diff --git a/src/main/java/io/gitlab/jfronny/respackopts/GuiFactory.java b/src/main/java/io/gitlab/jfronny/respackopts/GuiFactory.java
index 8f34ca8..f104cf1 100644
--- a/src/main/java/io/gitlab/jfronny/respackopts/GuiFactory.java
+++ b/src/main/java/io/gitlab/jfronny/respackopts/GuiFactory.java
@@ -13,7 +13,6 @@ import net.minecraft.util.Language;
 
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Objects;
 
 public class GuiFactory {
     public void buildCategory(JsonObject source, String screenId, ConfigCategory config, ConfigEntryBuilder entryBuilder) {
@@ -42,7 +41,10 @@ public class GuiFactory {
                         Respackopts.boolVals.get(screenId).put(n, defaultValue);
                     config.addEntry(entryBuilder.startBooleanToggle(getText(n, b), currentValue)
                             .setDefaultValue(defaultValue)
-                            .setSaveConsumer(v -> Respackopts.boolVals.get(screenId).put(n, v))
+                            .setSaveConsumer(v -> {
+                                Respackopts.updateShaders();
+                                Respackopts.boolVals.get(screenId).put(n, v);
+                            })
                             .build());
                 }
                 else if (p.isNumber()) {
@@ -54,7 +56,10 @@ public class GuiFactory {
                         Respackopts.numVals.get(screenId).put(n, defaultValue);
                     config.addEntry(entryBuilder.startDoubleField(getText(n, b), currentValue)
                             .setDefaultValue(defaultValue)
-                            .setSaveConsumer(v -> Respackopts.numVals.get(screenId).put(n, v))
+                            .setSaveConsumer(v -> {
+                                Respackopts.updateShaders();
+                                Respackopts.numVals.get(screenId).put(n, v);
+                            })
                             .build());
                 }
                 else if (p.isString()) {
@@ -66,7 +71,10 @@ public class GuiFactory {
                         Respackopts.strVals.get(screenId).put(n, defaultValue);
                     config.addEntry(entryBuilder.startStrField(getText(n, b), currentValue)
                             .setDefaultValue(defaultValue)
-                            .setSaveConsumer(v -> Respackopts.strVals.get(screenId).put(n, v))
+                            .setSaveConsumer(v -> {
+                                Respackopts.updateShaders();
+                                Respackopts.strVals.get(screenId).put(n, v);
+                            })
                             .build());
                 }
             }
diff --git a/src/main/java/io/gitlab/jfronny/respackopts/Respackopts.java b/src/main/java/io/gitlab/jfronny/respackopts/Respackopts.java
index 962942e..1c54cd8 100644
--- a/src/main/java/io/gitlab/jfronny/respackopts/Respackopts.java
+++ b/src/main/java/io/gitlab/jfronny/respackopts/Respackopts.java
@@ -27,6 +27,7 @@ public class Respackopts implements ClientModInitializer {
     @Override
     public void onInitializeClient() {
         load();
+        Respackopts.updateShaders();
     }
 
     public static void save() {
@@ -92,4 +93,27 @@ public class Respackopts implements ClientModInitializer {
         if (strVals == null)
             strVals = new HashMap<>();
     }
+
+    public static void updateShaders() {
+        StringBuilder sb = new StringBuilder();
+        numVals.forEach((s, v) -> v.forEach((s1, v1) -> {
+            sb.append("\n");
+            sb.append("#define ");
+            sb.append(s);
+            sb.append("_");
+            sb.append(s1);
+            sb.append(" ");
+            sb.append(v1);
+        }));
+        boolVals.forEach((s, v) -> v.forEach((s1, v1) -> {
+            if (v1) {
+                sb.append("\n");
+                sb.append("#define ");
+                sb.append(s);
+                sb.append("_");
+                sb.append(s1);
+            }
+        }));
+        System.out.println(sb.toString());
+    }
 }
diff --git a/src/main/java/io/gitlab/jfronny/respackopts/mixin/ResourcePackManagerMixin.java b/src/main/java/io/gitlab/jfronny/respackopts/mixin/ResourcePackManagerMixin.java
index 870f711..8dbbd94 100644
--- a/src/main/java/io/gitlab/jfronny/respackopts/mixin/ResourcePackManagerMixin.java
+++ b/src/main/java/io/gitlab/jfronny/respackopts/mixin/ResourcePackManagerMixin.java
@@ -3,6 +3,7 @@ package io.gitlab.jfronny.respackopts.mixin;
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
 import io.gitlab.jfronny.respackopts.Respackopts;
 import io.gitlab.jfronny.respackopts.data.Respackmeta;
 import net.minecraft.resource.ResourcePackManager;
@@ -18,6 +19,7 @@ import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.HashMap;
 import java.util.Map;
 
 @Mixin(ResourcePackManager.class)
@@ -30,18 +32,51 @@ public class ResourcePackManagerMixin {
             if (hasMetadata(v, "conf.json")) {
                 try {
                     Respackmeta conf = Respackopts.g.fromJson(readMetadata(v, "conf.json", Respackopts.g), Respackmeta.class);
+                    if (!Respackopts.boolVals.containsKey(conf.id))
+                        Respackopts.boolVals.put(conf.id, new HashMap<>());
+                    if (!Respackopts.numVals.containsKey(conf.id))
+                        Respackopts.numVals.put(conf.id, new HashMap<>());
+                    if (!Respackopts.strVals.containsKey(conf.id))
+                        Respackopts.strVals.put(conf.id, new HashMap<>());
+                    for (Map.Entry<String, JsonElement> entry : conf.conf.entrySet()) {
+                        String n = entry.getKey();
+                        if (n.contains(":") || n.contains(".")) {
+                            System.err.println(n + " contains invalid characters");
+                            continue;
+                        }
+                        JsonElement e = entry.getValue();
+                        if (e.isJsonPrimitive()) {
+                            JsonPrimitive p = e.getAsJsonPrimitive();
+                            if (p.isBoolean()) {
+                                if (!Respackopts.boolVals.get(conf.id).containsKey(n))
+                                    Respackopts.boolVals.get(conf.id).put(n, p.getAsBoolean());
+                            }
+                            else if (p.isNumber()) {
+                                if (!Respackopts.numVals.get(conf.id).containsKey(n))
+                                    Respackopts.numVals.get(conf.id).put(n, p.getAsDouble());
+                            }
+                            else if (p.isString()) {
+                                if (!Respackopts.strVals.get(conf.id).containsKey(n))
+                                    Respackopts.strVals.get(conf.id).put(n, p.getAsString());
+                            }
+                        }
+                        else {
+                            System.err.println("[respackopts] Unsupported non-primitive datatype");
+                        }
+                    }
                     if (Respackopts.metaVersion.equals(conf.version)) {
                         Respackopts.resPackMetas.put(v.getDisplayName().asString(), conf);
                     }
                     else {
                         System.err.println(s + " was not loaded as it specifies a different respackopts version than is installed");
                     }
-                } catch (IOException e) {
+                } catch (Throwable e) {
                     e.printStackTrace();
                 }
             }
         });
         Respackopts.load();
+        Respackopts.updateShaders();
         Respackopts.save();
     }