tweak zoom calculation

app/src/main/java/com/geode/launcher/GeometryDashActivity.kt

@@ -387,8 +387,7 @@ class GeometryDashActivity : AppCompatActivity(), Cocos2dxHelper.Cocos2dxHelperL
         }
 
         if (mScreenZoomFit && mScreenZoom != 1.0f) {
-            frameLayout.scaleX = 1/mScreenZoom
-            frameLayout.scaleY = 1/mScreenZoom
+            frameLayout.fitZoom = true
         }
 
         if (mScreenZoom != 1.0f) {

app/src/main/java/com/geode/launcher/utils/ConstrainedFrameLayout.kt

@@ -2,32 +2,19 @@ package com.geode.launcher.utils
 
 import android.content.Context
 import android.widget.FrameLayout
-import kotlin.math.roundToInt
+import kotlin.math.ceil
+import kotlin.math.floor
+import kotlin.math.min
 
 class ConstrainedFrameLayout(context: Context) : FrameLayout(context) {
     // avoid running the aspect ratio fix when we don't need it
     var aspectRatio: Float? = null
     var zoom: Float? = null
+    var fitZoom: Boolean = false
 
     override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
-        var paddingX = 0
-        var paddingY = 0
-
-        val currentAspectRatio = aspectRatio
-        if (currentAspectRatio != null) {
-            val width = MeasureSpec.getSize(widthMeasureSpec)
-            val height = MeasureSpec.getSize(heightMeasureSpec)
-            if (width == 0 || height == 0) {
-                super.onMeasure(widthMeasureSpec, heightMeasureSpec)
-                return
-            }
-
-            val calculatedWidth = height * currentAspectRatio
-            val padding = ((width - calculatedWidth) / 2).toInt()
-
-            // ignore paddings where the screen ends up looking odd
-            paddingX += padding
-        }
+        var paddingX = 0.0f
+        var paddingY = 0.0f
 
         val currentZoom = zoom
         if (currentZoom != null) {
@@ -38,16 +25,48 @@ class ConstrainedFrameLayout(context: Context) : FrameLayout(context) {
                 return
             }
 
-            val zoomFactor = 1 - currentZoom
-            val widthFactor = width/2.0f + paddingX/4.0f
-            val heightFactor = height/2.0f
+            val calculatedWidth = width * currentZoom
+            val calculatedHeight = height * currentZoom
 
-            paddingX = (widthFactor * zoomFactor).roundToInt()
-            paddingY = (heightFactor * zoomFactor).roundToInt()
+            paddingX = (width - calculatedWidth)/2
+            paddingY = (height - calculatedHeight)/2
         }
 
-        if (paddingX > 0 || paddingY > 0) {
-            setPadding(paddingX, paddingY, paddingX, paddingY)
+        val currentAspectRatio = aspectRatio
+        if (currentAspectRatio != null) {
+            val width = MeasureSpec.getSize(widthMeasureSpec)
+            val height = MeasureSpec.getSize(heightMeasureSpec)
+            if (width == 0 || height == 0) {
+                super.onMeasure(widthMeasureSpec, heightMeasureSpec)
+                return
+            }
+
+            val calculatedWidth = (height - paddingY * 2) * currentAspectRatio
+            val padding = (width - calculatedWidth) / 2
+
+            paddingX = padding
+        }
+
+        if (paddingX > 0.0 || paddingY > 0.0) {
+            if (fitZoom) {
+                val width = MeasureSpec.getSize(widthMeasureSpec)
+                val height = MeasureSpec.getSize(heightMeasureSpec)
+
+                val calculatedHeight = (height - paddingY * 2)
+                val calculatedWidth = (width - paddingX * 2)
+
+                val zoomFactor = min(height / calculatedHeight, width / calculatedWidth)
+
+                scaleX = zoomFactor
+                scaleY = zoomFactor
+            }
+
+            setPadding(
+                ceil(paddingX).toInt(),
+                ceil(paddingY).toInt(),
+                floor(paddingX).toInt(),
+                floor(paddingY).toInt()
+            )
         }
 
         super.onMeasure(