From 16f0a9844c0dcfd5d54922ec6a2cef022b77a486 Mon Sep 17 00:00:00 2001
From: yairm210 <yairm210@hotmail.com>
Date: Sun, 15 Dec 2024 12:22:46 +0200
Subject: [PATCH] perf(tile-update): cache base data for tile rendering to only
 recompute when base data changes

---
 .../tilegroups/layers/TileLayerCityButton.kt  | 11 ++++---
 .../tilegroups/layers/TileLayerTerrain.kt     | 31 ++++++++++++++++++-
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerCityButton.kt b/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerCityButton.kt
index 6941f5f028..5a1ac595b3 100644
--- a/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerCityButton.kt
+++ b/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerCityButton.kt
@@ -14,6 +14,7 @@ import com.unciv.utils.DebugUtils
 class TileLayerCityButton(tileGroup: TileGroup, size: Float) : TileLayer(tileGroup, size) {
 
     private var cityButton: CityButton? = null
+    val tile = tileGroup.tile
 
     init {
         touchable = Touchable.childrenOnly
@@ -21,18 +22,18 @@ class TileLayerCityButton(tileGroup: TileGroup, size: Float) : TileLayer(tileGro
     }
 
     override fun act(delta: Float) {
-        if (tileGroup.tile.isCityCenter())
+        if (tile.isCityCenter())
             super.act(delta)
     }
 
     override fun hit(x: Float, y: Float, touchable: Boolean): Actor? {
-        if (tileGroup.tile.isCityCenter())
+        if (tile.isCityCenter())
             return super.hit(x, y, touchable)
         return null
     }
 
     override fun draw(batch: Batch?, parentAlpha: Float) {
-        if (tileGroup.tile.isCityCenter())
+        if (tile.isCityCenter())
             super.draw(batch, parentAlpha)
     }
 
@@ -47,7 +48,7 @@ class TileLayerCityButton(tileGroup: TileGroup, size: Float) : TileLayer(tileGro
     override fun doUpdate(viewingCiv: Civilization?, localUniqueCache: LocalUniqueCache) {
         if (tileGroup !is WorldTileGroup) return
 
-        val city = tile().getCity()
+        val city = tile.getCity()
 
         // There used to be a city here but it was razed
         if (city == null && cityButton != null) {
@@ -56,7 +57,7 @@ class TileLayerCityButton(tileGroup: TileGroup, size: Float) : TileLayer(tileGro
         }
 
         if (viewingCiv == null) return
-        if (city == null || !tileGroup.tile.isCityCenter()) return
+        if (city == null || !tile.isCityCenter()) return
         
         // Create (if not yet) and update city button
         if (cityButton == null) {
diff --git a/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerTerrain.kt b/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerTerrain.kt
index e6686ba37f..2c2d77ce62 100644
--- a/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerTerrain.kt
+++ b/core/src/com/unciv/ui/components/tilegroups/layers/TileLayerTerrain.kt
@@ -47,6 +47,7 @@ class TileLayerTerrain(tileGroup: TileGroup, size: Float) : TileLayer(tileGroup,
         return ImageGetter.imageExists(strings().getTile("$shownImprovement-Pillaged"))
     }
 
+    var previousTileImageLocationData: TileImageLocationData? = null
     private fun getTileBaseImageLocations(viewingCiv: Civilization?): List<String> {
 
         val isForceVisible = tileGroup.isForceVisible
@@ -75,6 +76,20 @@ class TileLayerTerrain(tileGroup: TileGroup, size: Float) : TileLayer(tileGroup,
             }
         }
 
+        // Anything that, if changed, would change the terrain images - optimization to avoid unnecessary work
+        val tileImageLocationData = TileImageLocationData(
+            viewingCiv,
+            isForceVisible,
+            shownImprovement,
+            shouldShowImprovement,
+            shouldShowResource,
+            tile.baseTerrain,
+            tile.naturalWonder,
+            tile.terrainFeatures,
+        )
+        if (previousTileImageLocationData == tileImageLocationData) return tileImageIdentifiers
+        else previousTileImageLocationData = tileImageLocationData
+
         val terrainImages = if (tile.naturalWonder != null)
             sequenceOf(tile.baseTerrain, tile.naturalWonder!!)
         else  sequenceOf(tile.baseTerrain) + tile.terrainFeatures.asSequence()
@@ -88,7 +103,8 @@ class TileLayerTerrain(tileGroup: TileGroup, size: Float) : TileLayer(tileGroup,
         return when {
             strings().tileSetConfig.ruleVariants[allTogether] != null -> baseHexagon + 
                     strings().tileSetConfig.ruleVariants[allTogether]!!.map { strings().getTile(it) } + edgeImages
-            ImageGetter.imageExists(allTogetherLocation) -> baseHexagon + allTogetherLocation + edgeImages
+            ImageGetter.imageExists(allTogetherLocation) -> 
+                baseHexagon + allTogetherLocation + edgeImages
             tile.naturalWonder != null -> getNaturalWonderBackupImage(baseHexagon) + edgeImages
             else -> baseHexagon + getTerrainImageLocations(terrainImages) + edgeImages + getImprovementAndResourceImages(resourceAndImprovementSequence)
         }
@@ -121,8 +137,21 @@ class TileLayerTerrain(tileGroup: TileGroup, size: Float) : TileLayer(tileGroup,
             return@filter true
         }.map { it.fileName }
     }
+    
+    data class TileImageLocationData(
+        val viewingCiv: Civilization?,
+        val isForceVisible: Boolean,
+        val shownImprovement: String?,
+        val shouldShowImprovement: Boolean,
+        val shouldShowResource: Boolean,
+        val baseTerrain: String,
+        val naturalWonder: String?,
+        val terrainFeatures: List<String>,
+
+        )
 
     private fun updateTileImage(viewingCiv: Civilization?) {
+        
         val tileBaseImageLocations = getTileBaseImageLocations(viewingCiv)
         
         if (tileBaseImageLocations.size == tileImageIdentifiers.size) {