REDCODE/BlenderSharp
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Added more documentation and started pointer handling

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This commit is contained in:
Samuele Lorefice
2025-02-20 18:41:27 +01:00
parent d95c81f3f2
commit 6d565377a4
3 changed files with 72 additions and 11 deletions
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78
BlendFile/Reader.cs
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@@ -1,4 +1,3 @@
using System.Numerics;
using System.Reflection;
using System.Text;
using Kaitai;
@@ -7,20 +6,23 @@ using Kaitai;
namespace BlendFile;
public class Reader {
readonly string _path;
string _path;
private readonly Dictionary<int, Type> dnaTypes = new();
private List<object> objects = new();
public List<object> Objects => objects;
private Dictionary<(long, Type), object> objects = new();
public Dictionary<(long, Type), object> Objects => objects;
private Dictionary<long, Kaitai.BlendFile.FileBlock> memBlocks = new();
public List<object> GetObjects() => objects.Values.ToList();
public List<T> GetObjects<T>() => objects.Values.OfType<T>().ToList();
private SortedDictionary<long, Kaitai.BlendFile.FileBlock> memBlocks = new();
/// <summary>
/// Gets the block at the specified memory address
/// </summary>
/// <param name="memAddr">memory address in current system endianness</param>
/// <returns>A <see cref="Kaitai.BlendFile.FileBlock"/> object</returns>
public Kaitai.BlendFile.FileBlock? GetBlock(long memAddr) => memBlocks.GetValueOrDefault(memAddr);
public Kaitai.BlendFile.FileBlock? GetBlock(long memAddr) => memBlocks.SkipWhile(x => x.Key < memAddr).FirstOrDefault().Value;
/// <summary>
/// Creates a new instance of the <see cref="Reader"/> class
@@ -43,12 +45,18 @@ public class Reader {
}
}
public void Read(string path) {
_path = path;
Read();
}
public void Read() {
var file = new KaitaiStream(_path);
var blend = new Kaitai.BlendFile(file);
bool isLe = blend.Hdr.Endian == Kaitai.BlendFile.Endian.Le;
blend.Blocks.ForEach(block => memBlocks.Add(block.MemAddr.ToMemAddr(isLe), block));
//TODO: two blocks somehow have the same mem address... this sounds wrong.
blend.Blocks.ForEach(block => memBlocks.TryAdd(block.MemAddr.ToMemAddr(isLe), block));
foreach (var block in blend.Blocks)
{
@@ -68,21 +76,31 @@ public class Reader {
//create an instance of type "t" (the dna type we inferred before)
var obj = Activator.CreateInstance(t);
if(obj == null) continue; //should never happen
objects.Add(obj); //add the object to the list of objects
//fill the object with the data from the block
FillObject(block, ref obj, t.GetFields(), blockOffset);
//move the offset to the next object in the block
blockOffset += t.GetCustomAttribute<DNAClassAttribute>()!.Size;
}
}
}
private void FillObject(Kaitai.BlendFile.FileBlock block, ref object obj, FieldInfo[] fieldMetadata, int startOffset = 0) {
/// <summary>
///
/// </summary>
/// <param name="block"></param>
/// <param name="obj"></param>
/// <param name="fieldMetadata"></param>
/// <param name="startOffset"></param>
/// <returns></returns>
private void FillObject(Kaitai.BlendFile.FileBlock block, ref object? obj, FieldInfo[] fieldMetadata, int startOffset = 0) {
if(block.Code == "ENDB") return;
foreach (var field in fieldMetadata) {
//Get the DNAFieldAttribute of the current field
var attrib = field.GetCustomAttribute<DNAFieldAttribute>();
if (attrib == null) continue; //should never happen, but means a field has no metadata
//Calculate the offset from where the data of the field starts.
//Because the order of the fields is not guaranteed we need to compute it each time
int offset = fieldMetadata.Where(f => f.GetCustomAttribute<DNAFieldAttribute>()!.OriginalIndex < attrib.OriginalIndex)
@@ -93,10 +111,50 @@ public class Reader {
Array.Copy((byte[])block.Body, offset, data, 0, size);
//Convert the data to the correct type
object? value = ConvertFieldData(data, attrib.OriginalType);
if(value == null) continue; //should never happen, but means the data could not be converted
if(value == null){ //if the data could not be converted
//Check if the field is a pointer to another DNA structure
if (dnaTypes.Values.FirstOrDefault(x => x.GetCustomAttribute<DNAClassAttribute>()!.OriginalName == attrib.OriginalType) != null) {
//Create a new instance of the DNA structure type
object? newObj = Activator.CreateInstance(dnaTypes.Values.First(x =>
x.GetCustomAttribute<DNAClassAttribute>()!.OriginalName == attrib.OriginalType));
if(newObj == null) continue; //should never happen... type is missing?
//Get the information of the fields of the new object
var fieldInfo = newObj.GetType().GetFields();
//If the field is a pointer, we need to dereference it
if (attrib.IsPointer) {
//Get the memory address of the data
long addr = data.ToMemAddr();
//Get the closest block that contains the data
var derefBlock = GetBlock(addr);
//Calculate the relative address of the data in the block
long relAddr = addr - derefBlock!.MemAddr.ToMemAddr();
if(objects.TryGetValue((addr, newObj.GetType()), out object? o)){ //If the object is already created, we can just assign it
field.SetValue(obj, o);
continue;
}
//Fill the object with the data from the block (this is recursive)
FillObject(derefBlock, ref newObj, fieldInfo, (int)relAddr);
} else {
long relAddr = block.MemAddr.ToMemAddr() + offset;
if(objects.TryGetValue((relAddr, newObj.GetType()), out object? o)){ //If the object is already created, we can just assign it
field.SetValue(obj, o);
continue;
}
//Fill the object with the data from the block (this is recursive)
FillObject(block, ref newObj, fieldInfo, offset);
}
}
continue; //should never happen, but means the data could not be converted
}
//Additionally... some fields might not be nullable so it's better to not assign the value and leave the default one.
field.SetValue(obj, value);
}
objects.Add((block.MemAddr.ToMemAddr() + startOffset, obj!.GetType()), obj!);
}
private object? ConvertFieldData(byte[] data, string type)