cfg: asio driver selector must list both 32-bit and 64-bit drivers (#734)

## Link to GitHub Issue or related Pull Request, if one exists
#730 

## Description of change
spicecfg is a 32-bit application. When it uses the ASIO SDK it only saw
the 32-bit drivers.

There are some ASIO drivers that have different names under 32-bit and
64-bit (Xonar AE is one of them)... so we have to manually scan the
registry and surface both the WOW32 and WOW64 nodes.

## Testing
<img width="329" height="309" alt="image"
src="https://github.com/user-attachments/assets/7abecf76-6835-4df5-8c2e-e7b425130f4c"
/>

Checked both 32-bit and 64-bit configurator, identical results.

src/spice2x/CMakeLists.txt

@@ -494,6 +494,7 @@ set(SOURCE_FILES ${SOURCE_FILES}
         # hooks
         hooks/audio/acm.cpp
         hooks/audio/audio.cpp
+        hooks/audio/asio_driver_scan.cpp
         hooks/audio/asio_proxy.cpp
         hooks/audio/buffer.cpp
         hooks/audio/mme.cpp

src/spice2x/hooks/audio/asio_driver_scan.cpp

@@ -0,0 +1,74 @@
+#include "asio_driver_scan.h"
+
+#include <algorithm>
+
+#include <windows.h>
+
+#include "util/utils.h"
+
+namespace hooks::audio {
+
+    static constexpr char ASIO_REG_PATH[] = "software\\asio";
+    static constexpr char ASIO_REG_DESC[] = "description";
+
+    // enumerate a single registry view, appending to entries while merging
+    // duplicates discovered in another view. Drivers are matched by name (not
+    // CLSID): the game's ASIO loader selects drivers by name, and some vendors
+    // register the same CLSID under different 32-bit/64-bit names (e.g. "XONAR
+    // SOUND CARD" vs "XONAR SOUND CARD(64)"), which are distinct user choices.
+    static void scan_view(
+            REGSAM wow64_flag,
+            bool is_64bit,
+            std::vector<AsioDriverScanEntry> &entries) {
+
+        HKEY hkEnum = nullptr;
+        if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, ASIO_REG_PATH, 0,
+                KEY_READ | wow64_flag, &hkEnum) != ERROR_SUCCESS) {
+            return;
+        }
+
+        char key_name[256];
+        for (DWORD index = 0;
+             RegEnumKeyA(hkEnum, index, key_name, sizeof(key_name)) == ERROR_SUCCESS;
+             index++) {
+
+            // read description (display name), fall back to the key name
+            char desc[256] = { 0 };
+            DWORD size = sizeof(desc);
+            std::string name = key_name;
+            if (RegGetValueA(hkEnum,
+                             key_name,
+                             ASIO_REG_DESC,
+                             RRF_RT_REG_SZ | wow64_flag,
+                             nullptr,
+                             desc,
+                             &size) == ERROR_SUCCESS && desc[0]) {
+                name = desc;
+            }
+
+            // merge with an existing entry from the other view (match by name)
+            const std::string name_lower = strtolower(name);
+            auto it = std::find_if(entries.begin(), entries.end(), [&](const auto &e) {
+                return strtolower(e.name) == name_lower;
+            });
+            if (it == entries.end()) {
+                entries.push_back({ name });
+                it = entries.end() - 1;
+            }
+            it->found_32bit |= !is_64bit;
+            it->found_64bit |= is_64bit;
+        }
+
+        RegCloseKey(hkEnum);
+    }
+
+    std::vector<AsioDriverScanEntry> scan_asio_drivers() {
+        std::vector<AsioDriverScanEntry> entries;
+
+        // 64-bit view first so it wins ordering when present in both
+        scan_view(KEY_WOW64_64KEY, true, entries);
+        scan_view(KEY_WOW64_32KEY, false, entries);
+
+        return entries;
+    }
+}

src/spice2x/hooks/audio/asio_driver_scan.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace hooks::audio {
+
+    struct AsioDriverScanEntry {
+        std::string name;
+        bool found_32bit = false;
+        bool found_64bit = false;
+    };
+
+    std::vector<AsioDriverScanEntry> scan_asio_drivers();
+}

src/spice2x/overlay/windows/config.cpp

@@ -12,9 +12,9 @@
 #include "build/resource.h"
 #include "cfg/config.h"
 #include "cfg/configurator.h"
-#include "external/asio/asiolist.h"
 #include "external/imgui/imgui_internal.h"
 #include "external/imgui/misc/cpp/imgui_stdlib.h"
+#include "hooks/audio/asio_driver_scan.h"
 #include "games/io.h"
 #include "games/sdvx/sdvx.h"
 #include "games/popn/popn.h"
@@ -63,7 +63,7 @@ namespace overlay::windows {
     constexpr ImVec4 TEXT_COLOR_RED(1.f, 0.f, 0.f, 1.f);
     constexpr uint32_t OPTION_INPUT_TEXT_WIDTH = 512;
 
-    std::unique_ptr<AsioDriverList> asio_driver_list;
+    std::optional<std::vector<hooks::audio::AsioDriverScanEntry>> asio_driver_list;
 
     Config::Config(overlay::SpiceOverlay *overlay) : Window(overlay) {
         this->title = "Configuration";
@@ -4426,30 +4426,24 @@ namespace overlay::windows {
     void Config::build_option_value_picker(Option& option) {
         auto &definition = option.get_definition();
         if (definition.picker == OptionPickerType::AsioDriver) {
-            if (asio_driver_list == nullptr) {
-                asio_driver_list = std::make_unique<AsioDriverList>();
+            if (!asio_driver_list.has_value()) {
+                asio_driver_list = hooks::audio::scan_asio_drivers();
             }
 
-            ImGui::TextUnformatted("If your ASIO driver is not shown here, close this");
-            ImGui::TextUnformatted("popup and enter the driver name manually.");
-            ImGui::SameLine();
-            ImGui::HelpMarker(
-                "This list is populated by scanning the registry for ASIO drivers.\n\n"
-                "If your driver is not showing up, it may be because it is not properly registered in the system.\n\n"
-                "For 64-bit games, check in HKLM\\SOFTWARE\\ASIO\\.\n\n"
-                "For 32-bit games on 64-bit Windows, check in HKLM\\SOFTWARE\\WOW6432Node\\ASIO\\.\n\n"
-                "spicecfg runs in 32-bit, so it may not see 64-bit-only drivers.");
-
-            ImGui::TextUnformatted("");
-            if (asio_driver_list->driver_list.empty()) {
+            if (asio_driver_list->empty()) {
                 ImGui::TextUnformatted("No ASIO drivers found.");
             } else {
                 ImGui::TextUnformatted("Pick from ASIO drivers:");
                 ImGui::SetNextItemWidth(300.f);
                 if (ImGui::BeginListBox("##asiodrivers")) {
-                    for (const auto &driver : asio_driver_list->driver_list) {
-                        const bool is_selected = option.value == std::string(driver.name);
-                        if (ImGui::Selectable(fmt::format("[{}] {}", driver.id, driver.name).c_str(), is_selected)) {
+                    for (const auto &driver : *asio_driver_list) {
+                        const bool is_selected = option.value == driver.name;
+                        const char *arch = (driver.found_32bit && driver.found_64bit)
+                            ? "32/64-bit"
+                            : (driver.found_64bit ? "64-bit" : "32-bit");
+                        if (ImGui::Selectable(
+                                fmt::format("{} ({})", driver.name, arch).c_str(),
+                                is_selected)) {
                             option.value = driver.name;
                         }
                     }