From 384fad89e37af698f60f273ee4099ac3a8cb5fd0 Mon Sep 17 00:00:00 2001
From: Will Xyen <willxinc@hotmail.com>
Date: Mon, 9 Jun 2025 04:30:39 -0700
Subject: [PATCH] iidxhook9: add reverb ex fix

---
 src/main/iidxhook9/Module.mk   |  1 +
 src/main/iidxhook9/dllmain.c   |  3 ++
 src/main/iidxhook9/reverbfix.c | 56 ++++++++++++++++++++++++++++++++++
 src/main/iidxhook9/reverbfix.h |  6 ++++
 4 files changed, 66 insertions(+)
 create mode 100644 src/main/iidxhook9/reverbfix.c
 create mode 100644 src/main/iidxhook9/reverbfix.h

diff --git a/src/main/iidxhook9/Module.mk b/src/main/iidxhook9/Module.mk
index 09e56a8..ce1a00c 100644
--- a/src/main/iidxhook9/Module.mk
+++ b/src/main/iidxhook9/Module.mk
@@ -30,4 +30,5 @@ libs_iidxhook9      := \
 src_iidxhook9       := \
     config-io.c \
     fs-hook.c \
+    reverbfix.c \
     dllmain.c \
diff --git a/src/main/iidxhook9/dllmain.c b/src/main/iidxhook9/dllmain.c
index 7044d21..5927c96 100644
--- a/src/main/iidxhook9/dllmain.c
+++ b/src/main/iidxhook9/dllmain.c
@@ -27,6 +27,7 @@
 
 #include "iidxhook9/config-io.h"
 #include "iidxhook9/fs-hook.h"
+#include "iidxhook9/reverbfix.h"
 
 #include "camhook/cam.h"
 #include "camhook/config-cam.h"
@@ -165,6 +166,8 @@ static bool my_dll_entry_init(char *sidcode, struct property_node *param)
         iidxhook9_fs_hooks_init();
     }
 
+    reverbfixhook_init();
+
     rs232_hook_init();
     rs232_hook_limit_hooks();
 
diff --git a/src/main/iidxhook9/reverbfix.c b/src/main/iidxhook9/reverbfix.c
new file mode 100644
index 0000000..880b332
--- /dev/null
+++ b/src/main/iidxhook9/reverbfix.c
@@ -0,0 +1,56 @@
+#define LOG_MODULE "reverbfix-hook"
+
+// clang-format off
+// Don't format because the order is important here
+#include <windows.h>
+#include <initguid.h>
+// clang-format on
+
+#include <combaseapi.h>
+
+#include <stdio.h>
+
+#include "hook/com-proxy.h"
+#include "hook/table.h"
+
+#include "iidxhook9/reverbfix.h"
+
+#include "util/log.h"
+
+DEFINE_GUID(GUID_DSFX_STANDARD_I3DL2REVERB, 0xEF985E71,0xD5C7,0x42D4,0xBA,0x4D,0x2D,0x07,0x3E,0x2E,0x96,0xF4);
+DEFINE_GUID(GUID_DSFX_WAVES_REVERB,         0x87FC0268,0x9A55,0x4360,0x95,0xAA,0x00,0x4A,0x1D,0x9D,0xE2,0x6C);
+
+static HRESULT my_CoCreateInstance(
+    REFCLSID rclsid, LPUNKNOWN pUnkOuter, DWORD dwClsContext, REFIID riid, LPVOID *ppv);
+
+static HRESULT (*real_CoCreateInstance)(
+    REFCLSID rclsid, LPUNKNOWN pUnkOuter, DWORD dwClsContext, REFIID riid, LPVOID *ppv);
+
+static const struct hook_symbol reverbfix_ole_syms[] = {
+    {.name = "CoCreateInstance",
+     .patch = my_CoCreateInstance,
+     .link = (void **) &real_CoCreateInstance},
+};
+
+static HRESULT my_CoCreateInstance(
+    REFCLSID rclsid, LPUNKNOWN pUnkOuter, DWORD dwClsContext, REFIID riid, LPVOID *ppv)
+{
+    HRESULT result = real_CoCreateInstance(rclsid, pUnkOuter, dwClsContext, riid, ppv);
+    if (result == REGDB_E_CLASSNOTREG) {
+        if (IsEqualGUID(rclsid, &GUID_DSFX_STANDARD_I3DL2REVERB)) {
+            // replace effect used by REVERB EX with REVERB, based on CDmoSoundFx classes
+            result = real_CoCreateInstance(&GUID_DSFX_WAVES_REVERB, pUnkOuter, dwClsContext, riid, ppv);
+
+            log_info("DSFX_STANDARD_I3DL2REVERB class missing, replaced with DSFX_WAVES_REVERB");
+        }
+    }
+
+    return result;
+}
+
+void reverbfixhook_init()
+{
+    hook_table_apply(
+        NULL, "Ole32.dll", reverbfix_ole_syms, lengthof(reverbfix_ole_syms));
+    log_info("Inserted reverbfix hook");
+}
diff --git a/src/main/iidxhook9/reverbfix.h b/src/main/iidxhook9/reverbfix.h
new file mode 100644
index 0000000..013db3b
--- /dev/null
+++ b/src/main/iidxhook9/reverbfix.h
@@ -0,0 +1,6 @@
+#ifndef REVERBFIXHOOK_H
+#define REVERBFIXHOOK_H
+
+void reverbfixhook_init();
+
+#endif