Implemented Gamepad support via Raw Input on Windows

content/browser/gamepad/gamepad_standard_mappings_win.cc

Index: content/browser/gamepad/gamepad_standard_mappings_win.cc
diff --git a/content/browser/gamepad/gamepad_standard_mappings_win.cc b/content/browser/gamepad/gamepad_standard_mappings_win.cc
index 07adb9b82ad466131aaad5dbdd011b8f861b5e2d..16f6d90d27c02384f7ff3102208118b78203600f 100644
--- a/content/browser/gamepad/gamepad_standard_mappings_win.cc
+++ b/content/browser/gamepad/gamepad_standard_mappings_win.cc
@@ -10,6 +10,10 @@ namespace content {
 
 namespace {
 
+float AxisToButton(float input) {
+  return (input + 1.f) / 2.f;
+}
+
 // Maps 0..65535 to -1..1.
 float NormalizeDirectInputAxis(long value) {
   return (value * 1.f / 32767.5f) - 1.f;
@@ -23,6 +27,25 @@ float AxisPositiveAsButton(long value) {
   return (value > 32767) ? 1.f : 0.f;
 }
 
+void DpadFromAxis(blink::WebGamepad* mapped, float dir) {
+  // Dpad is mapped as a direction on one axis, where -1 is up and it
+  // increases clockwise to 1, which is up + left. It's set to a large (> 1.f)
+  // number when nothing is depressed, except on start up, sometimes it's 0.0
+  // for no data, rather than the large number.
+  if (dir == 0.0f) {
+    mapped->buttons[kButtonDpadUp] = 0.f;
+    mapped->buttons[kButtonDpadDown] = 0.f;
+    mapped->buttons[kButtonDpadLeft] = 0.f;
+    mapped->buttons[kButtonDpadRight] = 0.f;
+  } else {
+    mapped->buttons[kButtonDpadUp] = (dir >= -1.f && dir < -0.7f) ||
+                                     (dir >= .95f && dir <= 1.f);
+    mapped->buttons[kButtonDpadRight] = dir >= -.75f && dir < -.1f;
+    mapped->buttons[kButtonDpadDown] = dir >= -.2f && dir < .45f;
+    mapped->buttons[kButtonDpadLeft] = dir >= .4f && dir <= 1.f;
+  }
+}
+
 void MapperDragonRiseGeneric(
     const blink::WebGamepad& input,
     blink::WebGamepad* mapped) {
@@ -96,16 +119,52 @@ void Mapper2Axes8Keys(
   mapped->axesLength = 0;
 }
 
+void MapperDualshock4(
+    const blink::WebGamepad& input,
+    blink::WebGamepad* mapped) {
+  enum Dualshock4Buttons {
+    kTouchpadButton = kNumButtons,
+    kNumDualshock4Buttons
+  };
+
+  *mapped = input;
+  mapped->buttons[kButtonPrimary] = input.buttons[1];
+  mapped->buttons[kButtonSecondary] = input.buttons[2];
+  mapped->buttons[kButtonTertiary] = input.buttons[0];
+  mapped->buttons[kButtonQuaternary] = input.buttons[3];
+  mapped->buttons[kButtonLeftShoulder] = input.buttons[4];
+  mapped->buttons[kButtonRightShoulder] = input.buttons[5];
+  mapped->buttons[kButtonLeftTrigger] = AxisToButton(input.axes[3]);
+  mapped->buttons[kButtonRightTrigger] = AxisToButton(input.axes[4]);
+  mapped->buttons[kButtonBackSelect] = input.buttons[8];
+  mapped->buttons[kButtonStart] = input.buttons[9];
+  mapped->buttons[kButtonLeftThumbstick] = input.buttons[10];
+  mapped->buttons[kButtonRightThumbstick] = input.buttons[11];
+  mapped->buttons[kButtonMeta] = input.buttons[12];
+  mapped->buttons[kTouchpadButton] = input.buttons[13];
+  mapped->axes[kAxisRightStickY] = input.axes[5];
+  DpadFromAxis(mapped, input.axes[9]);
+
+  mapped->buttonsLength = kNumDualshock4Buttons;
+  mapped->axesLength = kNumAxes;
+}
+
 struct MappingData {
   const char* const vendor_id;
   const char* const product_id;
   GamepadStandardMappingFunction function;
 } AvailableMappings[] = {
   // http://www.linux-usb.org/usb.ids
+  { "054c", "05c4", MapperDualshock4 },  // Playstation Dualshock 4
+
+  // Untested DirectInput mappings. May not match Raw Input layout.
+  // TODO: Test and re-enable
+  /*
   { "0079", "0006", MapperDragonRiseGeneric },  // DragonRise Generic USB
   { "046d", "c216", MapperLogitechDualAction },  // Logitech DualAction
   { "046d", "c21a", MapperLogitechPrecision },  // Logitech Precision
   { "12bd", "d012", Mapper2Axes8Keys },  // 2Axes 8Keys Game Pad
+  */
 };
 
 }  // namespace