32-bit colors mode implementing

app/src/main/kotlin/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -336,6 +336,9 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 			return policy.isNetworkAllowed(connectivityManager)
 		}
 
+	val enhancedColors: Boolean
+		get() = prefs.getBoolean(KEY_32BIT_COLOR, false)
+
 	fun isTipEnabled(tip: String): Boolean {
 		return prefs.getStringSet(KEY_TIPS_CLOSED, emptySet())?.contains(tip) != true
 	}
@@ -491,6 +494,7 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		const val KEY_DISABLE_NSFW = "no_nsfw"
 		const val KEY_RELATED_MANGA = "related_manga"
 		const val KEY_NAV_MAIN = "nav_main"
+		const val KEY_32BIT_COLOR = "enhanced_colors"
 
 		// About
 		const val KEY_APP_UPDATE = "app_update"

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/config/ReaderSettings.kt

@@ -1,8 +1,11 @@
 package org.koitharu.kotatsu.reader.ui.config
 
 import android.content.SharedPreferences
+import android.graphics.Bitmap
 import android.view.View
 import androidx.lifecycle.MediatorLiveData
+import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
+import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView.Companion.preferredBitmapConfig
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
@@ -29,6 +32,9 @@ class ReaderSettings(
 	val colorFilter: ReaderColorFilter?
 		get() = colorFilterFlow.value?.takeUnless { it.isEmpty }
 
+	val enhancedColors: Boolean
+		get() = settings.enhancedColors
+
 	val isPagesNumbersEnabled: Boolean
 		get() = settings.isPagesNumbersEnabled
 
@@ -40,6 +46,15 @@ class ReaderSettings(
 		view.background = bg.resolve(view.context)
 	}
 
+	fun enhancedColorsMode() {
+		val modeEnabled = settings.enhancedColors
+		preferredBitmapConfig = if (modeEnabled) {
+			Bitmap.Config.ARGB_8888
+		} else {
+			Bitmap.Config.RGB_565
+		}
+	}
+
 	override fun onInactive() {
 		super.onInactive()
 		settings.unsubscribe(internalObserver)
@@ -78,7 +93,8 @@ class ReaderSettings(
 				key == AppSettings.KEY_PAGES_NUMBERS ||
 				key == AppSettings.KEY_WEBTOON_ZOOM ||
 				key == AppSettings.KEY_READER_ZOOM_BUTTONS ||
-				key == AppSettings.KEY_READER_BACKGROUND
+				key == AppSettings.KEY_READER_BACKGROUND ||
+				key == AppSettings.KEY_32BIT_COLOR
 			) {
 				notifyChanged()
 			}

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/standard/PageHolder.kt

@@ -4,10 +4,12 @@ import android.annotation.SuppressLint
 import android.graphics.PointF
 import android.net.Uri
 import android.view.View
+import androidx.core.view.drawToBitmap
 import androidx.core.view.isVisible
 import androidx.lifecycle.LifecycleOwner
 import com.davemorrissey.labs.subscaleview.ImageSource
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
+import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView.Companion.preferredBitmapConfig
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.model.ZoomMode
@@ -84,6 +86,7 @@ open class PageHolder(
 			binding.ssiv.height / binding.ssiv.sHeight.toFloat(),
 		)
 		binding.ssiv.colorFilter = settings.colorFilter?.toColorFilter()
+		settings.enhancedColorsMode()
 		when (settings.zoomMode) {
 			ZoomMode.FIT_CENTER -> {
 				binding.ssiv.minimumScaleType = SubsamplingScaleImageView.SCALE_TYPE_CENTER_INSIDE

app/src/main/res/values/strings.xml

@@ -492,4 +492,6 @@
 	<string name="keep_screen_on">Keep screen on</string>
 	<string name="keep_screen_on_summary">Do not turn the screen off while you\'re reading manga</string>
 	<string name="state_abandoned">Dropped</string>
+	<string name="enhanced_colors_summary">Reduces banding, but may impact performance</string>
+	<string name="enhanced_colors">32-bit color mode</string>
 </resources>

app/src/main/res/xml/pref_reader.xml

@@ -54,6 +54,12 @@
 		android:title="@string/pages_animation"
 		app:useSimpleSummaryProvider="true" />
 
+	<SwitchPreferenceCompat
+		android:defaultValue="false"
+		android:key="enhanced_colors"
+		android:summary="@string/enhanced_colors_summary"
+		android:title="@string/enhanced_colors" />
+
 	<SwitchPreferenceCompat
 		android:defaultValue="true"
 		android:key="reader_bar"