drs: rgb camera hook (#524)

## Link to GitHub Issue, if one exists
n/a

## Description of change
Add plug&play hooks for RGB camera in DRS.

## Testing
Seems to work with my crappy Logitech C270

Camera options (brightness etc) seem to work in test menu as well).

Tested by another user with realsense camera + logitech camera, both
cams were detected correctly.

src/spice2x/games/drs/drs.cpp

@@ -8,6 +8,7 @@
 #include "util/detour.h"
 #include "util/logging.h"
 #include "util/memutils.h"
+#include "rgb_cam.h"
 
 #pragma pack(push)
 
@@ -150,6 +151,7 @@ namespace games::drs {
     char DRS_TAPELED[DRS_TAPELED_COLS_TOTAL][3] {};
     bool DISABLE_TOUCH = false;
     bool TRANSPOSE_TOUCH = false;
+    bool RGB_CAMERA_HOOK = false;
 
     std::vector<TouchEvent> TOUCH_EVENTS;
 
@@ -313,6 +315,10 @@ namespace games::drs {
         } else {
             log_info("drs", "no native input method detected");
         }
+
+        if (RGB_CAMERA_HOOK) {
+            init_rgb_camera_hook();
+        }
     }
 
     void DRSGame::detach() {

src/spice2x/games/drs/drs.h

@@ -31,6 +31,7 @@ namespace games::drs {
     extern std::vector<TouchEvent> TOUCH_EVENTS;
     extern bool DISABLE_TOUCH;
     extern bool TRANSPOSE_TOUCH;
+    extern bool RGB_CAMERA_HOOK;
 
     void fire_touches(drs_touch_t *events, size_t event_count);
     void start_touch();

src/spice2x/games/drs/rgb_cam.cpp

@@ -0,0 +1,170 @@
+#include "games/drs/rgb_cam.h"
+
+// set version to Windows 7 to enable Media Foundation functions
+#ifdef _WIN32_WINNT
+#undef _WIN32_WINNT
+#endif
+#define _WIN32_WINNT 0x0601
+
+// turn on C-style COM objects
+#define CINTERFACE
+
+#include <mfobjects.h>
+#include <mfidl.h>
+#include <string>
+
+#include "avs/game.h"
+#include "cfg/configurator.h"
+#include "hooks/cfgmgr32hook.h"
+#include "util/detour.h"
+#include "util/memutils.h"
+#include "util/logging.h"
+#include "util/utils.h"
+
+static VTBL_TYPE(IMFActivate, GetAllocatedString) GetAllocatedString_orig = nullptr;
+static decltype(MFEnumDeviceSources) *MFEnumDeviceSources_orig = nullptr;
+
+namespace games::drs {
+
+    /*
+     * Camera related stuff
+     */
+    static std::wstring CAMERA0_ID;
+
+    static HRESULT WINAPI GetAllocatedString_hook(IMFActivate* This, REFGUID guidKey, LPWSTR *ppwszValue,
+                                                  UINT32 *pcchLength)
+    {
+        // call the original
+        HRESULT result = GetAllocatedString_orig(This, guidKey, ppwszValue, pcchLength);
+
+        // log the cam name
+        log_misc("drs::rgbcam", "obtained {}", ws2s(*ppwszValue));
+
+        // try first camera
+        wchar_t *pwc = nullptr;
+        if (CAMERA0_ID.length() == 23) {
+            pwc = wcsstr(*ppwszValue, CAMERA0_ID.c_str());
+        }
+
+        // check if camera could be identified
+        if (pwc) {
+
+            // fake the USB IDs
+            pwc[4] = L'2';
+            pwc[5] = L'8';
+            pwc[6] = L'8';
+            pwc[7] = L'c';
+
+            pwc[13] = L'0';
+            pwc[14] = L'0';
+            pwc[15] = L'0';
+            pwc[16] = L'2';
+
+            pwc[21] = L'0';
+            pwc[22] = L'0';
+
+            log_misc("drs::rgbcam", "replaced {}", ws2s(*ppwszValue));
+        }
+
+        // return original result
+        return result;
+    }
+
+    static void hook_camera(std::wstring camera_id, std::string camera_instance) {
+        // don't hook if camera 0 is already hooked
+        if (CAMERA0_ID.length() > 0) {
+            return;
+        }
+
+        // save the camera ID
+        CAMERA0_ID = camera_id;
+
+        // cfgmgr hook
+        CFGMGR32_HOOK_SETTING camera_setting;
+        camera_setting.device_instance = 0xDEADBEEF;
+        camera_setting.parent_instance = ~camera_setting.device_instance;
+        camera_setting.device_id = "USB\\VEN_8086&DEV_8C2D";
+        camera_setting.device_node_id = "USB\\VID_288C&PID_0002&MI_00\\?&????????&?&????";
+        if (camera_instance.length() == 17) {
+            for (int i = 0; i < 17; i++) {
+                camera_setting.device_node_id[28 + i] = camera_instance[i];
+            }
+        }
+        cfgmgr32hook_add(camera_setting);
+
+        log_info("drs::rgbcam", "hooked camera @ {}", ws2s(camera_id));
+    }
+
+    static void hook_camera_vtable(IMFActivate *camera) {
+
+        // hook allocated string method for camera identification
+        memutils::VProtectGuard camera_guard(camera->lpVtbl);
+        camera->lpVtbl->GetAllocatedString = GetAllocatedString_hook;
+    }
+
+    static HRESULT WINAPI MFEnumDeviceSources_hook(IMFAttributes *pAttributes, IMFActivate ***pppSourceActivate,
+                                                   UINT32 *pcSourceActivate) {
+
+        // call original function
+        HRESULT result_orig = MFEnumDeviceSources_orig(pAttributes, pppSourceActivate, pcSourceActivate);
+
+        // check for capture devices
+        if (FAILED(result_orig) || !*pcSourceActivate) {
+            return result_orig;
+        }
+
+        // get camera
+        IMFActivate *camera = **pppSourceActivate;
+
+        // save original method for later use
+        if (GetAllocatedString_orig == nullptr) {
+            GetAllocatedString_orig = camera->lpVtbl->GetAllocatedString;
+        }
+
+        // hook allocated string method for camera identification
+        hook_camera_vtable(camera);
+
+        // get camera link
+        LPWSTR camera_link_lpwstr;
+        UINT32 camera_link_length;
+        if (SUCCEEDED(GetAllocatedString_orig(
+                camera,
+                MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_SYMBOLIC_LINK,
+                &camera_link_lpwstr,
+                &camera_link_length))) {
+
+            // cut name to make ID
+            std::wstring camera_link_ws = std::wstring(camera_link_lpwstr);
+            std::wstring camera_id = camera_link_ws.substr(8, 23);
+
+            log_info("drs::rgbcam", "found video capture device: {}", ws2s(camera_link_ws));
+
+            // only support cameras that start with \\?\usb
+            if (!string_begins_with(camera_link_ws, L"\\\\?\\usb")) {
+                return result_orig;
+            }
+
+            // get camera instance
+            std::string camera_link = ws2s(camera_link_ws);
+            std::string camera_instance = camera_link.substr(32, 17);
+
+            // hook the camera
+            hook_camera(camera_id, camera_instance);
+        } else {
+            log_warning("drs::rgbcam", "failed to open camera");
+        }
+
+        // return result
+        return result_orig;
+    }
+
+    void init_rgb_camera_hook() {
+        log_info("drs::rgbcam", "initializing camera hook");
+
+        cfgmgr32hook_init(avs::game::DLL_INSTANCE);
+
+        // camera media framework hook
+        MFEnumDeviceSources_orig = detour::iat_try(
+                "MFEnumDeviceSources", MFEnumDeviceSources_hook, avs::game::DLL_INSTANCE);
+    }
+}

src/spice2x/games/drs/rgb_cam.h

@@ -0,0 +1,5 @@
+#pragma once
+
+namespace games::drs {
+    void init_rgb_camera_hook();
+}