C++利用ImGUI绘制D3D外部菜单

ImGUI 它是与平台无关的C++轻量级跨平台图形界面库，没有任何第三方依赖，可以将ImGUI的源码直接加到项目中使用，该框架通常会配合特定的D3Dx9等图形开发工具包一起使用，ImGUI常用来实现进程内的菜单功能，而有些辅助开发作者也会使用该框架开发菜单页面，总体来说这是一个很不错的绘图库，如下将公开新版ImGUI如何实现绘制外部菜单的功能。

ImGUI官方下载地址：https://github.com/ocornut/imgui/releases

在使用ImGUI页面之前需要先来实现一个简单的附着功能，即如何将一个窗体附着到另一个窗体之上，其实代码很简单，如下所示当用户输入进程PID时，会自动跟随窗体并附着在窗体顶部。

#include <Windows.h>
#include <iostream>

struct handle_data
{
unsigned long process_id;
HWND best_handle;
};

// By: LyShark
BOOL IsMainWindow(HWND handle)
{
return GetWindow(handle, GW_OWNER) == (HWND)0 && IsWindowVisible(handle);
}

BOOL CALLBACK EnumWindowsCallback(HWND handle, LPARAM lParam)
{
// By: LyShark
handle_data& data = *(handle_data*)lParam;
unsigned long process_id = 0;
GetWindowThreadProcessId(handle, &process_id);
if (data.process_id != process_id || !IsMainWindow(handle)) {
return TRUE;
}
data.best_handle = handle;
return FALSE;
}

// By: LyShark
HWND FindMainWindow(unsigned long process_id)
{
handle_data data;
data.process_id = process_id;
data.best_handle = 0;
EnumWindows(EnumWindowsCallback, (LPARAM)&data);
return data.best_handle;
}

int main(int argc, char* argv[])
{
DWORD pid = 28396;

std::cout << "输入进程PID: " << std::endl;
std::cin >> pid;

// 获取屏幕宽和高
int iWidth = ::GetSystemMetrics(SM_CXSCREEN);
int iHeight = ::GetSystemMetrics(SM_CYSCREEN);

// 根据PID寻找游戏窗口
HWND hwnd = FindMainWindow(pid);

while (1)
{
SetTimer(hwnd, 1, 150, NULL);

// 实现透明必须设置WS_EX_LAYERED标志
LONG lWinStyleEx = GetWindowLong(hwnd, GWL_EXSTYLE);
lWinStyleEx = lWinStyleEx | WS_EX_LAYERED;

SetWindowLong(hwnd, GWL_EXSTYLE, lWinStyleEx);
SetLayeredWindowAttributes(hwnd, 0, RGB(40, 40, 40), LWA_ALPHA);

// 去掉标题栏及边框
LONG_PTR Style = GetWindowLongPtr(hwnd, GWL_STYLE);
Style = Style & ~WS_CAPTION & ~WS_SYSMENU & ~WS_SIZEBOX;
SetWindowLongPtr(hwnd, GWL_STYLE, Style);

// 至顶层窗口 最大化
SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, iWidth, iHeight, SWP_SHOWWINDOW);

// 设置窗体可穿透鼠标
SetWindowLong(hwnd, GWL_EXSTYLE, WS_EX_TRANSPARENT | WS_EX_LAYERED);

// 绘图
HDC hdc = ::GetDC(hwnd);
HDC mdc = ::CreateCompatibleDC(hdc);

// 创建画笔
HPEN hpen = CreatePen(PS_SOLID, 10, RGB(0, 255, 0));
// DC 选择画笔
SelectObject(hdc, hpen);
// (画笔)从初始点移动到 50,50
MoveToEx(hdc, 100, 100, NULL);
// (画笔)从初始点画线到 100,100
LineTo(hdc, 1000, 1000);

RECT rect = {0};

rect.bottom = 10;
rect.left = 20;
rect.right = 20;
rect.top = 15;

DrawText(hdc, L"hello lyshark.com", strlen("hello lyshark.com"), &rect, DT_CALCRECT | DT_CENTER | DT_SINGLELINE);
}

return 0;
}

绘制效果图：

接着我们使用Imgui绘制一个动态菜单，首先下载imgui并打开项目中的examples目录，找到example_win32_directx9打开后自己配置好dx9SDK开发工具包。

代码直接调用，并附加到Counter-Strike Source游戏窗体之上即可，这段代码也很简单。

#include "imgui.h"
#include "imgui_impl_dx9.h"
#include "imgui_impl_win32.h"

#include <d3d9.h>
#include <tchar.h>
#include <iostream>

#pragma execution_character_set("utf-8")

// 全局变量
// lyshark.com
static HWND hwnd;
static HWND GameHwnd;
static RECT WindowRectangle;
static int WindowWide, WindowHeight;

static LPDIRECT3D9 g_pD3D = NULL;
static LPDIRECT3DDEVICE9 g_pd3dDevice = NULL;
static D3DPRESENT_PARAMETERS g_d3dpp = {};

// 单选框设置状态
bool show_another_window = false;

// imgui 回调函数
extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);

// By: LyShark
bool CreateDeviceD3D(HWND hWnd)
{
if ((g_pD3D = Direct3DCreate9(D3D_SDK_VERSION)) == NULL)
{
return false;
}

ZeroMemory(&g_d3dpp, sizeof(g_d3dpp));
g_d3dpp.Windowed = TRUE;
g_d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
g_d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
g_d3dpp.EnableAutoDepthStencil = TRUE;
g_d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
g_d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_ONE;

if (g_pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd, D3DCREATE_HARDWARE_VERTEXPROCESSING, &g_d3dpp, &g_pd3dDevice) < 0)
{
return false;
}
return true;
}

void CleanupDeviceD3D()
{
if (g_pd3dDevice)
{
g_pd3dDevice->Release();
g_pd3dDevice = NULL;
}

if (g_pD3D)
{
g_pD3D->Release();
g_pD3D = NULL;
}
}

void ResetDevice()
{
ImGui_ImplDX9_InvalidateDeviceObjects();
HRESULT hr = g_pd3dDevice->Reset(&g_d3dpp);
if (hr == D3DERR_INVALIDCALL)
{
IM_ASSERT(0);
}
ImGui_ImplDX9_CreateDeviceObjects();
}

LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
{
return true;
}

switch (msg)
{
case WM_SIZE:
if (g_pd3dDevice != NULL && wParam != SIZE_MINIMIZED)
{
g_d3dpp.BackBufferWidth = LOWORD(lParam);
g_d3dpp.BackBufferHeight = HIWORD(lParam);
ResetDevice();
}
return 0;

case WM_SYSCOMMAND:
if ((wParam & 0xfff0) == SC_KEYMENU)
{
return 0;
}
break;

case WM_DESTROY:
PostQuitMessage(0);
return 0;
}

return DefWindowProc(hWnd, msg, wParam, lParam);
}

// 绘制主方法
// www.cnblogs.com/lyshark
void DrawImGUI()
{
// 启动IMGUI自绘
ImGui_ImplDX9_NewFrame();
ImGui_ImplWin32_NewFrame();
ImGui::NewFrame();

static float f = 0.0f;
static int counter = 0;
static char sz[256] = { 0 };

ImGui::Begin("LyShark 辅助GUI主菜单");
ImGui::Text("这是一段测试字符串");
ImGui::Checkbox("弹出子窗口", &show_another_window);
ImGui::SliderFloat("浮点条", &f, 0.0f, 1.0f);

ImGui::InputText("输入内容", sz, 256, 0, 0, 0);

if (ImGui::Button("点我触发"))
counter++;
ImGui::SameLine();
ImGui::Text("触发次数 = ％d", counter);

ImGui::Text("当前FPS: ％.3f ms/frame (％.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
ImGui::End();

if (show_another_window)
{
ImGui::Begin("我是子窗体", &show_another_window);
ImGui::Text(" 您好,LyShark !");
if (ImGui::Button("关闭窗体"))
show_another_window = false;
ImGui::End();
}
ImGui::EndFrame();
}

// 自身窗口循环事件
void WindowMessageLoop()
{
bool done = false;
while (!done)
{
// 每次都将窗体置顶并跟随游戏窗体移动
GetWindowRect(GameHwnd, &WindowRectangle);
WindowWide = (WindowRectangle.right) - (WindowRectangle.left);
WindowHeight = (WindowRectangle.bottom) - (WindowRectangle.top);
DWORD dwStyle = GetWindowLong(GameHwnd, GWL_STYLE);
if (dwStyle & WS_BORDER)
{
WindowRectangle.top += 23;
WindowHeight -= 23;
}

// 跟随窗口移动
MoveWindow(hwnd, WindowRectangle.left + 8, WindowRectangle.top + 8, WindowWide - 11, WindowHeight - 11, true);

// 开始消息循环
MSG msg;
while (PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
if (msg.message == WM_QUIT)
{
done = true;
}
}

if (done)
{
break;
}

// 开始绘制
DrawImGUI();

g_pd3dDevice->SetRenderState(D3DRS_ZENABLE, FALSE);
g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
g_pd3dDevice->SetRenderState(D3DRS_SCISSORTESTENABLE, FALSE);
g_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0, 1.0f, 0);

if (g_pd3dDevice->BeginScene() >= 0)
{
ImGui::Render();
ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
g_pd3dDevice->EndScene();
}

HRESULT result = g_pd3dDevice->Present(NULL, NULL, NULL, NULL);
if (result == D3DERR_DEVICELOST && g_pd3dDevice->TestCooperativeLevel() == D3DERR_DEVICENOTRESET)
{
ResetDevice();
}
}
}

int main(int argc, char *argv[])
{
// 注册窗体类
WNDCLASSEX wc;

// 附加到指定窗体上
wc.cbClsExtra = NULL;
wc.cbSize = sizeof(WNDCLASSEX);
wc.cbWndExtra = NULL;
wc.hbrBackground = (HBRUSH)CreateSolidBrush(RGB(0, 0, 0));
wc.hCursor = LoadCursor(0, IDC_ARROW);
wc.hIcon = LoadIcon(0, IDI_APPLICATION);
wc.hIconSm = LoadIcon(0, IDI_APPLICATION);
wc.hInstance = GetModuleHandle(NULL);
wc.lpfnWndProc = (WNDPROC)WndProc;
wc.lpszClassName = L" ";
wc.lpszMenuName = L" ";
wc.style = CS_VREDRAW | CS_HREDRAW;

RegisterClassEx(&wc);

// 得到窗口句柄
GameHwnd = FindWindowA(NULL, "Counter-Strike Source");
GetWindowRect(GameHwnd, &WindowRectangle);
WindowWide = WindowRectangle.right - WindowRectangle.left;
WindowHeight = WindowRectangle.bottom - WindowRectangle.top;

// 创建窗体
hwnd = CreateWindowEx(WS_EX_TOPMOST | WS_EX_LAYERED | WS_EX_TOOLWINDOW, L" ", L" ", WS_POPUP, 1, 1, WindowWide, WindowHeight, 0, 0, wc.hInstance, 0);

// 显示窗口
SetLayeredWindowAttributes(hwnd, 0, RGB(0, 0, 0), LWA_ALPHA);
SetLayeredWindowAttributes(hwnd, 0, RGB(0, 0, 0), LWA_COLORKEY);
ShowWindow(hwnd, SW_SHOW);

// 初始化D3D
if (!CreateDeviceD3D(hwnd))
{
CleanupDeviceD3D();
UnregisterClass(wc.lpszClassName, wc.hInstance);
return 0;
}

// 更新窗体
UpdateWindow(hwnd);

// 初始化ImGUI
ImGui::CreateContext();
ImGuiIO& io = ImGui::GetIO(); (void)io;
io.Fonts->AddFontFromFileTTF("c:/windows/fonts/simhei.ttf", 13.0f, NULL, io.Fonts->GetGlyphRangesChineseSimplifiedCommon());

ImGui::StyleColorsDark();
ImGui_ImplWin32_Init(hwnd);
ImGui_ImplDX9_Init(g_pd3dDevice);

// 开始执行绘制循环事件
WindowMessageLoop();

ImGui_ImplDX9_Shutdown();
ImGui_ImplWin32_Shutdown();
ImGui::DestroyContext();

CleanupDeviceD3D();
DestroyWindow(hwnd);
UnregisterClass(wc.lpszClassName, wc.hInstance);
return 0;
}

绘制效果如下：

另外，Imgui也支持绘制到整个屏幕上，也可以当作全局GUI界面来使用。

#include "imgui.h"
#include "imgui_impl_dx9.h"
#include "imgui_impl_win32.h"

#include <d3d9.h>
#include <tchar.h>
#include <iostream>

#pragma execution_character_set("utf-8")

// 全局变量
static HWND hwnd;
static HWND GameHwnd;
static RECT WindowRectangle;
static int WindowWide, WindowHeight;

static LPDIRECT3D9 g_pD3D = NULL;
static LPDIRECT3DDEVICE9 g_pd3dDevice = NULL;
static D3DPRESENT_PARAMETERS g_d3dpp = {};

// 单选框设置状态
bool show_another_window = false;

// imgui 回调函数
// By: LyShark
extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);

bool CreateDeviceD3D(HWND hWnd)
{
if ((g_pD3D = Direct3DCreate9(D3D_SDK_VERSION)) == NULL)
{
return false;
}

ZeroMemory(&g_d3dpp, sizeof(g_d3dpp));
g_d3dpp.Windowed = TRUE;
g_d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
g_d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
g_d3dpp.EnableAutoDepthStencil = TRUE;
g_d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
g_d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_ONE;

if (g_pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd, D3DCREATE_HARDWARE_VERTEXPROCESSING, &g_d3dpp, &g_pd3dDevice) < 0)
{
return false;
}
return true;
}

void CleanupDeviceD3D()
{
if (g_pd3dDevice)
{
g_pd3dDevice->Release();
g_pd3dDevice = NULL;
}

if (g_pD3D)
{
g_pD3D->Release();
g_pD3D = NULL;
}
}
// https://www.cnblogs.com/lyshark
void ResetDevice()
{
ImGui_ImplDX9_InvalidateDeviceObjects();
HRESULT hr = g_pd3dDevice->Reset(&g_d3dpp);
if (hr == D3DERR_INVALIDCALL)
{
IM_ASSERT(0);
}
ImGui_ImplDX9_CreateDeviceObjects();
}

LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
{
return true;
}

switch (msg)
{
case WM_SIZE:
if (g_pd3dDevice != NULL && wParam != SIZE_MINIMIZED)
{
g_d3dpp.BackBufferWidth = LOWORD(lParam);
g_d3dpp.BackBufferHeight = HIWORD(lParam);
ResetDevice();
}
return 0;

case WM_SYSCOMMAND:
if ((wParam & 0xfff0) == SC_KEYMENU)
{
return 0;
}
break;

case WM_DESTROY:
PostQuitMessage(0);
return 0;
}

return DefWindowProc(hWnd, msg, wParam, lParam);
}

// 绘制主方法
// lyshark.com
void DrawImGUI()
{
// 启动IMGUI自绘
ImGui_ImplDX9_NewFrame();
ImGui_ImplWin32_NewFrame();
ImGui::NewFrame();

static float f = 0.0f;
static int counter = 0;
static char sz[256] = { 0 };

ImGui::Begin("LyShark 辅助GUI主菜单");
ImGui::Text("这是一段测试字符串");
ImGui::Checkbox("弹出子窗口", &show_another_window);
ImGui::SliderFloat("浮点条", &f, 0.0f, 1.0f);

ImGui::InputText("输入内容", sz, 256, 0, 0, 0);

if (ImGui::Button("点我触发"))
counter++;
ImGui::SameLine();
ImGui::Text("触发次数 = ％d", counter);

ImGui::Text("当前FPS: ％.3f ms/frame (％.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
ImGui::End();

if (show_another_window)
{
ImGui::Begin("我是子窗体", &show_another_window);
ImGui::Text(" 您好,LyShark !");
if (ImGui::Button("关闭窗体"))
show_another_window = false;
ImGui::End();
}
ImGui::EndFrame();
}

// 自身窗口循环事件
void WindowMessageLoop()
{
bool done = false;
while (!done)
{
// 每次都将窗体置顶并跟随游戏窗体移动
GetWindowRect(GameHwnd, &WindowRectangle);
WindowWide = (WindowRectangle.right) - (WindowRectangle.left);
WindowHeight = (WindowRectangle.bottom) - (WindowRectangle.top);
DWORD dwStyle = GetWindowLong(GameHwnd, GWL_STYLE);
if (dwStyle & WS_BORDER)
{
WindowRectangle.top += 23;
WindowHeight -= 23;
}

// 跟随窗口移动
MoveWindow(hwnd, WindowRectangle.left + 8, WindowRectangle.top + 8, WindowWide - 11, WindowHeight - 11, true);

// 开始消息循环
MSG msg;
while (PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
if (msg.message == WM_QUIT)
{
done = true;
}
}

if (done)
{
break;
}

// 开始绘制
DrawImGUI();

g_pd3dDevice->SetRenderState(D3DRS_ZENABLE, FALSE);
g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
g_pd3dDevice->SetRenderState(D3DRS_SCISSORTESTENABLE, FALSE);
g_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0, 1.0f, 0);

if (g_pd3dDevice->BeginScene() >= 0)
{
ImGui::Render();
ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
g_pd3dDevice->EndScene();
}

HRESULT result = g_pd3dDevice->Present(NULL, NULL, NULL, NULL);
if (result == D3DERR_DEVICELOST && g_pd3dDevice->TestCooperativeLevel() == D3DERR_DEVICENOTRESET)
{
ResetDevice();
}
}
}

int main(int argc, char *argv[])
{
// 注册窗体类
WNDCLASSEX wc;

// 附加到整个屏幕上
wc.cbClsExtra = NULL;
wc.cbSize = sizeof(WNDCLASSEX);
wc.cbWndExtra = NULL;
wc.hbrBackground = (HBRUSH)CreateSolidBrush(RGB(0, 0, 0));
wc.hCursor = LoadCursor(0, IDC_ARROW);
wc.hIcon = LoadIcon(0, IDI_APPLICATION);
wc.hIconSm = LoadIcon(0, IDI_APPLICATION);
wc.hInstance = GetModuleHandle(NULL);
wc.lpfnWndProc = (WNDPROC)WndProc;
wc.lpszClassName = L" ";
wc.lpszMenuName = L" ";
wc.style = CS_VREDRAW | CS_HREDRAW;
::RegisterClassEx(&wc);

// 屏幕宽度和高度
WindowWide = GetSystemMetrics(SM_CXSCREEN);
WindowHeight = GetSystemMetrics(SM_CYSCREEN);

// 创建窗体
HWND hwnd = CreateWindowEx(WS_EX_TOPMOST | WS_EX_LAYERED | WS_EX_TOOLWINDOW, L" ", L" ", WS_POPUP, 1, 1, WindowWide, WindowHeight, 0, 0, wc.hInstance, 0);

// 显示窗口
SetLayeredWindowAttributes(hwnd, 0, 1.0f, LWA_ALPHA);
SetLayeredWindowAttributes(hwnd, 0, RGB(0, 0, 0), LWA_COLORKEY);
ShowWindow(hwnd, SW_SHOW);

// 初始化D3D
if (!CreateDeviceD3D(hwnd))
{
CleanupDeviceD3D();
UnregisterClass(wc.lpszClassName, wc.hInstance);
return 0;
}

// 更新窗体
UpdateWindow(hwnd);

// 初始化ImGUI
ImGui::CreateContext();
ImGuiIO& io = ImGui::GetIO(); (void)io;
io.Fonts->AddFontFromFileTTF("c:/windows/fonts/simhei.ttf", 13.0f, NULL, io.Fonts->GetGlyphRangesChineseSimplifiedCommon());

ImGui::StyleColorsDark();
ImGui_ImplWin32_Init(hwnd);
ImGui_ImplDX9_Init(g_pd3dDevice);

// 开始执行绘制循环事件
WindowMessageLoop();

ImGui_ImplDX9_Shutdown();
ImGui_ImplWin32_Shutdown();
ImGui::DestroyContext();

CleanupDeviceD3D();
DestroyWindow(hwnd);
UnregisterClass(wc.lpszClassName, wc.hInstance);
return 0;
}

绘制效果如下：

来源：https://www.cnblogs.com/LyShark/p/16655693.html