lightmap to update every other frame, and rendering needs fix minor jitter

src/net/torvald/util/DebugTimers.kt

@@ -0,0 +1,37 @@
+package net.torvald.util
+
+/**
+ * Debugtimers will collect multiple measurements and will return stabilised time reading
+ *
+ * Created by minjaesong on 2021-08-14
+ */
+class DebugTimers {
+
+    private val BUFFER_SIZE = 16
+    private val bufs = ArrayListMap<String, CircularArray<Long>>()
+
+    fun put(key: String, value: Long) {
+        if (bufs[key] == null) bufs[key] = CircularArray(BUFFER_SIZE, true)
+        bufs[key]!!.appendHead(value)
+    }
+
+    operator fun get(key: String): Long? {
+        if (bufs[key] == null) return null
+        else {
+            var s = 0L; var c = 0
+            for (i in 0 until BUFFER_SIZE) {
+                bufs[key]!![i]?.let {
+                    s += it
+                    c += 1
+                }
+            }
+            return if (c == 0) 0L else s / c
+        }
+    }
+
+    fun forEach(action: (String, Long?) -> Unit) {
+        bufs.keys.forEach { key -> action(key, get(key)) }
+    }
+
+
+}