src/CMakeLists.txt

@@ -144,6 +144,7 @@ add_executable(MassBuilderSaveTool WIN32
     Maps/WeaponTypes.hpp
     ToastQueue/ToastQueue.h
     ToastQueue/ToastQueue.cpp
+    Utilities/Crc32.h
     FontAwesome/IconsFontAwesome5.h
     FontAwesome/IconsFontAwesome5Brands.h
     resource.rc

src/Utilities/Crc32.h

@@ -0,0 +1,62 @@
+#pragma once
+
+// MassBuilderSaveTool
+// Copyright (C) 2021-2022 Guillaume Jacquemin
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#include <Corrade/Containers/ArrayView.h>
+#include <Corrade/Containers/StaticArray.h>
+
+#include <Magnum/Types.h>
+
+using namespace Corrade;
+using namespace Magnum;
+
+struct Crc32 {
+    static const Containers::StaticArray<256, UnsignedInt> table;
+
+    static auto update(UnsignedInt initial, Containers::ArrayView<const void> data) -> UnsignedInt {
+        UnsignedInt c = initial ^ 0xFFFFFFFF;
+        auto u = Containers::arrayCast<const UnsignedByte>(data);
+
+        for(std::size_t i = 0; i < data.size(); ++i) {
+            c = table[(c ^ u[i]) & 0xFF] ^ (c >> 8);
+        }
+
+        return c ^ 0xFFFFFFFF;
+    }
+};
+
+const Containers::StaticArray<256, UnsignedInt> Crc32::table = []{
+    UnsignedInt polynomial = 0xEDB88320;
+    Containers::StaticArray<256, UnsignedInt> temp{ValueInit};
+
+    for(UnsignedInt i = 0; i < 256; i++) {
+        UnsignedInt c = i;
+
+        for(std::size_t j = 0; j < 8; j++) {
+            if(c & 1) {
+                c = polynomial ^ (c >> 1);
+            }
+            else {
+                c >>= 1;
+            }
+        }
+
+        temp[i] = c;
+    }
+
+    return temp;
+}();