From 778a6b6ccda03ee9aac808257b5ac1db212811a7 Mon Sep 17 00:00:00 2001
From: althafvly <althafvly@gmail.com>
Date: Tue, 16 Nov 2021 12:08:22 +0530
Subject: [PATCH] sweet: overlay: Configure RefreshRate brightness thresholds

The display uses different gamma curves for different refresh rates.
It's hard for panel vendor to tune the curves to have exact same brightness
for different refresh rate (lazy). To avoid flicker at darker environment,
set threshold for 120Hz, so 120Hz will be default in such conditions.

- values kanged from redfin, it works for our panel fine

Change-Id: Ie2042aa5d7b114c006841e1cd86c3257653242be
---
 .../base/core/res/res/values/config.xml       | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/overlay/frameworks/base/core/res/res/values/config.xml b/overlay/frameworks/base/core/res/res/values/config.xml
index 1a5fa21..a09508a 100644
--- a/overlay/frameworks/base/core/res/res/values/config.xml
+++ b/overlay/frameworks/base/core/res/res/values/config.xml
@@ -326,6 +326,28 @@
         <item>21</item>
     </integer-array>
 
+    <!-- The display uses different gamma curves for different refresh rates. It's hard for panel
+         vendor to tune the curves to have exact same brightness for different refresh rate. So
+         flicker could be observed at switch time. The issue is worse at the gamma lower end.
+         In addition, human eyes are more sensitive to the flicker at darker environment.
+         To prevent flicker, we only support higher refresh rates if the display brightness is above
+         a threshold. And the darker environment could have higher threshold.
+         For example, no higher refresh rate if
+             display brightness <= disp0 && ambient brightness <= amb0
+             || display brightness <= disp1 && ambient brightness <= amb1 -->
+    <integer-array name="config_brightnessThresholdsOfPeakRefreshRate">
+        <item>10</item> <!-- 33% UI brightness -->
+        <item>14</item> <!-- 40% UI brightness -->
+    </integer-array>
+    <integer-array name="config_ambientThresholdsOfPeakRefreshRate">
+        <item>-1</item>
+        <item>20</item>
+    </integer-array>
+
+    <!-- Default refresh rate in the zone defined by brightness and ambient thresholds.
+         If non-positive, then the refresh rate is unchanged even if thresholds are configured. -->
+    <integer name="config_defaultRefreshRateInZone">120</integer>
+
     <!-- Vibrator pattern for feedback about touching a virtual key -->
     <integer-array name="config_virtualKeyVibePattern">
         <item>0</item>