From c9a5cea93e4a80fa595c9d87c4f06085b920760b Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Mon, 16 Jan 2023 21:05:11 -0600
Subject: [PATCH] Add Sunshine protocol extension to support non-normalized key
 codes

---
 src/Input.h       | 2 +-
 src/InputStream.c | 8 ++++++--
 src/Limelight.h   | 8 ++++++++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/Input.h b/src/Input.h
index 4cc2029..3c0681b 100644
--- a/src/Input.h
+++ b/src/Input.h
@@ -17,7 +17,7 @@ typedef struct _NV_HAPTICS_PACKET {
 #define KEY_UP_EVENT_MAGIC 0x00000004
 typedef struct _NV_KEYBOARD_PACKET {
     NV_INPUT_HEADER header;
-    char zero1;
+    char flags; // Sunshine extension (always 0 for GFE)
     short keyCode;
     char modifiers;
     short zero2;
diff --git a/src/InputStream.c b/src/InputStream.c
index 523461f..7dc0546 100644
--- a/src/InputStream.c
+++ b/src/InputStream.c
@@ -675,7 +675,7 @@ int LiSendMouseButtonEvent(char action, int button) {
 }
 
 // Send a key press event to the streaming machine
-int LiSendKeyboardEvent(short keyCode, char keyAction, char modifiers) {
+int LiSendKeyboardEvent2(short keyCode, char keyAction, char modifiers, char flags) {
     PPACKET_HOLDER holder;
     int err;
 
@@ -732,7 +732,7 @@ int LiSendKeyboardEvent(short keyCode, char keyAction, char modifiers) {
 
     holder->packet.keyboard.header.size = BE32(sizeof(NV_KEYBOARD_PACKET) - sizeof(uint32_t));
     holder->packet.keyboard.header.magic = LE32((uint32_t)keyAction);
-    holder->packet.keyboard.zero1 = 0;
+    holder->packet.keyboard.flags = IS_SUNSHINE() ? flags : 0;
     holder->packet.keyboard.keyCode = LE16(keyCode);
     holder->packet.keyboard.modifiers = modifiers;
     holder->packet.keyboard.zero2 = 0;
@@ -747,6 +747,10 @@ int LiSendKeyboardEvent(short keyCode, char keyAction, char modifiers) {
     return err;
 }
 
+int LiSendKeyboardEvent(short keyCode, char keyAction, char modifiers) {
+    return LiSendKeyboardEvent2(keyCode, keyAction, modifiers, 0);
+}
+
 int LiSendUtf8TextEvent(const char *text, unsigned int length) {
     PPACKET_HOLDER holder;
     int err;
diff --git a/src/Limelight.h b/src/Limelight.h
index 8ce50a8..06d474d 100644
--- a/src/Limelight.h
+++ b/src/Limelight.h
@@ -546,6 +546,8 @@ int LiSendMouseMoveAsMousePositionEvent(short deltaX, short deltaY, short refere
 int LiSendMouseButtonEvent(char action, int button);
 
 // This function queues a keyboard event to be sent to the remote server.
+// Key codes are Win32 Virtual Key (VK) codes and interpreted as keys on
+// a US English layout.
 #define KEY_ACTION_DOWN 0x03
 #define KEY_ACTION_UP 0x04
 #define MODIFIER_SHIFT 0x01
@@ -554,6 +556,12 @@ int LiSendMouseButtonEvent(char action, int button);
 #define MODIFIER_META 0x08
 int LiSendKeyboardEvent(short keyCode, char keyAction, char modifiers);
 
+// Similar to LiSendKeyboardEvent() but allows the client to inform the host that
+// the keycode was not mapped to a standard US English scancode and should be
+// interpreted as-is. This is a Sunshine protocol extension.
+#define SS_KBE_FLAG_NON_NORMALIZED 0x01
+int LiSendKeyboardEvent2(short keyCode, char keyAction, char modifiers, char flags);
+
 // This function queues an UTF-8 encoded text to be sent to the remote server.
 int LiSendUtf8TextEvent(const char *text, unsigned int length);