Specify sprite positions as center pos + offset. Fixes #3611.

OpenRA.Game/Graphics/Animation.cs

@@ -38,20 +38,20 @@ namespace OpenRA.Graphics
 		int CurrentFrame { get { return backwards ? CurrentSequence.Start + CurrentSequence.Length - frame - 1 : frame; } }
 		public Sprite Image { get { return CurrentSequence.GetSprite(CurrentFrame, facingFunc()); } }
 
-		public IEnumerable<IRenderable> Render(WPos pos, int zOffset, PaletteReference palette, float scale)
+		public IEnumerable<IRenderable> Render(WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale)
 		{
 			if (CurrentSequence.ShadowStart >= 0)
 			{
 				var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
-				yield return new SpriteRenderable(shadow, pos, CurrentSequence.ShadowZOffset + zOffset, palette, scale);
+				yield return new SpriteRenderable(shadow, pos, offset, CurrentSequence.ShadowZOffset + zOffset, palette, scale);
 			}
 
-			yield return new SpriteRenderable(Image, pos, CurrentSequence.ZOffset + zOffset, palette, scale);
+			yield return new SpriteRenderable(Image, pos, offset, CurrentSequence.ZOffset + zOffset, palette, scale);
 		}
 
 		public IEnumerable<IRenderable> Render(WPos pos, PaletteReference palette)
 		{
-			return Render(pos, 0, palette, 1f);
+			return Render(pos, WVec.Zero, 0, palette, 1f);
 		}
 
 		public void Play(string sequenceName)

OpenRA.Game/Graphics/AnimationWithOffset.cs

@@ -37,12 +37,11 @@ namespace OpenRA.Graphics
 
 		public IEnumerable<IRenderable> Render(Actor self, WorldRenderer wr, PaletteReference pal, float scale)
 		{
-			var p = self.CenterPosition;
+			var center = self.CenterPosition;
-			if (OffsetFunc != null)
+			var offset = OffsetFunc != null ? OffsetFunc() : WVec.Zero;
-				p += OffsetFunc();
 
-			var z = (ZOffset != null) ? ZOffset(p) : 0;
+			var z = (ZOffset != null) ? ZOffset(center + offset) : 0;
-			return Animation.Render(p, z, pal, scale);
+			return Animation.Render(center, offset, z, pal, scale);
 		}
 
 		public static implicit operator AnimationWithOffset(Animation a)

OpenRA.Game/Graphics/Renderable.cs

@@ -52,42 +52,52 @@ namespace OpenRA.Graphics
 
 		readonly Sprite sprite;
 		readonly WPos pos;
+		readonly WVec offset;
 		readonly int zOffset;
 		readonly PaletteReference palette;
 		readonly float scale;
 
-		public SpriteRenderable(Sprite sprite, WPos pos, int zOffset, PaletteReference palette, float scale)
+		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale)
 		{
 			this.sprite = sprite;
 			this.pos = pos;
+			this.offset = offset;
 			this.zOffset = zOffset;
 			this.palette = palette;
 			this.scale = scale;
 		}
 
+		public SpriteRenderable(Sprite sprite, WPos pos, int zOffset, PaletteReference palette, float scale)
+			: this(sprite, pos, WVec.Zero, zOffset, palette, scale) { }
+
 		// Provided for legacy support only - Don't use for new things!
 		public SpriteRenderable(Sprite sprite, float2 pos, PaletteReference palette, int z)
 			: this(sprite, new PPos((int)pos.X, (int)pos.Y).ToWPos(0), z, palette, 1f) { }
 
-		public WPos Pos { get { return pos; } }
+		public WPos Pos { get { return pos + offset; } }
 		public float Scale { get { return scale; } }
 		public PaletteReference Palette { get { return palette; } }
 		public int ZOffset { get { return zOffset; } }
 
-		public IRenderable WithScale(float newScale) { return new SpriteRenderable(sprite, pos, zOffset, palette, newScale); }
+		public IRenderable WithScale(float newScale) { return new SpriteRenderable(sprite, pos, offset, zOffset, palette, newScale); }
-		public IRenderable WithPalette(PaletteReference newPalette) { return new SpriteRenderable(sprite, pos, zOffset, newPalette, scale); }
+		public IRenderable WithPalette(PaletteReference newPalette) { return new SpriteRenderable(sprite, pos, offset, zOffset, newPalette, scale); }
-		public IRenderable WithZOffset(int newOffset) { return new SpriteRenderable(sprite, pos, newOffset, palette, scale); }
+		public IRenderable WithZOffset(int newOffset) { return new SpriteRenderable(sprite, pos, offset, newOffset, palette, scale); }
-		public IRenderable WithPos(WPos pos) { return new SpriteRenderable(sprite, pos, zOffset, palette, scale); }
+		public IRenderable WithPos(WPos pos) { return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale); }
+
+		float2 ScreenPosition(WorldRenderer wr)
+		{
+			return wr.ScreenPxPosition(pos) + wr.ScreenPxOffset(offset) - (0.5f*scale*sprite.size).ToInt2();
+		}
 
 		public void BeforeRender(WorldRenderer wr) {}
 		public void Render(WorldRenderer wr)
 		{
-			sprite.DrawAt(wr.ScreenPxPosition(pos) - (0.5f*scale*sprite.size).ToInt2(), palette, scale);
+			sprite.DrawAt(ScreenPosition(wr), palette, scale);
 		}
 
 		public void RenderDebugGeometry(WorldRenderer wr)
 		{
-			var offset = wr.ScreenPxPosition(pos) - 0.5f*scale*sprite.size + sprite.offset;
+			var offset = ScreenPosition(wr) + sprite.offset;
 			Game.Renderer.WorldLineRenderer.DrawRect(offset, offset + sprite.size, Color.Red);
 		}
 	}

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -245,6 +245,13 @@ namespace OpenRA.Graphics
 			return new float[] {c*vec.X, c*vec.Y, c*vec.Z, 1};
 		}
 
+		public int2 ScreenPxOffset(WVec vec)
+		{
+			// Round to nearest pixel
+			var px = ScreenVector(vec);
+			return new int2((int)Math.Round(px[0]), (int)Math.Round(px[1] - px[2]));
+		}
+
 		public float ScreenZPosition(WPos pos, int zOffset) { return (pos.Y + pos.Z + zOffset)*Game.CellSize/1024f; }
 	}
 }

OpenRA.Mods.RA/Effects/Parachute.cs

@@ -76,7 +76,7 @@ namespace OpenRA.Mods.RA.Effects
 				yield return c.WithPos(pos);
 			}
 
-			foreach (var r in paraAnim.Render(pos + parachuteOffset, 1, rc.First().Palette, 1f))
+			foreach (var r in paraAnim.Render(pos, parachuteOffset, 1, rc.First().Palette, 1f))
 				yield return r;
 		}
 	}