Initial commit of mtgonline project

C++/libcockatrice_utility/libcockatrice/utility/clamped_arithmetic.h

@@ -0,0 +1,22 @@
+#ifndef CLAMPED_ARITHMETIC_H
+#define CLAMPED_ARITHMETIC_H
+
+#include <QtGlobal>
+#include <cstdint>
+
+/**
+ * @brief Overflow-safe clamped addition: returns value + delta bounded to [minValue, maxValue].
+ *
+ * Uses a 64-bit intermediate so the addition cannot overflow int. Shared by the bounded
+ * counter arithmetic in both the client and the server.
+ *
+ * @note Requires minValue <= maxValue. Bounds come from trusted compile-time call sites;
+ *       qBound() asserts this internally in debug builds.
+ */
+inline int addClamped(int value, int delta, int minValue, int maxValue)
+{
+    const auto result = static_cast<int64_t>(value) + static_cast<int64_t>(delta);
+    return static_cast<int>(qBound(static_cast<int64_t>(minValue), result, static_cast<int64_t>(maxValue)));
+}
+
+#endif // CLAMPED_ARITHMETIC_H