BangleApps/apps/openstmap/test/index.html

117 lines
4.3 KiB
HTML

<html>
<head>
<title>3 bit filter test</title>
</head>
<style>
</style>
</head>
<body>
<p>This file tests imagefilter.js to allow different filtering options
to be tested, so we can quickly see the easiest way of transforming OpenStreetMap tiles
into 3 bits
</p>
<canvas id="maptiles" style="display:none"></canvas>
<button id="getmap">Test</button><br/>
<input type="checkbox" id="finaldither" checked></input><span>Final dither (Bangle.js preview)</span><br/>
<input type="checkbox" id="sharpen" checked></input><span>Sharpen</span>
<input type="checkbox" id="dither"></input><span>Line Dither</span><br/>
<input type="range" id="slider_lo" min="0" max="255" value="140">Lo threshold<br/>
<input type="range" id="slider_hi" min="0" max="255" value="250">Hi threshold<br/>
<script src="../../../webtools/heatshrink.js"></script>
<script src="../../../webtools/imageconverter.js"></script>
<script src="../imagefilter.js"></script>
<script>
var TILESIZE = 96
// convert canvas into an actual tiled image file
function tilesLoaded(ctx, width, height, mapImageFile) {
var filterOptions = {
colLo : 0|document.getElementById("slider_lo").value,
colHi : 0|document.getElementById("slider_hi").value,
sharpen : 0|document.getElementById("sharpen").checked,
dither : 0|document.getElementById("dither").checked
}
console.log("filterOptions", filterOptions);
var preview = document.getElementById("finaldither").checked;
var options = {
compression:false, output:"raw",
mode:"3bit",
diffusion:"bayer2"
};
/* If in 3 bit mode, go through all the data beforehand and
turn the saturation up to maximum, so when thresholded it
works a lot better */
var imageData = ctx.getImageData(0,0,width,height);
var dstData = ctx.createImageData(width, height);
imageFilterFor3BPP(imageData, dstData, filterOptions);
ctx.putImageData(dstData,0,0);
console.log("Compression options", options);
var tiledImage;
if (preview) {
var w = Math.round(width / TILESIZE);
var h = Math.round(height / TILESIZE);
for (var y=0;y<h;y++) {
for (var x=0;x<w;x++) {
var imageData = ctx.getImageData(x*TILESIZE, y*TILESIZE, TILESIZE, TILESIZE);
var rgba = imageData.data;
options.rgbaOut = rgba;
options.width = TILESIZE;
options.height = TILESIZE;
var imgstr = imageconverter.RGBAtoString(rgba, options);
ctx.putImageData(imageData,x*TILESIZE, y*TILESIZE); // write preview
/*var compress = 'require("heatshrink").decompress('
if (!imgstr.startsWith(compress)) throw "Data in wrong format";
imgstr = imgstr.slice(compress.length,-1);*/
if (tiledImage) tiledImage += imgstr.substr(3); // skip header
else tiledImage = imgstr; // for first image, keep the header
}
}
}
return [{
name:mapImageFile,
content:tiledImage
}];
}
// Render everything to a canvas...
var canvas = document.getElementById("maptiles");
canvas.style.display="";
var ctx = canvas.getContext('2d');
var img = new Image();
img.crossOrigin = "Anonymous";
img.onload = function(){
canvas.width = img.width;
canvas.height = img.height;
ctx.drawImage(img,0,0);
tilesLoaded(ctx, canvas.width, canvas.height, "");
};
img.src = "osm-test.png"
function update() {
ctx.drawImage(img,0,0);
tilesLoaded(ctx, canvas.width, canvas.height, "");
}
document.getElementById("getmap").addEventListener("click", update);
document.getElementById("slider_lo").addEventListener("change",update);
document.getElementById("slider_hi").addEventListener("change",update);
document.getElementById("finaldither").addEventListener("click",update);
document.getElementById("sharpen").addEventListener("click",update);
document.getElementById("dither").addEventListener("click",update);
</script>
</body>
</html>