms-",""]; // for looping through adding styles
var div_style = $div.style; // short cut to actually adding styles
var color1, color2;
// sets next current and next index of gradients array
function set_next(num) {
return (num + 1 < gradients.length) ? num + 1 : 0;
}
// work out how big each rgb step is
function calc_step_size(a,b) {
return (a - b) / steps_total;
}
// populate the rgb_values and rgb_steps objects
function calc_steps() {
for (var key in rgb_values) {if (window.CP.shouldStopExecution(2)){break;}
if (rgb_values.hasOwnProperty(key)) {
for(var i = 0; i < 3; i++) {if (window.CP.shouldStopExecution(1)){break;}
rgb_values[key][i] = gradients[currentIndex][key][i];
rgb_steps[key][i] = calc_step_size(gradients[nextIndex][key][i],rgb_values[key][i]);
}
window.CP.exitedLoop(1);
}
}
window.CP.exitedLoop(2);
}
// update current rgb vals, update DOM element with new CSS background
function updateGradient(){
// update the current rgb vals
for (var key in rgb_values) {if (window.CP.shouldStopExecution(4)){break;}
if (rgb_values.hasOwnProperty(key)) {
for(var i = 0; i < 3; i++) {if (window.CP.shouldStopExecution(3)){break;}
rgb_values[key][i] += rgb_steps[key][i];
}
window.CP.exitedLoop(3);
}
}
window.CP.exitedLoop(4);
// generate CSS rgb values
var t_color1 = "rgb("+(rgb_values.start[0] | 0)+","+(rgb_values.start[1] | 0)+","+(rgb_values.start[2] | 0)+")";
var t_color2 = "rgb("+(rgb_values.stop[0] | 0)+","+(rgb_values.stop[1] | 0)+","+(rgb_values.stop[2] | 0)+")";
// has anything changed on this interation
if (t_color1 != color1 || t_color2 != color2) {
// update cols strings
color1 = t_color1;
color2 = t_color2;
// update DOM element style attribute
div_style.backgroundImage = "-webkit-gradient(linear, left bottom, right top, from("+color1+"), to("+color2+"))";
for (var i = 0; i < 4; i++) {if (window.CP.shouldStopExecution(5)){break;}
div_style.backgroundImage = prefixes[i]+"linear-gradient(45deg, "+color1+", "+color2+")";
}
window.CP.exitedLoop(5);
}
// we did another step
steps_count++;
// did we do too many steps?
if (steps_count > steps_total) {
// reset steps count
steps_count = 0;
// set new indexs
currentIndex = set_next(currentIndex);
nextIndex = set_next(nextIndex);
// calc steps
calc_steps();
}
if (div_style.backgroundImage.indexOf("gradient") != -1) {
window.requestAnimationFrame(updateGradient)
}
}
// initial step calc
calc_steps();
// go go go!
window.requestAnimationFrame(updateGradient);
//# sourceURL=pen.js
</script>
</body></html>
