Add gamepad hardware data fetcher, and higher level thread container

content/browser/gamepad/data_fetcher_win.cc

+// 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"
+
+#pragma comment(lib, "xinput.lib")
+
+namespace gamepad {
+
+using namespace WebKit;
+
+namespace {
+
+// See http://goo.gl/5VSJR.
+const WebUChar* const GamepadSubTypeName(BYTE sub_type) {
+  switch (sub_type) {
+    case XINPUT_DEVSUBTYPE_GAMEPAD: return L"GAMEPAD";
+    case XINPUT_DEVSUBTYPE_WHEEL: return L"WHEEL";
+    case XINPUT_DEVSUBTYPE_ARCADE_STICK: return L"ARCADE_STICK";
+    //case XINPUT_DEVSUBTYPE_FLIGHT_STICK: return L"FLIGHT_STICK";
+    case XINPUT_DEVSUBTYPE_DANCE_PAD: return L"DANCE_PAD";
+    case XINPUT_DEVSUBTYPE_GUITAR: return L"GUITAR";
+    //case XINPUT_DEVSUBTYPE_GUITAR_ALTERNATE: return L"GUITAR_ALTERNATE";
+    case XINPUT_DEVSUBTYPE_DRUM_KIT: return L"DRUM_KIT";
+    //case XINPUT_DEVSUBTYPE_GUITAR_BASS: return L"GUITAR_BASS";
+    //case XINPUT_DEVSUBTYPE_ARCADE_PAD: return L"ARCADE_PAD";
+    default: return L"<UNKNOWN>";
+  }
+}
+
+}
+
+void DataFetcherWindows::GetGamepadData(WebGamepads& pads,
+                                        bool devices_changed_hint) {
+  TRACE_EVENT0("GAMEPAD", "DataFetcherWindows::GetGamepadData");
+  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