1 files changed, 68 insertions, 0 deletions
diff --git a/src/android/app/src/main/java/org/yuzu/yuzu_emu/utils/ControllerMappingHelper.kt b/src/android/app/src/main/java/org/yuzu/yuzu_emu/utils/ControllerMappingHelper.kt
new file mode 100644
index 000000000..791cea904
--- /dev/null
+++ b/src/android/app/src/main/java/org/yuzu/yuzu_emu/utils/ControllerMappingHelper.kt
@@ -0,0 +1,68 @@
+// SPDX-FileCopyrightText: 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package org.yuzu.yuzu_emu.utils
+
+import android.view.InputDevice
+import android.view.KeyEvent
+import android.view.MotionEvent
+
+/**
+ * Some controllers have incorrect mappings. This class has special-case fixes for them.
+ */
+class ControllerMappingHelper {
+    /**
+     * Some controllers report extra button presses that can be ignored.
+     */
+    fun shouldKeyBeIgnored(inputDevice: InputDevice, keyCode: Int): Boolean {
+        return if (isDualShock4(inputDevice)) {
+            // The two analog triggers generate analog motion events as well as a keycode.
+            // We always prefer to use the analog values, so throw away the button press
+            keyCode == KeyEvent.KEYCODE_BUTTON_L2 || keyCode == KeyEvent.KEYCODE_BUTTON_R2
+        } else false
+    }
+
+    /**
+     * Scale an axis to be zero-centered with a proper range.
+     */
+    fun scaleAxis(inputDevice: InputDevice, axis: Int, value: Float): Float {
+        if (isDualShock4(inputDevice)) {
+            // Android doesn't have correct mappings for this controller's triggers. It reports them
+            // as RX & RY, centered at -1.0, and with a range of [-1.0, 1.0]
+            // Scale them to properly zero-centered with a range of [0.0, 1.0].
+            if (axis == MotionEvent.AXIS_RX || axis == MotionEvent.AXIS_RY) {
+                return (value + 1) / 2.0f
+            }
+        } else if (isXboxOneWireless(inputDevice)) {
+            // Same as the DualShock 4, the mappings are missing.
+            if (axis == MotionEvent.AXIS_Z || axis == MotionEvent.AXIS_RZ) {
+                return (value + 1) / 2.0f
+            }
+            if (axis == MotionEvent.AXIS_GENERIC_1) {
+                // This axis is stuck at ~.5. Ignore it.
+                return 0.0f
+            }
+        } else if (isMogaPro2Hid(inputDevice)) {
+            // This controller has a broken axis that reports a constant value. Ignore it.
+            if (axis == MotionEvent.AXIS_GENERIC_1) {
+                return 0.0f
+            }
+        }
+        return value
+    }
+
+    // Sony DualShock 4 controller
+    private fun isDualShock4(inputDevice: InputDevice): Boolean {
+        return inputDevice.vendorId == 0x54c && inputDevice.productId == 0x9cc
+    }
+
+    // Microsoft Xbox One controller
+    private fun isXboxOneWireless(inputDevice: InputDevice): Boolean {
+        return inputDevice.vendorId == 0x45e && inputDevice.productId == 0x2e0
+    }
+
+    // Moga Pro 2 HID
+    private fun isMogaPro2Hid(inputDevice: InputDevice): Boolean {
+        return inputDevice.vendorId == 0x20d6 && inputDevice.productId == 0x6271
+    }
+}