From 49e013d164538e2afc39c37f1b4bc156720ece86 Mon Sep 17 00:00:00 2001
From: xezon <4720891+xezon@users.noreply.github.com>
Date: Sun, 1 Nov 2026 17:12:26 +0100
Subject: [PATCH] bugfix(baseheightmap): Restore Generals retail compatibility
 from floor math changes in BaseHeightMapRenderObjClass::getHeightMapHeight()

Merging the Height Map code made getHeightMapHeight() of Generals use fast_float_floor
instead of floorf. The game sets the FPU to round to nearest, under which
fast_float_floor returns n-1 for negative whole numbers. Positions on a negative
multiple of the cell size then use the neighbouring cell and get a different height.

A retail compatible Zero Hour keeps fast_float_floor, because its replays depend on its
results. All other configurations use WWMath::Floorf, which is floorf, or gm_floorf with
deterministic math. This restores the retail heights for a retail compatible Generals.
Without retail compatibility, Generals and Zero Hour now floor these positions right.

The FAST_REAL_TRUNC, FAST_REAL_CEIL and FAST_REAL_FLOOR macros lost their last user and
are removed.
---
 .../Source/W3DDevice/GameClient/BaseHeightMap.cpp        | 9 +++++++--
 Core/Libraries/Source/Lib/Include/Lib/BaseFunctions.h    | 4 ----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/Core/GameEngineDevice/Source/W3DDevice/GameClient/BaseHeightMap.cpp b/Core/GameEngineDevice/Source/W3DDevice/GameClient/BaseHeightMap.cpp
index 10df2b9d77f..19d7e5dc8ea 100644
--- a/Core/GameEngineDevice/Source/W3DDevice/GameClient/BaseHeightMap.cpp
+++ b/Core/GameEngineDevice/Source/W3DDevice/GameClient/BaseHeightMap.cpp
@@ -908,8 +908,13 @@ Real BaseHeightMapRenderObjClass::getHeightMapHeight(Real x, Real y, Coord3D* no
 	float xdiv = x * MAP_XY_FACTOR_INV;
 	float ydiv = y * MAP_XY_FACTOR_INV;
 
-	float ixf = FAST_REAL_FLOOR(xdiv);
-	float iyf = FAST_REAL_FLOOR(ydiv);
+#if RTS_ZEROHOUR && RETAIL_COMPATIBLE_CRC
+	float ixf = fast_float_floor(xdiv);
+	float iyf = fast_float_floor(ydiv);
+#else
+	float ixf = WWMath::Floorf(xdiv);
+	float iyf = WWMath::Floorf(ydiv);
+#endif
 
 	float fx = xdiv - ixf; //get fraction
 	float fy = ydiv - iyf; //get fraction
diff --git a/Core/Libraries/Source/Lib/Include/Lib/BaseFunctions.h b/Core/Libraries/Source/Lib/Include/Lib/BaseFunctions.h
index 9a359d02cdd..c481fb73c0d 100644
--- a/Core/Libraries/Source/Lib/Include/Lib/BaseFunctions.h
+++ b/Core/Libraries/Source/Lib/Include/Lib/BaseFunctions.h
@@ -101,10 +101,6 @@ __forceinline float fast_float_ceil(float f)
 #define REAL_TO_INT_FLOOR(x)			(fast_float2long_round(fast_float_floor(x)))
 #endif
 
-#define FAST_REAL_TRUNC(x)        fast_float_trunc(x)
-#define FAST_REAL_CEIL(x)         fast_float_ceil(x)
-#define FAST_REAL_FLOOR(x)        fast_float_floor(x)
-
 //-------------------------------------------------------------------------------------------------
 // Checking whether a size matches the bit flags count from an enum definition:
 // enum MyEnum