From 703f0277170c7e2d1acaa00b274f6fd479045abd Mon Sep 17 00:00:00 2001
From: tucvbif <47757803+tucvbif@users.noreply.github.com>
Date: Wed, 18 Aug 2021 02:40:00 +0300
Subject: [PATCH] Allow for removal of hysteresis on 4x encoders (#13698)

* Remove hysteresis on 4x encoders

Sometimes, controller skips encoder pulses and when it returns to default position, the encoder_pulses variable isn't equals 0. And when I turn encoder in opposite direciton, it skips first click becase of encoder_pulses crosses zero. To prevent this, I add the ENCODER_DEFAULT_POS constant, and reset encoder_pulses into 0 when the state variable equals ENCODER_DEFAULT_POS.

* Documentation for ENCODER_DEFAULT_POS
---
 docs/feature_encoders.md | 6 ++++++
 quantum/encoder.c        | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/docs/feature_encoders.md b/docs/feature_encoders.md
index a56f093a398..509f55b917e 100644
--- a/docs/feature_encoders.md
+++ b/docs/feature_encoders.md
@@ -38,6 +38,12 @@ It can also be defined per-encoder, by instead defining:
 #define ENCODER_RESOLUTIONS { 4, 2 }
 ```
 
+For 4× encoders you also can assign default position if encoder skips pulses when it changes direction. For example, if your encoder send high level on both pins by default, define this:
+
+```c
+#define ENCODER_DEFAULT_POS 0x3
+```
+
 ## Split Keyboards
 
 If you are using different pinouts for the encoders on each half of a split keyboard, you can define the pinout (and optionally, resolutions) for the right half like this:
diff --git a/quantum/encoder.c b/quantum/encoder.c
index c30bf01cb2f..8fb87281c2b 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -119,6 +119,11 @@ static bool encoder_update(uint8_t index, uint8_t state) {
         encoder_update_kb(index, ENCODER_CLOCKWISE);
     }
     encoder_pulses[i] %= resolution;
+#ifdef ENCODER_DEFAULT_POS
+    if ((state & 0x3) == ENCODER_DEFAULT_POS) {
+        encoder_pulses[i] = 0;
+    }
+#endif
     return changed;
 }