From 8a5bd522c7706a3ef180bc19ddba9288d4aa416c Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Fri, 21 Jan 2022 15:47:40 +0100
Subject: [PATCH] Fixed scaling of discrete wheel input.

---
 client/common/client.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/client/common/client.c b/client/common/client.c
index 52d63596a..b21b2833a 100644
--- a/client/common/client.c
+++ b/client/common/client.c
@@ -1029,19 +1029,25 @@ BOOL freerdp_client_send_wheel_event(rdpClientContext* cctx, UINT16 mflags)
 		UINT rc;
 		UINT64 flags = 0;
 		INT32 x = 0, y = 0;
+		INT32 value = mflags & 0xFF;
+
+		if (mflags & PTR_FLAGS_WHEEL_NEGATIVE)
+			value = -1 * (0x100 - value);
+
 		if (mflags & PTR_FLAGS_WHEEL)
 		{
 			flags |= AINPUT_FLAGS_WHEEL;
-			x = flags & 0xff;
-			if (mflags & PTR_FLAGS_WHEEL_NEGATIVE)
-				x = -x;
+			y = value;
 		}
+
+		/* We have discrete steps, scale this so we can also support high
+		 * resolution wheels. */
+		value *= 0x10000;
+
 		if (mflags & PTR_FLAGS_HWHEEL)
 		{
 			flags |= AINPUT_FLAGS_WHEEL;
-			y = flags & 0xff;
-			if (mflags & PTR_FLAGS_WHEEL_NEGATIVE)
-				y = -y;
+			x = value;
 		}
 
 		WINPR_ASSERT(cctx->ainput->AInputSendInputEvent);