expose sound channels params

src/game_api/script/sol_helper.hpp

@@ -0,0 +1,95 @@
+#pragma once
+
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <span>
+#include <stdexcept>
+
+template <class T>
+struct ZeroIndexArray
+{
+    using value_type = T;
+    using iterator_category = std::contiguous_iterator_tag;
+    using difference_type = size_t;
+    using pointer = T*;
+    using reference = T&;
+    using iterator = T*;
+
+    ZeroIndexArray(T* data, size_t size)
+        : data(data), data_size(size){};
+
+    ZeroIndexArray(std::span<T> arr)
+    {
+        data = arr.data();
+        data_size = arr.size();
+    };
+    ~ZeroIndexArray()
+    {
+        data_size = 0;
+    };
+
+    T& operator[](int index)
+    {
+        return data[index];
+    }
+    T& operator=(T&& other) noexcept
+    {
+        // Guard self assignment
+        if (this == &other)
+            return *this;
+
+        data = other.data;
+        data_size = other.data_size;
+        return *this;
+    }
+    iterator begin() const
+    {
+        return iterator(data);
+    }
+    iterator end() const
+    {
+        return iterator(data + data_size);
+    }
+    bool empty() const
+    {
+        return data_size == 0;
+    }
+    size_t size() const
+    {
+        return data_size;
+    }
+    T* data;
+    size_t data_size{0};
+};
+
+namespace sol
+{
+template <class T>
+struct is_container<ZeroIndexArray<T>> : std::true_type
+{
+};
+
+template <class T>
+struct usertype_container<ZeroIndexArray<T>>
+{
+    static int size(lua_State* L)
+    {
+        ZeroIndexArray<T>& v = sol::stack::get<ZeroIndexArray<T>&>(L, 1);
+        return stack::push(L, v.size());
+    }
+    // Used by default implementation
+    static auto begin(lua_State*, ZeroIndexArray<T>& self)
+    {
+        return self.begin();
+    }
+    static auto end(lua_State*, ZeroIndexArray<T>& self)
+    {
+        return self.end();
+    }
+    static std::ptrdiff_t index_adjustment(lua_State*, ZeroIndexArray<T>&)
+    {
+        return 0;
+    }
+};
+} // namespace sol

src/game_api/script/usertypes/sound_lua.cpp

@@ -27,6 +27,7 @@
 #include "logger.h"               // for DEBUG
 #include "script/lua_backend.hpp" // for LuaBackend
 #include "script/safe_cb.hpp"     // for make_safe_cb
+#include "script/sol_helper.hpp"  //
 #include "sound_manager.hpp"      // for CustomSound, PlayingSound, SoundMa...
 #include "string_aliases.hpp"     // for VANILLA_SOUND
 
@@ -167,10 +168,12 @@ void register_usertypes(sol::state& lua, SoundManager* sound_manager)
         &SoundMeta::x,
         "y",
         &SoundMeta::y,
-        //"left_channel",
-        //&SoundMeta::left_channel, // TODO: index 0-37 instead of 1-38
-        //"right_channel",
-        //&SoundMeta::right_channel,
+        "left_channel",
+        sol::property([&lua](SoundMeta* sm) // -> std::array<float, 38>
+                      { return ZeroIndexArray<float>(sm->left_channel) /**/; }),
+        "right_channel",
+        sol::property([](SoundMeta* sm) // -> std::array<float, 38>
+                      { return ZeroIndexArray<float>(sm->right_channel) /**/; }),
         "start_over",
         &SoundMeta::start_over,
         "playing",

src/game_api/sound_manager.hpp

@@ -264,10 +264,13 @@ struct SoundMeta
 {
     float x;
     float y;
-    SoundInfo* sound_info;               // param to FMOD::Studio::EventInstance::SetParameterByID (this ptr + 0x30)
-    uint64_t fmod_param_id;              // param to FMOD::Studio::EventInstance::SetParameterByID
-    std::array<float, 38> left_channel;  // VANILLA_SOUND_PARAM
-    std::array<float, 38> right_channel; // VANILLA_SOUND_PARAM
+    SoundInfo* sound_info;  // param to FMOD::Studio::EventInstance::SetParameterByID (this ptr + 0x30)
+    uint64_t fmod_param_id; // param to FMOD::Studio::EventInstance::SetParameterByID
+
+    /// Use VANILLA_SOUND_PARAM as index, warning: special case with first index at 0, loop using pairs will get you all results but the key/index will be wrong, ipairs will have correct key/index but will skip the first element
+    std::array<float, 38> left_channel;
+    /// Use VANILLA_SOUND_PARAM as index warning: special case with first index at 0, loop using pairs will get you all results but the key/index will be wrong, ipairs will have correct key/index but will skip the first element
+    std::array<float, 38> right_channel;
 
     /// when false, current track starts from the beginning, is immediately set back to true
     bool start_over;