Fix CA1822

OpenRA.Game/Graphics/ModelRenderer.cs

@@ -302,7 +302,7 @@ namespace OpenRA.Graphics
 			return fbo;
 		}
 
-		void DisableFrameBuffer(IFrameBuffer fbo)
+		static void DisableFrameBuffer(IFrameBuffer fbo)
 		{
 			Game.Renderer.Flush();
 			Game.Renderer.Context.DisableDepthBuffer();

OpenRA.Game/Graphics/RgbaColorRenderer.cs

@@ -80,7 +80,7 @@ namespace OpenRA.Graphics
 		/// Will behave badly if the lines are parallel.
 		/// Z position is the average of a and b (ignores actual intersection point if it exists).
 		/// </summary>
-		float3 IntersectionOf(in float3 a, in float3 da, in float3 b, in float3 db)
+		static float3 IntersectionOf(in float3 a, in float3 da, in float3 b, in float3 db)
 		{
 			var crossA = a.X * (a.Y + da.Y) - a.Y * (a.X + da.X);
 			var crossB = b.X * (b.Y + db.Y) - b.Y * (b.X + db.X);

OpenRA.Game/Graphics/SpriteFont.cs

@@ -123,7 +123,7 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		float2 Rotate(float2 v, float sina, float cosa, float2 offset)
+		static float2 Rotate(float2 v, float sina, float cosa, float2 offset)
 		{
 			return new float2(
 				v.X * cosa - v.Y * sina + offset.X,

OpenRA.Game/Graphics/SpriteRenderer.cs

@@ -114,7 +114,7 @@ namespace OpenRA.Graphics
 			return new int2(sheetIndex, secondarySheetIndex);
 		}
 
-		float ResolveTextureIndex(Sprite s, PaletteReference pal)
+		static float ResolveTextureIndex(Sprite s, PaletteReference pal)
 		{
 			if (pal == null)
 				return 0;

OpenRA.Game/Graphics/Viewport.cs

@@ -172,7 +172,7 @@ namespace OpenRA.Graphics
 				UpdateViewportZooms();
 		}
 
-		float CalculateMinimumZoom(float minHeight, float maxHeight)
+		static float CalculateMinimumZoom(float minHeight, float maxHeight)
 		{
 			var h = Game.Renderer.NativeResolution.Height;