From ed4ee26fe6d6ec113efc54d188c5864f44c1e14d Mon Sep 17 00:00:00 2001
From: KiritoDv <kiritodev01@gmail.com>
Date: Fri, 6 Dec 2024 14:44:36 -0600
Subject: Implemented rom preprocessing system and comptool support

---
 src/preprocess/CompTool.cpp | 86 +++++++++++++++++++++++++++++++++++++++++++++
 src/preprocess/CompTool.h   | 18 ++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 src/preprocess/CompTool.cpp
 create mode 100644 src/preprocess/CompTool.h

(limited to 'src/preprocess')

diff --git a/src/preprocess/CompTool.cpp b/src/preprocess/CompTool.cpp
new file mode 100644
index 0000000..9f585ef
--- /dev/null
+++ b/src/preprocess/CompTool.cpp
@@ -0,0 +1,86 @@
+#include "CompTool.h"
+#include "utils/Decompressor.h"
+#include "lib/binarytools/BinaryWriter.h"
+#include "lib/binarytools/BinaryReader.h"
+#include <fstream>
+
+uint32_t CompTool::FindFileTable(std::vector<uint8_t>& rom) {
+    uint8_t query_one[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x50, 0x00, 0x00, 0x00, 0x00 };
+    uint8_t query_two[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x60, 0x00, 0x00, 0x00, 0x00 };
+
+    for(size_t i = 0; i < rom.size() - sizeof(query_one); i++) {
+        if(memcmp(rom.data() + i, query_one, sizeof(query_one)) == 0){
+            return i;
+        }
+
+        if(memcmp(rom.data() + i, query_two, sizeof(query_two)) == 0){
+            return i;
+        }
+    }
+
+    throw std::runtime_error("Failed to find file table");
+}
+
+std::vector<uint8_t> CompTool::Decompress(std::vector<uint8_t> rom){
+    LUS::BinaryReader basefile((char*) rom.data(), rom.size());
+    basefile.SetEndianness(Torch::Endianness::Big);
+
+    LUS::BinaryWriter decompfile;
+    decompfile.SetEndianness(Torch::Endianness::Big);
+    decompfile.Write((uint8_t)0x80);
+
+    uint32_t table = CompTool::FindFileTable(rom);
+    uint32_t count = 0;
+    while (true){
+        auto entry = table + 0x10 * count;
+        basefile.Seek(entry, LUS::SeekOffsetType::Start);
+
+        auto v_begin = basefile.ReadInt32();
+        auto p_begin = basefile.ReadInt32();
+        auto p_end = basefile.ReadInt32();
+        auto comp_flag = basefile.ReadInt32();
+
+        auto p_size = p_end - p_begin;
+        auto v_size = (int32_t) 0;
+        DataChunk* decoded = nullptr;
+
+        if(v_begin == 0 && p_end == 0){
+            break;
+        }
+
+        basefile.Seek(p_begin, LUS::SeekOffsetType::Start);
+
+        auto bytes = new uint8_t[p_size];
+        basefile.Read((char*) bytes, p_size);
+
+        switch ((CompType) comp_flag) {
+            case CompType::UNCOMPRESSED:
+                v_size = p_size;
+                break;
+            case CompType::COMPRESSED:
+                decoded = Decompressor::Decode(std::vector(bytes, bytes + p_size), 0, CompressionType::MIO0, true);
+                bytes = decoded->data;
+                v_size = decoded->size;
+                break;
+            default:
+                throw std::runtime_error("Invalid compression flag. There may be a problem with your ROM.");
+        }
+
+        decompfile.Seek(v_begin, LUS::SeekOffsetType::Start);
+        decompfile.Write((char*) bytes, v_size);
+        auto v_end = v_begin + v_size;
+
+        decompfile.Seek(entry + 4, LUS::SeekOffsetType::Start);
+        decompfile.Write(v_begin);
+        decompfile.Write(v_end);
+        decompfile.Write((uint32_t) CompType::UNCOMPRESSED);
+        count++;
+    }
+
+    decompfile.Seek(0x10, LUS::SeekOffsetType::Start);
+    decompfile.Write(0xA7D5F194); // CRC1
+    decompfile.Write(0xFE3DF761); // CRC2
+
+    auto result = decompfile.ToVector();
+    return { (uint8_t*) result.data(), (uint8_t*) result.data() + result.size() };
+}
\ No newline at end of file
diff --git a/src/preprocess/CompTool.h b/src/preprocess/CompTool.h
new file mode 100644
index 0000000..15b7db5
--- /dev/null
+++ b/src/preprocess/CompTool.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+enum class CompType {
+    UNCOMPRESSED,
+    COMPRESSED,
+    UNKNOWN
+};
+
+class CompTool {
+public:
+    static std::vector<uint8_t> Decompress(std::vector<uint8_t> rom);
+private:
+    static uint32_t FindFileTable(std::vector<uint8_t>& rom);
+};
\ No newline at end of file
-- 
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