Add Gamepad mapping for Samsung EI-GP20

device/gamepad/gamepad_standard_mappings_linux.cc

Index: device/gamepad/gamepad_standard_mappings_linux.cc
diff --git a/device/gamepad/gamepad_standard_mappings_linux.cc b/device/gamepad/gamepad_standard_mappings_linux.cc
index 7755e1f936debddac6d0b81ec76826c16a226175..173a6b860bbe613e5e41afdd34099e4fe3286f49 100644
--- a/device/gamepad/gamepad_standard_mappings_linux.cc
+++ b/device/gamepad/gamepad_standard_mappings_linux.cc
@@ -290,6 +290,39 @@ void MapperMogaPro(const blink::WebGamepad& input, blink::WebGamepad* mapped) {
   mapped->axesLength = AXIS_INDEX_COUNT;
 }
 
+void MapperSamsung_EI_GP20(const blink::WebGamepad& input,
+                           blink::WebGamepad* mapped) {
+  *mapped = input;
+  mapped->buttons[BUTTON_INDEX_PRIMARY] = input.buttons[0];
+  mapped->buttons[BUTTON_INDEX_SECONDARY] = input.buttons[1];
+  mapped->buttons[BUTTON_INDEX_TERTIARY] = input.buttons[3];

[scottmg, 2016/11/07 17:39:24]

What are buttons[2] and [5]? :)

[j-hyun.lee, 2016/11/08 06:16:20]

There are no H/W buttons [2] and [5] on gamepad EI_GP20. :)
Those index numbers are skipped same as [8] and [9].

+  mapped->buttons[BUTTON_INDEX_QUATERNARY] = input.buttons[4];
+  mapped->buttons[BUTTON_INDEX_LEFT_SHOULDER] = NullButton();
+  mapped->buttons[BUTTON_INDEX_RIGHT_SHOULDER] = NullButton();
+  mapped->buttons[BUTTON_INDEX_LEFT_TRIGGER] = input.buttons[6];
+  mapped->buttons[BUTTON_INDEX_RIGHT_TRIGGER] = input.buttons[7];
+  mapped->buttons[BUTTON_INDEX_BACK_SELECT] = input.buttons[10];
+  mapped->buttons[BUTTON_INDEX_START] = input.buttons[11];
+  mapped->buttons[BUTTON_INDEX_LEFT_THUMBSTICK] = NullButton();
+  mapped->buttons[BUTTON_INDEX_RIGHT_THUMBSTICK] = NullButton();
+
+  mapped->buttons[BUTTON_INDEX_DPAD_UP] = AxisNegativeAsButton(input.axes[5]);
+  mapped->buttons[BUTTON_INDEX_DPAD_DOWN] = AxisPositiveAsButton(input.axes[5]);
+  mapped->buttons[BUTTON_INDEX_DPAD_LEFT] = AxisNegativeAsButton(input.axes[4]);
+  mapped->buttons[BUTTON_INDEX_DPAD_RIGHT] =
+      AxisPositiveAsButton(input.axes[4]);
+  mapped->buttons[BUTTON_INDEX_META] = input.buttons[15];
+  mapped->buttons[BUTTON_INDEX_COUNT] = NullButton();

[scottmg, 2016/11/07 17:39:24]

Don't set INDEX_COUNT, it's for a maximum value.

[j-hyun.lee, 2016/11/08 06:16:20]

Ok, I will fix it.

+
+  mapped->axes[AXIS_INDEX_LEFT_STICK_X] = input.axes[0];
+  mapped->axes[AXIS_INDEX_LEFT_STICK_Y] = input.axes[1];
+  mapped->axes[AXIS_INDEX_RIGHT_STICK_X] = input.axes[2];
+  mapped->axes[AXIS_INDEX_RIGHT_STICK_Y] = input.axes[3];
+
+  mapped->buttonsLength = BUTTON_INDEX_COUNT;
+  mapped->axesLength = AXIS_INDEX_COUNT;
+}
+
 struct MappingData {
   const char* const vendor_id;
   const char* const product_id;
@@ -303,6 +336,7 @@ struct MappingData {
     {"046d", "c21d", MapperXInputStyleGamepad},  // Logitech F310
     {"046d", "c21e", MapperXInputStyleGamepad},  // Logitech F510
     {"046d", "c21f", MapperXInputStyleGamepad},  // Logitech F710
+    {"04e8", "a000", MapperSamsung_EI_GP20},     // Samsung Gamepad EI-GP20
     {"054c", "0268", MapperPlaystationSixAxis},  // Playstation SIXAXIS
     {"054c", "05c4", MapperDualshock4},          // Playstation Dualshock 4
     {"0583", "2060", MapperIBuffalo},            // iBuffalo Classic