static void InjectSaveHook()
{
var saveWorld = typeDef_WorldFile.GetMethod("saveWorld", MethodFlags.Public | MethodFlags.Static, typeSys.Boolean.ToTypeDefOrRef(), typeSys.Boolean.ToTypeDefOrRef());
MethodDef invokeSaveWorld;
var saveWorldDel = context.CreateDelegate("Terraria.PrismInjections", "WorldFile_OnSaveWorldDel", typeSys.Void, out invokeSaveWorld, typeSys.Boolean);
var onSaveWorld = new FieldDefUser("P_OnSaveWorld", new FieldSig(saveWorldDel.ToTypeSig()), FieldAttributes.Public | FieldAttributes.Static);
typeDef_WorldFile.Fields.Add(onSaveWorld);
OpCode[] toFind =
{
OpCodes.Ldloc_S,
OpCodes.Call,
OpCodes.Leave_S
};
Instruction[] toInject =
{
Instruction.Create(OpCodes.Ldsfld, onSaveWorld),
Instruction.Create(OpCodes.Ldarg_0),
Instruction.Create(OpCodes.Callvirt, invokeSaveWorld)
};
var swb = saveWorld.Body;
using (var swbproc = swb.GetILProcessor())
{
var instr = swb.FindInstrSeqStart(toFind).Next(swbproc).Next(swbproc);
for (int i = 0; i < toInject.Length; i++)
{
swbproc.InsertBefore(instr, toInject[i]);
}
}
}
/// <summary>
/// Wraps a method using a fancy delegate. Replaces all references of the method with the wrapped one and creates an "On[MethodName]" hook which passes the method's parent type followed by the type parameters of the original method.
/// </summary>
/// <param name="context">The current Cecil context.</param>
/// <param name="delegateNS">The namespace of the delegate type to create.</param>
/// <param name="delegateTypeName">The name of the delegate type to create.</param>
/// <param name="origMethod">The method to wrap.</param>
public static void Wrap(this MethodDef origMethod, DNContext context, string delegateNS, string delegateTypeName, string fieldName)
{
MethodDef invokeDelegate;
//SingletonTRArr[0] = origMethod.DeclaringType.ToTypeSig();
////If anyone knows a better way to insert one element at the beginning of an array and scoot
////all the other elements down one index then go ahead and do it lol. I dunno how2array.
var delegateArgs = origMethod.Parameters.Select(p => p.Type).ToArray();
var newDelegateType = context.CreateDelegate(delegateNS, delegateTypeName, origMethod.ReturnType, out invokeDelegate, delegateArgs);
var newMethod = origMethod.ReplaceAndHook(invokeDelegate, origMethod, fieldName);
// you're not special anymore!
if ((origMethod.Attributes & MethodAttributes.SpecialName) != 0)
origMethod.Attributes ^= MethodAttributes.SpecialName;
if ((origMethod.Attributes & MethodAttributes.RTSpecialName) != 0)
origMethod.Attributes ^= MethodAttributes.RTSpecialName;
origMethod.ReplaceAllMethodRefs(newMethod, context);
}
static void AddPlaceThingHook()
{
/*
*
* IL_2D37: ldsfld int32 Terraria.Player::tileTargetX
* IL_2D3C: ldsfld int32 Terraria.Player::tileTargetY
* IL_2D41: ldarg.0
* IL_2D42: ldfld class Terraria.Item[] Terraria.Player::inventory
* IL_2D47: ldarg.0
* IL_2D48: ldfld int32 Terraria.Player::selectedItem
* IL_2D4D: ldelem.ref
* IL_2D4E: ldfld int32 Terraria.Item::createTile
* IL_2D53: ldc.i4.0
* IL_2D54: ldloc.s 78
* IL_2D56: ldarg.0
* IL_2D57: ldfld int32 Terraria.Entity::whoAmI
* IL_2D5C: ldloc.s 72
* IL_2D5E: call bool Terraria.WorldGen::PlaceTile(int32, int32, int32, bool, bool, int32, int32)
* IL_2D63: stloc.s 79
*/
OpCode[] toFind =
{
OpCodes.Ldsfld,
OpCodes.Ldsfld,
OpCodes.Ldarg_0,
OpCodes.Ldfld,
OpCodes.Ldarg_0,
OpCodes.Ldfld,
OpCodes.Ldelem_Ref,
OpCodes.Ldfld,
OpCodes.Ldc_I4_0,
OpCodes.Ldloc_S,
OpCodes.Ldarg_0,
OpCodes.Ldfld,
OpCodes.Ldloc_S,
OpCodes.Call,
OpCodes.Stloc_S
};
var placeThing = typeDef_Player.GetMethod("PlaceThing");
MethodDef invokePlaceThing;
var onPlaceThingDel = context.CreateDelegate("Terraria.PrismInjections", "Player_OnPlaceThingDel", typeSys.Void, out invokePlaceThing, typeSys.Boolean);
var onPlaceThing = new FieldDefUser("P_OnPlaceThing", new FieldSig(onPlaceThingDel.ToTypeSig()), FieldAttributes.Public | FieldAttributes.Static);
typeDef_Player.Fields.Add(onPlaceThing);
var ptb = placeThing.Body;
using (var ptbproc = ptb.GetILProcessor())
{
Instruction[] toInj =
{
Instruction.Create(OpCodes.Ldsfld, onPlaceThing),
Instruction.Create(OpCodes.Ldloc, ptb.Variables[79]),
Instruction.Create(OpCodes.Callvirt, invokePlaceThing)
};
var first = ptb.FindInstrSeqStart(toFind);
for (int i = 0; i < toFind.Length - 1; i++)
{
first = first.Next(ptbproc);
}
foreach (var i in toInj.Reverse())
{
ptbproc.InsertAfter(first, i);
}
}
}
static void AddPreDrawHook()
{
OpCode[] toFind =
{
/*
* spriteBatch.Draw(...);
*
* IL_29AF: ldsfld class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.SpriteBatch Terraria.Main::spriteBatch
* IL_29B4: ldc.i4.0
* IL_29B5: ldsfld class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.BlendState [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.BlendState::AlphaBlend
* IL_29BA: ldsfld class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.SamplerState [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.SamplerState::LinearClamp
* IL_29BF: ldsfld class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.DepthStencilState [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.DepthStencilState::None
* IL_29C4: ldarg.0
* IL_29C5: ldfld class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.RasterizerState Terraria.Main::Rasterizer
* IL_29CA: ldnull
* IL_29CB: ldarg.0
* IL_29CC: ldfld valuetype [Microsoft.Xna.Framework]Microsoft.Xna.Framework.Matrix Terraria.Main::Transform
* IL_29D1: callvirt instance void [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.SpriteBatch::Begin(valuetype [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.SpriteSortMode, class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.BlendState, class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.SamplerState, class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.DepthStencilState, class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.RasterizerState, class [Microsoft.Xna.Framework.Graphics]Microsoft.Xna.Framework.Graphics.Effect, valuetype [Microsoft.Xna.Framework]Microsoft.Xna.Framework.Matrix)
*/
OpCodes.Ldsfld,
OpCodes.Ldc_I4_0,
OpCodes.Ldsfld,
OpCodes.Ldsfld,
OpCodes.Ldsfld,
OpCodes.Ldarg_0,
OpCodes.Ldfld,
OpCodes.Ldnull,
OpCodes.Ldarg_0,
OpCodes.Ldfld,
OpCodes.Callvirt
};
var draw = typeDef_Main.GetMethod("Draw");
var spriteBatch = typeDef_Main.GetField("spriteBatch");
MethodDef invokePreDraw;
var onPreDrawDel = context.CreateDelegate("Terraria.PrismInjections", "Main_OnPreDrawDel", typeSys.Void, out invokePreDraw, spriteBatch.FieldType);
var onPreDraw = new FieldDefUser("P_OnPreDraw", new FieldSig(onPreDrawDel.ToTypeSig()), FieldAttributes.Public | FieldAttributes.Static);
typeDef_Main.Fields.Add(onPreDraw);
var drb = draw.Body;
using (var drbproc = drb.GetILProcessor())
{
Instruction[] toInj =
{
Instruction.Create(OpCodes.Ldsfld, onPreDraw),
Instruction.Create(OpCodes.Ldsfld, spriteBatch),
Instruction.Create(OpCodes.Callvirt, invokePreDraw)
};
var first = drb.FindInstrSeqStart(toFind);
for (int i = 0; i < toFind.Length; i++)
{
first = first.Next(drbproc);
}
foreach (var i in toInj.Reverse())
{
drbproc.InsertAfter(first, i);
}
// rewire the if before it to end at the injected instructions instead of the code we looked for
//foreach (var i in drb.Instructions)
// if (i.Operand == first)
// i.Operand = toInj[0];
// not rewiring the if will lead to invalid IL, because the target instruction won't exist (because we're removing it here)
}
}
static void ReplaceSoundHitCalls()
{
#region ReflectProjectile
{ // introduce a new scope level here so variables can be reused in the StrikeNPC part
var reflectProjectile = typeDef_NPC.GetMethod("ReflectProjectile");
// first statement in the method is "Main.PlaySound(...);"
// instruction after the "call Main.PlaySound" is a ldc.i4.0 (first one in the method)
MethodDef invokeSoundHit;
var onReflProjSoundHit = context.CreateDelegate("Terraria.PrismInjections", "NPC_ReflectProjectile_PlaySoundHitDel", typeSys.Void, out invokeSoundHit, typeDef_NPC.ToTypeSig(), typeSys.Int32);
var reflectProjectile_PlaySoundHit = new FieldDefUser("P_ReflectProjectile_PlaySoundHit", new FieldSig(onReflProjSoundHit.ToTypeSig()), FieldAttributes.Public | FieldAttributes.Static);
typeDef_NPC.Fields.Add(reflectProjectile_PlaySoundHit);
using (var rpproc = reflectProjectile.Body.GetILProcessor())
{
rpproc.RemoveInstructions(reflectProjectile.Body.Instructions.TakeWhile(i => i.OpCode.Code != Code.Ldc_I4_0).ToArray() /* must enumerate this already, invalidoperation will be thrown otherwise */);
var first = reflectProjectile.Body.Instructions[0];
rpproc.InsertBefore(first, Instruction.Create(OpCodes.Ldsfld, reflectProjectile_PlaySoundHit));
rpproc.EmitWrapperCall(invokeSoundHit, first);
}
}
#endregion
#region StrikeNPC
{
var strikeNpc = typeDef_NPC.GetMethod("StrikeNPC");
MethodDef invokeSoundHit;
var onStrikeNpcSoundHit = context.CreateDelegate("Terraria.PrismInjections", "NPC_StrikeNPC_PlaySoundHitDel", typeSys.Void, out invokeSoundHit,
new[] { typeDef_NPC.ToTypeSig(), typeSys.Int32, typeSys.Single, typeSys.Int32, typeSys.Boolean, typeSys.Boolean, typeSys.Boolean });
var strikeNpc_PlaySoundHit = new FieldDefUser("P_StrikeNPC_PlaySoundHit", new FieldSig(onStrikeNpcSoundHit.ToTypeSig()), FieldAttributes.Public | FieldAttributes.Static);
typeDef_NPC.Fields.Add(strikeNpc_PlaySoundHit);
var snb = strikeNpc.Body;
using (var snproc = snb.GetILProcessor())
{
OpCode[] toRem =
{
OpCodes.Ldarg_0,
OpCodes.Ldfld, // NPC.soundHit
OpCodes.Ldc_I4_0,
OpCodes.Ble_S, // <after the call>
OpCodes.Ldc_I4_3, // soundHit ID
OpCodes.Ldarg_0,
OpCodes.Ldflda, // Entity.position
OpCodes.Ldfld, // Vector2.X
OpCodes.Conv_I4,
OpCodes.Ldarg_0,
OpCodes.Ldflda, // Entity.position
OpCodes.Ldfld, // Vector2.X
OpCodes.Conv_I4,
OpCodes.Ldarg_0,
OpCodes.Ldfld, // NPC.soundHit
OpCodes.Call // Main.PlaySound(int, int, int, int)
};
var instrs = snb.FindInstrSeqStart(toRem);
var instrs_ = snproc.RemoveInstructions(instrs, toRem.Length);
Instruction newF;
snproc.InsertBefore(instrs_, newF = Instruction.Create(OpCodes.Ldsfld, strikeNpc_PlaySoundHit));
snproc.EmitWrapperCall(invokeSoundHit, instrs_);
for (int i = 0; i < snb.Instructions.Count; i++)
{
if (snb.Instructions[i].Operand == instrs)
{
snb.Instructions[i].Operand = newF;
}
}
}
}
#endregion
}