Add terrain orientation support for Mobile.

OpenRA.Game/Map/Map.cs

@@ -900,6 +900,14 @@ namespace OpenRA
 			return new WDist(offset.Z);
 		}
 
+		public WRot TerrainOrientation(CPos cell)
+		{
+			if (!Ramp.Contains(cell))
+				return WRot.None;
+
+			return Grid.Ramps[Ramp[cell]].Orientation;
+		}
+
 		public WVec Offset(CVec delta, int dz)
 		{
 			if (Grid.Type == MapGridType.Rectangular)

OpenRA.Game/Map/MapGrid.cs

@@ -27,9 +27,11 @@ namespace OpenRA
 		public readonly int CenterHeightOffset;
 		public readonly WVec[] Corners;
 		public readonly WVec[][] Polygons;
+		public readonly WRot Orientation;
 
-		public CellRamp(MapGridType type, RampCornerHeight tl = RampCornerHeight.Low, RampCornerHeight tr = RampCornerHeight.Low, RampCornerHeight br = RampCornerHeight.Low,  RampCornerHeight bl = RampCornerHeight.Low, RampSplit split = RampSplit.Flat)
+		public CellRamp(MapGridType type, WRot orientation, RampCornerHeight tl = RampCornerHeight.Low, RampCornerHeight tr = RampCornerHeight.Low, RampCornerHeight br = RampCornerHeight.Low,  RampCornerHeight bl = RampCornerHeight.Low, RampSplit split = RampSplit.Flat)
 		{
+			Orientation = orientation;
 			if (type == MapGridType.RectangularIsometric)
 			{
 				Corners = new[]
@@ -138,41 +140,52 @@ namespace OpenRA
 					throw new InvalidDataException("Subcell default index must be a valid index into the offset triples and must be greater than 0 for mods with subcells");
 			}
 
+			// Rotation axes and amounts for the different slope types
+			var southEast = new WVec(724, 724, 0);
+			var southWest = new WVec(-724, 724, 0);
+			var south = new WVec(0, 1024, 0);
+			var east = new WVec(1024, 0, 0);
+
+			var forward = new WAngle(64);
+			var backward = -forward;
+			var halfForward = new WAngle(48);
+			var halfBackward = -halfForward;
+
 			// Slope types are hardcoded following the convention from the TS and RA2 map format
 			Ramps = new[]
 			{
 				// Flat
-				new CellRamp(Type),
+				new CellRamp(Type, WRot.None),
 
 				// Two adjacent corners raised by half a cell
-				new CellRamp(Type, tr: RampCornerHeight.Half, br: RampCornerHeight.Half),
+				new CellRamp(Type, new WRot(southEast, backward), tr: RampCornerHeight.Half, br: RampCornerHeight.Half),
-				new CellRamp(Type, br: RampCornerHeight.Half, bl: RampCornerHeight.Half),
+				new CellRamp(Type, new WRot(southWest, backward), br: RampCornerHeight.Half, bl: RampCornerHeight.Half),
-				new CellRamp(Type, tl: RampCornerHeight.Half, bl: RampCornerHeight.Half),
+				new CellRamp(Type, new WRot(southEast, forward), tl: RampCornerHeight.Half, bl: RampCornerHeight.Half),
-				new CellRamp(Type, tl: RampCornerHeight.Half, tr: RampCornerHeight.Half),
+				new CellRamp(Type, new WRot(southWest, forward), tl: RampCornerHeight.Half, tr: RampCornerHeight.Half),
 
 				// One corner raised by half a cell
-				new CellRamp(Type, br: RampCornerHeight.Half, split: RampSplit.X),
+				new CellRamp(Type, new WRot(south, halfBackward), br: RampCornerHeight.Half, split: RampSplit.X),
-				new CellRamp(Type, bl: RampCornerHeight.Half, split: RampSplit.Y),
+				new CellRamp(Type, new WRot(east, halfForward), bl: RampCornerHeight.Half, split: RampSplit.Y),
-				new CellRamp(Type, tl: RampCornerHeight.Half, split: RampSplit.X),
+				new CellRamp(Type, new WRot(south, halfForward), tl: RampCornerHeight.Half, split: RampSplit.X),
-				new CellRamp(Type, tr: RampCornerHeight.Half, split: RampSplit.Y),
+				new CellRamp(Type, new WRot(east, halfBackward), tr: RampCornerHeight.Half, split: RampSplit.Y),
 
 				// Three corners raised by half a cell
-				new CellRamp(Type, tr: RampCornerHeight.Half, br: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.X),
+				new CellRamp(Type, new WRot(south, halfBackward), tr: RampCornerHeight.Half, br: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.X),
-				new CellRamp(Type, tl: RampCornerHeight.Half, br: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.Y),
+				new CellRamp(Type, new WRot(east, halfForward), tl: RampCornerHeight.Half, br: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.Y),
-				new CellRamp(Type, tl: RampCornerHeight.Half, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.X),
+				new CellRamp(Type, new WRot(south, halfForward), tl: RampCornerHeight.Half, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.X),
-				new CellRamp(Type, tl: RampCornerHeight.Half, tr: RampCornerHeight.Half, br: RampCornerHeight.Half, split: RampSplit.Y),
+				new CellRamp(Type, new WRot(east, halfBackward), tl: RampCornerHeight.Half, tr: RampCornerHeight.Half, br: RampCornerHeight.Half, split: RampSplit.Y),
 
 				// Full tile sloped (mid corners raised by half cell, far corner by full cell)
-				new CellRamp(Type, tr: RampCornerHeight.Half, br: RampCornerHeight.Full, bl: RampCornerHeight.Half),
+				new CellRamp(Type, new WRot(south, backward), tr: RampCornerHeight.Half, br: RampCornerHeight.Full, bl: RampCornerHeight.Half),
-				new CellRamp(Type, tl: RampCornerHeight.Half, br: RampCornerHeight.Half, bl: RampCornerHeight.Full),
+				new CellRamp(Type, new WRot(east, forward), tl: RampCornerHeight.Half, br: RampCornerHeight.Half, bl: RampCornerHeight.Full),
-				new CellRamp(Type, tl: RampCornerHeight.Full, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half),
+				new CellRamp(Type, new WRot(south, forward), tl: RampCornerHeight.Full, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half),
-				new CellRamp(Type, tl: RampCornerHeight.Half, tr: RampCornerHeight.Full, br: RampCornerHeight.Half),
+				new CellRamp(Type, new WRot(east, backward), tl: RampCornerHeight.Half, tr: RampCornerHeight.Full, br: RampCornerHeight.Half),
 
 				// Two opposite corners raised by half a cell
-				new CellRamp(Type, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.Y),
+				new CellRamp(Type, WRot.None, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.Y),
-				new CellRamp(Type, tl: RampCornerHeight.Half, br: RampCornerHeight.Half, split: RampSplit.Y),
+				new CellRamp(Type, WRot.None, tl: RampCornerHeight.Half, br: RampCornerHeight.Half, split: RampSplit.Y),
-				new CellRamp(Type, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.X),
+				new CellRamp(Type, WRot.None, tr: RampCornerHeight.Half, bl: RampCornerHeight.Half, split: RampSplit.X),
-				new CellRamp(Type, tl: RampCornerHeight.Half, br: RampCornerHeight.Half, split: RampSplit.X),
+				new CellRamp(Type, WRot.None, tl: RampCornerHeight.Half, br: RampCornerHeight.Half, split: RampSplit.X),
 			};
 
 			TilesByDistance = CreateTilesByDistance();

OpenRA.Mods.Common/Activities/Move/Move.cs

@@ -221,7 +221,12 @@ namespace OpenRA.Mods.Common.Activities
 			var to = Util.BetweenCells(self.World, mobile.FromCell, mobile.ToCell) +
 				(map.Grid.OffsetOfSubCell(mobile.FromSubCell) + map.Grid.OffsetOfSubCell(mobile.ToSubCell)) / 2;
 
-			QueueChild(new MoveFirstHalf(this, from, to, mobile.Facing, mobile.Facing, carryoverProgress));
+			WRot? toTerrainOrientation = null;
+			var margin = mobile.Info.TerrainOrientationAdjustmentMargin.Length;
+			if (margin >= 0)
+				toTerrainOrientation = WRot.SLerp(map.TerrainOrientation(mobile.FromCell), map.TerrainOrientation(mobile.ToCell), 1, 2);
+
+			QueueChild(new MoveFirstHalf(this, from, to, mobile.Facing, mobile.Facing, null, toTerrainOrientation, margin, carryoverProgress));
 			carryoverProgress = 0;
 			return false;
 		}
@@ -389,6 +394,7 @@ namespace OpenRA.Mods.Common.Activities
 			protected readonly Move Move;
 			protected readonly WPos From, To;
 			protected readonly WAngle FromFacing, ToFacing;
+			protected readonly WRot? FromTerrainOrientation, ToTerrainOrientation;
 			protected readonly bool EnableArc;
 			protected readonly WPos ArcCenter;
 			protected readonly int ArcFromLength;
@@ -396,17 +402,22 @@ namespace OpenRA.Mods.Common.Activities
 			protected readonly int ArcToLength;
 			protected readonly WAngle ArcToAngle;
 			protected readonly int Distance;
+			readonly int terrainOrientationMargin;
 			protected int progress;
 
-			public MovePart(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing, int carryoverProgress)
+			public MovePart(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing,
+				WRot? fromTerrainOrientation, WRot? toTerrainOrientation, int terrainOrientationMargin, int carryoverProgress)
 			{
 				Move = move;
 				From = from;
 				To = to;
 				FromFacing = fromFacing;
 				ToFacing = toFacing;
+				FromTerrainOrientation = fromTerrainOrientation;
+				ToTerrainOrientation = toTerrainOrientation;
 				progress = carryoverProgress;
 				Distance = (to - from).Length;
+				this.terrainOrientationMargin = Math.Min(terrainOrientationMargin, Distance / 2);
 
 				IsInterruptible = false; // See comments in Move.Cancel()
 
@@ -471,6 +482,21 @@ namespace OpenRA.Mods.Common.Activities
 					pos -= new WVec(WDist.Zero, WDist.Zero, self.World.Map.DistanceAboveTerrain(pos));
 
 				mobile.SetCenterPosition(self, pos);
+
+				// Smoothly interpolate over terrain orientation changes
+				if (FromTerrainOrientation.HasValue && progress < terrainOrientationMargin)
+				{
+					var currentCellOrientation = self.World.Map.TerrainOrientation(mobile.FromCell);
+					var orientation = WRot.SLerp(FromTerrainOrientation.Value, currentCellOrientation, progress, terrainOrientationMargin);
+					mobile.SetTerrainRampOrientation(self, orientation);
+				}
+				else if (ToTerrainOrientation.HasValue && Distance - progress < terrainOrientationMargin)
+				{
+					var currentCellOrientation = self.World.Map.TerrainOrientation(mobile.FromCell);
+					var orientation = WRot.SLerp(ToTerrainOrientation.Value, currentCellOrientation, Distance - progress, terrainOrientationMargin);
+					mobile.SetTerrainRampOrientation(self, orientation);
+				}
+
 				mobile.Facing = WAngle.Lerp(FromFacing, ToFacing, progress, Distance);
 				return false;
 			}
@@ -485,8 +511,9 @@ namespace OpenRA.Mods.Common.Activities
 
 		class MoveFirstHalf : MovePart
 		{
-			public MoveFirstHalf(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing, int carryoverProgress)
+			public MoveFirstHalf(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing,
-				: base(move, from, to, fromFacing, toFacing, carryoverProgress) { }
+				WRot? fromTerrainOrientation, WRot? toTerrainOrientation, int terrainOrientationMargin, int carryoverProgress)
+				: base(move, from, to, fromFacing, toFacing, fromTerrainOrientation, toTerrainOrientation, terrainOrientationMargin, carryoverProgress) { }
 
 			static bool IsTurn(Mobile mobile, CPos nextCell, Map map)
 			{
@@ -513,12 +540,20 @@ namespace OpenRA.Mods.Common.Activities
 					if (!mobile.IsTraitPaused && !mobile.IsTraitDisabled && IsTurn(mobile, nextCell.Value.Cell, map))
 					{
 						var nextSubcellOffset = map.Grid.OffsetOfSubCell(nextCell.Value.SubCell);
+						WRot? nextToTerrainOrientation = null;
+						var margin = mobile.Info.TerrainOrientationAdjustmentMargin.Length;
+						if (margin >= 0)
+							nextToTerrainOrientation = WRot.SLerp(map.TerrainOrientation(mobile.ToCell), map.TerrainOrientation(nextCell.Value.Cell), 1, 2);
+
 						var ret = new MoveFirstHalf(
 							Move,
 							Util.BetweenCells(self.World, mobile.FromCell, mobile.ToCell) + (fromSubcellOffset + toSubcellOffset) / 2,
 							Util.BetweenCells(self.World, mobile.ToCell, nextCell.Value.Cell) + (toSubcellOffset + nextSubcellOffset) / 2,
 							mobile.Facing,
 							map.FacingBetween(mobile.ToCell, nextCell.Value.Cell, mobile.Facing),
+							ToTerrainOrientation,
+							nextToTerrainOrientation,
+							margin,
 							progress - Distance);
 
 						mobile.FinishedMoving(self);
@@ -538,6 +573,9 @@ namespace OpenRA.Mods.Common.Activities
 					toPos + toSubcellOffset,
 					mobile.Facing,
 					mobile.Facing,
+					ToTerrainOrientation,
+					null,
+					mobile.Info.TerrainOrientationAdjustmentMargin.Length,
 					progress - Distance);
 
 				mobile.EnteringCell(self);
@@ -548,8 +586,9 @@ namespace OpenRA.Mods.Common.Activities
 
 		class MoveSecondHalf : MovePart
 		{
-			public MoveSecondHalf(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing, int carryoverProgress)
+			public MoveSecondHalf(Move move, WPos from, WPos to, WAngle fromFacing, WAngle toFacing,
-				: base(move, from, to, fromFacing, toFacing, carryoverProgress) { }
+				WRot? fromTerrainOrientation, WRot? toTerrainOrientation, int terrainOrientationMargin, int carryoverProgress)
+				: base(move, from, to, fromFacing, toFacing, fromTerrainOrientation, toTerrainOrientation, terrainOrientationMargin, carryoverProgress) { }
 
 			protected override MovePart OnComplete(Actor self, Mobile mobile, Move parent)
 			{

OpenRA.Mods.Common/Graphics/ModelRenderable.cs

@@ -133,8 +133,12 @@ namespace OpenRA.Mods.Common.Graphics
 				this.model = model;
 				var draw = model.models.Where(v => v.IsVisible);
 
+				var map = wr.World.Map;
+				var groundOrientation = map.TerrainOrientation(map.CellContaining(model.pos));
+				var groundNormal = OpenRA.Graphics.Util.MatrixVectorMultiply(OpenRA.Graphics.Util.MakeFloatMatrix(groundOrientation.AsMatrix()), GroundNormal);
+
 				renderProxy = Game.Renderer.WorldModelRenderer.RenderAsync(
-					wr, draw, model.camera, model.scale, GroundNormal, model.lightSource,
+					wr, draw, model.camera, model.scale, groundNormal, model.lightSource,
 					model.lightAmbientColor, model.lightDiffuseColor,
 					model.palette, model.normalsPalette, model.shadowPalette);
 			}

OpenRA.Mods.Common/Traits/Mobile.cs

@@ -74,6 +74,10 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Boolean expression defining the condition under which this actor cannot be nudged by other actors.")]
 		public readonly BooleanExpression ImmovableCondition = null;
 
+		[Desc("The distance from the edge of a cell over which the actor will adjust its tilt when moving between cells with different ramp types.",
+			"-1 means that the actor does not tilt on slopes.")]
+		public readonly WDist TerrainOrientationAdjustmentMargin = new WDist(-1);
+
 		IEnumerable<ActorInit> IActorPreviewInitInfo.ActorPreviewInits(ActorInfo ai, ActorPreviewType type)
 		{
 			yield return new FacingInit(PreviewFacing);
@@ -183,6 +187,7 @@ namespace OpenRA.Mods.Common.Traits
 		}
 		#endregion
 
+		WRot terrainRampOrientation = WRot.None;
 		WAngle oldFacing;
 		WRot orientation;
 		WPos oldPos;
@@ -211,7 +216,7 @@ namespace OpenRA.Mods.Common.Traits
 			set => orientation = orientation.WithYaw(value);
 		}
 
-		public WRot Orientation => orientation;
+		public WRot Orientation => orientation.Rotate(terrainRampOrientation);
 
 		public WAngle TurnSpeed => Info.TurnSpeed;
 
@@ -485,6 +490,9 @@ namespace OpenRA.Mods.Common.Traits
 			CenterPosition = pos;
 			self.World.UpdateMaps(self, this);
 
+			var map = self.World.Map;
+			SetTerrainRampOrientation(self, map.TerrainOrientation(map.CellContaining(pos)));
+
 			// The first time SetCenterPosition is called is in the constructor before creation, so we need a null check here as well
 			if (notifyCenterPositionChanged == null)
 				return;
@@ -493,6 +501,12 @@ namespace OpenRA.Mods.Common.Traits
 				n.CenterPositionChanged(self, fromCell.Layer, toCell.Layer);
 		}
 
+		public void SetTerrainRampOrientation(Actor self, WRot orientation)
+		{
+			if (Info.TerrainOrientationAdjustmentMargin.Length >= 0)
+				terrainRampOrientation = orientation;
+		}
+
 		public bool IsLeavingCell(CPos location, SubCell subCell = SubCell.Any)
 		{
 			return ToCell != location && fromCell == location

mods/ts/rules/defaults.yaml

@@ -780,6 +780,7 @@
 		Locomotor: wheeled
 		TurnSpeed: 20
 		Voice: Move
+		TerrainOrientationAdjustmentMargin: 256
 	Selectable:
 		Bounds: 1206, 1448
 	Voiced:

mods/ts/rules/gdi-vehicles.yaml

@@ -67,6 +67,7 @@ HVR:
 	Mobile:
 		Speed: 99
 		Locomotor: hover
+		TerrainOrientationAdjustmentMargin: -1
 	Selectable:
 		Bounds: 1206, 1448, 0, -603
 	Health:
@@ -123,6 +124,7 @@ SMECH:
 		TurnSpeed: 20
 		Speed: 99
 		AlwaysTurnInPlace: true
+		TerrainOrientationAdjustmentMargin: -1
 	Health:
 		HP: 17500
 	Armor:
@@ -176,6 +178,7 @@ MMCH:
 		TurnSpeed: 20
 		Speed: 56
 		AlwaysTurnInPlace: true
+		TerrainOrientationAdjustmentMargin: -1
 	Health:
 		HP: 40000
 	Armor:
@@ -341,6 +344,7 @@ JUGG:
 		AlwaysTurnInPlace: true
 		ImmovableCondition: !undeployed
 		RequireForceMoveCondition: !undeployed
+		TerrainOrientationAdjustmentMargin: -1
 	RevealsShroud:
 		RequiresCondition: !inside-tunnel
 		Range: 9c0