0040-Fix-brightness-slider-curve-for-some-devices.patch

From 9fbe4871e5380d0b1366f34f66e69ea723cb0eb5 Mon Sep 17 00:00:00 2001
From: ChonDoit <thphantomblog@gmail.com>
Date: Thu, 24 Aug 2023 15:58:15 -0300
Subject: [PATCH 40/46] Fix brightness slider curve for some devices

Some devices report max brightness as 2047 or 4095
---
 .../settingslib/display/BrightnessUtils.java      | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/packages/SettingsLib/DisplayUtils/src/com/android/settingslib/display/BrightnessUtils.java b/packages/SettingsLib/DisplayUtils/src/com/android/settingslib/display/BrightnessUtils.java
index 66ed10433459..f6820b4436fc 100644
--- a/packages/SettingsLib/DisplayUtils/src/com/android/settingslib/display/BrightnessUtils.java
+++ b/packages/SettingsLib/DisplayUtils/src/com/android/settingslib/display/BrightnessUtils.java
@@ -16,13 +16,18 @@
 
 package com.android.settingslib.display;
 
+import android.os.SystemProperties;
 import android.util.MathUtils;
 
+import com.android.internal.display.BrightnessSynchronizer;
+
 /** Utility methods for calculating the display brightness. */
 public class BrightnessUtils {
 
+    public static final boolean LowGammaBrightness = Boolean.parseBoolean(SystemProperties.get("persist.sys.phh.low_gamma_brightness", "false"));
+
     public static final int GAMMA_SPACE_MIN = 0;
-    public static final int GAMMA_SPACE_MAX = 65535;
+    public static final int GAMMA_SPACE_MAX = LowGammaBrightness ? 255 : 65535;
 
     // Hybrid Log Gamma constant values
     private static final float R = 0.5f;
@@ -88,9 +93,8 @@ public class BrightnessUtils {
         // it shouldn't be out of bounds.
         final float normalizedRet = MathUtils.constrain(ret, 0, 12);
 
-        // Re-normalize to the range [0, 1]
-        // in order to derive the correct setting value.
-        return MathUtils.lerp(min, max, normalizedRet / 12);
+        return LowGammaBrightness ? MathUtils.constrain(BrightnessSynchronizer.brightnessIntToFloat(val),
+                         min, max) : MathUtils.lerp(min, max, normalizedRet / 12);
     }
 
     /**
@@ -137,6 +141,7 @@ public class BrightnessUtils {
             ret = A * MathUtils.log(normalizedVal - B) + C;
         }
 
-        return Math.round(MathUtils.lerp(GAMMA_SPACE_MIN, GAMMA_SPACE_MAX, ret));
+        return LowGammaBrightness ? BrightnessSynchronizer.brightnessFloatToInt(
+                       MathUtils.constrain(val, min, max)) : Math.round(MathUtils.lerp(GAMMA_SPACE_MIN, GAMMA_SPACE_MAX, ret));
     }
 }
-- 
2.34.1