iidxcamhook: detect game camera count during init (#917)

## Link to GitHub Issue or related Pull Request, if one exists
Fixes #916

## Description of change
- Read the camera manager actual vector length instead of assuming 2
cameras. Front camera is gone in IIDX 34. :(
- Resolve texture-registry entries through AFP texture handles instead
of assuming slots 0 and 2. Generally fix up the internal game structure
layouts, as I made some incorrect assumptions about them last time.
- Replace the existing D3D-device offset pattern, as it was resolving to
an incorrect offset in IIDX 34.

## Testing
- Booted IIDX 27-34 to gameplay with camera on, though with only one
attached.
- Batch scanned all known game DLLs to ensure the pattern was resolving
correctly.

Co-authored-by: Codex <codex@openai.com>

src/spice2x/games/iidx/camera.cpp

@@ -199,11 +199,11 @@ namespace games::iidx {
         addr_camera_manager = (addr_camera_manager_ptr - (uint8_t*) iidx_module) + disp_camera_manager + 7;
 
         // addr_device_offset
-        search_from = (addr_hook_a_ptr - (uint8_t*) iidx_module);
+        search_from = addr_hook_a;
         uint8_t *addr_device_ptr = reinterpret_cast<uint8_t *>(find_pattern_from(
                 iidx_module,
-                "488B89",
+                "488B8F00000000488B014C8B870000000033D2FF9028010000",
-                "XXX",
+                "XXX????XXXXXX????XXXXXXXX",
                 3, 0, search_from));
 
         if (addr_device_ptr == nullptr) {
@@ -211,7 +211,7 @@ namespace games::iidx {
             return FALSE;
         }
 
-        addr_device_offset = *addr_device_ptr;
+        addr_device_offset = *reinterpret_cast<uint32_t*>(addr_device_ptr);
 
         // --- addr_afp_texture_offset ---
         uint8_t *addr_afp_texture_ptr = reinterpret_cast<uint8_t *>(find_pattern(
@@ -233,13 +233,27 @@ namespace games::iidx {
     static void **__fastcall camera_hook_a(PBYTE a1) {
         std::call_once(hook_a_init, [&]{
             device = *reinterpret_cast<LPDIRECT3DDEVICE9EX*>(a1 + addr_device_offset);
-            auto const preview = *reinterpret_cast<LPDIRECT3DTEXTURE9**>((uint8_t*)iidx_module + addr_textures);
+            auto const registry = reinterpret_cast<Camera::TextureRegistry*>(
+                reinterpret_cast<uint8_t*>(iidx_module) + addr_textures - offsetof(Camera::TextureRegistry, begin));
             auto const manager = reinterpret_cast<Camera::CCameraManager2*>((uint8_t*)iidx_module + addr_camera_manager);
 
-            camera_texture_a = manager->cameras->a->d3d9_texture(addr_afp_texture_offset);
+            auto const camera_count = manager->begin ? manager->end - manager->begin : 0;
-            camera_texture_b = manager->cameras->b->d3d9_texture(addr_afp_texture_offset);
+            auto const bind_camera = [&](size_t index, LPDIRECT3DTEXTURE9*& texture, LPDIRECT3DTEXTURE9*& preview) {
-            preview_texture_a = preview;
+                if (index >= static_cast<size_t>(camera_count)) {
-            preview_texture_b = preview + 2;
+                    return; // IIDX 34 only has the TOP camera.
+                }
+                auto const camera = manager->begin[index];
+                auto const afp = camera ? camera->afp_texture(addr_afp_texture_offset) : nullptr;
+                if (!afp || !registry->begin || afp->handle < registry->handle_base ||
+                    afp->handle - registry->handle_base >= registry->end - registry->begin) {
+                    log_warning("iidx:camhook", "invalid texture destination for camera {}", index);
+                    return;
+                }
+                texture = &afp->texture;
+                preview = registry->begin + (afp->handle - registry->handle_base);
+            };
+            bind_camera(0, camera_texture_a, preview_texture_a);
+            bind_camera(1, camera_texture_b, preview_texture_b);
 
             init_local_camera();
         });
@@ -381,10 +395,10 @@ namespace games::iidx {
             log_misc("iidx:camhook", "Adding user-preferred cameras");
             for (size_t i = 0; i < numDevices && LOCAL_CAMERA_LIST.size() < 2; i++) {
                 auto pActivate = ppDevices[i];
-                if ((int)i == preferred_top_index && top_camera == nullptr) {
+                if ((int)i == preferred_top_index && top_camera == nullptr && camera_texture_a != nullptr) {
                     log_misc("iidx:camhook", "Adding user-preferred top camera {} / '{}'", i, top_camera_id);
                     top_camera = add_top_camera(pActivate);
-                } else if ((int)i == preferred_front_index && front_camera == nullptr) {
+                } else if ((int)i == preferred_front_index && front_camera == nullptr && camera_texture_b != nullptr) {
                     log_misc("iidx:camhook", "Adding user-preferred front camera {} / '{}'", i, front_camera_id);
                     front_camera = add_front_camera(pActivate);
                 }
@@ -402,16 +416,16 @@ namespace games::iidx {
 
                 if (!FLIP_CAMS) {
                     // top camera first, then front
-                    if (top_camera == nullptr) {
+                    if (top_camera == nullptr && camera_texture_a != nullptr) {
                         top_camera = add_top_camera(pActivate);
-                    } else if (front_camera == nullptr) {
+                    } else if (front_camera == nullptr && camera_texture_b != nullptr) {
                         front_camera = add_front_camera(pActivate);
                     }
                 } else {
                     // front first, then top
-                    if (front_camera == nullptr) {
+                    if (front_camera == nullptr && camera_texture_b != nullptr) {
                         front_camera = add_front_camera(pActivate);
-                    } else if (top_camera == nullptr) {
+                    } else if (top_camera == nullptr && camera_texture_a != nullptr) {
                         top_camera = add_top_camera(pActivate);
                     }
                 }

src/spice2x/games/iidx/local_camera.h

@@ -70,21 +70,31 @@ namespace games::iidx {
     class IIDXCameraSourceReaderCallback;
 
     namespace Camera {
+        struct AfpTexture {
+            void* vftbl;
+            IDirect3DTexture9* texture;
+            uint32_t handle;
+        };
+
+        struct TextureRegistry {
+            uint32_t handle_base;
+            uint32_t next_slot;
+            IDirect3DTexture9** begin;
+            IDirect3DTexture9** end;
+            IDirect3DTexture9** capacity_end;
+        };
+
         struct PlayVideoCamera {
-            IDirect3DTexture9** d3d9_texture(const uintptr_t offset) {
+            AfpTexture* afp_texture(const uintptr_t offset) {
-                auto const afp_texture = *reinterpret_cast<uint8_t**>
+                return *reinterpret_cast<AfpTexture**>(reinterpret_cast<uint8_t*>(this) + offset);
-                    (reinterpret_cast<uint8_t*>(this) + offset);
-                return reinterpret_cast<IDirect3DTexture9**>(afp_texture + 0x8);
             }
         };
 
         struct CCameraManager2 {
-            using camera_pointers = struct {
-                PlayVideoCamera* a;
-                PlayVideoCamera* b;
-            };
             void* vftbl;
-            camera_pointers* cameras;
+            PlayVideoCamera** begin;
+            PlayVideoCamera** end;
+            PlayVideoCamera** capacity_end;
         };
     }