Fog modes for new rendering.

- For each fog mode, compile a different version of each shader.
 - Could maybe do some fancier preprocessing to make writing shaders easier?

src/main/java/com/simibubi/create/content/contraptions/components/structureMovement/render/ContraptionProgram.java

@@ -1,5 +1,6 @@
 package com.simibubi.create.content.contraptions.components.structureMovement.render;
 
+import com.simibubi.create.foundation.render.backend.gl.shader.ProgramFogMode;
 import org.lwjgl.opengl.GL20;
 
 import com.simibubi.create.foundation.render.backend.gl.BasicProgram;
@@ -15,8 +16,8 @@ public class ContraptionProgram extends BasicProgram {
 
     protected int uLightVolume;
 
-    public ContraptionProgram(ResourceLocation name, int handle) {
-        super(name, handle);
+    public ContraptionProgram(ResourceLocation name, int handle, ProgramFogMode.Factory fogFactory) {
+        super(name, handle, fogFactory);
         uLightBoxSize = getUniformLocation("uLightBoxSize");
         uLightBoxMin = getUniformLocation("uLightBoxMin");
         uModel = getUniformLocation("uModel");

src/main/java/com/simibubi/create/content/logistics/block/belts/tunnel/BeltTunnelBlock.java

@@ -26,6 +26,7 @@ import net.minecraft.util.Direction;
 import net.minecraft.util.Direction.Axis;
 import net.minecraft.util.Direction.AxisDirection;
 import net.minecraft.util.IStringSerializable;
+import net.minecraft.util.Rotation;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.shapes.ISelectionContext;
 import net.minecraft.util.math.shapes.VoxelShape;
@@ -211,6 +212,14 @@ public class BeltTunnelBlock extends Block implements ITE<BeltTunnelTileEntity>,
 		return ActionResultType.SUCCESS;
 	}
 
+	@Override
+	public BlockState rotate(BlockState state, Rotation rotation) {
+		Direction fromAxis = Direction.getFacingFromAxis(AxisDirection.POSITIVE, state.get(HORIZONTAL_AXIS));
+		Direction rotated = rotation.rotate(fromAxis);
+
+		return state.with(HORIZONTAL_AXIS, rotated.getAxis());
+	}
+
 	@Override
 	public void neighborChanged(BlockState state, World worldIn, BlockPos pos, Block blockIn, BlockPos fromPos,
 		boolean isMoving) {

src/main/java/com/simibubi/create/foundation/render/backend/Backend.java

@@ -4,10 +4,14 @@ import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.FloatBuffer;
+import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.function.Predicate;
 
+import com.simibubi.create.foundation.render.backend.gl.GlFog;
+import com.simibubi.create.foundation.render.backend.gl.GlFogMode;
+import com.simibubi.create.foundation.render.backend.gl.shader.*;
 import com.simibubi.create.foundation.render.backend.gl.versioned.GlFeatureCompat;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -16,10 +20,6 @@ import org.lwjgl.opengl.GLCapabilities;
 import org.lwjgl.system.MemoryUtil;
 
 import com.simibubi.create.foundation.config.AllConfigs;
-import com.simibubi.create.foundation.render.backend.gl.shader.GlProgram;
-import com.simibubi.create.foundation.render.backend.gl.shader.GlShader;
-import com.simibubi.create.foundation.render.backend.gl.shader.ProgramSpec;
-import com.simibubi.create.foundation.render.backend.gl.shader.ShaderType;
 
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.texture.TextureUtil;
@@ -31,11 +31,13 @@ import net.minecraftforge.resource.ISelectiveResourceReloadListener;
 import net.minecraftforge.resource.VanillaResourceType;
 
 public class Backend {
+    public static final Boolean SHADER_DEBUG_OUTPUT = false;
+
     public static final Logger log = LogManager.getLogger(Backend.class);
     public static final FloatBuffer MATRIX_BUFFER = MemoryUtil.memAllocFloat(16);
 
     private static final Map<ResourceLocation, ProgramSpec<?>> registry = new HashMap<>();
-    private static final Map<ProgramSpec<?>, GlProgram> programs = new HashMap<>();
+    private static final Map<ProgramSpec<?>, ProgramGroup<?>> programs = new HashMap<>();
 
     private static boolean enabled;
 
@@ -60,7 +62,7 @@ public class Backend {
 
     @SuppressWarnings("unchecked")
     public static <P extends GlProgram, S extends ProgramSpec<P>> P getProgram(S spec) {
-        return (P) programs.get(spec);
+        return (P) programs.get(spec).get(GlFog.getFogMode());
     }
 
     public static boolean available() {
@@ -109,7 +111,7 @@ public class Backend {
 
             if (gl20()) {
 
-                programs.values().forEach(GlProgram::delete);
+                programs.values().forEach(ProgramGroup::delete);
                 programs.clear();
                 for (ProgramSpec<?> shader : registry.values()) {
                     loadProgram(manager, shader);
@@ -123,23 +125,39 @@ public class Backend {
     }
 
     private static <P extends GlProgram, S extends ProgramSpec<P>> void loadProgram(IResourceManager manager, S programSpec) {
-        GlShader vert = null;
-        GlShader frag = null;
         try {
-            vert = loadShader(manager, programSpec.getVert(), ShaderType.VERTEX, programSpec.defines);
-            frag = loadShader(manager, programSpec.getFrag(), ShaderType.FRAGMENT, programSpec.defines);
+            Map<GlFogMode, P> programGroup = new EnumMap<>(GlFogMode.class);
 
-            GlProgram.Builder builder = GlProgram.builder(programSpec.name).attachShader(vert).attachShader(frag);
+            for (GlFogMode fogMode : GlFogMode.values()) {
+                programGroup.put(fogMode, loadProgram(manager, programSpec, fogMode));
+            }
 
-            programSpec.attributes.forEach(builder::addAttribute);
-
-            P program = builder.build(programSpec.factory);
-
-            programs.put(programSpec, program);
+            programs.put(programSpec, new ProgramGroup<>(programGroup));
 
             log.info("Loaded program {}", programSpec.name);
         } catch (IOException ex) {
             log.error("Failed to load program {}", programSpec.name, ex);
+            return;
+        }
+    }
+
+    private static <P extends GlProgram, S extends ProgramSpec<P>> P loadProgram(IResourceManager manager, S programSpec, GlFogMode fogMode) throws IOException {
+        GlShader vert = null;
+        GlShader frag = null;
+        try {
+            ShaderConstants defines = new ShaderConstants(programSpec.defines);
+
+            defines.defineAll(fogMode.getDefines());
+
+            vert = loadShader(manager, programSpec.getVert(), ShaderType.VERTEX, defines);
+            frag = loadShader(manager, programSpec.getFrag(), ShaderType.FRAGMENT, defines);
+
+            GlProgram.Builder builder = GlProgram.builder(programSpec.name, fogMode).attachShader(vert).attachShader(frag);
+
+            programSpec.attributes.forEach(builder::addAttribute);
+
+            return builder.build(programSpec.factory);
+
         } finally {
             if (vert != null) vert.delete();
             if (frag != null) frag.delete();

src/main/java/com/simibubi/create/foundation/render/backend/gl/BasicProgram.java

@@ -1,5 +1,6 @@
 package com.simibubi.create.foundation.render.backend.gl;
 
+import com.simibubi.create.foundation.render.backend.gl.shader.ProgramFogMode;
 import org.lwjgl.opengl.GL20;
 
 import com.simibubi.create.foundation.render.backend.Backend;
@@ -14,20 +15,20 @@ public class BasicProgram extends GlProgram {
     protected final int uViewProjection;
     protected final int uDebug;
     protected final int uCameraPos;
-    protected final int uFogRange;
-    protected final int uFogColor;
+
+    protected final ProgramFogMode fogMode;
 
     protected int uBlockAtlas;
     protected int uLightMap;
 
-    public BasicProgram(ResourceLocation name, int handle) {
+    public BasicProgram(ResourceLocation name, int handle, ProgramFogMode.Factory fogFactory) {
         super(name, handle);
         uTime = getUniformLocation("uTime");
         uViewProjection = getUniformLocation("uViewProjection");
         uDebug = getUniformLocation("uDebug");
         uCameraPos = getUniformLocation("uCameraPos");
-        uFogRange = getUniformLocation("uFogRange");
-        uFogColor = getUniformLocation("uFogColor");
+
+        fogMode = fogFactory.create(this);
 
         bind();
         registerSamplers();
@@ -48,8 +49,7 @@ public class BasicProgram extends GlProgram {
         uploadMatrixUniform(uViewProjection, viewProjection);
         GL20.glUniform3f(uCameraPos, (float) camX, (float) camY, (float) camZ);
 
-        GL20.glUniform2f(uFogRange, GlFog.getFogStart(), GlFog.getFogEnd());
-        GL20.glUniform4fv(uFogColor, GlFog.FOG_COLOR);
+        fogMode.bind();
     }
 
     protected static void uploadMatrixUniform(int uniform, Matrix4f mat) {

src/main/java/com/simibubi/create/foundation/render/backend/gl/GlFog.java

@@ -1,6 +1,7 @@
 package com.simibubi.create.foundation.render.backend.gl;
 
 import com.mojang.blaze3d.platform.GlStateManager;
+import org.lwjgl.opengl.GL11;
 
 public class GlFog {
     public static float[] FOG_COLOR = new float[] {0, 0, 0, 0};
@@ -9,7 +10,7 @@ public class GlFog {
         return GlStateManager.FOG.field_179049_a.field_179201_b;
     }
 
-    public static int getFogMode() {
+    public static int getFogModeGlEnum() {
         return GlStateManager.FOG.field_179047_b;
     }
 
@@ -24,4 +25,22 @@ public class GlFog {
     public static float getFogStart() {
         return GlStateManager.FOG.field_179045_d;
     }
+
+    public static GlFogMode getFogMode() {
+        if (!fogEnabled()) {
+            return GlFogMode.NONE;
+        }
+
+        int mode = getFogModeGlEnum();
+
+        switch (mode) {
+        case GL11.GL_EXP2:
+        case GL11.GL_EXP:
+            return GlFogMode.EXP2;
+        case GL11.GL_LINEAR:
+            return GlFogMode.LINEAR;
+        default:
+            throw new UnsupportedOperationException("Unknown fog mode: " + mode);
+        }
+    }
 }

src/main/java/com/simibubi/create/foundation/render/backend/gl/GlFogMode.java

@@ -0,0 +1,39 @@
+package com.simibubi.create.foundation.render.backend.gl;
+
+import com.google.common.collect.Lists;
+import com.simibubi.create.foundation.render.backend.gl.shader.GlShader;
+import com.simibubi.create.foundation.render.backend.gl.shader.ProgramFogMode;
+import org.lwjgl.opengl.GL11;
+
+import java.util.Collections;
+import java.util.List;
+
+public enum GlFogMode {
+    NONE(ProgramFogMode.None::new),
+    LINEAR(ProgramFogMode.Linear::new, "USE_FOG_LINEAR"),
+    EXP2(ProgramFogMode.Exp2::new, "USE_FOG_EXP2"),
+    ;
+
+    public static final String USE_FOG = "USE_FOG";
+
+    private final ProgramFogMode.Factory fogFactory;
+    private final List<String> defines;
+
+    GlFogMode(ProgramFogMode.Factory fogFactory) {
+        this.fogFactory = fogFactory;
+        this.defines = Collections.emptyList();
+    }
+
+    GlFogMode(ProgramFogMode.Factory fogFactory, String name) {
+        this.fogFactory = fogFactory;
+        this.defines = Lists.newArrayList(USE_FOG, name);
+    }
+
+    public List<String> getDefines() {
+        return defines;
+    }
+
+    public ProgramFogMode.Factory getFogFactory() {
+        return fogFactory;
+    }
+}

src/main/java/com/simibubi/create/foundation/render/backend/gl/shader/GlProgram.java

@@ -1,5 +1,6 @@
 package com.simibubi.create.foundation.render.backend.gl.shader;
 
+import com.simibubi.create.foundation.render.backend.gl.GlFogMode;
 import org.lwjgl.opengl.GL20;
 
 import com.simibubi.create.foundation.render.backend.Backend;
@@ -17,8 +18,8 @@ public abstract class GlProgram extends GlObject {
         this.name = name;
     }
 
-    public static Builder builder(ResourceLocation name) {
-        return new Builder(name);
+    public static Builder builder(ResourceLocation name, GlFogMode fogMode) {
+        return new Builder(name, fogMode);
     }
 
     public void bind() {
@@ -37,7 +38,7 @@ public abstract class GlProgram extends GlObject {
     public int getUniformLocation(String uniform) {
         int index = GL20.glGetUniformLocation(this.handle(), uniform);
 
-        if (index < 0) {
+        if (index < 0 && Backend.SHADER_DEBUG_OUTPUT) {
             Backend.log.warn("No active uniform '{}' exists in program '{}'. Could be unused.", uniform, this.name);
         }
 
@@ -69,12 +70,14 @@ public abstract class GlProgram extends GlObject {
     public static class Builder {
         private final ResourceLocation name;
         private final int program;
+        private final GlFogMode fogMode;
 
         private int attributeIndex;
 
-        public Builder(ResourceLocation name) {
+        public Builder(ResourceLocation name, GlFogMode fogMode) {
             this.name = name;
             this.program = GL20.glCreateProgram();
+            this.fogMode = fogMode;
         }
 
         public Builder attachShader(GlShader shader) {
@@ -113,12 +116,12 @@ public abstract class GlProgram extends GlObject {
                 throw new RuntimeException("Shader program linking failed, see log for details");
             }
 
-            return factory.create(this.name, this.program);
+            return factory.create(this.name, this.program, this.fogMode.getFogFactory());
         }
     }
 
     @FunctionalInterface
     public interface ProgramFactory<P extends GlProgram> {
-        P create(ResourceLocation name, int handle);
+        P create(ResourceLocation name, int handle, ProgramFogMode.Factory fogFactory);
     }
 }

src/main/java/com/simibubi/create/foundation/render/backend/gl/shader/GlShader.java

@@ -19,6 +19,8 @@ public class GlShader extends GlObject {
 
         if (preProcessor != null) {
             source = preProcessor.process(source);
+
+            if (Backend.SHADER_DEBUG_OUTPUT)
                 Backend.log.info("Preprocessor run on " + name);// + ":\n" + source);
         }
 

src/main/java/com/simibubi/create/foundation/render/backend/gl/shader/ProgramFogMode.java

@@ -0,0 +1,57 @@
+package com.simibubi.create.foundation.render.backend.gl.shader;
+
+import com.simibubi.create.foundation.render.backend.gl.GlFog;
+import org.lwjgl.opengl.GL20;
+
+public abstract class ProgramFogMode {
+
+    public abstract void bind();
+
+    public static class None extends ProgramFogMode {
+
+        public None(GlProgram program) {
+
+        }
+
+        @Override
+        public void bind() {
+
+        }
+    }
+
+    public static class Linear extends ProgramFogMode {
+        private final int uFogColor;
+        private final int uFogRange;
+
+        public Linear(GlProgram program) {
+            this.uFogColor = program.getUniformLocation("uFogColor");
+            this.uFogRange = program.getUniformLocation("uFogRange");
+        }
+
+        @Override
+        public void bind() {
+            GL20.glUniform2f(uFogRange, GlFog.getFogStart(), GlFog.getFogEnd());
+            GL20.glUniform4fv(uFogColor, GlFog.FOG_COLOR);
+        }
+    }
+
+    public static class Exp2 extends ProgramFogMode {
+        private final int uFogColor;
+        private final int uFogDensity;
+
+        public Exp2(GlProgram program) {
+            this.uFogColor = program.getUniformLocation("uFogColor");
+            this.uFogDensity = program.getUniformLocation("uFogDensity");
+        }
+
+        @Override
+        public void bind() {
+            GL20.glUniform1f(uFogDensity, GlFog.getFogDensity());
+            GL20.glUniform4fv(uFogColor, GlFog.FOG_COLOR);
+        }
+    }
+
+    public interface Factory {
+        ProgramFogMode create(GlProgram program);
+    }
+}

src/main/java/com/simibubi/create/foundation/render/backend/gl/shader/ProgramGroup.java

@@ -0,0 +1,22 @@
+package com.simibubi.create.foundation.render.backend.gl.shader;
+
+import com.simibubi.create.foundation.render.backend.gl.GlFogMode;
+
+import java.util.Map;
+
+public class ProgramGroup<P extends GlProgram> {
+
+    private final Map<GlFogMode, P> programs;
+
+    public ProgramGroup(Map<GlFogMode, P> programs) {
+        this.programs = programs;
+    }
+
+    public P get(GlFogMode fogMode) {
+        return programs.get(fogMode);
+    }
+
+    public void delete() {
+        programs.values().forEach(GlProgram::delete);
+    }
+}

src/main/java/com/simibubi/create/foundation/render/backend/gl/shader/ProgramSpec.java

@@ -50,7 +50,7 @@ public class ProgramSpec<P extends GlProgram> {
     public static class Builder<P extends GlProgram> {
         private ResourceLocation vert;
         private ResourceLocation frag;
-        private ShaderConstants defines = null;
+        private ShaderConstants defines = ShaderConstants.EMPTY;
 
         private final ResourceLocation name;
         private final GlProgram.ProgramFactory<P> factory;

src/main/java/com/simibubi/create/foundation/render/backend/gl/shader/ShaderConstants.java

@@ -1,12 +1,16 @@
 package com.simibubi.create.foundation.render.backend.gl.shader;
 
+import com.google.common.collect.Lists;
+
 import java.io.BufferedReader;
 import java.io.StringReader;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 public class ShaderConstants implements GlShader.PreProcessor {
+    public static final ShaderConstants EMPTY = new ShaderConstants();
 
     private final ArrayList<String> defines;
 
@@ -14,6 +18,10 @@ public class ShaderConstants implements GlShader.PreProcessor {
         defines = new ArrayList<>();
     }
 
+    public ShaderConstants(ShaderConstants other) {
+        this.defines = Lists.newArrayList(other.defines);
+    }
+
     public static ShaderConstants define(String def) {
         return new ShaderConstants().def(def);
     }
@@ -23,6 +31,11 @@ public class ShaderConstants implements GlShader.PreProcessor {
         return this;
     }
 
+    public ShaderConstants defineAll(Collection<String> defines) {
+        this.defines.addAll(defines);
+        return this;
+    }
+
     public ArrayList<String> getDefines() {
         return defines;
     }

src/main/resources/assets/create/shader/belt.vert

@@ -33,7 +33,10 @@ uniform mat4 uViewProjection;
 uniform int uDebug;
 
 uniform vec3 uCameraPos;
+
+#if defined(USE_FOG)
 varying float FragDistance;
+#endif
 
 mat4 rotate(vec3 axis, float angle) {
     float s = sin(angle);
@@ -71,12 +74,16 @@ void main() {
     mat4 normalMat = uModel * localRotation;
 
     BoxCoord = (worldPos.xyz - uLightBoxMin) / uLightBoxSize;
+    #if defined(USE_FOG)
     FragDistance = length(worldPos.xyz);
+    #endif
     #else
     mat4 normalMat = localRotation;
 
+    #if defined(USE_FOG)
     FragDistance = length(worldPos.xyz - uCameraPos);
     #endif
+    #endif
 
     vec3 norm = normalize(normalMat * vec4(aNormal, 0.)).xyz;
 

src/main/resources/assets/create/shader/contraption.frag

@@ -4,17 +4,35 @@ varying vec2 TexCoords;
 varying vec4 Color;
 varying float Diffuse;
 varying vec2 Light;
-varying float FragDistance;
 
 varying vec3 BoxCoord;
 
-uniform vec2 uFogRange;
-uniform vec4 uFogColor;
-
 uniform sampler2D uBlockAtlas;
 uniform sampler2D uLightMap;
 uniform sampler3D uLightVolume;
 
+#if defined(USE_FOG)
+varying float FragDistance;
+uniform vec4 uFogColor;
+#endif
+
+#if defined(USE_FOG_LINEAR)
+uniform vec2 uFogRange;
+
+float fogFactor() {
+    return (uFogRange.y - FragDistance) / (uFogRange.y - uFogRange.x);
+}
+#endif
+
+#ifdef USE_FOG_EXP2
+uniform float uFogDensity;
+
+float fogFactor() {
+    float dist = FragDistance * uFogDensity;
+    return 1. / exp2(dist * dist);
+}
+#endif
+
 vec4 light() {
     vec2 lm = texture3D(uLightVolume, BoxCoord).rg * 0.9375 + 0.03125;
     return texture2D(uLightMap, max(lm, Light));
@@ -25,9 +43,12 @@ void main() {
 
     vec4 color = vec4(tex.rgb * light().rgb * Diffuse * Color.rgb, tex.a);
 
-    float fog = (uFogRange.y - FragDistance) / (uFogRange.y - uFogRange.x);
-    fog = clamp(fog, 0., 1.);
+#if defined(USE_FOG)
+    float fog = clamp(fogFactor(), 0., 1.);
 
     gl_FragColor = mix(uFogColor, color, fog);
     gl_FragColor.a = color.a;
+#else
+    gl_FragColor = color;
+#endif
 }

src/main/resources/assets/create/shader/contraption_actor.vert

@@ -29,7 +29,10 @@ uniform mat4 uViewProjection;
 uniform int uDebug;
 
 uniform vec3 uCameraPos;
+
+#if defined(USE_FOG)
 varying float FragDistance;
+#endif
 
 mat4 rotate(vec3 axis, float angle) {
     float s = sin(angle);
@@ -77,9 +80,12 @@ void main() {
     Diffuse = diffuse(norm);
     TexCoords = aTexCoords;
     Light = aModelLight;
-    FragDistance = length(worldPos.xyz);
     gl_Position = uViewProjection * worldPos;
 
+    #if defined(USE_FOG)
+    FragDistance = length(worldPos.xyz);
+    #endif
+
     if (uDebug == 2) {
         Color = vec4(norm, 1.);
     } else {

src/main/resources/assets/create/shader/contraption_structure.vert

@@ -22,7 +22,10 @@ uniform mat4 uViewProjection;
 uniform int uDebug;
 
 uniform vec3 uCameraPos;
+
+#if defined(USE_FOG)
 varying float FragDistance;
+#endif
 
 mat4 rotate(vec3 axis, float angle) {
     float s = sin(angle);
@@ -52,8 +55,10 @@ void main() {
     Color = aColor / diffuse(aNormal);
     TexCoords = aTexCoords;
     Light = aModelLight;
-    FragDistance = length(viewPos.xyz);
     gl_Position = uViewProjection * viewPos;
+    #if defined(USE_FOG)
+    FragDistance = length(viewPos.xyz);
+    #endif
 
     if (uDebug == 2) {
         Color = vec4(norm, 1.);

src/main/resources/assets/create/shader/flap.vert

@@ -35,7 +35,10 @@ uniform mat4 uViewProjection;
 uniform int uDebug;
 
 uniform vec3 uCameraPos;
+
+#if defined(USE_FOG)
 varying float FragDistance;
+#endif
 
 float diffuse(vec3 normal) {
     float x = normal.x;
@@ -86,12 +89,16 @@ void main() {
     mat4 normalMat = uModel * orientation * flapRotation;
 
     BoxCoord = (worldPos.xyz - uLightBoxMin) / uLightBoxSize;
+    #if defined(USE_FOG)
     FragDistance = length(worldPos.xyz);
+    #endif
     #else
     mat4 normalMat = orientation * flapRotation;
 
+    #if defined(USE_FOG)
     FragDistance = length(worldPos.xyz - uCameraPos);
     #endif
+    #endif
 
     vec3 norm = normalize(normalMat * vec4(aNormal, 0.)).xyz;
 

src/main/resources/assets/create/shader/instanced.frag

@@ -4,14 +4,32 @@ varying vec2 TexCoords;
 varying vec2 Light;
 varying float Diffuse;
 varying vec4 Color;
-varying float FragDistance;
-
-uniform vec2 uFogRange;
-uniform vec4 uFogColor;
 
 uniform sampler2D uBlockAtlas;
 uniform sampler2D uLightMap;
 
+#if defined(USE_FOG)
+varying float FragDistance;
+uniform vec4 uFogColor;
+#endif
+
+#if defined(USE_FOG_LINEAR)
+uniform vec2 uFogRange;
+
+float fogFactor() {
+    return (uFogRange.y - FragDistance) / (uFogRange.y - uFogRange.x);
+}
+#endif
+
+#ifdef USE_FOG_EXP2
+uniform float uFogDensity;
+
+float fogFactor() {
+    float dist = FragDistance * uFogDensity;
+    return 1. / exp2(dist * dist);
+}
+#endif
+
 vec4 light() {
     vec2 lm = Light * 0.9375 + 0.03125;
     return texture2D(uLightMap, lm);
@@ -22,9 +40,12 @@ void main() {
 
     vec4 color = vec4(tex.rgb * light().rgb * Diffuse, tex.a) * Color;
 
-    float fog = (uFogRange.y - FragDistance) / (uFogRange.y - uFogRange.x);
-    fog = clamp(fog, 0., 1.);
+#if defined(USE_FOG)
+    float fog = clamp(fogFactor(), 0., 1.);
 
     gl_FragColor = mix(uFogColor, color, fog);
     gl_FragColor.a = color.a;
+#else
+    gl_FragColor = color;
+#endif
 }

src/main/resources/assets/create/shader/rotating.vert

@@ -29,7 +29,10 @@ uniform mat4 uViewProjection;
 uniform int uDebug;
 
 uniform vec3 uCameraPos;
+
+#if defined(USE_FOG)
 varying float FragDistance;
+#endif
 
 mat4 rotate(vec3 axis, float angle) {
     float s = sin(angle);
@@ -69,12 +72,16 @@ void main() {
     mat4 normalMat = uModel * kineticRotation;
 
     BoxCoord = (worldPos.xyz - uLightBoxMin) / uLightBoxSize;
+    #if defined(USE_FOG)
     FragDistance = length(worldPos.xyz);
+    #endif
     #else
     mat4 normalMat = kineticRotation;
 
+    #if defined(USE_FOG)
     FragDistance = length(worldPos.xyz - uCameraPos);
     #endif
+    #endif
 
     vec3 norm = normalize(normalMat * vec4(aNormal, 0.)).xyz;