Add GCA poll rate to controller settings

Author: Motobug

Readme.md

@@ -20,9 +20,9 @@ This is a work-in-progress version of the Dolphin Emulator built for usage with
   * Discord Rich Presence support
   * Separate Minimum and Player buffers in netplay window
   * Client side music toggle in netplay window
+  * Gamecube adapter polling rate in controller settings 
 
 * To-Do
-  * Gamecube adapter polling rate in controller settings 
   * Spectator button in netplay window
   * Overwrite Dolphin updater functions with our own
   * "On SI Read" polling method

Source/Core/DolphinQt/Config/Mapping/GCPadWiiUConfigDialog.cpp

@@ -6,6 +6,7 @@
 #include <QCheckBox>
 #include <QDialogButtonBox>
 #include <QLabel>
+#include <QTimer>
 #include <QVBoxLayout>
 
 #include "Core/Config/MainSettings.h"
@@ -36,25 +37,32 @@ void GCPadWiiUConfigDialog::CreateLayout()
 
   m_layout = new QVBoxLayout();
   m_status_label = new QLabel();
+  m_poll_rate_label = new QLabel();
   m_rumble = new QCheckBox(tr("Enable Rumble"));
   m_simulate_bongos = new QCheckBox(tr("Simulate DK Bongos"));
   m_button_box = new QDialogButtonBox(QDialogButtonBox::Ok);
 
   UpdateAdapterStatus();
+  UpdatePollRate();
+  
+  m_poll_rate_timer = new QTimer(this);
 
   auto callback = [this] { QueueOnObject(this, &GCPadWiiUConfigDialog::UpdateAdapterStatus); };
   GCAdapter::SetAdapterCallback(callback);
 
   m_layout->addWidget(m_status_label);
   m_layout->addWidget(m_rumble);
-  m_layout->addWidget(m_simulate_bongos);
+  m_layout->addWidget(m_poll_rate_label);
+  // m_layout->addWidget(m_simulate_bongos); //we're not using bongos for this lol
   m_layout->addWidget(m_button_box);
 
   setLayout(m_layout);
 }
 
 void GCPadWiiUConfigDialog::ConnectWidgets()
 {
+  connect(m_poll_rate_timer, &QTimer::timeout, this, &GCPadWiiUConfigDialog::UpdatePollRate);
+  m_poll_rate_timer->start(1500);
   connect(m_rumble, &QCheckBox::toggled, this, &GCPadWiiUConfigDialog::SaveSettings);
   connect(m_simulate_bongos, &QCheckBox::toggled, this, &GCPadWiiUConfigDialog::SaveSettings);
   connect(m_button_box, &QDialogButtonBox::accepted, this, &GCPadWiiUConfigDialog::accept);
@@ -83,6 +91,13 @@ void GCPadWiiUConfigDialog::UpdateAdapterStatus()
 
   m_rumble->setEnabled(detected);
   m_simulate_bongos->setEnabled(detected);
+  m_poll_rate_label->setHidden(!detected);
+}
+
+void GCPadWiiUConfigDialog::UpdatePollRate()
+{
+  QString poll_rate_text = tr("Poll Rate: %1 hz").arg(1000.0 / GCAdapter::ReadRate());
+  m_poll_rate_label->setText(poll_rate_text);
 }
 
 void GCPadWiiUConfigDialog::LoadSettings()

Source/Core/DolphinQt/Config/Mapping/GCPadWiiUConfigDialog.h

@@ -9,6 +9,7 @@ class QCheckBox;
 class QLabel;
 class QDialogButtonBox;
 class QVBoxLayout;
+class QTimer;
 
 class GCPadWiiUConfigDialog final : public QDialog
 {
@@ -26,11 +27,14 @@ class GCPadWiiUConfigDialog final : public QDialog
 
 private:
   void UpdateAdapterStatus();
+  void UpdatePollRate();
 
   int m_port;
 
   QVBoxLayout* m_layout;
   QLabel* m_status_label;
+  QLabel* m_poll_rate_label;
+  QTimer* m_poll_rate_timer;
   QDialogButtonBox* m_button_box;
 
   // Checkboxes

Source/Core/InputCommon/GCAdapter.cpp

@@ -171,6 +171,10 @@ static std::optional<Config::ConfigChangedCallbackID> s_config_callback_id = std
 static bool s_is_adapter_wanted = false;
 static std::array<bool, SerialInterface::MAX_SI_CHANNELS> s_config_rumble_enabled{};
 
+// P+ change: for poll rate display
+static u64 s_consecutive_slow_transfers = 0;
+static double s_read_rate = 0.0;
+
 static void ReadThreadFunc()
 {
   Common::SetCurrentThreadName("GCAdapter Read Thread");
@@ -206,16 +210,40 @@ static void ReadThreadFunc()
 
   // Reset rumble once on initial reading
   ResetRumble();
+  
+  // P+ change: for poll rate display
+  s_read_rate = 0.0;
 
   while (s_read_adapter_thread_running.IsSet())
   {
 #if GCADAPTER_USE_LIBUSB_IMPLEMENTATION
     std::array<u8, CONTROLLER_INPUT_PAYLOAD_EXPECTED_SIZE> input_buffer;
 
     int payload_size = 0;
+	
+	// P+ change: for poll rate display
+    std::chrono::high_resolution_clock::time_point start =
+        std::chrono::high_resolution_clock::now();
     int error = libusb_interrupt_transfer(s_handle, s_endpoint_in, input_buffer.data(),
                                           int(input_buffer.size()), &payload_size, USB_TIMEOUT_MS);
-    if (error != LIBUSB_SUCCESS)
+    // P+ change: for poll rate display
+    std::chrono::high_resolution_clock::time_point now = std::chrono::high_resolution_clock::now();
+   
+   double elapsed_ms =
+        std::chrono::duration_cast<std::chrono::nanoseconds>(now - start).count() / 1000000.0;
+
+    if (elapsed_ms > 15.0)
+    {
+      s_consecutive_slow_transfers++;
+    }
+    else
+    {
+      s_consecutive_slow_transfers = 0;
+    }
+
+    s_read_rate = elapsed_ms;
+
+	if (error != LIBUSB_SUCCESS)
     {
       ERROR_LOG_FMT(CONTROLLERINTERFACE, "Read: libusb_interrupt_transfer failed: {}",
                     LibusbUtils::ErrorWrap(error));
@@ -491,6 +519,18 @@ void StopScanThread()
   }
 }
 
+// P+ change: for poll rate display
+bool IsReadingAtReducedRate()
+{
+  return s_consecutive_slow_transfers > 80;
+}
+
+
+double ReadRate()
+{
+  return s_read_rate;
+}
+
 static void Setup()
 {
 #if GCADAPTER_USE_LIBUSB_IMPLEMENTATION

Source/Core/InputCommon/GCAdapter.h

@@ -18,6 +18,10 @@ void SetAdapterCallback(std::function<void(void)> func);
 void StartScanThread();
 void StopScanThread();
 
+// P+ change: for poll rate display
+bool IsReadingAtReducedRate();
+double ReadRate();
+
 // Buttons have PAD_GET_ORIGIN set on new connection
 // Netplay and CSIDevice_GCAdapter make use of this.
 GCPadStatus Input(int chan);

Source/Core/VideoCommon/OnScreenUI.cpp

@@ -12,6 +12,7 @@
 #include "Core/Config/NetplaySettings.h"
 #include "Core/Movie.h"
 #include "Core/System.h"
+#include "InputCommon/GCAdapter.h"
 
 #include "VideoCommon/AbstractGfx.h"
 #include "VideoCommon/AbstractPipeline.h"
@@ -329,8 +330,29 @@ void OnScreenUI::DrawDebugText()
   const std::string profile_output = Common::Profiler::ToString();
   if (!profile_output.empty())
     ImGui::TextUnformatted(profile_output.c_str());
+
+  // P+ change: warn if adapter is being read at reduced rate
+  if (GCAdapter::IsReadingAtReducedRate())
+  {
+    ImGui::TextWrapped(
+        "Your GameCube Controller Adapter is reading inputs at a reduced rate.\n"
+        "You can still play normally but you will experience higher input lag.\n"
+        "This indicates a potential hardware issue.\n"
+        "\n"
+        "Go to the Dolphin -> Controllers page, click 'Configure' next to your "
+        "controller's port, then check what your pollrate is."
+        "\n"
+        "If it is considerably lower than 125 hz, keep trying different USB ports until it "
+        "is around 125 hz."
+        "\n"
+        "For more help, please ask in the official P+ Discord server.");
+
+  }
 }
 
+ 
+
+
 void OnScreenUI::DrawChallengesAndLeaderboards()
 {
   if (!Config::Get(Config::MAIN_OSD_MESSAGES))