Created
March 18, 2012 20:02
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Javascript functions for doing fast binary/hex/RGB color conversions using bitwise operations.
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// convert 0..255 R,G,B values to binary string | |
RGBToBin = function(r,g,b){ | |
var bin = r << 16 | g << 8 | b; | |
return (function(h){ | |
return new Array(25-h.length).join("0")+h | |
})(bin.toString(2)) | |
} | |
// convert 0..255 R,G,B values to a hexidecimal color string | |
RGBToHex = function(r,g,b){ | |
var bin = r << 16 | g << 8 | b; | |
return (function(h){ | |
return new Array(7-h.length).join("0")+h | |
})(bin.toString(16).toUpperCase()) | |
} | |
// convert a 24 bit binary color to 0..255 R,G,B | |
binToRGB = function(bin){ | |
var pbin = parseInt(bin,2); | |
var r = pbin >> 16; | |
var g = pbin >> 8 & 0xFF; | |
var b = pbin & 0xFF; | |
return [r,g,b]; | |
} | |
// convert a hexidecimal color string to 0..255 R,G,B | |
hexToRGB = function(hex){ | |
var r = hex >> 16; | |
var g = hex >> 8 & 0xFF; | |
var b = hex & 0xFF; | |
return [r,g,b]; | |
} | |
// simple log function for web/nodejs | |
log = function(item){ | |
if (document.body){ | |
document.body.innerHTML = document.body.innerHTML+'<pre>'+item+'</pre>'; | |
} else { | |
console.log(item); | |
} | |
} | |
// convert some RGB color values to hex and to binary | |
new Array( | |
[000,000,000], // black | |
[000,255,000], // green | |
[255,255,255] // white | |
).forEach(function(rgb){ | |
var hex = RGBToHex(rgb[0],rgb[1],rgb[2]); | |
var bin = RGBToBin(rgb[0],rgb[1],rgb[2]); | |
log('-> RGB: '+rgb+' \n<- HEX: '+hex+' \n<- BIN: '+bin+'\n\n'); | |
}); | |
// convert some hexidecimal color values to RGB | |
new Array( | |
'000000', // black | |
'00FF00', // green | |
'FFFFFF' // white | |
).forEach(function(hex){ | |
var rgb = hexToRGB(parseInt(hex,16)); | |
log('-> HEX: '+hex+' \n<- RGB: '+rgb+'\n\n'); | |
}); | |
// convert some 24 bit binary color values to RGB | |
new Array( | |
'000000000000000000000000', // black | |
'000000001111111100000000', // green | |
'111111111111111111111111' // white | |
).forEach(function(bin){ | |
var rgb = binToRGB(bin); | |
log('-> BIN: '+bin+' \n<- RGB: '+rgb+'\n\n'); | |
}); |
Array(7-h.length).join("0")
can be replaced with "0".repeat(6-h.length)
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the hex needs to start with "0x", for those who couldn't get it working