Fix broken fog when using Chroma Key with Sodium (fixes #726)

src/main/java/com/replaymod/render/mixin/Mixin_ChromaKeyDisableFog.java

@@ -1,5 +1,6 @@
 package com.replaymod.render.mixin;
 
+import com.mojang.blaze3d.platform.GlStateManager;
 import com.replaymod.core.versions.MCVer;
 import com.replaymod.render.hooks.EntityRendererHandler;
 import net.minecraft.client.render.BackgroundRenderer;
@@ -20,6 +21,17 @@ public abstract class Mixin_ChromaKeyDisableFog {
                 ((EntityRendererHandler.IEntityRenderer) MCVer.getMinecraft().gameRenderer).replayModRender_getHandler();
         if (handler == null) return;
         if (handler.getSettings().getChromaKeyingColor() != null) {
+            // Starting with 1.15, fog is no longer enabled in this method but is instead managed by the RenderLayer
+            // system (and with 1.17, they are enabled permanently / depend only on the shader). Therefore, cancelling
+            // this method is no longer sufficient, and we additionally also need to set the start value to get rid of
+            // fog (this doesn't hurt on 1.14 either).
+            // Note: This only becomes noticeable with Sodium because Vanilla would already set the start to max for
+            //       unrelated reasons. But Sodium does some math which gives wrong results if end isn't greater than
+            //       start, as would be the case in these cases. Sodium doing math is also the reason we don't set start
+            //       equal to end (that'll result in undefined behavior because it sticks those into a smoothstep on old
+            //       versions), and we don't set it to MAX_VALUE because that also gives wrong results.
+            GlStateManager.fogStart(1E10F);
+            GlStateManager.fogEnd(2E10F);
             ci.cancel();
         }
     }