making xinput to actually work (tested with xbone gamepad)

src/net/torvald/terrarum/controller/TerrarumController.kt

@@ -0,0 +1,66 @@
+package net.torvald.terrarum.controller
+
+/**
+ * Created by minjaesong on 2019-02-09.
+ */
+interface TerrarumController {
+
+    /**
+     * 0, 1, 2, 3 : A B X Y
+     *
+     * 4, 5 : L/R Shoulder
+     *
+     * 6, 7 : Back Start
+     *
+     * 8, 9 : L/R Trigger
+     *
+     * DirectInput devices may need external Index-to-button mapping (just a config file)
+     *
+     */
+    fun getButton(index: Int): Boolean
+
+    /**
+     * 0: Left Y
+     *
+     * 1: Left X
+     *
+     * 2: Right Y
+     *
+     * 3: Right X
+     *
+     * 4: Left Trigger
+     *
+     * 5: Right Trigger
+     *
+     * DirectInput devices may need external Index-to-button mapping (just a config file).
+     *
+     * Warning: Under DirectInput, Xbox controllers' LT and RT shares the same axis #4, and thus it's impossible to read LT+RT input.
+     *
+     * @return 0f..1f for the axis
+     */
+    fun getAxis(index: Int): Float
+
+    /**
+     * ```
+     * 12 8 9
+     *  4 0 1
+     *  6 2 3
+     * ```
+     */
+    fun getPov(): Int
+    fun getName(): String
+
+    fun setRumble(left: Float, right: Float)
+
+    companion object {
+        const val POV_E = 1
+        const val POV_S = 2
+        const val POV_W = 4
+        const val POV_N = 8
+
+        const val POV_SE = POV_E or POV_S
+        const val POV_SW = POV_W or POV_S
+        const val POV_NW = POV_W or POV_N
+        const val POV_NE = POV_E or POV_N
+    }
+}