Sky lights data saving (optimization)

src/lighting/Lightmap.cpp

@@ -20,12 +20,27 @@ void Lightmap::set(const Lightmap* lightmap) {
 	}
 }
 
+void Lightmap::set(light_t* map) {
+	delete[] this->map;
+	this->map = map;
+}
+
 static_assert(sizeof(light_t) == 2, "replace dataio calls to new light_t");
 
 ubyte* Lightmap::encode() const {
-	ubyte* buffer = new ubyte[CHUNK_VOL * sizeof(light_t)];
-	for (uint i = 0; i < CHUNK_VOL; i++) {
-		dataio::write_int16_big(map[i], buffer, i * sizeof(light_t));
+	ubyte* buffer = new ubyte[LIGHTMAP_DATA_LEN];
+	for (uint i = 0; i < CHUNK_VOL; i+=2) {
+		buffer[i/2] = ((map[i] >> 12) & 0xF) | ((map[i+1] >> 8) & 0xF0);
 	}
 	return buffer;
 }
+
+light_t* Lightmap::decode(ubyte* buffer) {
+	light_t* lights = new light_t[CHUNK_VOL];
+	for (uint i = 0; i < CHUNK_VOL; i+=2) {
+		ubyte b = buffer[i/2];
+		lights[i] = ((b & 0xF) << 12);
+		lights[i+1] = ((b & 0xF0) << 8);
+	} 
+	return lights;
+}