Merge pull request #21611 from RandomShaper/fix-wacom-input

Fix multitouch input not working on certain devices on Windows

platform/windows/os_windows.cpp

@@ -249,7 +249,11 @@ bool OS_Windows::can_draw() const {
 
 #define MI_WP_SIGNATURE 0xFF515700
 #define SIGNATURE_MASK 0xFFFFFF00
+// Keeping the name suggested by Microsoft, but this macro really answers:
+// Is this mouse event emulated from touch or pen input?
 #define IsPenEvent(dw) (((dw)&SIGNATURE_MASK) == MI_WP_SIGNATURE)
+// This one tells whether the event comes from touchscreen (and not from pen)
+#define IsTouchEvent(dw) (IsPenEvent(dw) && ((dw)&0x80))
 
 void OS_Windows::_touch_event(bool p_pressed, float p_x, float p_y, int idx) {
 
@@ -469,7 +473,7 @@ LRESULT OS_Windows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			if (input->is_emulating_mouse_from_touch()) {
 				// Universal translation enabled; ignore OS translation
 				LPARAM extra = GetMessageExtraInfo();
-				if (IsPenEvent(extra)) {
+				if (IsTouchEvent(extra)) {
 					break;
 				}
 			}
@@ -560,7 +564,7 @@ LRESULT OS_Windows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			if (input->is_emulating_mouse_from_touch()) {
 				// Universal translation enabled; ignore OS translations for left button
 				LPARAM extra = GetMessageExtraInfo();
-				if (IsPenEvent(extra)) {
+				if (IsTouchEvent(extra)) {
 					break;
 				}
 			}