HID: Added functions to emulate the touchpad.

src/core/hle/service/hid/hid.cpp

@@ -29,6 +29,10 @@ static u32 next_pad_index = 0;
 static s16 next_pad_circle_x = 0;
 static s16 next_pad_circle_y = 0;
 
+static u32 next_touch_index = 0;
+static u16 next_touch_x = 0;
+static u16 next_touch_y = 0;
+
 /**
  * Gets a pointer to the PadData structure inside HID shared memory
  */
@@ -125,6 +129,50 @@ void PadUpdateComplete() {
     g_event_pad_or_touch_2->Signal();
 }
 
+void TouchPress(u16 x, u16 y) {
+    next_touch_x = x;
+    next_touch_y = y;
+}
+
+void TouchRelease() {
+    next_touch_x = 0;
+    next_touch_y = 0;
+}
+
+void TouchUpdateComplete() {
+    SharedMem* shared_mem = GetSharedMem();
+
+    if (shared_mem == nullptr)
+        return;
+
+    shared_mem->touch.index = next_touch_index;
+    next_touch_index = (next_touch_index + 1) % shared_mem->touch.entries.size();
+
+    // Get the current touch entry
+    TouchDataEntry* current_touch_entry = &shared_mem->touch.entries[shared_mem->touch.index];
+
+    // Set touchpad position
+    current_touch_entry->x = next_touch_x;
+    current_touch_entry->y = next_touch_y;
+
+    // TODO(bunnei): Verify this behavior on real hardware
+    current_touch_entry->data_valid = (next_touch_x || next_touch_y) ? 1 : 0;
+
+    // TODO(bunnei): We're not doing anything with offset 0xA8 + 0x18 of HID SharedMemory, which
+    // supposedly is "Touch-screen entry, which contains the raw coordinate data prior to being
+    // converted to pixel coordinates." (http://3dbrew.org/wiki/HID_Shared_Memory#Offset_0xA8).
+
+    // If we just updated index 0, provide a new timestamp
+    if (shared_mem->touch.index == 0) {
+        shared_mem->touch.index_reset_ticks_previous = shared_mem->touch.index_reset_ticks;
+        shared_mem->touch.index_reset_ticks = (s64)Core::g_app_core->GetTicks();
+    }
+    
+    // Signal both handles when there's an update to Pad or touch
+    g_event_pad_or_touch_1->Signal();
+    g_event_pad_or_touch_2->Signal();
+}
+
 void GetIPCHandles(Service::Interface* self) {
     u32* cmd_buff = Kernel::GetCommandBuffer();
 

src/core/hle/service/hid/hid.h

@@ -180,6 +180,19 @@ void PadButtonRelease(const PadState& pad_state);
  */
 void PadUpdateComplete();
 
+/**
+ * Signal that the touchpad has been pressed
+ * @param x Touchpad x-coordinate in bottom screen pixels (between 0 and 320)
+ * @param y Touchpad y-coordinate in bottom screen pixels (between 0 and 240)
+ */
+void TouchPress(u16 x, u16 y);
+
+/// Signal that touchpad has been released
+void TouchRelease();
+
+/// Signal that touchpad updates have been completed
+void TouchUpdateComplete();
+
 void HIDInit();
 void HIDShutdown();