Document some build square assumptions and expose build grid resoluti…

…on to Lua. (#1865)
beyond-all-reason · Jan 8, 2025 · cec8d5c · cec8d5c
1 parent 71a2a4d
commit cec8d5c
Show file tree

Hide file tree

Showing 4 changed files with 28 additions and 3 deletions.
diff --git a/rts/Game/Game.cpp b/rts/Game/Game.cpp
@@ -543,8 +543,11 @@ void CGame::LoadMap(const std::string& mapFileName)
 		helper->Init();
 		readMap = CReadMap::LoadMap(mapFileName);
 
-		// half size; building positions are snapped to multiples of BUILD_SQUARE_SIZE
+		/* Uses half-size grid because it *incorrectly* assumes
+		 * building positions are always snapped to the build grid. */
+		static_assert(BUILD_GRID_RESOLUTION == 2);
 		buildingMaskMap.Init(mapDims.hmapx * mapDims.hmapy);
+
 		groundBlockingObjectMap.Init(mapDims.mapSquares);
 		yardmapStatusEffectsMap.InitNewYardmapStatusEffectsMap();
 	}

diff --git a/rts/Game/GameHelper.cpp b/rts/Game/GameHelper.cpp
@@ -986,6 +986,8 @@ float3 CGameHelper::Pos2BuildPos(const BuildInfo& buildInfo, bool synced)
 	RECOIL_DETAILED_TRACY_ZONE;
 	float3 pos;
 
+	static_assert(BUILD_GRID_RESOLUTION == 2);
+
 	// snap build-positions to 16-elmo grid
 	if (buildInfo.GetXSize() & 2)
 		pos.x = math::floor((buildInfo.pos.x              ) / BUILD_SQUARE_SIZE) * BUILD_SQUARE_SIZE + SQUARE_SIZE;
@@ -1125,6 +1127,11 @@ float3 CGameHelper::ClosestBuildPos(
 		const int xsize = bi.GetXSize();
 		const int zsize = bi.GetZSize();
 
+		/* I'm not sure which of these two the `2` below represents,
+		 * maybe it even assumes both are the same? */
+		static_assert(BUILD_GRID_RESOLUTION == 2);
+		static_assert(SPRING_FOOTPRINT_SCALE == 2);
+
 		int xmin = std::max(           0, xsqr - (xsize    ) / 2 - minDistance);
 		int zmin = std::max(           0, zsqr - (zsize    ) / 2 - minDistance);
 		int xmax = std::min(mapDims.mapx, xsqr + (xsize + 1) / 2 + minDistance);

diff --git a/rts/Lua/LuaConstGame.cpp b/rts/Lua/LuaConstGame.cpp
@@ -121,6 +121,7 @@ bool LuaConstGame::PushEntries(lua_State* L)
 		LuaPushNamedNumber(L, "squareSize", SQUARE_SIZE);
 		LuaPushNamedNumber(L, "metalMapSquareSize", METAL_MAP_SQUARE_SIZE);
 		LuaPushNamedNumber(L, "buildSquareSize", BUILD_SQUARE_SIZE);
+		LuaPushNamedNumber(L, "buildGridResolution", BUILD_GRID_RESOLUTION);
 		LuaPushNamedNumber(L, "footprintScale", SPRING_FOOTPRINT_SCALE);
 	}
 

diff --git a/rts/Sim/Misc/GlobalConstants.h b/rts/Sim/Misc/GlobalConstants.h
@@ -21,8 +21,22 @@ static constexpr int SPRING_FOOTPRINT_SCALE = 2;
  *
  * Defines the size of 1 heightmap square as 8 elmos.
  */
-static constexpr int       SQUARE_SIZE =               8;
-static constexpr int BUILD_SQUARE_SIZE = SQUARE_SIZE * 2;
+static constexpr int SQUARE_SIZE = 8;
+
+/**
+ * @brief Building grid resolution
+ *
+ * Defines the resolution of the native build placement GUI, and maybe
+ * other related things.
+ *
+ * This probably makes the most sense to equal `SPRING_FOOTPRINT_SCALE`,
+ * but it doesn't have to be. It would be good to make it controllable
+ * by games at some point (modrule?), but there may be many assumptions
+ * elsewhere that this is equal to `SPRING_FOOTPRINT_SCALE` or to 2.
+ * Some are marked via static asserts but coverage is NOT comprehensive. */
+static constexpr int BUILD_GRID_RESOLUTION = SPRING_FOOTPRINT_SCALE;
+
+static constexpr int BUILD_SQUARE_SIZE = SQUARE_SIZE * BUILD_GRID_RESOLUTION;
 
 
 /**