Add gamepad hardware data fetcher, and higher level thread container

content/browser/gamepad/data_fetcher_win.cc

Index: content/browser/gamepad/data_fetcher_win.cc
diff --git a/content/browser/gamepad/data_fetcher_win.cc b/content/browser/gamepad/data_fetcher_win.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ad10ac15a5d77b0892f1fb35cd2611288c94e07b
--- /dev/null
+++ b/content/browser/gamepad/data_fetcher_win.cc
@@ -0,0 +1,173 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/gamepad/data_fetcher_win.h"
+
+#include "base/debug/trace_event.h"
+#include "content/common/gamepad_messages.h"
+#include "content/common/gamepad_hardware_buffer.h"
+
+#include <delayimp.h>
+
+#pragma comment(lib, "delayimp.lib")
+#pragma comment(lib, "xinput.lib")
+
+namespace gamepad {
+
+using namespace WebKit;
+
+namespace {
+
+// See http://goo.gl/5VSJR. These are not available in all versions of the
+// header, but they can be returned from the driver, so we define our own
+// versions here.
+static const BYTE kDeviceSubTypeGamepad = 1;
+static const BYTE kDeviceSubTypeWheel = 2;
+static const BYTE kDeviceSubTypeArcadeStick = 3;
+static const BYTE kDeviceSubTypeFlightStick = 4;
+static const BYTE kDeviceSubTypeDancePad = 5;
+static const BYTE kDeviceSubTypeGuitar = 6;
+static const BYTE kDeviceSubTypeGuitarAlternate = 7;
+static const BYTE kDeviceSubTypeDrumKit = 8;
+static const BYTE kDeviceSubTypeGuitarBass = 11;
+static const BYTE kDeviceSubTypeArcadePad = 19;
+
+const WebUChar* const GamepadSubTypeName(BYTE sub_type) {
+  switch (sub_type) {
+    case kDeviceSubTypeGamepad: return L"GAMEPAD";
+    case kDeviceSubTypeWheel: return L"WHEEL";
+    case kDeviceSubTypeArcadeStick: return L"ARCADE_STICK";
+    case kDeviceSubTypeFlightStick: return L"FLIGHT_STICK";
+    case kDeviceSubTypeDancePad: return L"DANCE_PAD";
+    case kDeviceSubTypeGuitar: return L"GUITAR";
+    case kDeviceSubTypeGuitarAlternate: return L"GUITAR_ALTERNATE";
+    case kDeviceSubTypeDrumKit: return L"DRUM_KIT";
+    case kDeviceSubTypeGuitarBass: return L"GUITAR_BASS";
+    case kDeviceSubTypeArcadePad: return L"ARCADE_PAD";
+    default: return L"<UNKNOWN>";
+  }
+}
+
+// Trap only the exceptions that DELAYLOAD can throw, otherwise rethrow.
+// See http://msdn.microsoft.com/en-us/library/1c9e046h(v=VS.90).aspx.
+LONG WINAPI DelayLoadDllExceptionFilter(PEXCEPTION_POINTERS pExcPointers) {
+ LONG disposition = EXCEPTION_EXECUTE_HANDLER;
+ switch (pExcPointers->ExceptionRecord->ExceptionCode) {
+   case VcppException(ERROR_SEVERITY_ERROR, ERROR_MOD_NOT_FOUND):
+   case VcppException(ERROR_SEVERITY_ERROR, ERROR_PROC_NOT_FOUND):
+      break;
+   default:
+      // Exception is not related to delay loading

[cpu_(ooo_6.6-7.5), 2011/11/23 01:58:27]

period

[scottmg, 2011/11/23 02:10:10]

Done.

+      disposition = EXCEPTION_CONTINUE_SEARCH;
+      break;
+   }
+   return disposition;
+}
+
+bool XInputAvailable() {

[cpu_(ooo_6.6-7.5), 2011/11/23 01:58:27]

my only beef is that the function name implies a query but the actual code is an
action: enable.

how about bool EnableXInput()?

[scottmg, 2011/11/23 02:10:10]

Done.

+  // We have specified DELAYLOAD for xinput1_3.dll. If the DLL is not
+  // installed (XP w/o DirectX redist installed), we disable functionality.
+  __try {
+    XInputEnable(true);
+  } __except(DelayLoadDllExceptionFilter(GetExceptionInformation())) {
+    return false;
+  }
+  return true;
+}
+
+}
+
+DataFetcherWindows::DataFetcherWindows()
+    : xinput_available_(XInputAvailable()) {
+}
+
+void DataFetcherWindows::GetGamepadData(WebGamepads* pads,
+                                        bool devices_changed_hint) {
+  TRACE_EVENT0("GAMEPAD", "DataFetcherWindows::GetGamepadData");
+
+  // If there's no XInput DLL on the system, early out so that we don't
+  // call any other XInput functions.
+  if (!xinput_available_) {
+    pads->length = 0;
+    return;
+  }
+
+  pads->length = WebGamepads::itemsLengthCap;
+
+  // If we got notification that system devices have been updated, then
+  // run GetCapabilities to update the connected status and the device
+  // identifier. It can be slow to do to both GetCapabilities and
+  // GetState on unconnected devices, so we want to avoid a 2-5ms pause
+  // here by only doing this when the devices are updated (despite
+  // documentation claiming it's OK to call it any time).
+  if (devices_changed_hint) {
+    for (unsigned i = 0; i < WebGamepads::itemsLengthCap; ++i) {
+      WebGamepad& pad = pads->items[i];
+      TRACE_EVENT1("GAMEPAD", "DataFetcherWindows::GetCapabilities", "id", i);
+      XINPUT_CAPABILITIES caps;
+      DWORD res = XInputGetCapabilities(i, XINPUT_FLAG_GAMEPAD, &caps);
+      if (res == ERROR_DEVICE_NOT_CONNECTED) {
+        pad.connected = false;
+      } else {
+        pad.connected = true;
+        base::swprintf(pad.id,
+                       WebGamepad::idLengthCap,
+                       L"Xbox 360 Controller (XInput %ls)",
+                       GamepadSubTypeName(caps.SubType));
+      }
+    }
+  }
+
+  // We've updated the connection state if necessary, now update the actual
+  // data for the devices that are connected.
+  for (unsigned i = 0; i < WebGamepads::itemsLengthCap; ++i) {
+    WebGamepad& pad = pads->items[i];
+
+    // We rely on device_changed and GetCapabilities to tell us that
+    // something's been connected, but we will mark as disconnected if
+    // GetState returns that we've lost the pad.
+    if (!pad.connected)
+      continue;
+
+    XINPUT_STATE state;
+    memset(&state, 0, sizeof(XINPUT_STATE));
+    TRACE_EVENT_BEGIN1("GAMEPAD", "XInputGetState", "id", i);
+    DWORD dwResult = XInputGetState(i, &state);
+    TRACE_EVENT_END1("GAMEPAD", "XInputGetState", "id", i);
+
+    if (dwResult == ERROR_SUCCESS) {
+      pad.timestamp = state.dwPacketNumber;
+      pad.buttonsLength = 0;
+#define ADD(b) pad.buttons[pad.buttonsLength++] = \
+    ((state.Gamepad.wButtons & (b)) ? 1.0 : 0.0);
+      ADD(XINPUT_GAMEPAD_A);
+      ADD(XINPUT_GAMEPAD_B);
+      ADD(XINPUT_GAMEPAD_X);
+      ADD(XINPUT_GAMEPAD_Y);
+      ADD(XINPUT_GAMEPAD_LEFT_SHOULDER);
+      ADD(XINPUT_GAMEPAD_RIGHT_SHOULDER);
+      pad.buttons[pad.buttonsLength++] = state.Gamepad.bLeftTrigger / 255.0;
+      pad.buttons[pad.buttonsLength++] = state.Gamepad.bRightTrigger / 255.0;
+      ADD(XINPUT_GAMEPAD_BACK);
+      ADD(XINPUT_GAMEPAD_START);
+      ADD(XINPUT_GAMEPAD_LEFT_THUMB);
+      ADD(XINPUT_GAMEPAD_RIGHT_THUMB);
+      ADD(XINPUT_GAMEPAD_DPAD_UP);
+      ADD(XINPUT_GAMEPAD_DPAD_DOWN);
+      ADD(XINPUT_GAMEPAD_DPAD_LEFT);
+      ADD(XINPUT_GAMEPAD_DPAD_RIGHT);
+#undef ADD
+      pad.axesLength = 0;
+      // XInput are +up/+right, -down/-left, we want -up/-left.
+      pad.axes[pad.axesLength++] = state.Gamepad.sThumbLX / 32767.0;
+      pad.axes[pad.axesLength++] = -state.Gamepad.sThumbLY / 32767.0;
+      pad.axes[pad.axesLength++] = state.Gamepad.sThumbRX / 32767.0;
+      pad.axes[pad.axesLength++] = -state.Gamepad.sThumbRY / 32767.0;
+    } else {
+      pad.connected = false;
+    }
+  }
+}
+
+} // namespace gamepad