add gamepad example

Makefile

@@ -5,6 +5,7 @@ example:
 	make opengl
 	make mac-load
 	make hello-world
+	make gamepad
 	make save-file
 	make button
 	make checkbox
@@ -38,6 +39,8 @@ mac-load:
 	gcc $(ARGS) examples/general/mac-load.c -I./ -framework Cocoa -o mac-load
 hello-world:
 	gcc $(ARGS) examples/general/hello-world.c -I./ -framework Cocoa -o hello-world
+gamepad:
+	gcc $(ARGS) examples/general/gamepad.c -I./ -framework Cocoa -framework IOKit -o gamepad
 events:
 	gcc $(ARGS) examples/general/events.c -I./ -framework Cocoa -o events
 

examples/general/gamepad.c

@@ -0,0 +1,150 @@
+#define GL_SILENCE_DEPRECATION
+#define SILICON_IMPLEMENTATION
+#include <silicon.h>
+
+#include <IOKit/IOKitLib.h>
+#include <IOKit/hid/IOHIDManager.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <stdio.h>
+
+
+NSApplication* NSApp;
+
+// Callback for device input value changes
+void inputValueChangedCallback(void *context, IOReturn result, void *sender, IOHIDValueRef value) {
+    IOHIDElementRef element = IOHIDValueGetElement(value);
+
+    // Get the usage page and usage
+    uint32_t usagePage = IOHIDElementGetUsagePage(element);
+    uint32_t usage = IOHIDElementGetUsage(element);
+
+    // Get the integer value of the input
+    CFIndex intValue = IOHIDValueGetIntegerValue(value);
+
+    // Handle buttons
+    if (usagePage == kHIDPage_Button) {
+        printf("Button %u: %s\n", usage, intValue ? "Pressed" : "Released");
+    }
+
+    // Handle joystick movements (axes)
+    if (usagePage == kHIDPage_GenericDesktop) {
+        switch (usage) {
+            case kHIDUsage_GD_X:
+                printf("Joystick X-axis: %ld\n", intValue);
+                break;
+            case kHIDUsage_GD_Y:
+                printf("Joystick Y-axis: %ld\n", intValue);
+                break;
+            case kHIDUsage_GD_Z:
+                printf("Joystick Z-axis: %ld\n", intValue);
+                break;
+            case kHIDUsage_GD_Rx:
+                printf("Joystick Rx-axis: %ld\n", intValue);
+                break;
+            case kHIDUsage_GD_Ry:
+                printf("Joystick Ry-axis: %ld\n", intValue);
+                break;
+            default:
+                break;
+        }
+    }
+}
+
+// Callback for when an HID device is added
+void deviceAddedCallback(void *context, IOReturn result, void *sender, IOHIDDeviceRef device) {
+    CFNumberRef usageRef = IOHIDDeviceGetProperty(device, CFSTR(kIOHIDPrimaryUsageKey));
+
+    int usage = 0;
+    if (usageRef)
+        CFNumberGetValue(usageRef, kCFNumberIntType, &usage);
+
+    CFStringRef deviceName = IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductKey));
+    if (deviceName) {
+        char buffer[128];
+        if (CFStringGetCString(deviceName, buffer, sizeof(buffer), kCFStringEncodingUTF8)) {
+            printf("Device added: %s\n", buffer);
+        }
+    }
+
+    if (usage != kHIDUsage_GD_Joystick && usage != kHIDUsage_GD_GamePad && usage != kHIDUsage_GD_MultiAxisController) {
+        printf("Device is not a controller. Ignoring...s\n");
+        return;
+    }
+
+    // Register input value callback for the device
+    IOHIDDeviceRegisterInputValueCallback(device, inputValueChangedCallback, NULL);
+}
+
+// Callback for when an HID device is removed
+void deviceRemovedCallback(void *context, IOReturn result, void *sender, IOHIDDeviceRef device) {
+    printf("Device removed.\n");
+}
+
+int main(int argc, char* argv[]) {
+    NSApp = NSApplication_sharedApplication();
+
+    NSWindow* window1 = NSWindow_init(NSMakeRect(100, 100, 300, 300), NSWindowStyleMaskTitled | NSWindowStyleMaskClosable | NSWindowStyleMaskMiniaturizable | NSWindowStyleMaskResizable, NSBackingStoreBuffered, false);
+    NSWindow_setIsVisible(window1, true);
+
+    NSApplication_setActivationPolicy(NSApp, NSApplicationActivationPolicyRegular);
+    NSApplication_finishLaunching(NSApp);
+
+    // Create an IOHIDManager
+    IOHIDManagerRef hidManager = IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone);
+    if (!hidManager) {
+        fprintf(stderr, "Failed to create IOHIDManager.\n");
+        return -1;
+    }
+
+    // Define the matching criteria for devices
+    CFMutableDictionaryRef matchingDictionary = CFDictionaryCreateMutable(
+        kCFAllocatorDefault,
+        0,
+        &kCFTypeDictionaryKeyCallBacks,
+        &kCFTypeDictionaryValueCallBacks
+    );
+    if (!matchingDictionary) {
+        fprintf(stderr, "Failed to create matching dictionary.\n");
+        CFRelease(hidManager);
+        return -1;
+    }
+
+    // Specify usage page and usage for generic desktop controls (joysticks, gamepads, etc.)
+    CFDictionarySetValue(
+        matchingDictionary,
+        CFSTR(kIOHIDDeviceUsagePageKey),
+        CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &(int){kHIDPage_GenericDesktop})
+    );
+
+    // Set the matching criteria to the HID manager
+    IOHIDManagerSetDeviceMatching(hidManager, matchingDictionary);
+
+    // Register callbacks for device detection
+    IOHIDManagerRegisterDeviceMatchingCallback(hidManager, deviceAddedCallback, NULL);
+    IOHIDManagerRegisterDeviceRemovalCallback(hidManager, deviceRemovedCallback, NULL);
+
+    // Schedule the HID manager with the run loop
+    IOHIDManagerScheduleWithRunLoop(hidManager, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
+
+    // Open the HID manager
+    IOHIDManagerOpen(hidManager, kIOHIDOptionsTypeNone);
+    printf("Listening for HID devices and input. Press Ctrl+C to exit.\n");
+
+    // Execute the run loop once in order to register any initially-attached joysticks
+    CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, false);
+
+    // Run the main loop
+    while (true) {
+        NSEvent* event = NSApplication_nextEventMatchingMask(NSApp, NSEventMaskAny, NULL, NSDefaultRunLoopMode, true);
+
+        NSApplication_sendEvent(NSApp, event);
+        NSApplication_updateWindows(NSApp);
+    }
+
+    // Clean up
+    CFRelease(matchingDictionary);
+    IOHIDManagerClose(hidManager, kIOHIDOptionsTypeNone);
+    CFRelease(hidManager);
+
+    return 0;
+}