Rumble using MacBook's Taptic Engine (take 2)

CMakeLists.txt

@@ -1394,13 +1394,15 @@ if(NOT LIBRETRO)
 			find_library(AUDIO_TOOLBOX_LIBRARY AudioToolbox)
 			find_library(OPENGL_LIBRARY OpenGL)
 			find_library(IOSURFACE_LIBRARY IOSurface)
+			find_library(MULTITOUCH_SUPPORT_LIBRARY MultitouchSupport /System/Library/PrivateFrameworks)
 
 			target_link_libraries(${PROJECT_NAME} PRIVATE
 				${AUDIO_UNIT_LIBRARY}
 				${FOUNDATION_LIBRARY}
 				${AUDIO_TOOLBOX_LIBRARY}
 				${OPENGL_LIBRARY}
-				${IOSURFACE_LIBRARY})
+				${IOSURFACE_LIBRARY}
+				${MULTITOUCH_SUPPORT_LIBRARY})
 
 			add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
             	COMMAND ${CMAKE_COMMAND} -E copy "$ENV{VULKAN_SDK}/lib/libMoltenVK.dylib"

core/sdl/sdl_keyboard.h

@@ -2,6 +2,25 @@
 #include "input/keyboard_device.h"
 #include "sdl.h"
 
+#ifdef __APPLE__
+#include <CoreFoundation/CoreFoundation.h>
+#include <IOKit/IOTypes.h>
+#include <stack>
+// Rumbling Taptic Engine by Private MultitouchSupport.framework
+extern "C" {
+typedef void *MTDeviceRef;
+bool MTDeviceIsAvailable(void);
+MTDeviceRef MTDeviceCreateDefault(void);
+OSStatus MTDeviceGetDeviceID(MTDeviceRef, uint64_t*) __attribute__ ((weak_import));
+CFTypeRef MTActuatorCreateFromDeviceID(UInt64 deviceID);
+IOReturn MTActuatorOpen(CFTypeRef actuatorRef);
+IOReturn MTActuatorClose(CFTypeRef actuatorRef);
+IOReturn MTActuatorActuate(CFTypeRef actuatorRef, SInt32 actuationID, UInt32 unknown1, Float32 unknown2, Float32 unknown3);
+bool MTActuatorIsOpen(CFTypeRef actuatorRef);
+enum ActuatePattern { minimal = 3, weak = 5, medium = 4, strong = 6 };
+}
+#endif
+
 class SDLKeyboardDevice : public KeyboardDeviceTemplate<SDL_Scancode>
 {
 public:
@@ -35,6 +54,12 @@ public:
 		}
 		else
 			input_mapper = getDefaultMapping();
+
+#ifdef __APPLE__
+		uint64_t deviceID;
+		if ( MTDeviceIsAvailable() && MTDeviceGetDeviceID(MTDeviceCreateDefault(), &deviceID) == 0 && (vib_device = MTActuatorCreateFromDeviceID(deviceID)) != NULL && MTActuatorOpen(vib_device) == kIOReturnSuccess)
+			rumbleEnabled = true;
+#endif
 	}
 
 	const char *get_button_name(u32 code) override
@@ -45,6 +70,59 @@ public:
 		return name;
 	}
 
+#ifdef __APPLE__
+	void rumble(float power, float inclination, u32 duration_ms) override
+	{
+		if (rumbleEnabled)
+		{
+			vib_stop_time = os_GetSeconds() + duration_ms / 1000.0;
+			
+			__block int pattern;
+			if (power >= 0.75)
+				pattern = ActuatePattern::strong;
+			else if (power >= 0.5)
+				pattern = ActuatePattern::medium;
+			else if (power >= 0.25)
+				pattern = ActuatePattern::weak;
+			else if (power > 0)
+				pattern = ActuatePattern::minimal;
+			else
+			{
+				while(!vib_timer_stack.empty())
+				{
+					dispatch_source_cancel(vib_timer_stack.top());
+					vib_timer_stack.pop();
+				}
+				return;
+			}
+			// Since the Actuator API does not support duration
+			// using a interval timer with `10ms * rumblePower percentage` to fake it
+			__block dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0));
+			vib_timer_stack.push(_timer);
+			dispatch_source_set_timer(_timer, DISPATCH_TIME_NOW, 10 * NSEC_PER_MSEC * rumblePower / 100.f, 0);
+			
+			dispatch_source_set_event_handler(_timer, ^{
+				if ( vib_stop_time - os_GetSeconds() < 0 )
+				{
+					dispatch_source_cancel(_timer);
+					return;
+				}
+				MTActuatorActuate(vib_device, pattern, 0, 0.0, 0.0);
+			});
+			
+			dispatch_resume(_timer);
+		}
+	}
+	
+	~SDLKeyboardDevice() {
+		if (rumbleEnabled)
+		{
+			MTActuatorClose(vib_device);
+			CFRelease(vib_device);
+		}
+	}
+#endif
+
 protected:
 	u8 convert_keycode(SDL_Scancode scancode) override
 	{
@@ -53,4 +131,11 @@ protected:
 		else
 			return (u8)scancode;
 	}
+
+#ifdef __APPLE__
+private:
+	std::stack<dispatch_source_t> vib_timer_stack;
+	CFTypeRef vib_device = NULL;
+	double vib_stop_time = 0;
+#endif
 };