idzio/shifter.c: Factor out shifter sim logic

idzio/meson.build

@@ -12,6 +12,8 @@ idzio_dll = shared_library(
         'backend.h',
         'dllmain.c',
         'idzio.h',
+        'shifter.c',
+        'shifter.h',
         'xi.c',
         'xi.h',
     ],

idzio/shifter.c

@@ -0,0 +1,32 @@
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "idzio/shifter.h"
+
+static bool idz_shifter_shifting;
+static uint8_t idz_shifter_gear;
+
+void idz_shifter_reset(void)
+{
+    idz_shifter_gear = 0;
+}
+
+void idz_shifter_update(bool shift_dn, bool shift_up)
+{
+    if (!idz_shifter_shifting) {
+        if (shift_dn && idz_shifter_gear > 0) {
+            idz_shifter_gear--;
+        }
+
+        if (shift_up && idz_shifter_gear < 6) {
+            idz_shifter_gear++;
+        }
+    }
+
+    idz_shifter_shifting = shift_dn || shift_up;
+}
+
+uint8_t idz_shifter_current_gear(void)
+{
+    return idz_shifter_gear;
+}

idzio/shifter.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+void idz_shifter_reset(void);
+void idz_shifter_update(bool shift_dn, bool shift_up);
+uint8_t idz_shifter_current_gear(void);

idzio/xi.c

@@ -7,6 +7,7 @@
 
 #include "idzio/backend.h"
 #include "idzio/idzio.h"
+#include "idzio/shifter.h"
 #include "idzio/xi.h"
 
 #include "util/dprintf.h"
@@ -21,9 +22,6 @@ static const struct idz_io_backend idz_xi_backend = {
     .jvs_read_analogs   = idz_xi_jvs_read_analogs,
 };
 
-static bool idz_xi_shifting;
-static uint8_t idz_xi_gear;
-
 HRESULT idz_xi_init(const struct idz_io_backend **backend)
 {
     assert(backend != NULL);
@@ -77,8 +75,8 @@ static void idz_xi_jvs_read_buttons(uint8_t *gamebtn_out)
 
 static void idz_xi_jvs_read_shifter(uint8_t *gear)
 {
-    bool shift_inc;
-    bool shift_dec;
+    bool shift_dn;
+    bool shift_up;
     XINPUT_STATE xi;
     WORD xb;
 
@@ -89,24 +87,16 @@ static void idz_xi_jvs_read_shifter(uint8_t *gear)
     xb = xi.Gamepad.wButtons;
 
     if (xb & XINPUT_GAMEPAD_START) {
-        idz_xi_gear = 0; /* Reset to Neutral when start is pressed */
+        /* Reset to Neutral when start is pressed */
+        idz_shifter_reset();
     }
 
-    shift_inc = xb & (XINPUT_GAMEPAD_X | XINPUT_GAMEPAD_RIGHT_SHOULDER);
-    shift_dec = xb & (XINPUT_GAMEPAD_Y | XINPUT_GAMEPAD_LEFT_SHOULDER);
+    shift_dn = xb & (XINPUT_GAMEPAD_Y | XINPUT_GAMEPAD_LEFT_SHOULDER);
+    shift_up = xb & (XINPUT_GAMEPAD_X | XINPUT_GAMEPAD_RIGHT_SHOULDER);
 
-    if (!idz_xi_shifting) {
-        if (shift_inc && idz_xi_gear < 6) {
-            idz_xi_gear++;
-        }
+    idz_shifter_update(shift_dn, shift_up);
 
-        if (shift_dec && idz_xi_gear > 0) {
-            idz_xi_gear--;
-        }
-    }
-
-    idz_xi_shifting = shift_inc || shift_dec;
-    *gear = idz_xi_gear;
+    *gear = idz_shifter_current_gear();
 }
 
 static void idz_xi_jvs_read_analogs(struct idz_io_analog_state *out)