Fix various issues with NintendoSwitchBackend

.github/workflows/build-device-config.yml

@@ -34,7 +34,7 @@ jobs:
       BIN_EXT: ${{ matrix.bin_ext }}
     strategy:
       fail-fast: false
-      matrix: 
+      matrix:
         include: ${{ fromJson(needs.metadata.outputs.meta_json).build }}
 
     steps:

HAL/pico/include/comms/NintendoSwitchBackend.hpp

@@ -55,7 +55,7 @@ class NintendoSwitchBackend : public CommunicationBackend {
 
   protected:
     static const uint8_t _report_id = 0;
-    static uint8_t _descriptor[];
+    static const uint8_t _descriptor[];
 
     switch_gamepad_report_t _report;
 

HAL/pico/src/comms/NintendoSwitchBackend.cpp

@@ -2,6 +2,7 @@
 
 #include "core/CommunicationBackend.hpp"
 #include "core/state.hpp"
+#include "util/analog_filters.hpp"
 
 #include <Adafruit_TinyUSB.h>
 #include <TUCompositeHID.hpp>
@@ -61,7 +62,10 @@
 
 // clang-format on
 
-uint8_t NintendoSwitchBackend::_descriptor[] = { HID_REPORT_DESC() };
+const uint8_t NintendoSwitchBackend::_descriptor[] = { HID_REPORT_DESC() };
+
+const uint8_t DEADZONE = 11;
+const int RADIUS = 256;
 
 NintendoSwitchBackend::NintendoSwitchBackend(
     InputState &inputs,
@@ -139,10 +143,10 @@ void NintendoSwitchBackend::SendReport() {
     _report.home = _outputs.home;
 
     // Analog outputs
-    _report.lx = (_outputs.leftStickX - 128) * 1.25 + 128;
-    _report.ly = 255 - ((_outputs.leftStickY - 128) * 1.25 + 128);
-    _report.rx = (_outputs.rightStickX - 128) * 1.25 + 128;
-    _report.ry = 255 - ((_outputs.rightStickY - 128) * 1.25 + 128);
+    _report.lx = apply_radius(apply_deadzone(_outputs.leftStickX, DEADZONE, true), RADIUS);
+    _report.ly = 255 - apply_radius(apply_deadzone(_outputs.leftStickY, DEADZONE, true), RADIUS);
+    _report.rx = apply_radius(apply_deadzone(_outputs.rightStickX, DEADZONE, true), RADIUS);
+    _report.ry = 255 - apply_radius(apply_deadzone(_outputs.rightStickY, DEADZONE, true), RADIUS);
 
     // D-pad Hat Switch
     _report.hat =

include/util/analog_filters.hpp

@@ -0,0 +1,9 @@
+#ifndef _UTIL_ANALOG_FILTERS_HPP
+#define _UTIL_ANALOG_FILTERS_HPP
+
+#include "stdlib.hpp"
+
+uint8_t apply_deadzone(uint8_t value, uint8_t deadzone, bool scale);
+uint8_t apply_radius(uint8_t value, int radius);
+
+#endif

lib/TUCompositeHID/include/TUCompositeHID.hpp

@@ -7,7 +7,7 @@
 namespace TUCompositeHID {
     extern Adafruit_USBD_HID _usb_hid;
 
-    bool addDescriptor(uint8_t *descriptor, size_t descriptor_len);
+    bool addDescriptor(const uint8_t *descriptor, size_t descriptor_len);
 }
 
 #endif

lib/TUCompositeHID/include/TUGamepad.hpp

@@ -67,7 +67,7 @@ class TUGamepad {
 
   protected:
     static const uint8_t _report_id = 1;
-    static uint8_t _descriptor[];
+    static const uint8_t _descriptor[];
 
     gamepad_report_t _report;
 

lib/TUCompositeHID/include/TUKeyboard.hpp

@@ -20,7 +20,7 @@ class TUKeyboard {
 
   private:
     static const uint8_t _report_id = 2;
-    static uint8_t _descriptor[];
+    static const uint8_t _descriptor[];
 
     hid_keyboard_report_t _report;
 };

lib/TUCompositeHID/src/TUCompositeHID.cpp

@@ -16,7 +16,7 @@ namespace TUCompositeHID {
         false
     );
 
-    bool addDescriptor(uint8_t *descriptor, size_t descriptor_len) {
+    bool addDescriptor(const uint8_t *descriptor, size_t descriptor_len) {
         if (_current_descriptor_len + descriptor_len > HID_DESCRIPTOR_BUFSIZE) {
             return false;
         }

lib/TUCompositeHID/src/TUGamepad.cpp

@@ -71,7 +71,7 @@ SOFTWARE.
 
 // clang-format on
 
-uint8_t TUGamepad::_descriptor[] = { HID_REPORT_DESC(HID_REPORT_ID(_report_id)) };
+const uint8_t TUGamepad::_descriptor[] = { HID_REPORT_DESC(HID_REPORT_ID(_report_id)) };
 
 TUGamepad::TUGamepad() {}
 

lib/TUCompositeHID/src/TUKeyboard.cpp

@@ -3,7 +3,9 @@
 #include <Adafruit_TinyUSB.h>
 #include <TUCompositeHID.hpp>
 
-uint8_t TUKeyboard::_descriptor[] = { TUD_HID_REPORT_DESC_KEYBOARD(HID_REPORT_ID(_report_id)) };
+// clang-format off
+const uint8_t TUKeyboard::_descriptor[] = { TUD_HID_REPORT_DESC_KEYBOARD(HID_REPORT_ID(_report_id)) };
+// clang-format on
 
 #define MODIFIER_MASK(mod_kc) (1 << (mod_kc & 0x0F))
 

src/util/analog_filters.cpp

@@ -0,0 +1,29 @@
+#include "util/analog_filters.hpp"
+
+#include <math.h>
+
+#define SIGNUM(x) ((x > 0) - (x < 0))
+
+uint8_t apply_deadzone(uint8_t value, uint8_t deadzone, bool scale) {
+    int8_t value_signed = value - 128;
+    if (abs(value_signed) > deadzone) {
+        // If outside deadzone, must subtract deadzone from result so that axis values start from 1
+        // instead of having lower values cut off.
+        int8_t post_deadzone = value_signed - deadzone * SIGNUM(value_signed);
+        // If a radius value is passed in, scale up the values linearly so that the same effective
+        // value is given on the rim.
+        if (scale) {
+            int8_t sign = SIGNUM(post_deadzone);
+            int8_t post_scaling = min(127, abs(post_deadzone) * 128.0 / (128 - deadzone)) * sign;
+            return post_scaling + 128;
+        }
+        return post_deadzone + 128;
+    }
+    return 128;
+}
+
+uint8_t apply_radius(uint8_t value, int radius) {
+    int8_t value_signed = value - 128;
+    int8_t sign = SIGNUM(value_signed);
+    return min(127, (int)(abs(value_signed) * radius / 128.0)) * sign + 128;
+}