1 files changed, 86 insertions, 0 deletions
diff --git a/src/main/java/moe/nea/firmament/init/HandledScreenRiser.java b/src/main/java/moe/nea/firmament/init/HandledScreenRiser.java
new file mode 100644
index 0000000..3222a91
--- /dev/null
+++ b/src/main/java/moe/nea/firmament/init/HandledScreenRiser.java
@@ -0,0 +1,86 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.init;
+
+import me.shedaniel.mm.api.ClassTinkerers;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.InsnNode;
+import org.objectweb.asm.tree.JumpInsnNode;
+import org.objectweb.asm.tree.LabelNode;
+import org.objectweb.asm.tree.LdcInsnNode;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.tree.VarInsnNode;
+
+import java.lang.reflect.Modifier;
+
+public class HandledScreenRiser extends RiserUtils {
+    String Screen = remapper.mapClassName("intermediary", "net.minecraft.class_437");
+    String HandledScreen = remapper.mapClassName("intermediary", "net.minecraft.class_465");
+    Type mouseScrolledDesc = Type.getMethodType(Type.BOOLEAN_TYPE, Type.DOUBLE_TYPE, Type.DOUBLE_TYPE, Type.DOUBLE_TYPE, Type.DOUBLE_TYPE);
+    String mouseScrolled = remapper.mapMethodName("intermediary", "net.minecraft.class_364", "method_25401",
+                                                  mouseScrolledDesc.getDescriptor());
+
+    @Override
+    public void addTinkerers() {
+        ClassTinkerers.addTransformation(HandledScreen, this::handle);
+    }
+
+    void handle(ClassNode classNode) {
+        MethodNode mouseScrolledNode = findMethod(classNode, mouseScrolled, mouseScrolledDesc);
+        if (mouseScrolledNode == null) {
+            mouseScrolledNode = new MethodNode(
+                Modifier.PUBLIC,
+                mouseScrolled,
+                mouseScrolledDesc.getDescriptor(),
+                null,
+                new String[0]
+            );
+            var insns = mouseScrolledNode.instructions;
+            // ALOAD 0, load this
+            insns.add(new VarInsnNode(Opcodes.ALOAD, 0));
+            // DLOAD 1-4, load the 4 argument doubles. Note that since doubles are two entries wide we skip 2 each time.
+            insns.add(new VarInsnNode(Opcodes.DLOAD, 1));
+            insns.add(new VarInsnNode(Opcodes.DLOAD, 3));
+            insns.add(new VarInsnNode(Opcodes.DLOAD, 5));
+            insns.add(new VarInsnNode(Opcodes.DLOAD, 7));
+            // INVOKESPECIAL call super method
+            insns.add(new MethodInsnNode(Opcodes.INVOKESPECIAL, getTypeForClassName(Screen).getInternalName(), mouseScrolled, mouseScrolledDesc.getDescriptor()));
+            // IRETURN return int on stack (booleans are int at runtime)
+            insns.add(new InsnNode(Opcodes.IRETURN));
+            classNode.methods.add(mouseScrolledNode);
+        }
+
+        var insns = new InsnList();
+        // ALOAD 0, load this
+        insns.add(new VarInsnNode(Opcodes.ALOAD, 0));
+        // DLOAD 1-4, load the 4 argument doubles. Note that since doubles are two entries wide we skip 2 each time.
+        insns.add(new VarInsnNode(Opcodes.DLOAD, 1));
+        insns.add(new VarInsnNode(Opcodes.DLOAD, 3));
+        insns.add(new VarInsnNode(Opcodes.DLOAD, 5));
+        insns.add(new VarInsnNode(Opcodes.DLOAD, 7));
+        // INVOKEVIRTUAL call custom handler
+        insns.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL,
+                                     getTypeForClassName(HandledScreen).getInternalName(),
+                                     "mouseScrolled_firmament",
+                                     mouseScrolledDesc.getDescriptor()));
+        // Create jump target (but not insert it yet)
+        var jumpIfFalse = new LabelNode();
+        // IFEQ (if returned boolean == 0), jump to jumpIfFalse
+        insns.add(new JumpInsnNode(Opcodes.IFEQ, jumpIfFalse));
+        // LDC 1 (as int, which is what booleans are at runtime)
+        insns.add(new LdcInsnNode(1));
+        // IRETURN return int on stack (booleans are int at runtime)
+        insns.add(new InsnNode(Opcodes.IRETURN));
+        insns.add(jumpIfFalse);
+        mouseScrolledNode.instructions.insert(insns);
+    }
+
+}