From 1db9de390a331a7d55c35591c93d9e89184cce5f Mon Sep 17 00:00:00 2001
From: eds-collabora <88155680+eds-collabora@users.noreply.github.com>
Date: Fri, 21 Jan 2022 07:38:30 +0000
Subject: [PATCH] Fixes for driving mode changes (#866)

- Use a float divisor to reduce the high resolution counter to a gray
  code. This gives a more stable rate of change for the gray code when
  using a sensitivity other than 1.
- Slightly remap the axis space, so that the positive and negative
  ranges are the same. The new range is [64,-1] [1, 64]. We don't need
  zero, because of the analog dead zone.
- Reorder the Event enum as suggested for on PR860.
---
 src/emucore/Driving.cxx | 10 +++++-----
 src/emucore/Event.hxx   |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/emucore/Driving.cxx b/src/emucore/Driving.cxx
index 2dba825fb..32d94c7f3 100644
--- a/src/emucore/Driving.cxx
+++ b/src/emucore/Driving.cxx
@@ -124,15 +124,15 @@ void Driving::updateControllerAxes()
   int a_axis = myEvent.get(myAnalogEvent);
 
   if( abs(a_axis) > Controller::analogDeadZone()) {
-    /* a_axis is in -2^15 to +2^15-1; dividing by 2^9 gives us -2^6 to
-       +2^6-1, which gives us roughly the same range as digital
-       inputs.
+    /* a_axis is in -2^15 to +2^15-1; adding 1 when non-negative and
+       dividing by 2^9 gives us -2^6 to +2^6, which gives us the same
+       range as digital inputs.
     */
-    myCounterHires += a_axis/512;
+    myCounterHires += (a_axis/512) + (a_axis >= 0);
   }
 
   // Only consider the lower-most bits (corresponding to pins 1 & 2)
-  myGrayIndex = Int32((myCounterHires / 256) * SENSITIVITY) & 0b11;
+  myGrayIndex = Int32((myCounterHires / 256.0) * SENSITIVITY) & 0b11;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
diff --git a/src/emucore/Event.hxx b/src/emucore/Event.hxx
index bbde53729..1b01cf729 100644
--- a/src/emucore/Event.hxx
+++ b/src/emucore/Event.hxx
@@ -183,7 +183,7 @@ class Event
     enum Group
     {
       Menu, Emulation,
-      Misc, AudioVideo, States, Console, Joystick, Paddles, Keyboard, Driving,
+      Misc, AudioVideo, States, Console, Joystick, Paddles, Driving, Keyboard,
       Devices,
       Debug, Combo,
       LastGroup