Rendering performance improvements - much smoother scrolling!

android/build.gradle

@@ -21,8 +21,8 @@ android {
         applicationId "com.unciv.app"
         minSdkVersion 14
         targetSdkVersion 28
-        versionCode 207
-        versionName "2.13.7"
+        versionCode 208
+        versionName "2.13.8"
     }
 
     // Had to add this crap for Travis to build, it wanted to sign the app

core/src/com/unciv/ui/cityscreen/CityTileGroup.kt

@@ -13,6 +13,7 @@ class CityTileGroup(private val city: CityInfo, tileInfo: TileInfo) : TileGroup(
 
 
     init {
+        isTransform=false // performance helper - nothing here is rotated or scaled
         addActor(yieldGroup)
         if (city.location == tileInfo.position) {
             populationImage = ImageGetter.getImage("StatIcons/City_Center_(Civ6).png")

core/src/com/unciv/ui/tilegroups/TileGroup.kt

@@ -1,6 +1,7 @@
 package com.unciv.ui.tilegroups
 
 import com.badlogic.gdx.graphics.Color
+import com.badlogic.gdx.graphics.g2d.Batch
 import com.badlogic.gdx.scenes.scene2d.Actor
 import com.badlogic.gdx.scenes.scene2d.Group
 import com.badlogic.gdx.scenes.scene2d.ui.Image
@@ -51,7 +52,7 @@ open class TileGroup(var tileInfo: TileInfo) : Group() {
         addCircleImage()
         addFogImage(groupSize)
         addCrosshairImage()
-        isTransform = false
+        isTransform=false // performance helper - nothing here is rotated or scaled
     }
 
 
@@ -287,6 +288,11 @@ open class TileGroup(var tileInfo: TileInfo) : Group() {
             addActor(image)
         }
 
+
+    }
+
+    override fun draw(batch: Batch?, parentAlpha: Float) {
+        super.draw(batch, parentAlpha)
     }
 
     private fun updateTileColor(isViewable: Boolean) {

core/src/com/unciv/ui/utils/IconCircleGroup.kt

@@ -6,6 +6,7 @@ import com.badlogic.gdx.scenes.scene2d.Group
 class IconCircleGroup(size:Float, val image: Actor): Group(){
     val circle = ImageGetter.getCircle().apply { setSize(size, size) }
     init {
+        isTransform=false // performance helper - nothing here is rotated or scaled
         setSize(size, size)
         addActor(circle)
         image.setSize(size * 0.75f, size * 0.75f)

core/src/com/unciv/ui/utils/UnitGroup.kt

@@ -28,6 +28,8 @@ class UnitGroup(val unit: MapUnit, val size: Float): Group() {
         if (unit.health < 100) { // add health bar
             addActor(ImageGetter.getHealthBar(unit.health.toFloat(), 100f, size))
         }
+
+        isTransform=false // performance helper - nothing here is rotated or scaled
     }
 
     fun getBackgroundImageForUnit(unit: MapUnit): Image {