Merge pull request #27 from SnipUndercover/spike-refill-controller

Implement Spike Refill Controllers

Entities/SpikeRefillController.cs

@@ -0,0 +1,69 @@
+using Celeste.Mod.Entities;
+using Microsoft.Xna.Framework;
+using Mono.Cecil.Cil;
+using Monocle;
+using MonoMod.Cil;
+using MonoMod.RuntimeDetour;
+using System;
+using System.Reflection;
+
+namespace Celeste.Mod.MaxHelpingHand.Entities {
+    [Tracked]
+    [CustomEntity("MaxHelpingHand/SpikeRefillController")]
+    public class SpikeRefillController : Entity {
+        private static readonly MethodInfo m_OrigUpdate = typeof(Player).GetMethod("orig_Update");
+        private static ILHook Hook_OrigUpdate;
+
+        public string Flag { get; private set; }
+        public bool FlagInverted { get; private set; }
+
+        private bool IsFlagSatisfied => string.IsNullOrWhiteSpace(Flag) || (FlagInverted ^ SceneAs<Level>().Session.GetFlag(Flag));
+
+        public SpikeRefillController(EntityData data, Vector2 offset) : base(data.Position + offset) {
+            Flag = data.Attr("flag");
+            FlagInverted = data.Bool("flagInverted");
+        }
+
+        public static void Load() {
+            Hook_OrigUpdate = new ILHook(m_OrigUpdate, HookSpikeRefillPrevention);
+        }
+
+        public static void Unload() {
+            Hook_OrigUpdate?.Dispose();
+        }
+
+        private static void HookSpikeRefillPrevention(ILContext il) {
+            ILCursor cursor = new ILCursor(il);
+
+            if (!cursor.TryGotoNext(MoveType.After, instr => instr.MatchCall("Monocle.Entity", "System.Boolean CollideCheck<Celeste.Spikes>(Microsoft.Xna.Framework.Vector2)"))) {
+                Logger.Log(LogLevel.Error, "MaxHelpingHand/SpikeRefillController",
+                    $"Could not find CollideCheck<Spikes> in {il.Method.FullName}!");
+                return;
+            }
+
+            Logger.Log(LogLevel.Verbose, "MaxHelpingHand/SpikeRefillController",
+                $"Hooking CollideCheck<Spikes> in {il.Method.FullName} @ {InstructionToString(cursor.Next)}");
+
+            cursor.Emit(OpCodes.Ldarg_0);
+            cursor.EmitDelegate(OverrideRefillPreventionInSpikes);
+        }
+
+        private static bool OverrideRefillPreventionInSpikes(bool collidedWithSpikes, Player self) {
+            // return true to prevent refills
+            if (!collidedWithSpikes)
+                return collidedWithSpikes;
+
+            return !(self.Scene.Tracker.GetEntity<SpikeRefillController>()?.IsFlagSatisfied ?? false);
+        }
+
+        // stringifying branch instructions crashes because of monomod, very cool
+        private static string InstructionToString(Instruction instr) {
+            Instruction toStringify = instr;
+            if (instr.Operand is ILLabel target) {
+                toStringify = Instruction.Create(toStringify.OpCode, target.Target);
+                toStringify.Offset = instr.Offset;
+            }
+            return toStringify.ToString();
+        }
+    }
+}

Loenn/entities/spikeRefillController.lua

@@ -0,0 +1,15 @@
+local spikeRefillController = {}
+
+spikeRefillController.name = "MaxHelpingHand/SpikeRefillController"
+spikeRefillController.justification = { 0.5, 0.5 }
+spikeRefillController.placements = {
+    name = 'normal',
+    data = {
+        flag = "",
+        flagInverted = false
+    }
+}
+
+spikeRefillController.texture = "objects/MaxHelpingHand/spikeRefillController/controller"
+
+return spikeRefillController

Loenn/lang/en_gb.lang

@@ -1392,4 +1392,9 @@ entities.MaxHelpingHand/ReverseJelly.attributes.description.tutorial=Whether the
 entities.MaxHelpingHand/ReverseJelly.attributes.description.glow=Whether the entity should glow in the dark.
 
 # Reversible Retention Booster
-entities.MaxHelpingHand/ReversibleRetentionBooster.placements.name.booster=Reversible Retention Booster
+entities.MaxHelpingHand/ReversibleRetentionBooster.placements.name.booster=Reversible Retention Booster
+
+# Spike Refill Controller
+entities.MaxHelpingHand/SpikeRefillController.placements.name.normal=Spike Refill Controller
+entities.MaxHelpingHand/SpikeRefillController.attributes.description.flag=The flag this controller should check to determine whether it's active.
+entities.MaxHelpingHand/SpikeRefillController.attributes.description.flagInverted=If checked, the controller will be active if the flag is disabled.

Module/MaxHelpingHandModule.cs

@@ -102,6 +102,7 @@ public override void Load() {
             FrozenJelly.Load();
             ReverseJelly.Load();
             ReversibleRetentionBooster.Load();
+            SpikeRefillController.Load();
 
             Everest.Events.Level.OnLoadBackdrop += onLoadBackdrop;
 
@@ -186,6 +187,7 @@ public override void Unload() {
             ReverseJelly.Unload();
             ReversibleRetentionBooster.Unload();
             UpsideDownMovingPlatformGravityHelper.Unload();
+            SpikeRefillController.Unload();
 
             Everest.Events.Level.OnLoadBackdrop -= onLoadBackdrop;