From 6a7b33046393d85a151dbd846e76e5c28961adf4 Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Wed, 28 Jun 2023 04:47:12 +0300
Subject: [PATCH] engine: common: net_encode: fix Delta_CompareField to include
 integer clamping, in case if no updates happen in significant bits

---
 engine/common/net_encode.c | 62 +++++++++++++++++++++++++++++++-------
 1 file changed, 51 insertions(+), 11 deletions(-)

diff --git a/engine/common/net_encode.c b/engine/common/net_encode.c
index 3a5ced96..f19930cf 100644
--- a/engine/common/net_encode.c
+++ b/engine/common/net_encode.c
@@ -948,6 +948,7 @@ static qboolean Delta_CompareField( delta_t *pField, void *from, void *to, doubl
 	uint8_t *from_field = (uint8_t *)from + pField->offset;
 	uint8_t *to_field = (uint8_t *)to + pField->offset;
 	uint field_type = pField->flags & ~DT_SIGNED;
+	int signbit = FBitSet( pField->flags, DT_SIGNED ) ? 1 : 0;
 	int fromF;
 	int toF;
 
@@ -957,29 +958,68 @@ static qboolean Delta_CompareField( delta_t *pField, void *from, void *to, doubl
 	switch( field_type )
 	{
 	case DT_BYTE:
-		return *to_field == *from_field;
+		if( signbit )
+		{
+			fromF = *(int8_t *)from_field;
+			toF   = *(int8_t *)to_field;
+		}
+		else
+		{
+			fromF = *(uint8_t *)from_field;
+			toF   = *(uint8_t *)to_field;
+		}
+		break;
 	case DT_SHORT:
-		return *(uint16_t *)to_field == *(uint16_t *)from_field;
+		if( signbit )
+		{
+			fromF = *(int16_t *)from_field;
+			toF   = *(int16_t *)to_field;
+		}
+		else
+		{
+			fromF = *(uint16_t *)from_field;
+			toF   = *(uint16_t *)to_field;
+		}
+		break;
 	case DT_INTEGER:
+		if( signbit )
+		{
+			fromF = *(int32_t *)from_field;
+			toF   = *(int32_t *)to_field;
+		}
+		else
+		{
+			fromF = *(uint32_t *)from_field;
+			toF   = *(uint32_t *)to_field;
+		}
+		break;
 	case DT_ANGLE:
 	case DT_FLOAT:
 		return *(uint32_t *)to_field == *(uint32_t *)from_field;
 	case DT_TIMEWINDOW_8:
-		fromF = (int)((*(float *)from_field) * 100.0f );
-		toF   = (int)((*(float *)to_field) * 100.0f );
-		return toF == fromF;
+		fromF = Q_rint((*(float *)from_field) * 100.0f );
+		toF   = Q_rint((*(float *)to_field) * 100.0f );
+		return fromF == toF;
 	case DT_TIMEWINDOW_BIG:
-		fromF = (int)((*(float *)from_field) * pField->multiplier );
-		toF   = (int)((*(float *)to_field) * pField->multiplier );
-		return toF == fromF;
+		fromF = Q_rint((*(float *)from_field) * 1000.0f );
+		toF   = Q_rint((*(float *)to_field) * 1000.0f );
+		return fromF == toF;
 	case DT_STRING:
 		return Q_strcmp( to_field, from_field ) == 0;
 	default:
-		break;
+		Con_Reportf( S_ERROR "bad field %s type: %d\n", pField->name, pField->flags );
+		return true;
 	}
 
-	Con_Reportf( S_ERROR "bad field %s type: %d\n", pField->name, pField->flags );
-	return false;
+	// if fields are equal, no need to clamp, return immediately
+	if( toF == fromF )
+		return true;
+
+	// clamp integer fields
+	fromF = Delta_ClampIntegerField( pField, fromF, signbit, pField->bits );
+	toF   = Delta_ClampIntegerField( pField, toF, signbit, pField->bits );
+
+	return toF == fromF;
 }
 
 /*