dojox
Version:
Dojo eXtensions, a rollup of many useful sub-projects and varying states of maturity – from very stable and robust, to alpha and experimental. See individual projects contain README files for details.
105 lines (100 loc) • 3.51 kB
HTML
<html>
<head>
<title>Compress colors</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
@import "../../../../dojo/resources/dojo.css";
@import "../../../../dijit/tests/css/dijitTests.css";
.pane { margin-top: 2em; }
</style>
<script type="text/javascript" src="../../../../dojo/dojo.js" data-dojo-config="isDebug: true"></script>
<script type="text/javascript">
dojo.require("dojox.encoding.tests.compression.colors");
dojo.require("dojox.encoding.easy64");
dojo.require("dojox.encoding.bits");
dojo.require("dojox.encoding.compression.splay");
dojo.require("dojox.encoding.compression.lzw");
var dc = dojox.encoding, dcc = dc.compression, colors = dc.tests.compression.colors;
var run = function(){
var empty = {}, names = [];
for(var i in colors){
if(i in empty){ continue; }
names.push(i);
}
names.sort();
var output = new dc.bits.OutputStream(), result = [];
// encode names
var s = names.join("{"), encoder = new dcc.lzw.Encoder(27);
result.push("<div>Input is " + s.length + " bytes long.</div>");
result.push("<div>Input: " + s + ".</div>");
for(var i = 0; i < s.length; ++i){
var v = s.charCodeAt(i) - 97;
if(v < 0 || v > 26) console.debug("error!", v);
encoder.encode(v, output);
}
encoder.flush(output);
var w = output.getWidth();
result.push("<div>Output is " + Math.ceil(w / 8) + " bytes (" + w + " bits) long.</div>");
var buf = output.getBuffer();
{
var input = new dc.bits.InputStream(buf, buf.length * 8), decoder = new dcc.lzw.Decoder(27);
var t = [];
for(var w = 0; w < s.length;){
var v = decoder.decode(input);
t.push(v);
w += v.length;
}
t = t.join("");
var p = [];
for(var i = 0; i < t.length; ++i){
p.push(String.fromCharCode(t.charCodeAt(i) + 97));
}
p = p.join("");
result.push("<div>Control: " + p + ".</div>");
}
while(buf.length % 3){ buf.push(0); }
var e64 = dc.easy64.encode(buf);
result.push("<div>Encoded output is " + e64.length + " bytes.</div>");
result.push("<div><textarea>" + e64 + "</textarea></div>");
// test
{
var buf = dc.easy64.decode(e64);
var input = new dc.bits.InputStream(buf, buf.length * 8), decoder = new dcc.lzw.Decoder(27);
var t = [];
for(var w = 0; w < s.length;){
var v = decoder.decode(input);
t.push(v);
w += v.length;
}
t = t.join("");
var p = [];
for(var i = 0; i < t.length; ++i){
p.push(String.fromCharCode(t.charCodeAt(i) + 97));
}
p = p.join("");
result.push("<div>Control: " + p + ".</div>");
}
// encode values
buf = [];
for(var i = 0; i < names.length; ++i){
var c = colors[names[i]];
buf.push(c[0], c[1], c[2]);
}
result.push("<div>Output is " + buf.length + " bytes long.</div>");
while(buf.length % 4){ buf.push(0); }
e64 = dc.easy64.encode(buf);
result.push("<div>Encoded output is " + e64.length + " bytes.</div>");
result.push("<div><textarea>" + e64 + "</textarea></div>");
dojo.byId("status").innerHTML = result.join("\n");
};
dojo.addOnLoad(function(){
dojo.connect(dojo.byId("run"), "onclick", run);
});
</script>
</head>
<body>
<h1>Compress colors</h1>
<p><button id="run">Run</button></p>
<div id="status" class="pane"><em>No status yet.</em></div>
</body>
</html>