custom keyboard handling wip

src/net/torvald/terrarum/gamecontroller/IME.kt

@@ -0,0 +1,60 @@
+package net.torvald.terrarum.gamecontroller
+
+import com.badlogic.gdx.Gdx
+import net.torvald.terrarum.App.printdbg
+
+typealias TerrarumKeyLayout = Array<Array<String?>>
+
+/**
+ * IME consists of two keyboard layers:
+ * - Low layer: "english" keyboard (qwerty, colemak, etc), stateless
+ * - High layer: chinese/japanese/korean/etc. keyboard, stateful
+ *
+ * Input to the IME Keyboard layout is always GDX/LWJGL3 keycode (only LWJGL3 offers OS-Keylayout-independent keycodes)
+ *
+ * Created by minjaesong on 2021-10-20.
+ */
+object IME {
+
+    const val KEYLAYOUT_DIR = "assets/keylayout/"
+    const val KEYLAYOUT_EXTENSION = ".key"
+
+    private val cached = HashMap<String, TerrarumKeyLayout>()
+
+    private val context = org.graalvm.polyglot.Context.newBuilder("js")
+            .allowHostAccess(org.graalvm.polyglot.HostAccess.NONE)
+            .allowHostClassLookup { false }
+            .allowIO(false)
+            .build()
+
+    fun getLowLayerByName(name: String): TerrarumKeyLayout {
+        return cached.getOrPut(name) { parseKeylayoutFile("$KEYLAYOUT_DIR$name$KEYLAYOUT_EXTENSION") }
+    }
+
+
+
+    private fun parseKeylayoutFile(path: String): TerrarumKeyLayout {
+        val file = Gdx.files.internal(path)
+        val src = file.readString("UTF-8")
+        val jsval = context.eval("js", src)
+        val out = Array(256) { Array<String?>(4) { null } }
+        for (keycode in 0L until 256L) {
+            val a = jsval.getArrayElement(keycode)
+            if (!a.isNull) {
+                for (layer in 0L until 4L) {
+                    if (a.arraySize > layer) {
+                        val b = a.getArrayElement(layer)
+                        if (!b.isNull) {
+                            out[keycode.toInt()][layer.toInt()] = b.asString()
+                        }
+                    }
+                }
+            }
+        }
+
+        //println("[IME] Test Keymap print:"); for (keycode in 0 until 256) { print("$keycode:\t"); println(out[keycode].joinToString("\t")) }
+
+        return out
+    }
+
+}