Add EAX extensions (EAX 2.0-5.0, X-RAM) (#632)

* Add EAX extensions (EAX 2.0-5.0, X-RAM)

* Comment out C++17 leftovers

* Remove everything related to patching

* Update alsoftrc.sample

* Rewrite integration

* Fix GCC compilation under Linux

* Always reset EAX effect properties when loading it into FX slot

1 files changed, 164 insertions, 0 deletions

diff --git a/al/eax_utils.h b/al/eax_utils.h
new file mode 100644
index 00000000..68e35fcd
--- /dev/null
+++ b/al/eax_utils.h
@@ -0,0 +1,164 @@
+#ifndef EAX_UTILS_INCLUDED
+#define EAX_UTILS_INCLUDED
+
+
+#include <cstdint>
+
+#include <algorithm>
+#include <string>
+#include <type_traits>
+
+
+struct ALCcontext;
+
+
+struct EaxAlLowPassParam
+{
+    float gain;
+    float gain_hf;
+}; // EaxAlLowPassParam
+
+
+// Required to call macro `DO_UPDATEPROPS`.
+class EaxAlContextWrapper
+{
+public:
+    explicit EaxAlContextWrapper(
+        ALCcontext& al_context) noexcept
+        :
+        al_context_{&al_context}
+    {
+    }
+
+    constexpr ALCcontext* get() noexcept
+    {
+        return al_context_;
+    }
+
+    constexpr ALCcontext* operator->() noexcept
+    {
+        return al_context_;
+    }
+
+
+private:
+    ALCcontext* al_context_;
+}; // EaxAlContextWrapper
+
+
+void eax_log_exception(
+    const char* message = nullptr) noexcept;
+
+
+template<
+    typename TException,
+    typename TValue
+>
+void eax_validate_range(
+    const char* value_name,
+    const TValue& value,
+    const TValue& min_value,
+    const TValue& max_value)
+{
+    if (value >= min_value && value <= max_value)
+    {
+        return;
+    }
+
+    const auto message =
+        std::string{value_name} +
+        " out of range (value: " +
+        std::to_string(value) + "; min: " +
+        std::to_string(min_value) + "; max: " +
+        std::to_string(max_value) + ").";
+
+    throw TException{message.c_str()};
+}
+
+
+namespace detail
+{
+
+
+template<
+    typename T
+>
+struct EaxIsBitFieldStruct
+{
+private:
+    using yes = std::true_type;
+    using no = std::false_type;
+
+    template<
+        typename U
+    >
+    static auto test(int) -> decltype(std::declval<typename U::EaxIsBitFieldStruct>(), yes{});
+
+    template<
+        typename
+    >
+    static no test(...);
+
+
+public:
+    static constexpr auto value = std::is_same<decltype(test<T>(0)), yes>::value;
+}; // EaxIsBitFieldStruct
+
+
+template<
+    typename T,
+    typename TValue
+>
+inline bool eax_bit_fields_are_equal(
+    const T& lhs,
+    const T& rhs) noexcept
+{
+    static_assert(sizeof(T) == sizeof(TValue), "Invalid type size.");
+
+    return reinterpret_cast<const TValue&>(lhs) == reinterpret_cast<const TValue&>(rhs);
+}
+
+
+} // namespace detail
+
+
+template<
+    typename T,
+    std::enable_if_t<detail::EaxIsBitFieldStruct<T>::value, int> = 0
+>
+inline bool operator==(
+    const T& lhs,
+    const T& rhs) noexcept
+{
+    using Value = std::conditional_t<
+        sizeof(T) == 1,
+        std::uint8_t,
+        std::conditional_t<
+            sizeof(T) == 2,
+            std::uint16_t,
+            std::conditional_t<
+                sizeof(T) == 4,
+                std::uint32_t,
+                void
+            >
+        >
+    >;
+
+    static_assert(!std::is_same<Value, void>::value, "Unsupported type.");
+
+    return detail::eax_bit_fields_are_equal<T, Value>(lhs, rhs);
+}
+
+template<
+    typename T,
+    std::enable_if_t<detail::EaxIsBitFieldStruct<T>::value, int> = 0
+>
+inline bool operator!=(
+    const T& lhs,
+    const T& rhs) noexcept
+{
+    return !(lhs == rhs);
+}
+
+
+#endif // !EAX_UTILS_INCLUDED