feat: Add bt d3d9 hook specific imgui overlay (#318)

For now, we focus on internal overlays for bemanitools
that hook into an existing d3d9 context. The current
abstraction is fairly thin and should be fine as a start.

Implementations are called “components” and hook
up with a single frame_update function to execute
and logic and drawing updates with imgui

Module.mk

@@ -161,6 +161,7 @@ include src/main/iidxio-ezusb2/Module.mk
 include src/main/iidxio/Module.mk
 include src/main/iidxiotest/Module.mk
 include src/main/imgui/Module.mk
+include src/main/imgui-bt/Module.mk
 include src/main/inject/Module.mk
 include src/main/jbio-magicbox/Module.mk
 include src/main/jbio-p4io/Module.mk

src/main/imgui-bt/Module.mk

@@ -0,0 +1,10 @@
+libs            += imgui-bt
+
+libs_imgui-bt     := \
+    hook \
+    hooklib \
+    util \
+    imgui \
+
+src_imgui-bt      := \
+    imgui-d3d9-hook.c \

src/main/imgui-bt/cimgui.h

@@ -0,0 +1,10 @@
+#ifndef IMGUI_BT_CIMGUI_H
+#define IMGUI_BT_CIMGUI_H
+
+// Comprehensive header file for including cimgui correctly for integration in this project
+#define CIMGUI_DEFINE_ENUMS_AND_STRUCTS
+#include "imgui/cimgui.h"
+#include "imgui/cimgui_impl_dx9.h"
+#include "imgui/cimgui_impl_win32.h"
+
+#endif

src/main/imgui-bt/component.h

@@ -0,0 +1,12 @@
+#ifndef IMGUI_BT_COMPONENT_H
+#define IMGUI_BT_COMPONENT_H
+
+#include "imgui-bt/cimgui.h"
+
+typedef void (*imgui_bt_component_frame_update_t)(ImGuiContext *ctx);
+
+typedef struct imgui_bt_component {
+    imgui_bt_component_frame_update_t frame_update;
+} imgui_bt_component_t;
+
+#endif

src/main/imgui-bt/imgui-d3d9-hook.c

@@ -0,0 +1,143 @@
+#define LOG_MODULE "imgui-d3d9-hook"
+
+#include "hook/d3d9.h"
+#include "hook/table.h"
+
+#include "imgui-bt/cimgui.h"
+#include "imgui-bt/component.h"
+
+#include "util/defs.h"
+#include "util/log.h"
+#include "util/mem.h"
+
+typedef LRESULT WINAPI (*RegisterClassA_t)(WNDCLASSA *lpwcx);
+typedef LRESULT WINAPI (*WndProc_t)(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
+
+static LRESULT WINAPI _imgui_d3d9_hook_RegisterClassA(WNDCLASSA *lpwcx);
+
+static bool _imgui_d3d9_hook_initialized;
+static ImGuiContext *_imgui_d3d9_hook_imgui_ctx;
+static RegisterClassA_t _imgui_d3d9_hook_original_RegisterClassA;
+static WndProc_t _imgui_d3d9_hook_original_wndproc;
+static imgui_bt_component_t *_imgui_d3d9_hook_components;
+static size_t _imgui_d3d9_hook_component_count;
+
+static const struct hook_symbol _imgui_d3d9_hook_syms[] = {
+    {.name = "RegisterClassA",
+     .patch = _imgui_d3d9_hook_RegisterClassA,
+     .link = (void **) &_imgui_d3d9_hook_original_RegisterClassA},
+};
+
+CIMGUI_API LRESULT igImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
+
+static LRESULT WINAPI _imgui_d3d9_hook_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    LRESULT result;
+    
+    result = igImplWin32_WndProcHandler(hWnd, msg, wParam, lParam);
+
+    if (result) {
+        return result;
+    }
+
+    return _imgui_d3d9_hook_original_wndproc(hWnd, msg, wParam, lParam);
+}
+
+static LRESULT WINAPI _imgui_d3d9_hook_RegisterClassA(WNDCLASSA *lpwcx)
+{
+    log_info("Swapping out WndProc handler for wrapper handler in RegisterClassA %s", lpwcx->lpszClassName);
+
+    _imgui_d3d9_hook_original_wndproc = lpwcx->lpfnWndProc;
+    lpwcx->lpfnWndProc = _imgui_d3d9_hook_WndProc;
+
+    return _imgui_d3d9_hook_original_RegisterClassA(lpwcx);
+}
+
+void imgui_d3d9_hook_init(const imgui_bt_component_t *components, size_t component_count)
+{
+    ImGuiIO *io;
+    ImGuiStyle* style;
+
+    log_assert(components);
+    log_assert(component_count > 0);
+
+    _imgui_d3d9_hook_components = (imgui_bt_component_t *) xmalloc(component_count * sizeof(imgui_bt_component_t));
+    memcpy(_imgui_d3d9_hook_components, components, component_count * sizeof(imgui_bt_component_t));
+    _imgui_d3d9_hook_component_count = component_count;
+
+    _imgui_d3d9_hook_imgui_ctx = igCreateContext(NULL);
+    io = igGetIO();
+
+    io->ConfigFlags = ImGuiConfigFlags_NavEnableKeyboard
+        | ImGuiConfigFlags_DockingEnable
+        | ImGuiConfigFlags_ViewportsEnable;
+
+    io->MouseDrawCursor = true;
+    io->IniFilename = NULL;
+    io->FontAllowUserScaling = true;
+
+    hook_table_apply(NULL, "user32.dll", _imgui_d3d9_hook_syms, lengthof(_imgui_d3d9_hook_syms));
+
+    // Setup style
+    style = igGetStyle();
+    style->Colors[ImGuiCol_WindowBg] = (ImVec4){0.0f, 0.0f, 0.0f, 1.0f};
+    style->Colors[ImGuiCol_PlotLines] = (ImVec4){1.0f, 1.0f, 0.0f, 1.0f};
+
+    _imgui_d3d9_hook_initialized = true;
+}
+
+void imgui_d3d9_hook_fini()
+{
+    hook_table_revert(NULL, "user32.dll", _imgui_d3d9_hook_syms, lengthof(_imgui_d3d9_hook_syms));
+
+    igImplDX9_Shutdown();
+    igImplWin32_Shutdown();
+    igDestroyContext(NULL);
+
+    _imgui_d3d9_hook_initialized = false;
+}
+
+HRESULT imgui_hook_d3d9_irp_handler(struct hook_d3d9_irp *irp)
+{
+    HRESULT hr;
+
+    log_assert(irp);
+
+    if (!_imgui_d3d9_hook_initialized) {
+        return hook_d3d9_irp_invoke_next(irp);
+    }
+
+    switch (irp->op) {
+        case HOOK_D3D9_IRP_OP_CTX_CREATE_DEVICE:
+            hr = hook_d3d9_irp_invoke_next(irp);
+
+            if (hr == S_OK) {
+                igImplWin32_Init(irp->args.ctx_create_device.hwnd);
+                igImplDX9_Init(*irp->args.ctx_create_device.pdev);
+            }
+
+            return hr;
+        
+        case HOOK_D3D9_IRP_OP_DEV_BEGIN_SCENE:
+            igImplDX9_NewFrame();
+            igImplWin32_NewFrame();
+            igNewFrame();
+
+            for (size_t i = 0; i < _imgui_d3d9_hook_component_count; i++) {
+                _imgui_d3d9_hook_components[i].frame_update(_imgui_d3d9_hook_imgui_ctx);
+            }
+        
+            return hook_d3d9_irp_invoke_next(irp);
+
+        case HOOK_D3D9_IRP_OP_DEV_END_SCENE:
+            igRender();
+            igImplDX9_RenderDrawData(igGetDrawData());
+
+            return hook_d3d9_irp_invoke_next(irp);
+        
+        default:
+            return hook_d3d9_irp_invoke_next(irp);
+    }
+
+    log_fatal("Illegal state");
+}

src/main/imgui-bt/imgui-d3d9-hook.h

@@ -0,0 +1,13 @@
+#ifndef IMGUI_D3D9_HOOK_H
+#define IMGUI_D3D9_HOOK_H
+
+#include "hook/d3d9.h"
+
+#include "imgui-bt/component.h"
+
+void imgui_d3d9_hook_init(const imgui_bt_component_t *components, size_t component_count);
+void imgui_d3d9_hook_fini();
+
+HRESULT imgui_hook_d3d9_irp_handler(struct hook_d3d9_irp *irp);
+
+#endif