From 74fbdfa044fe06992191aebb3c0d2f03c97f9f32 Mon Sep 17 00:00:00 2001
From: Nick Deakin <deakin@google.com>
Date: Tue, 25 Apr 2023 17:47:39 -0400
Subject: SilkFX: add gainmap metadata testing

Add the ability to test adjustments to the gainmap metadata and compare
to the original metadata.

Bug: 279647216
Test: Played with new gainmap metadata menu; working as intended
Change-Id: Icec81a693e03c1cf2d4a854b06ebdfb05565b518
---
 tests/SilkFX/res/layout/gainmap_image.xml          |  33 ++-
 tests/SilkFX/res/layout/gainmap_metadata.xml       | 264 +++++++++++++++++++
 .../com/android/test/silkfx/hdr/GainmapImage.kt    |  20 +-
 .../test/silkfx/hdr/GainmapMetadataEditor.kt       | 284 +++++++++++++++++++++
 4 files changed, 593 insertions(+), 8 deletions(-)
 create mode 100644 tests/SilkFX/res/layout/gainmap_metadata.xml
 create mode 100644 tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapMetadataEditor.kt

diff --git a/tests/SilkFX/res/layout/gainmap_image.xml b/tests/SilkFX/res/layout/gainmap_image.xml
index 89bbb709d0bf..b0ed9147585e 100644
--- a/tests/SilkFX/res/layout/gainmap_image.xml
+++ b/tests/SilkFX/res/layout/gainmap_image.xml
@@ -34,7 +34,7 @@
                          android:layout_width="wrap_content"
                          android:layout_weight="1"
                          android:layout_height="wrap_content"
-                         android:text="SDR original" />
+                         android:text="SDR" />
 
             <RadioButton android:id="@+id/output_gainmap"
                          android:layout_width="wrap_content"
@@ -46,13 +46,34 @@
                          android:layout_width="wrap_content"
                          android:layout_weight="1"
                          android:layout_height="wrap_content"
-                         android:text="HDR (sdr+gainmap)" />
+                         android:text="HDR" />
+
+            <RadioButton android:id="@+id/output_hdr_test"
+                         android:layout_width="wrap_content"
+                         android:layout_weight="1"
+                         android:layout_height="wrap_content"
+                         android:text="HDR (test)" />
         </RadioGroup>
 
-        <Spinner
-            android:id="@+id/image_selection"
+        <LinearLayout
             android:layout_width="match_parent"
-            android:layout_height="wrap_content" />
+            android:layout_height="wrap_content"
+            android:orientation="horizontal">
+
+            <Spinner
+                android:id="@+id/image_selection"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content" />
+
+            <Button
+                android:id="@+id/gainmap_metadata"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Gainmap Metadata..." />
+
+        </LinearLayout>
 
         <TextView
             android:id="@+id/error_msg"
@@ -67,4 +88,4 @@
 
     </LinearLayout>
 
-</com.android.test.silkfx.hdr.GainmapImage>
\ No newline at end of file
+</com.android.test.silkfx.hdr.GainmapImage>
diff --git a/tests/SilkFX/res/layout/gainmap_metadata.xml b/tests/SilkFX/res/layout/gainmap_metadata.xml
new file mode 100644
index 000000000000..0dabaca457f0
--- /dev/null
+++ b/tests/SilkFX/res/layout/gainmap_metadata.xml
@@ -0,0 +1,264 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2023 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<RelativeLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content">
+
+    <LinearLayout
+        android:layout_width="350dp"
+        android:layout_height="300dp"
+        android:layout_centerHorizontal="true"
+        android:padding="8dp"
+        android:orientation="vertical"
+        android:background="#444444">
+
+        <TextView
+            android:id="@+id/gainmap_metadata_title"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:text="Metadata for &quot;HDR (test)&quot; (values in linear space):" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:orientation="horizontal">
+
+            <TextView
+                android:id="@+id/gainmap_metadata_gainmapmin_text"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Gain Map Min:" />
+
+            <TextView
+                android:id="@+id/gainmap_metadata_gainmapmin_val"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:ems="4"
+                android:text="TODO" />
+
+            <SeekBar
+                android:id="@+id/gainmap_metadata_gainmapmin"
+                android:min="0"
+                android:max="100"
+                android:layout_width="150dp"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:orientation="horizontal">
+
+            <TextView
+                android:id="@+id/gainmap_metadata_gainmapmax_text"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Gain Map Max:" />
+
+            <TextView
+                android:id="@+id/gainmap_metadata_gainmapmax_val"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:ems="4"
+                android:text="TODO" />
+
+            <SeekBar
+                android:id="@+id/gainmap_metadata_gainmapmax"
+                android:min="0"
+                android:max="100"
+                android:layout_width="150dp"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:orientation="horizontal">
+
+            <TextView
+                android:id="@+id/gainmap_metadata_capacitymin_text"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Capacity Min:" />
+
+            <TextView
+                android:id="@+id/gainmap_metadata_capacitymin_val"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:ems="4"
+                android:text="TODO" />
+
+            <SeekBar
+                android:id="@+id/gainmap_metadata_capacitymin"
+                android:min="0"
+                android:max="100"
+                android:layout_width="150dp"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:orientation="horizontal">
+
+            <TextView
+                android:id="@+id/gainmap_metadata_capacitymax_text"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Capacity Max:" />
+
+            <TextView
+                android:id="@+id/gainmap_metadata_capacitymax_val"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:ems="4"
+                android:text="TODO" />
+
+            <SeekBar
+                android:id="@+id/gainmap_metadata_capacitymax"
+                android:min="0"
+                android:max="100"
+                android:layout_width="150dp"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:orientation="horizontal">
+
+            <TextView
+                android:id="@+id/gainmap_metadata_gamma_text"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Gamma:" />
+
+            <TextView
+                android:id="@+id/gainmap_metadata_gamma_val"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:ems="4"
+                android:text="TODO" />
+
+            <SeekBar
+                android:id="@+id/gainmap_metadata_gamma"
+                android:min="0"
+                android:max="100"
+                android:layout_width="150dp"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:orientation="horizontal">
+
+            <TextView
+                android:id="@+id/gainmap_metadata_offsetsdr_text"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Offset SDR:" />
+
+            <TextView
+                android:id="@+id/gainmap_metadata_offsetsdr_val"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:ems="4"
+                android:text="TODO" />
+
+            <SeekBar
+                android:id="@+id/gainmap_metadata_offsetsdr"
+                android:min="0"
+                android:max="100"
+                android:layout_width="150dp"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:orientation="horizontal">
+
+            <TextView
+                android:id="@+id/gainmap_metadata_offsethdr_text"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Offset HDR:" />
+
+            <TextView
+                android:id="@+id/gainmap_metadata_offsethdr_val"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:ems="4"
+                android:text="TODO" />
+
+            <SeekBar
+                android:id="@+id/gainmap_metadata_offsethdr"
+                android:min="0"
+                android:max="100"
+                android:layout_width="150dp"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal">
+
+            <Button
+                android:id="@+id/gainmap_metadata_reset"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Reset" />
+
+            <Button
+                android:id="@+id/gainmap_metadata_done"
+                android:layout_width="match_parent"
+                android:layout_weight="1"
+                android:layout_height="wrap_content"
+                android:text="Done" />
+
+        </LinearLayout>
+
+    </LinearLayout>
+
+</RelativeLayout>
diff --git a/tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapImage.kt b/tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapImage.kt
index 78bc4c45fa4f..7cf69b7780d9 100644
--- a/tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapImage.kt
+++ b/tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapImage.kt
@@ -27,6 +27,7 @@ import android.util.AttributeSet
 import android.view.View
 import android.widget.AdapterView
 import android.widget.ArrayAdapter
+import android.widget.Button
 import android.widget.FrameLayout
 import android.widget.RadioGroup
 import android.widget.Spinner
@@ -44,6 +45,7 @@ class GainmapImage(context: Context, attrs: AttributeSet?) : FrameLayout(context
     private var gainmap: Gainmap? = null
     private var gainmapVisualizer: Bitmap? = null
     private lateinit var imageView: SubsamplingScaleImageView
+    private lateinit var gainmapMetadataEditor: GainmapMetadataEditor
 
     init {
         gainmapImages = context.assets.list("gainmaps")!!
@@ -58,6 +60,7 @@ class GainmapImage(context: Context, attrs: AttributeSet?) : FrameLayout(context
         super.onFinishInflate()
 
         imageView = findViewById(R.id.image)!!
+        gainmapMetadataEditor = GainmapMetadataEditor(this, imageView)
 
         findViewById<RadioGroup>(R.id.output_mode)!!.also {
             it.check(outputMode)
@@ -92,6 +95,10 @@ class GainmapImage(context: Context, attrs: AttributeSet?) : FrameLayout(context
             }
         }
 
+        findViewById<Button>(R.id.gainmap_metadata)!!.setOnClickListener {
+            gainmapMetadataEditor.openEditor()
+        }
+
         setImage(0)
 
         imageView.apply {
@@ -132,6 +139,7 @@ class GainmapImage(context: Context, attrs: AttributeSet?) : FrameLayout(context
             findViewById<RadioGroup>(R.id.output_mode)!!.visibility = View.VISIBLE
 
             gainmap = bitmap!!.gainmap
+            gainmapMetadataEditor.setGainmap(gainmap)
             val map = gainmap!!.gainmapContents
             if (map.config != Bitmap.Config.ALPHA_8) {
                 gainmapVisualizer = map
@@ -175,7 +183,15 @@ class GainmapImage(context: Context, attrs: AttributeSet?) : FrameLayout(context
 
         imageView.setImage(ImageSource.cachedBitmap(when (outputMode) {
             R.id.output_hdr -> {
-                bitmap!!.gainmap = gainmap; bitmap!!
+                gainmapMetadataEditor.useOriginalMetadata()
+                bitmap!!.gainmap = gainmap
+                bitmap!!
+            }
+
+            R.id.output_hdr_test -> {
+                gainmapMetadataEditor.useEditMetadata()
+                bitmap!!.gainmap = gainmap
+                bitmap!!
             }
 
             R.id.output_sdr -> {
@@ -186,4 +202,4 @@ class GainmapImage(context: Context, attrs: AttributeSet?) : FrameLayout(context
             else -> throw IllegalStateException()
         }))
     }
-}
\ No newline at end of file
+}
diff --git a/tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapMetadataEditor.kt b/tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapMetadataEditor.kt
new file mode 100644
index 000000000000..8a653045c97b
--- /dev/null
+++ b/tests/SilkFX/src/com/android/test/silkfx/hdr/GainmapMetadataEditor.kt
@@ -0,0 +1,284 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.test.silkfx.hdr
+
+import android.graphics.Gainmap
+import android.view.Gravity
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.Button
+import android.widget.PopupWindow
+import android.widget.SeekBar
+import android.widget.TextView
+import com.android.test.silkfx.R
+
+data class GainmapMetadata(
+    var ratioMin: Float,
+    var ratioMax: Float,
+    var capacityMin: Float,
+    var capacityMax: Float,
+    var gamma: Float,
+    var offsetSdr: Float,
+    var offsetHdr: Float
+)
+
+class GainmapMetadataEditor(val parent: ViewGroup, val renderView: View) {
+    private var gainmap: Gainmap? = null
+    private var showingEdits = false
+
+    private var metadataPopup: PopupWindow? = null
+
+    private var originalMetadata: GainmapMetadata = GainmapMetadata(
+        1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f)
+    private var currentMetadata: GainmapMetadata = originalMetadata.copy()
+
+    private val maxProgress = 100.0f
+
+    private val minRatioMin = .001f
+    private val maxRatioMin = 1.0f
+    private val minRatioMax = 1.0f
+    private val maxRatioMax = 16.0f
+    private val minCapacityMin = 1.0f
+    private val maxCapacityMin = maxRatioMax
+    private val minCapacityMax = 1.001f
+    private val maxCapacityMax = maxRatioMax
+    private val minGamma = 0.1f
+    private val maxGamma = 3.0f
+    // Min and max offsets are 0.0 and 1.0 respectively
+
+    fun setGainmap(newGainmap: Gainmap?) {
+        gainmap = newGainmap
+        originalMetadata = GainmapMetadata(gainmap!!.getRatioMin()[0],
+            gainmap!!.getRatioMax()[0], gainmap!!.getMinDisplayRatioForHdrTransition(),
+            gainmap!!.getDisplayRatioForFullHdr(), gainmap!!.getGamma()[0],
+            gainmap!!.getEpsilonSdr()[0], gainmap!!.getEpsilonHdr()[0])
+        currentMetadata = originalMetadata.copy()
+    }
+
+    fun useOriginalMetadata() {
+        showingEdits = false
+        applyMetadata(originalMetadata)
+    }
+
+    fun useEditMetadata() {
+        showingEdits = true
+        applyMetadata(currentMetadata)
+    }
+
+    fun closeEditor() {
+        metadataPopup?.let {
+            it.dismiss()
+            metadataPopup = null
+        }
+    }
+
+    fun openEditor() {
+        if (metadataPopup != null) return
+
+        val view = LayoutInflater.from(parent.getContext()).inflate(R.layout.gainmap_metadata, null)
+
+        metadataPopup = PopupWindow(view, ViewGroup.LayoutParams.WRAP_CONTENT,
+            ViewGroup.LayoutParams.WRAP_CONTENT)
+        metadataPopup!!.showAtLocation(view, Gravity.CENTER, 0, 0)
+
+        (view.getParent() as ViewGroup).removeView(view)
+        parent.addView(view)
+
+        view.findViewById<Button>(R.id.gainmap_metadata_done)!!.setOnClickListener {
+            closeEditor()
+        }
+
+        view.findViewById<Button>(R.id.gainmap_metadata_reset)!!.setOnClickListener {
+            resetGainmapMetadata()
+        }
+
+        updateMetadataUi()
+
+        val gainmapMinSeek = view.findViewById<SeekBar>(R.id.gainmap_metadata_gainmapmin)
+        val gainmapMaxSeek = view.findViewById<SeekBar>(R.id.gainmap_metadata_gainmapmax)
+        val capacityMinSeek = view.findViewById<SeekBar>(R.id.gainmap_metadata_capacitymin)
+        val capacityMaxSeek = view.findViewById<SeekBar>(R.id.gainmap_metadata_capacitymax)
+        val gammaSeek = view.findViewById<SeekBar>(R.id.gainmap_metadata_gamma)
+        val offsetSdrSeek = view.findViewById<SeekBar>(R.id.gainmap_metadata_offsetsdr)
+        val offsetHdrSeek = view.findViewById<SeekBar>(R.id.gainmap_metadata_offsethdr)
+        arrayOf(gainmapMinSeek, gainmapMaxSeek, capacityMinSeek, capacityMaxSeek, gammaSeek,
+            offsetSdrSeek, offsetHdrSeek).forEach {
+            it.setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener{
+                override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {
+                    if (!fromUser) return
+                    val normalized = progress.toFloat() / maxProgress
+                    when (seekBar) {
+                        gainmapMinSeek -> updateGainmapMin(normalized)
+                        gainmapMaxSeek -> updateGainmapMax(normalized)
+                        capacityMinSeek -> updateCapacityMin(normalized)
+                        capacityMaxSeek -> updateCapacityMax(normalized)
+                        gammaSeek -> updateGamma(normalized)
+                        offsetSdrSeek -> updateOffsetSdr(normalized)
+                        offsetHdrSeek -> updateOffsetHdr(normalized)
+                    }
+                }
+
+                override fun onStartTrackingTouch(seekBar: SeekBar) {}
+                override fun onStopTrackingTouch(seekBar: SeekBar) {}
+            })
+        }
+    }
+
+    private fun updateMetadataUi() {
+        val gainmapMinSeek = parent.findViewById<SeekBar>(R.id.gainmap_metadata_gainmapmin)
+        val gainmapMaxSeek = parent.findViewById<SeekBar>(R.id.gainmap_metadata_gainmapmax)
+        val capacityMinSeek = parent.findViewById<SeekBar>(R.id.gainmap_metadata_capacitymin)
+        val capacityMaxSeek = parent.findViewById<SeekBar>(R.id.gainmap_metadata_capacitymax)
+        val gammaSeek = parent.findViewById<SeekBar>(R.id.gainmap_metadata_gamma)
+        val offsetSdrSeek = parent.findViewById<SeekBar>(R.id.gainmap_metadata_offsetsdr)
+        val offsetHdrSeek = parent.findViewById<SeekBar>(R.id.gainmap_metadata_offsethdr)
+
+        gainmapMinSeek.setProgress(
+            ((currentMetadata.ratioMin - minRatioMin) / maxRatioMin * maxProgress).toInt())
+        gainmapMaxSeek.setProgress(
+            ((currentMetadata.ratioMax - minRatioMax) / maxRatioMax * maxProgress).toInt())
+        capacityMinSeek.setProgress(
+            ((currentMetadata.capacityMin - minCapacityMin) / maxCapacityMin * maxProgress).toInt())
+        capacityMaxSeek.setProgress(
+            ((currentMetadata.capacityMax - minCapacityMax) / maxCapacityMax * maxProgress).toInt())
+        gammaSeek.setProgress(
+            ((currentMetadata.gamma - minGamma) / maxGamma * maxProgress).toInt())
+        // Log base 3 via: log_b(x) = log_y(x) / log_y(b)
+        offsetSdrSeek.setProgress(
+            ((1.0 - Math.log(currentMetadata.offsetSdr.toDouble() / Math.log(3.0)) / -11.0)
+             .toFloat() * maxProgress).toInt())
+        offsetHdrSeek.setProgress(
+            ((1.0 - Math.log(currentMetadata.offsetHdr.toDouble() / Math.log(3.0)) / -11.0)
+             .toFloat() * maxProgress).toInt())
+
+        parent.findViewById<TextView>(R.id.gainmap_metadata_gainmapmin_val)!!.setText(
+            "%.3f".format(currentMetadata.ratioMin))
+        parent.findViewById<TextView>(R.id.gainmap_metadata_gainmapmax_val)!!.setText(
+            "%.3f".format(currentMetadata.ratioMax))
+        parent.findViewById<TextView>(R.id.gainmap_metadata_capacitymin_val)!!.setText(
+            "%.3f".format(currentMetadata.capacityMin))
+        parent.findViewById<TextView>(R.id.gainmap_metadata_capacitymax_val)!!.setText(
+            "%.3f".format(currentMetadata.capacityMax))
+        parent.findViewById<TextView>(R.id.gainmap_metadata_gamma_val)!!.setText(
+            "%.3f".format(currentMetadata.gamma))
+        parent.findViewById<TextView>(R.id.gainmap_metadata_offsetsdr_val)!!.setText(
+            "%.5f".format(currentMetadata.offsetSdr))
+        parent.findViewById<TextView>(R.id.gainmap_metadata_offsethdr_val)!!.setText(
+            "%.5f".format(currentMetadata.offsetHdr))
+    }
+
+    private fun resetGainmapMetadata() {
+        currentMetadata = originalMetadata.copy()
+        applyMetadata(currentMetadata)
+        updateMetadataUi()
+    }
+
+    private fun applyMetadata(newMetadata: GainmapMetadata) {
+        gainmap!!.setRatioMin(newMetadata.ratioMin, newMetadata.ratioMin, newMetadata.ratioMin)
+        gainmap!!.setRatioMax(newMetadata.ratioMax, newMetadata.ratioMax, newMetadata.ratioMax)
+        gainmap!!.setMinDisplayRatioForHdrTransition(newMetadata.capacityMin)
+        gainmap!!.setDisplayRatioForFullHdr(newMetadata.capacityMax)
+        gainmap!!.setGamma(newMetadata.gamma, newMetadata.gamma, newMetadata.gamma)
+        gainmap!!.setEpsilonSdr(newMetadata.offsetSdr, newMetadata.offsetSdr, newMetadata.offsetSdr)
+        gainmap!!.setEpsilonHdr(newMetadata.offsetHdr, newMetadata.offsetHdr, newMetadata.offsetHdr)
+        renderView.invalidate()
+    }
+
+    private fun updateGainmapMin(normalized: Float) {
+        val newValue = minRatioMin + normalized * (maxRatioMin - minRatioMin)
+        parent.findViewById<TextView>(R.id.gainmap_metadata_gainmapmin_val)!!.setText(
+            "%.3f".format(newValue))
+        currentMetadata.ratioMin = newValue
+        if (showingEdits) {
+            gainmap!!.setRatioMin(newValue, newValue, newValue)
+            renderView.invalidate()
+        }
+    }
+
+    private fun updateGainmapMax(normalized: Float) {
+        val newValue = minRatioMax + normalized * (maxRatioMax - minRatioMax)
+        parent.findViewById<TextView>(R.id.gainmap_metadata_gainmapmax_val)!!.setText(
+            "%.3f".format(newValue))
+        currentMetadata.ratioMax = newValue
+        if (showingEdits) {
+            gainmap!!.setRatioMax(newValue, newValue, newValue)
+            renderView.invalidate()
+        }
+    }
+
+    private fun updateCapacityMin(normalized: Float) {
+        val newValue = minCapacityMin + normalized * (maxCapacityMin - minCapacityMin)
+        parent.findViewById<TextView>(R.id.gainmap_metadata_capacitymin_val)!!.setText(
+            "%.3f".format(newValue))
+        currentMetadata.capacityMin = newValue
+        if (showingEdits) {
+            gainmap!!.setMinDisplayRatioForHdrTransition(newValue)
+            renderView.invalidate()
+        }
+    }
+
+    private fun updateCapacityMax(normalized: Float) {
+        val newValue = minCapacityMax + normalized * (maxCapacityMax - minCapacityMax)
+        parent.findViewById<TextView>(R.id.gainmap_metadata_capacitymax_val)!!.setText(
+            "%.3f".format(newValue))
+        currentMetadata.capacityMax = newValue
+        if (showingEdits) {
+            gainmap!!.setDisplayRatioForFullHdr(newValue)
+            renderView.invalidate()
+        }
+    }
+
+    private fun updateGamma(normalized: Float) {
+        val newValue = minGamma + normalized * (maxGamma - minGamma)
+        parent.findViewById<TextView>(R.id.gainmap_metadata_gamma_val)!!.setText(
+            "%.3f".format(newValue))
+        currentMetadata.gamma = newValue
+        if (showingEdits) {
+            gainmap!!.setGamma(newValue, newValue, newValue)
+            renderView.invalidate()
+        }
+    }
+
+    private fun updateOffsetSdr(normalized: Float) {
+        var newValue = 0.0f
+        if (normalized > 0.0f ) {
+            newValue = Math.pow(3.0, (1.0 - normalized.toDouble()) * -11.0).toFloat()
+        }
+        parent.findViewById<TextView>(R.id.gainmap_metadata_offsetsdr_val)!!.setText(
+            "%.5f".format(newValue))
+        currentMetadata.offsetSdr = newValue
+        if (showingEdits) {
+            gainmap!!.setEpsilonSdr(newValue, newValue, newValue)
+            renderView.invalidate()
+        }
+    }
+
+    private fun updateOffsetHdr(normalized: Float) {
+        var newValue = 0.0f
+        if (normalized > 0.0f ) {
+            newValue = Math.pow(3.0, (1.0 - normalized.toDouble()) * -11.0).toFloat()
+        }
+        parent.findViewById<TextView>(R.id.gainmap_metadata_offsethdr_val)!!.setText(
+            "%.5f".format(newValue))
+        currentMetadata.offsetHdr = newValue
+        if (showingEdits) {
+            gainmap!!.setEpsilonHdr(newValue, newValue, newValue)
+            renderView.invalidate()
+        }
+    }
+}
-- 
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