World fog color and density can now be controlled through an event

src/main/java/net/minecraftforge/client/event/EntityViewRenderEvent.java

@@ -0,0 +1,62 @@
+package net.minecraftforge.client.event;
+
+import net.minecraft.block.Block;
+import net.minecraft.client.renderer.EntityRenderer;
+import net.minecraft.entity.EntityLivingBase;
+import cpw.mods.fml.common.eventhandler.Cancelable;
+import cpw.mods.fml.common.eventhandler.Event;
+
+/**
+ * Event that hooks into EntityRenderer, allowing any feature to customize visual attributes of
+ * fog the player sees.
+ */
+public abstract class EntityViewRenderEvent extends Event
+{
+    public final EntityRenderer renderer;
+    public final EntityLivingBase entity;
+    public final Block block;
+    public final double renderPartialTicks;
+
+    public EntityViewRenderEvent(EntityRenderer renderer, EntityLivingBase entity, Block block, double renderPartialTicks)
+    {
+        this.renderer = renderer;
+        this.entity = entity;
+        this.block = block;
+        this.renderPartialTicks = renderPartialTicks;
+    }
+
+    /**
+     * Event that allows any feature to customize the fog density the player sees.
+     * NOTE: In order to make this event have an effect, you must cancel the event
+     */
+    @Cancelable
+    public static class FogDensity extends EntityViewRenderEvent
+    {
+        public float density;
+
+        public FogDensity(EntityRenderer renderer, EntityLivingBase entity, Block block, double renderPartialTicks, float density)
+        {
+            super(renderer, entity, block, renderPartialTicks);
+            this.density = density;
+        }
+    }
+
+    /**
+     * Event that allows any feature to customize the color of fog the player sees.
+     * NOTE: Any change made to one of the color variables will affect the result seen in-game.
+     */
+    public static class FogColors extends EntityViewRenderEvent
+    {
+        public float red;
+        public float green;
+        public float blue;
+
+        public FogColors(EntityRenderer renderer, EntityLivingBase entity, Block block, double renderPartialTicks, float red, float green, float blue)
+        {
+            super(renderer, entity, block, renderPartialTicks);
+            this.red = red;
+            this.green = green;
+            this.blue = blue;
+        }
+    }
+}