Working

versions/1.21.4/src/main/java/org/saturnclient/saturnclient/mixin/MatrixStackMixin.java

@@ -4,11 +4,44 @@ import org.joml.Quaternionf;
 import org.saturnclient.common.minecraft.bindings.SaturnQuaternionf;
 import org.saturnclient.common.minecraft.render.IMatrixStack;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.gen.Invoker;
 
 import net.minecraft.client.util.math.MatrixStack;
 
 @Mixin(MatrixStack.class)
-public class MatrixStackMixin extends MatrixStack implements IMatrixStack {
+public abstract class MatrixStackMixin implements IMatrixStack {
+
+    @Shadow
+    public abstract void translate(double x, double y, double z);
+
+    @Shadow
+    public abstract void translate(float x, float y, float z);
+
+    @Shadow
+    public abstract void scale(float x, float y, float z);
+
+    @Shadow
+    public abstract void multiply(Quaternionf quaternion);
+
+    @Shadow
+    public abstract void multiply(Quaternionf quaternion, float originX, float originY, float originZ);
+
+    @Shadow
+    public abstract void push();
+
+    @Shadow
+    public abstract void pop();
+
+    @Invoker("peek")
+    public abstract MatrixStack.Entry peekM();
+
+    @Shadow
+    public abstract boolean isEmpty();
+
+    @Shadow
+    public abstract void loadIdentity();
+
     @Override
     public void multiply(SaturnQuaternionf quaternion) {
         this.multiply((Quaternionf) quaternion.inner);
@@ -18,4 +51,9 @@ public class MatrixStackMixin extends MatrixStack implements IMatrixStack {
     public void multiply(SaturnQuaternionf quaternion, float originX, float originY, float originZ) {
         this.multiply((Quaternionf) quaternion.inner, originX, originY, originZ);
     }
-}
+
+    @Override
+    public Object peek() {
+        return this.peekM();
+    }
+}