[hal,wpilib] Add Touchpad support (#8401)

hal/src/mrc/include/mrc/NetComm.h

@@ -186,10 +186,60 @@ struct JoystickButtons {
   uint8_t Count{0};
 };
 
+struct TouchpadFinger {
+  bool Down{false};
+  uint16_t X{0};
+  uint16_t Y{0};
+};
+
+struct Touchpad {
+  std::span<TouchpadFinger> Fingers() {
+    return std::span{FingersStore.data(), GetFingerCount()};
+  }
+
+  std::span<const TouchpadFinger> Fingers() const {
+    return std::span{FingersStore.data(), GetFingerCount()};
+  }
+
+  size_t GetFingerCount() const { return FingerCount; }
+
+  void SetFingerCount(uint8_t NewCount) {
+    FingerCount =
+        (std::min)(NewCount,
+                   static_cast<uint8_t>(MRC_MAX_NUM_TOUCHPAD_FINGERS));
+  }
+
+ private:
+  std::array<TouchpadFinger, MRC_MAX_NUM_TOUCHPAD_FINGERS> FingersStore{};
+  uint8_t FingerCount{0};
+};
+
+struct JoystickTouchpads {
+  std::span<Touchpad> Touchpads() {
+    return std::span{TouchpadsStore.data(), GetTouchpadCount()};
+  }
+
+  std::span<const Touchpad> Touchpads() const {
+    return std::span{TouchpadsStore.data(), GetTouchpadCount()};
+  }
+
+  size_t GetTouchpadCount() const { return TouchpadCount; }
+
+  void SetTouchpadCount(uint8_t NewCount) {
+    TouchpadCount =
+        (std::min)(NewCount, static_cast<uint8_t>(MRC_MAX_NUM_TOUCHPADS));
+  }
+
+ private:
+  std::array<Touchpad, MRC_MAX_NUM_TOUCHPADS> TouchpadsStore{};
+  uint8_t TouchpadCount{0};
+};
+
 struct Joystick {
   JoystickAxes Axes;
   JoystickPovs Povs;
   JoystickButtons Buttons;
+  JoystickTouchpads Touchpads;
 };
 
 struct ControlData {

hal/src/mrc/include/mrc/NtNetComm.h

@@ -66,3 +66,5 @@
 #define MRC_MAX_JOYSTICK_NAME_LEN 256
 #define MRC_MAX_VERSION_SIZE 256
 #define MRC_MAX_ERROR_INFO_STR_LEN 10000
+#define MRC_MAX_NUM_TOUCHPAD_FINGERS 2
+#define MRC_MAX_NUM_TOUCHPADS 2

hal/src/mrc/proto/MrcComm.proto

@@ -4,6 +4,16 @@ package mrc.proto;
 
 option java_package = "com.mrc.proto";
 
+message ProtobufFingerData {
+    uint32 X = 1;
+    uint32 Y = 2;
+    bool Down = 3;
+}
+
+message ProtobufTouchpadData {
+    repeated ProtobufFingerData Fingers = 1;
+}
+
 message ProtobufJoystickData {
     uint64 AvailableButtons = 1;
     uint64 Buttons = 2;
@@ -13,6 +23,7 @@ message ProtobufJoystickData {
     // We can fit 8 in here.
     uint32 POVCount = 5;
     uint32 POVs = 6;
+    repeated ProtobufTouchpadData Touchpads = 7;
 }
 
 message ProtobufControlData {