Merge pull request #700 from e4z9/foohid

Add virtual joystick output for macOS

1 files changed, 162 insertions, 0 deletions

diff --git a/proto-iokit-foohid/foohidjoystick.cpp b/proto-iokit-foohid/foohidjoystick.cpp
new file mode 100644
index 00000000..17a4bcb5
--- /dev/null
+++ b/proto-iokit-foohid/foohidjoystick.cpp
@@ -0,0 +1,162 @@
+/* Copyright (c) 2017, Eike Ziller                                               *
+ *                                                                               *
+ * Permission to use, copy, modify, and/or distribute this software for any      *
+ * purpose with or without fee is hereby granted, provided that the above        *
+ * copyright notice and this permission notice appear in all copies.             *
+ */
+
+#include "foohidjoystick.h"
+
+#include <QCoreApplication>
+
+const char FOOHID_SERVICE_NAME[] = "it_unbit_foohid";
+
+enum class FooHIDMethod {
+    Create = 0,
+    Destroy,
+    Send,
+    List,
+    Subscribe
+};
+
+// Joystick USB descriptor
+static unsigned char report_descriptor[] = {
+    0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)
+    0x09, 0x04,                    // USAGE (Joystick)
+    0xa1, 0x01,                    // COLLECTION (Application)
+    0x09, 0x01,                    //   USAGE (Pointer)
+    0xa1, 0x00,                    //   COLLECTION (Physical)
+    0x05, 0x01,                    //     USAGE_PAGE (Generic Desktop)
+    0x09, 0x30,                    //     USAGE (X)
+    0x09, 0x31,                    //     USAGE (Y)
+    0x09, 0x32,                    //     USAGE (Z)
+    0x09, 0x33,                    //     USAGE (RX)
+    0x09, 0x34,                    //     USAGE (RY)
+    0x09, 0x35,                    //     USAGE (RZ)
+    0x15, 0x00,                    //     LOGICAL_MINIMUM (0)
+    0x26, 0xff, 0x00,              //     LOGICAL_MAXIMUM (255)
+    0x75, 0x08,                    //     REPORT_SIZE (8)
+    0x95, 0x06,                    //     REPORT_COUNT (6)
+    0x81, 0x02,                    //     INPUT (Data,Var,Abs)
+    0xc0,                          //   END_COLLECTION
+    0xc0                           // END_COLLECTION
+};
+
+static bool connectToService(io_connect_t *connection, QString *errorMessage)
+{
+    io_iterator_t iterator;
+    io_service_t service;
+    // Get an iterator over all IOService instances
+    kern_return_t ret = IOServiceGetMatchingServices(kIOMasterPortDefault,
+                                                     IOServiceMatching(FOOHID_SERVICE_NAME),
+                                                     &iterator);
+    if (ret != KERN_SUCCESS) {
+        *errorMessage = QCoreApplication::translate("iokit-foohid", "Unable to find FooHID IOService.");
+        return false;
+    }
+    // Iterate over services and try to open connection
+    bool found = false;
+    while ((service = IOIteratorNext(iterator)) != IO_OBJECT_NULL) {
+        ret = IOServiceOpen(service, mach_task_self(), 0, connection);
+        if (ret == KERN_SUCCESS) {
+            found = true;
+            break;
+        }
+        IOObjectRelease(service);
+    }
+    IOObjectRelease(iterator);
+    if (!found) {
+        *errorMessage = QCoreApplication::translate("iokit-foohid", "Unable to connect to FooHID IOService.");
+        return false;
+    }
+    return true;
+}
+
+static void disconnectFromService(io_connect_t connection)
+{
+    IOServiceClose(connection);
+    // ignore errors
+}
+
+FooHIDJoystick::FooHIDJoystick(const QByteArray &name, const QByteArray &serialNumber)
+    : name(name), serialNumber(serialNumber)
+{
+    connectionOpened = connectToService(&connection, &_errorMessage);
+    _hasError = !connectionOpened;
+    if (!_hasError) {
+        // first try to destroy device, in case it was left-over (from a crash/interrupt)
+        destroyDevice();
+        deviceCreated = createDevice();
+        _hasError = !deviceCreated;
+        if (!deviceCreated)
+            _errorMessage = QCoreApplication::translate("iokit-foohid",
+                                                        "Failed to create virtual joystick");
+    }
+}
+
+FooHIDJoystick::~FooHIDJoystick()
+{
+    if (deviceCreated)
+        destroyDevice();
+    if (connectionOpened)
+        disconnectFromService(connection);
+}
+
+bool FooHIDJoystick::hasError() const
+{
+    return _hasError;
+}
+
+QString FooHIDJoystick::errorMessage() const
+{
+    return _errorMessage;
+}
+
+void FooHIDJoystick::setValue(JoystickValues newValues)
+{
+    values = newValues;
+    if (!sendToDevice()) {
+        _hasError = true;
+        _errorMessage = QCoreApplication::translate("iokit-foohid",
+                                                    "Failed to send values to virtual joystick");
+    }
+}
+
+bool FooHIDJoystick::createDevice() const
+{
+    uint64_t params[8];
+    params[0] = uint64_t(name.constData());         // pointer to name
+    params[1] = uint64_t(name.size());              // size of name without \0
+    params[2] = uint64_t(report_descriptor);        // pointer to report descriptor
+    params[3] = sizeof(report_descriptor);          // size of report descriptor
+    params[4] = uint64_t(serialNumber.constData()); // pointer to serial number
+    params[5] = uint64_t(serialNumber.size());      // size of serial number without \0
+    params[6] = uint64_t(2);                        // vendor ID
+    params[7] = uint64_t(3);                        // device ID
+
+    kern_return_t ret = IOConnectCallScalarMethod(connection, int(FooHIDMethod::Create), params,
+                                                  sizeof(params)/sizeof(params[0]), NULL, 0);
+    return ret == KERN_SUCCESS;
+}
+
+bool FooHIDJoystick::sendToDevice() const
+{
+    uint64_t params[4];
+    params[0] = uint64_t(name.constData());        // pointer to name
+    params[1] = uint64_t(name.size());             // size of name without \0
+    params[2] = uint64_t(&values);                 // pointer to values
+    params[3] = sizeof(struct JoystickValues);     // length of value struct
+    kern_return_t ret = IOConnectCallScalarMethod(connection, int(FooHIDMethod::Send), params,
+                                                  sizeof(params)/sizeof(params[0]), NULL, 0);
+    return ret == KERN_SUCCESS;
+}
+
+void FooHIDJoystick::destroyDevice() const
+{
+    uint64_t params[2];
+    params[0] = uint64_t(name.constData()); // pointer to name
+    params[1] = uint64_t(name.size());      // size of name without \0
+    IOConnectCallScalarMethod(connection, int(FooHIDMethod::Destroy), params,
+                              sizeof(params)/sizeof(params[0]), NULL, 0);
+    // ignore failure
+}