fix: fade state may get inconsistent on rapid ui open-close; correct logscale impl

src/net/torvald/terrarum/audio/AudioMixer.kt

@@ -11,9 +11,7 @@ import net.torvald.terrarum.audio.TerrarumAudioMixerTrack.Companion.SAMPLING_RAT
 import net.torvald.terrarum.audio.TerrarumAudioMixerTrack.Companion.SAMPLING_RATEF
 import net.torvald.terrarum.modulebasegame.MusicContainer
 import net.torvald.terrarum.tryDispose
-import kotlin.math.log
+import kotlin.math.*
-import kotlin.math.log10
-import kotlin.math.pow
 
 /**
  * Any audio reference fed into this manager will get lost; you must manually store and dispose of them on your own.
@@ -79,6 +77,8 @@ object AudioMixer: Disposable {
     private var lpLength = 0.4
     private var lpOutFired = false
     private var lpInFired = false
+    private var lpStart = SAMPLING_RATED / 2.0
+    private var lpTarget = SAMPLING_RATED / 2.0
 
     // TODO make sidechaining work
     // TODO master volume controls the master track
@@ -122,28 +122,30 @@ object AudioMixer: Disposable {
 
         if (lpOutFired) {
             lpAkku += delta
-            val x = lpAkku / lpLength
+            // https://www.desmos.com/calculator/dmhve2awxm
-            val q = 400.0
+            val t = (lpAkku / lpLength).coerceIn(0.0, 1.0)
-            val step = (q.pow(x) - 1) / (q - 1) // https://www.desmos.com/calculator/sttaq2qhzm
+            val b = ln(lpStart / lpTarget) / -1.0
-            val cutoff = FastMath.interpolateLinear(step, SAMPLING_RATED / 100.0, SAMPLING_RATED)
+            val a = lpStart
+            val cutoff = a * exp(b * t)
             faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(cutoff) }
 
 
             if (lpAkku >= lpLength) {
                 lpOutFired = false
-                faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(SAMPLING_RATEF) }
+                faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(lpTarget) }
             }
         }
         else if (lpInFired) {
             lpAkku += delta
-            val x = lpAkku / lpLength
+            // https://www.desmos.com/calculator/dmhve2awxm
-            val q = 400.0
+            val t = (lpAkku / lpLength).coerceIn(0.0, 1.0)
-            val step = log((q-1) * x + 1.0, q) // https://www.desmos.com/calculator/sttaq2qhzm
+            val b = ln(lpStart / lpTarget) / -1.0
-            val cutoff = FastMath.interpolateLinear(step, SAMPLING_RATED, SAMPLING_RATED / 100.0)
+            val a = lpStart
+            val cutoff = a * exp(b * t)
             faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(cutoff) }
 
             if (lpAkku >= lpLength) {
-                faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(SAMPLING_RATEF / 100.0) }
+                faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(lpTarget) }
                 lpInFired = false
             }
         }
@@ -194,6 +196,8 @@ object AudioMixer: Disposable {
             lpLength = length.coerceAtLeast(1.0/1024.0)
             lpAkku = 0.0
             lpOutFired = true
+            lpStart = (musicTrack.filters[0] as Lowpass).cutoff
+            lpTarget = SAMPLING_RATED / 2.0
         }
     }
 
@@ -202,6 +206,8 @@ object AudioMixer: Disposable {
             lpLength = length.coerceAtLeast(1.0/1024.0)
             lpAkku = 0.0
             lpInFired = true
+            lpStart = (musicTrack.filters[0] as Lowpass).cutoff
+            lpTarget = SAMPLING_RATED / 100.0
         }
     }
 

src/net/torvald/terrarum/modulebasegame/BuildingMaker.kt

@@ -302,7 +302,7 @@ class BuildingMaker(batch: FlippingSpriteBatch) : IngameInstance(batch) {
 
     override fun show() {
         Gdx.input.inputProcessor = BuildingMakerController(this)
-        (AudioMixer.musicTrack.filters[0] as Lowpass).setCutoff(TerrarumAudioMixerTrack.SAMPLING_RATEF)
+        (AudioMixer.musicTrack.filters[0] as Lowpass).setCutoff(TerrarumAudioMixerTrack.SAMPLING_RATEF / 2)
         super.show()
     }
 

src/net/torvald/terrarum/modulebasegame/TerrarumIngame.kt

@@ -292,7 +292,7 @@ open class TerrarumIngame(batch: FlippingSpriteBatch) : IngameInstance(batch) {
         IngameRenderer.setRenderedWorld(world)
         blockMarkingActor.isVisible = true
 
-        AudioMixer.faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(SAMPLING_RATEF) }
+        AudioMixer.faderTrack.forEach { (it.filters[0] as Lowpass).setCutoff(SAMPLING_RATEF / 2) }
 
 
         super.show() // this function sets gameInitialised = true

src/net/torvald/terrarum/modulebasegame/TitleScreen.kt

@@ -296,7 +296,7 @@ class TitleScreen(batch: FlippingSpriteBatch) : IngameInstance(batch) {
         UILoadGovernor.reset()
 
 
-        (AudioMixer.musicTrack.filters[0] as Lowpass).setCutoff(TerrarumAudioMixerTrack.SAMPLING_RATEF)
+        (AudioMixer.musicTrack.filters[0] as Lowpass).setCutoff(TerrarumAudioMixerTrack.SAMPLING_RATEF / 2)
 
 
         loadThingsWhileIntroIsVisible()

src/net/torvald/terrarum/modulebasegame/ui/UIInventoryFull.kt

@@ -365,8 +365,8 @@ class UIInventoryFull(
         INGAME.pause()
         INGAME.setTooltipMessage(null)
 
-        AudioMixer.requestLowpassIn(0.4)
+        AudioMixer.requestLowpassIn(0.3)
-        AudioMixer.requestFadeOut(0.4, 0.5)
+        AudioMixer.requestFadeOut(0.3, 0.5)
     }
 
     override fun doClosing(delta: Float) {
@@ -375,8 +375,8 @@ class UIInventoryFull(
         INGAME.resume()
         INGAME.setTooltipMessage(null)
 
-        AudioMixer.requestLowpassOut(0.4)
+        AudioMixer.requestLowpassOut(0.3)
-        AudioMixer.requestFadeIn(0.4, 1.0)
+        AudioMixer.requestFadeIn(0.3, 1.0)
     }
 
     override fun endOpening(delta: Float) {

src/net/torvald/terrarum/ui/BasicDebugInfoWindow.kt

@@ -14,6 +14,7 @@ import net.torvald.terrarum.TerrarumAppConfiguration.TILE_SIZE
 import net.torvald.terrarum.audio.*
 import net.torvald.terrarum.audio.MixerTrackProcessor.Companion.BACK_BUF_COUNT
 import net.torvald.terrarum.audio.TerrarumAudioMixerTrack.Companion.BUFFER_SIZE
+import net.torvald.terrarum.audio.TerrarumAudioMixerTrack.Companion.SAMPLING_RATED
 import net.torvald.terrarum.controller.TerrarumController
 import net.torvald.terrarum.gameworld.GameWorld
 import net.torvald.terrarum.gameworld.fmod
@@ -27,9 +28,7 @@ import net.torvald.terrarum.weather.WeatherStateBox
 import net.torvald.terrarum.worlddrawer.LightmapRenderer
 import net.torvald.terrarum.worlddrawer.WorldCamera
 import net.torvald.terrarumsansbitmap.gdx.TextureRegionPack
-import kotlin.math.absoluteValue
+import kotlin.math.*
-import kotlin.math.max
-import kotlin.math.roundToInt
 
 /**
  * Created by minjaesong on 2016-03-14.
@@ -499,6 +498,16 @@ class BasicDebugInfoWindow : UICanvas() {
     private fun drawFilterParam(batch: SpriteBatch, x: Int, y: Int, filter: TerrarumAudioFilter, track: TerrarumAudioMixerTrack) {
         when (filter) {
             is Lowpass -> {
+                // https://www.desmos.com/calculator/dmhve2awxm
+                val f = filter.cutoff
+                val b = ln(24 / 24000.0) / -1.0
+                val a = 24.0
+                val perc = (ln(f / a) / b).toFloat()
+                batch.color = COL_METER_GRAD2
+                Toolkit.fillArea(batch, x.toFloat(), y.toFloat(), stripW * perc, 14f)
+                batch.color = COL_METER_GRAD
+                Toolkit.fillArea(batch, x.toFloat(), y+14f, stripW * perc, 2f)
+
                 batch.color = FILTER_NAME_ACTIVE
                 App.fontSmallNumbers.draw(batch, "F:${filter.cutoff.toInt()}", x+3f, y+1f)
             }

src/net/torvald/terrarum/ui/UICanvas.kt

@@ -341,7 +341,7 @@ abstract class UICanvas(
     }
 
     companion object {
-        const val OPENCLOSE_GENERIC = 0.0666f
+        const val OPENCLOSE_GENERIC = 0.1f
 
         fun doOpeningFade(ui: UICanvas, openCloseTime: Second) {
             ui.handler.opacity = max(0f, ui.handler.openCloseCounter - 0.02f) / openCloseTime // fade start 1/50 sec late, it's intended