From 8ad18ad1611928f36e0f9babf807f4d38d29a4a7 Mon Sep 17 00:00:00 2001
From: Oliver Brakmann <ob-web2013+github@posteo.net>
Date: Fri, 26 Aug 2016 22:06:10 +0200
Subject: [PATCH] Rewrite color inversal in a reusable way

---
 OpenRA.Game/Graphics/SpriteFont.cs               |  6 ++++++
 OpenRA.Game/Widgets/WidgetUtils.cs               |  6 ++++++
 .../Widgets/SupportPowerTimerWidget.cs           | 16 ++++++++--------
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/OpenRA.Game/Graphics/SpriteFont.cs b/OpenRA.Game/Graphics/SpriteFont.cs
index b25c29cc34..ccc3a5f9e6 100644
--- a/OpenRA.Game/Graphics/SpriteFont.cs
+++ b/OpenRA.Game/Graphics/SpriteFont.cs
@@ -14,6 +14,7 @@ using System.Drawing;
 using System.Linq;
 using OpenRA.Primitives;
 using OpenRA.Support;
+using OpenRA.Widgets;
 using SharpFont;
 
 namespace OpenRA.Graphics
@@ -93,6 +94,11 @@ namespace OpenRA.Graphics
 			DrawText(text, location, fg);
 		}
 
+		public void DrawTextWithContrast(string text, float2 location, Color fg, Color bgDark, Color bgLight, int offset)
+		{
+			DrawTextWithContrast(text, location, fg, WidgetUtils.GetContrastColor(fg, bgDark, bgLight), offset);
+		}
+
 		public int2 Measure(string text)
 		{
 			if (string.IsNullOrEmpty(text))
diff --git a/OpenRA.Game/Widgets/WidgetUtils.cs b/OpenRA.Game/Widgets/WidgetUtils.cs
index 993d3472a7..c02d013792 100644
--- a/OpenRA.Game/Widgets/WidgetUtils.cs
+++ b/OpenRA.Game/Widgets/WidgetUtils.cs
@@ -250,6 +250,12 @@ namespace OpenRA.Widgets
 
 			return trimmed;
 		}
+
+		public static Color GetContrastColor(Color fgColor, Color bgDark, Color bgLight)
+		{
+			var fg = new HSLColor(fgColor);
+			return fg.RGB == Color.White || fg.L > 80 ? bgDark : bgLight;
+		}
 	}
 
 	public class CachedTransform<T, U>
diff --git a/OpenRA.Mods.Common/Widgets/SupportPowerTimerWidget.cs b/OpenRA.Mods.Common/Widgets/SupportPowerTimerWidget.cs
index bd9038fd87..c67e48e3d0 100644
--- a/OpenRA.Mods.Common/Widgets/SupportPowerTimerWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/SupportPowerTimerWidget.cs
@@ -29,7 +29,8 @@ namespace OpenRA.Mods.Common.Widgets
 
 		readonly int timestep;
 		readonly IEnumerable<SupportPowerInstance> powers;
-		Tuple<string, Color, Color>[] texts;
+		readonly Color bgDark, bgLight;
+		Pair<string, Color>[] texts;
 
 		[ObjectCreator.UseCtor]
 		public SupportPowerTimerWidget(World world)
@@ -43,6 +44,9 @@ namespace OpenRA.Mods.Common.Widgets
 			timestep = world.Timestep;
 			if (world.IsReplay)
 				timestep = world.WorldActor.Trait<MapOptions>().GameSpeed.Timestep;
+
+			bgDark = ChromeMetrics.Get<Color>("TextContrastColorDark");
+			bgLight = ChromeMetrics.Get<Color>("TextContrastColorLight");
 		}
 
 		public override void Tick()
@@ -66,11 +70,7 @@ namespace OpenRA.Mods.Common.Widgets
 
 				var color = !p.Ready || Game.LocalTick % 50 < 25 ? playerColor : Color.White;
 
-				var inversedColor = self.Owner.Color;
-				var inversedL = color == Color.White || inversedColor.L > 128 ? (byte)0 : (byte)255;
-				inversedColor = new HSLColor(inversedColor.H, 0, inversedL);
-
-				return Tuple.Create(text, color, inversedColor.RGB);
+				return Pair.New(text, color);
 			}).ToArray();
 		}
 
@@ -83,8 +83,8 @@ namespace OpenRA.Mods.Common.Widgets
 			foreach (var t in texts)
 			{
 				var font = Game.Renderer.Fonts[Font];
-				font.DrawTextWithContrast(t.Item1, new float2(Bounds.Location) + new float2(0, y), t.Item2, t.Item3, 1);
-				y += (font.Measure(t.Item1).Y + 5) * (int)Order;
+				font.DrawTextWithContrast(t.First, new float2(Bounds.Location) + new float2(0, y), t.Second, bgDark, bgLight, 1);
+				y += (font.Measure(t.First).Y + 5) * (int)Order;
 			}
 		}