27 lines
971 B
JavaScript
27 lines
971 B
JavaScript
var ewww_webp_supported = false;
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// webp detection adapted from https://developers.google.com/speed/webp/faq#how_can_i_detect_browser_support_using_javascript
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function check_webp_feature(feature, callback) {
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callback = (typeof callback !== 'undefined') ? callback : function(){};
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if (ewww_webp_supported) {
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callback(ewww_webp_supported);
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return;
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}
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var kTestImages = {
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alpha: "UklGRkoAAABXRUJQVlA4WAoAAAAQAAAAAAAAAAAAQUxQSAwAAAARBxAR/Q9ERP8DAABWUDggGAAAABQBAJ0BKgEAAQAAAP4AAA3AAP7mtQAAAA==",
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};
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var img = new Image();
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img.onload = function () {
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ewww_webp_supported = (img.width > 0) && (img.height > 0);
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if (callback) {
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callback(ewww_webp_supported);
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}
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};
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img.onerror = function () {
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if (callback) {
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callback(false);
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}
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};
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img.src = "data:image/webp;base64," + kTestImages[feature];
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}
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check_webp_feature('alpha');
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