registerShakeEffect and time expiring shaking

OpenRa.Game/Traits/World/ScreenShaker.cs

@@ -1,6 +1,8 @@
 
 using System;
 using OpenRa.Traits;
+using System.Collections.Generic;
+using OpenRa.FileFormats;
 
 namespace OpenRa.Traits
 {
@@ -12,26 +14,57 @@ namespace OpenRa.Traits
 	public class ScreenShaker : ITick
 	{
 		int ticks = 0;
+		static List<Tuple<int, float2, int>> shakeEffects = new List<Tuple<int, float2, int>>();
 		
 		public ScreenShaker (Actor self){}
 		
 		public void Tick (Actor self)
 		{
 			Game.viewport.Scroll(getScrollOffset());
+			updateList();
 			ticks++;
 		}
 		
-		//public void registerShakeEffect(float2 position, int time)
-		//{
-		//}
+		private void updateList()
+		{
+			var toRemove = new List<Tuple<int, float2, int>>();
+			
+			for (int i = 0; i < shakeEffects.Count; i++){
+				var tuple = shakeEffects[i];
+				tuple.a = tuple.a - 1;
+				shakeEffects[i] = tuple;
+				
+				if (tuple.a == 0) 
+					toRemove.Add(tuple);
+			}
+			
+			foreach(Tuple<int, float2, int> t in toRemove){
+				shakeEffects.Remove(t);
+			}
+		}
+		
+		public static void registerShakeEffect(int time, float2 position, int intensity)
+		{
+			shakeEffects.Add(Tuple.New<int, float2, int>(time, position, intensity));
+		}
 		
 		public float2 getScrollOffset()
 		{
 			int xFreq = 4;
 			int yFreq = 5;
-			int intensity = 3;
 			
-			return intensity * new float2( (float) Math.Sin((ticks*2*Math.PI)/xFreq) , (float) Math.Cos((ticks*2*Math.PI)/yFreq));
+			return getIntensity() * new float2( (float) Math.Sin((ticks*2*Math.PI)/xFreq) , (float) Math.Cos((ticks*2*Math.PI)/yFreq));
+		}
+		
+		public float getIntensity()
+		{
+			float intensity = 0;
+			foreach(Tuple<int, float2, int> tuple in shakeEffects)
+			{
+				intensity += (24*24*100*tuple.c)/( (tuple.b.X - Game.viewport.Location.X) * (tuple.b.X - Game.viewport.Location.X) 
+				                + (tuple.b.Y - Game.viewport.Location.Y) * (tuple.b.Y - Game.viewport.Location.Y) ); 
+			}
+			return Math.Min(intensity, 10);	
 		}
 		
 	}