missing class from previous commits (derp)

src/main/java/mods/betterfoliage/client/WindTracker.java

@@ -0,0 +1,63 @@
+package mods.betterfoliage.client;
+
+import java.util.Random;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.world.World;
+import net.minecraftforge.event.world.WorldEvent;
+import cpw.mods.fml.common.eventhandler.SubscribeEvent;
+import cpw.mods.fml.common.gameevent.TickEvent;
+import cpw.mods.fml.common.gameevent.TickEvent.ClientTickEvent;
+
+public class WindTracker {
+
+	public Random random = new Random();
+	
+	public double targetX;
+	public double targetZ;
+
+	public double currentX;
+	public double currentZ;
+	
+	public long nextChange = 0;
+	
+	public void changeWind(World world) {
+		long changeTime = 120;
+		nextChange = world.getWorldInfo().getWorldTime() + changeTime;
+		
+		double direction = 2.0 * Math.PI * random.nextDouble();
+		double speed = Math.abs(random.nextGaussian()) * 0.025;
+		if (world.isRaining()) speed += Math.abs(random.nextGaussian()) * 0.05;
+		
+		targetX = Math.cos(direction) * speed;
+		targetZ = Math.sin(direction) * speed;
+	}
+	
+	@SubscribeEvent
+	public void handleWorldTick(ClientTickEvent event) {
+		if (event.phase != TickEvent.Phase.START) return;
+		World world = Minecraft.getMinecraft().theWorld;
+		if (world == null) return;
+		
+		// change target wind speed
+		if (world.getWorldInfo().getWorldTime() >= nextChange) changeWind(world);
+		
+		// change current wind speed
+		double changeRate = world.isRaining() ? 0.00075 : 0.00025;
+		
+		double deltaX = targetX - currentX;
+		if (deltaX < -changeRate) deltaX = -changeRate;
+		if (deltaX > changeRate) deltaX = changeRate;
+		double deltaZ = targetZ - currentZ;
+		if (deltaZ < -changeRate) deltaZ = -changeRate;
+		if (deltaZ > changeRate) deltaZ = changeRate;
+		
+		currentX += deltaX;
+		currentZ += deltaZ;
+	}
+	
+	@SubscribeEvent
+	public void handleWorldLoad(WorldEvent.Load event) {
+		if (event.world.isRemote) changeWind(event.world);
+	}
+}