TilePropCodex is now object, torch flicker (WIP as all the torches are in unison)

Former-commit-id: df9c0e3a9ace2ba976da5e81f1f2d2217db541a0
Former-commit-id: 81a25a938023f318937e1f4ded15e6047fdf8864

src/net/torvald/terrarum/tileproperties/TilePropUtil.kt

@@ -0,0 +1,57 @@
+package net.torvald.terrarum.tileproperties
+
+import com.jme3.math.FastMath
+import net.torvald.random.HQRNG
+import net.torvald.terrarum.Terrarum
+import net.torvald.terrarum.mapdrawer.LightmapRenderer
+
+/**
+ * Created by minjaesong on 16-06-16.
+ */
+object TilePropUtil {
+    var flickerFuncX = 0 // in milliseconds; saves current status of func
+    val flickerFuncDomain = 50 // time between two noise sample, in milliseconds
+    val flickerFuncRange = 0.012f // intensity [0, 1]
+    //val torchIntensityOffset = -0.04f
+
+    val random = HQRNG();
+    var funcY = 0f
+
+    var patternThis = getNewPattern()
+    var patternNext = getNewPattern()
+
+    init {
+
+    }
+
+    fun getTorchFlicker(baseLum: Int): Int {
+        funcY = linearInterpolation1D(patternThis, patternNext,
+                flickerFuncX.toFloat() / flickerFuncDomain
+        )
+
+        return LightmapRenderer.brightenUniform(baseLum, funcY)
+    }
+
+    fun torchFlickerTickClock() {
+        flickerFuncX += Terrarum.game.DELTA_T
+
+        if (flickerFuncX > flickerFuncDomain) {
+            flickerFuncX -= flickerFuncDomain
+
+            patternThis = patternNext
+            patternNext = getNewPattern()
+        }
+    }
+
+    private fun getNewPattern(): Float = random.nextFloat().times(2).minus(1f) * flickerFuncRange
+
+    private fun cosineInterpolation1D(a: Float, b: Float, x: Float): Float{
+        val ft: Float = x * FastMath.PI;
+        val f: Float = (1 - FastMath.cos(ft)) * 0.5f;
+
+        return a * (1 - f) + b * f;
+    }
+
+    private fun linearInterpolation1D(a: Float, b: Float, x: Float) =
+            a * (1 - x) + b * x;
+}