1 files changed, 124 insertions, 0 deletions
diff --git a/src/utils/Decompressor.cpp b/src/utils/Decompressor.cpp
new file mode 100644
index 0000000..064adc6
--- /dev/null
+++ b/src/utils/Decompressor.cpp
@@ -0,0 +1,124 @@
+#include "Decompressor.h"
+
+#include <stdexcept>
+#include "spdlog/spdlog.h"
+#include <Companion.h>
+
+extern "C" {
+#include <libmio0/mio0.h>
+}
+
+std::unordered_map<uint32_t, DataChunk*> gCachedChunks;
+
+DataChunk* Decompressor::Decode(const std::vector<uint8_t>& buffer, const uint32_t offset, const CompressionType type) {
+
+    if(gCachedChunks.contains(offset)){
+        return gCachedChunks[offset];
+    }
+
+    const unsigned char* in_buf = buffer.data() + offset;
+
+	switch (type) {
+        case CompressionType::MIO0: {
+
+            mio0_header_t head;
+            if(!mio0_decode_header(in_buf, &head)){
+                throw std::runtime_error("Failed to decode MIO0 header");
+            }
+
+            const auto decompressed = new uint8_t[head.dest_size];
+            mio0_decode(in_buf, decompressed, nullptr);
+            gCachedChunks[offset] = new DataChunk{ decompressed, head.dest_size };
+            return gCachedChunks[offset];
+        }
+        default:
+            throw std::runtime_error("Unknown compression type");
+    }
+}
+
+DecompressedData Decompressor::AutoDecode(YAML::Node& node, std::vector<uint8_t>& buffer) {
+    if(!node["offset"]){
+        throw std::runtime_error("Failed to find offset");
+    }
+
+    const auto offset = TranslateAddr(node["offset"].as<uint32_t>());
+
+    if(node["mio0"]){
+        const auto mio0 = node["mio0"].as<uint32_t>();
+        auto decoded = Decode(buffer, offset, CompressionType::MIO0);
+        auto size = node["size"] ? node["size"].as<size_t>() : decoded->size - mio0;
+
+        return {
+            .root = decoded,
+            .segment = { decoded->data + mio0, size }
+        };
+    }
+
+    if(node["yay0"]){
+        throw std::runtime_error("Yay0 not implemented");
+    }
+
+    if(node["yaz0"]){
+        throw std::runtime_error("Yaz0 not implemented");
+    }
+
+    return {
+        .root = nullptr,
+        .segment = { buffer.data() + offset, buffer.size() - offset }
+    };
+}
+
+uint32_t Decompressor::TranslateAddr(uint32_t addr){
+    if(IS_SEGMENTED(addr)){
+        const auto segment = Companion::Instance->GetSegmentedAddr(SEGMENT_NUMBER(addr));
+
+        if(!segment.has_value()) {
+            SPDLOG_ERROR("Segment data missing from game config\nPlease add an entry for segment {}", SEGMENT_NUMBER(addr));
+            return 0;
+        }
+
+        return segment.value() + SEGMENT_OFFSET(addr);
+    }
+
+    return addr;
+}
+
+bool Decompressor::IsSegmented(uint32_t addr) {
+    if(IS_SEGMENTED(addr)){
+        const auto segment = Companion::Instance->GetSegmentedAddr(SEGMENT_NUMBER(addr));
+
+        if(!segment.has_value()) {
+            SPDLOG_ERROR("Segment data missing from game config\nPlease add an entry for segment {}", SEGMENT_NUMBER(addr));
+            return false;
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+bool Decompressor::IsCompressed(YAML::Node& node) {
+    return node["mio0"] || node["yay0"] || node["yaz0"];
+}
+
+void Decompressor::CopyCompression(YAML::Node& from, YAML::Node& to){
+    if(from["mio0"]){
+        to["mio0"] = from["mio0"];
+    }
+
+    if(from["yay0"]){
+        to["yay0"] = from["yay0"];
+    }
+
+    if(from["yaz0"]){
+        to["yaz0"] = from["yaz0"];
+    }
+}
+
+void Decompressor::ClearCache() {
+    for(auto& [key, value] : gCachedChunks){
+        delete value->data;
+    }
+    gCachedChunks.clear();
+}