init

python

PCSurvey/libs/plasio/workers/laz-loader-worker.js

@@ -0,0 +1,144 @@
+// laz-loader-worker.js
+//
+
+//importScripts('laz-perf.js');
+
+let instance = null; // laz-perf instance
+
+function readAs(buf, Type, offset, count) {
+	count = (count === undefined || count === 0 ? 1 : count);
+	var sub = buf.slice(offset, offset + Type.BYTES_PER_ELEMENT * count);
+
+	var r = new Type(sub);
+	if (count === undefined || count === 1)
+		return r[0];
+
+	var ret = [];
+	for (var i = 0 ; i < count ; i ++) {
+		ret.push(r[i]);
+	}
+
+	return ret;
+}
+
+function parseLASHeader(arraybuffer) {
+	var o = {};
+
+	o.pointsOffset = readAs(arraybuffer, Uint32Array, 32*3);
+	o.pointsFormatId = readAs(arraybuffer, Uint8Array, 32*3+8);
+	o.pointsStructSize = readAs(arraybuffer, Uint16Array, 32*3+8+1);
+	o.pointsCount = readAs(arraybuffer, Uint32Array, 32*3 + 11);
+
+
+	var start = 32*3 + 35;
+	o.scale = readAs(arraybuffer, Float64Array, start, 3); start += 24; // 8*3
+	o.offset = readAs(arraybuffer, Float64Array, start, 3); start += 24;
+
+	var bounds = readAs(arraybuffer, Float64Array, start, 6); start += 48; // 8*6;
+	o.maxs = [bounds[0], bounds[2], bounds[4]];
+	o.mins = [bounds[1], bounds[3], bounds[5]];
+
+	return o;
+}
+
+function handleEvent(msg) {
+	switch(msg.type) {
+		case "open":
+			try {
+				instance = new Module.LASZip();
+				var abInt = new Uint8Array(msg.arraybuffer);
+				var buf = Module._malloc(msg.arraybuffer.byteLength);
+
+				instance.arraybuffer = msg.arraybuffer;
+				instance.buf = buf;
+				Module.HEAPU8.set(abInt, buf);
+				instance.open(buf, msg.arraybuffer.byteLength);
+
+				instance.readOffset = 0;
+
+				postMessage({ type: "open", status: 1});
+			}catch(e) {
+				debugger;
+				postMessage({ type: "open", status: 0, details: e });
+			}
+			break;
+
+		case "header":
+			if (!instance)
+				throw new Error("You need to open the file before trying to read header");
+
+
+
+			var header = parseLASHeader(instance.arraybuffer);
+			header.pointsFormatId &= 0x3f;
+			instance.header = header;
+			postMessage({type: "header", status: 1, header: header});
+			break;
+
+		case "read":
+			if (!instance)
+				throw new Error("You need to open the file before trying to read stuff");
+
+			var start = msg.start, count = msg.count, skip = msg.skip;
+			var o = instance;
+
+			if (!o.header)
+				throw new Error("You need to query header before reading, I maintain state that way, sorry :(");
+
+			var pointsToRead = Math.min(count * skip, o.header.pointsCount - o.readOffset);
+			var bufferSize = Math.ceil(pointsToRead / skip);
+			var pointsRead = 0;
+
+			let buffer = new ArrayBuffer(bufferSize * o.header.pointsStructSize);
+			let this_buf = new Uint8Array(buffer);
+			var buf_read = Module._malloc(o.header.pointsStructSize);
+			for (var i = 0 ; i < pointsToRead ; i ++) {
+				o.getPoint(buf_read);
+
+				if (i % skip === 0) {
+					var a = new Uint8Array(Module.HEAPU8.buffer, buf_read, o.header.pointsStructSize);
+					this_buf.set(a, pointsRead * o.header.pointsStructSize, o.header.pointsStructSize);
+					pointsRead ++;
+				}
+
+				o.readOffset ++;
+			}
+			Module._free(buf_read);
+
+			let transferables = [buffer];
+
+			postMessage({
+				type: 'header',
+				status: 1,
+				buffer: buffer,
+				count: pointsRead,
+				hasMoreData: o.readOffset < o.header.pointsCount
+			}, transferables);
+
+			break;
+
+
+		case "close":
+			if (instance !== null) {
+				Module._free(instance.buf);
+				instance.delete();
+				instance = null;
+			}else{
+				debugger;
+			}
+			
+			postMessage({ type: "close", status: 1});
+			break;
+	}
+}
+
+onmessage = function(event) {
+	try {
+		handleEvent(event.data);
+	} catch(e) {
+		debugger;
+		postMessage({type: event.data.type, status: 0, details: e});
+	}
+};
+
+