1 files changed, 94 insertions, 0 deletions
diff --git a/src/KingSystem/Resource/resOffsetReadFileDevice.cpp b/src/KingSystem/Resource/resOffsetReadFileDevice.cpp
new file mode 100644
index 00000000..5bc3f9ac
--- /dev/null
+++ b/src/KingSystem/Resource/resOffsetReadFileDevice.cpp
@@ -0,0 +1,94 @@
+#include "KingSystem/Resource/resOffsetReadFileDevice.h"
+#include <heap/seadHeapMgr.h>
+#include <math/seadMathCalcCommon.h>
+#include "KingSystem/Resource/resSystem.h"
+
+namespace ksys::res {
+
+OffsetReadFileDevice::OffsetReadFileDevice(sead::Heap* heap) : sead::MainFileDevice(heap) {
+    resetOffsetRead();
+}
+
+void OffsetReadFileDevice::setFileDevice(sead::FileDevice* device) {
+    OffsetRead::setFileDevice(device);
+}
+
+/// This is a modified version of `sead::FileDevice::doLoad_`.
+u8* OffsetReadFileDevice::doLoad_(sead::FileDevice::LoadArg& arg) {
+    if (arg.buffer && arg.buffer_size == 0) {
+        stubbedLogFunction();
+        return nullptr;
+    }
+
+    sead::FileDevice* device = mOffsetReadFileDevice;
+    if (!device)
+        device = this;
+
+    sead::FileHandle handle;
+    if (!device->tryOpen(&handle, arg.path, FileDevice::cFileOpenFlag_ReadOnly, arg.div_size))
+        return nullptr;
+
+    u32 bytesToRead = arg.buffer_size;
+    if (!arg.buffer || arg.check_read_entire_file) {
+        u32 fileSize = 0;
+        if (!device->tryGetFileSize(&fileSize, &handle))
+            return nullptr;
+
+        if (fileSize == 0) {
+            stubbedLogFunction();
+            return nullptr;
+        }
+
+        if (bytesToRead != 0) {
+            if (bytesToRead < fileSize) {
+                stubbedLogFunction();
+                return nullptr;
+            }
+        } else {
+            bytesToRead = mOffsetReadOffset + sead::Mathi::roundUpPow2Positive(
+                                                  fileSize, FileDevice::cBufferMinAlignment);
+        }
+    }
+
+    u8* buf = arg.buffer;
+    bool allocated = false;
+
+    if (buf == nullptr) {
+        const s32 sign = (arg.alignment < 0) ? -1 : 1;
+        s32 alignment = sead::abs(arg.alignment);
+        alignment = sign * ((alignment < cBufferMinAlignment) ? cBufferMinAlignment : alignment);
+
+        sead::Heap* heap = arg.heap;
+        if (!heap)
+            heap = sead::HeapMgr::instance()->getCurrentHeap();
+
+        void* raw_buf = heap->tryAlloc(bytesToRead, alignment);
+        if (!raw_buf)
+            return nullptr;
+
+        buf = new (raw_buf) u8[bytesToRead];
+        allocated = true;
+    }
+
+    u32 bytesRead = 0;
+    if (!device->tryRead(&bytesRead, &handle, buf + mOffsetReadOffset,
+                         bytesToRead - mOffsetReadOffset)) {
+        if (allocated)
+            delete[] buf;
+        return nullptr;
+    }
+
+    if (!device->tryClose(&handle)) {
+        if (allocated)
+            delete[] buf;
+        return nullptr;
+    }
+
+    arg.read_size = bytesRead;
+    arg.roundup_size = bytesToRead;
+    arg.need_unload = allocated;
+
+    return buf;
+}
+
+}  // namespace ksys::res