imgui

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imgui_impl_win32.cpp (26485B)


      1 // dear imgui: Platform Backend for Windows (standard windows API for 32 and 64 bits applications)
      2 // This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
      3 
      4 // Implemented features:
      5 //  [X] Platform: Clipboard support (for Win32 this is actually part of core dear imgui)
      6 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
      7 //  [X] Platform: Keyboard arrays indexed using VK_* Virtual Key Codes, e.g. ImGui::IsKeyPressed(VK_SPACE).
      8 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
      9 
     10 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
     11 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
     12 // Read online: https://github.com/ocornut/imgui/tree/master/docs
     13 
     14 #include "imgui.h"
     15 #include "imgui_impl_win32.h"
     16 #ifndef WIN32_LEAN_AND_MEAN
     17 #define WIN32_LEAN_AND_MEAN
     18 #endif
     19 #include <windows.h>
     20 #include <tchar.h>
     21 #include <dwmapi.h>
     22 
     23 // Configuration flags to add in your imconfig.h file:
     24 //#define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD              // Disable gamepad support (this used to be meaningful before <1.81) but we know load XInput dynamically so the option is less relevant now.
     25 
     26 // Using XInput for gamepad (will load DLL dynamically)
     27 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     28 #include <xinput.h>
     29 typedef DWORD (WINAPI *PFN_XInputGetCapabilities)(DWORD, DWORD, XINPUT_CAPABILITIES*);
     30 typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
     31 #endif
     32 
     33 // CHANGELOG
     34 // (minor and older changes stripped away, please see git history for details)
     35 //  2021-03-23: Inputs: Clearing keyboard down array when losing focus (WM_KILLFOCUS).
     36 //  2021-02-18: Added ImGui_ImplWin32_EnableAlphaCompositing(). Non Visual Studio users will need to link with dwmapi.lib (MinGW/gcc: use -ldwmapi).
     37 //  2021-02-17: Fixed ImGui_ImplWin32_EnableDpiAwareness() attempting to get SetProcessDpiAwareness from shcore.dll on Windows 8 whereas it is only supported on Windows 8.1.
     38 //  2021-01-25: Inputs: Dynamically loading XInput DLL.
     39 //  2020-12-04: Misc: Fixed setting of io.DisplaySize to invalid/uninitialized data when after hwnd has been closed.
     40 //  2020-03-03: Inputs: Calling AddInputCharacterUTF16() to support surrogate pairs leading to codepoint >= 0x10000 (for more complete CJK inputs)
     41 //  2020-02-17: Added ImGui_ImplWin32_EnableDpiAwareness(), ImGui_ImplWin32_GetDpiScaleForHwnd(), ImGui_ImplWin32_GetDpiScaleForMonitor() helper functions.
     42 //  2020-01-14: Inputs: Added support for #define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD/IMGUI_IMPL_WIN32_DISABLE_LINKING_XINPUT.
     43 //  2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
     44 //  2019-05-11: Inputs: Don't filter value from WM_CHAR before calling AddInputCharacter().
     45 //  2019-01-17: Misc: Using GetForegroundWindow()+IsChild() instead of GetActiveWindow() to be compatible with windows created in a different thread or parent.
     46 //  2019-01-17: Inputs: Added support for mouse buttons 4 and 5 via WM_XBUTTON* messages.
     47 //  2019-01-15: Inputs: Added support for XInput gamepads (if ImGuiConfigFlags_NavEnableGamepad is set by user application).
     48 //  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
     49 //  2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
     50 //  2018-06-10: Inputs: Fixed handling of mouse wheel messages to support fine position messages (typically sent by track-pads).
     51 //  2018-06-08: Misc: Extracted imgui_impl_win32.cpp/.h away from the old combined DX9/DX10/DX11/DX12 examples.
     52 //  2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors and ImGuiBackendFlags_HasSetMousePos flags + honor ImGuiConfigFlags_NoMouseCursorChange flag.
     53 //  2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value and WM_SETCURSOR message handling).
     54 //  2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
     55 //  2018-02-06: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
     56 //  2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
     57 //  2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
     58 //  2018-01-08: Inputs: Added mapping for ImGuiKey_Insert.
     59 //  2018-01-05: Inputs: Added WM_LBUTTONDBLCLK double-click handlers for window classes with the CS_DBLCLKS flag.
     60 //  2017-10-23: Inputs: Added WM_SYSKEYDOWN / WM_SYSKEYUP handlers so e.g. the VK_MENU key can be read.
     61 //  2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
     62 //  2016-11-12: Inputs: Only call Win32 ::SetCursor(NULL) when io.MouseDrawCursor is set.
     63 
     64 // Win32 Data
     65 static HWND                 g_hWnd = NULL;
     66 static INT64                g_Time = 0;
     67 static INT64                g_TicksPerSecond = 0;
     68 static ImGuiMouseCursor     g_LastMouseCursor = ImGuiMouseCursor_COUNT;
     69 static bool                 g_HasGamepad = false;
     70 static bool                 g_WantUpdateHasGamepad = true;
     71 
     72 // XInput DLL and functions
     73 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     74 static HMODULE                      g_XInputDLL = NULL;
     75 static PFN_XInputGetCapabilities    g_XInputGetCapabilities = NULL;
     76 static PFN_XInputGetState           g_XInputGetState = NULL;
     77 #endif
     78 
     79 // Functions
     80 bool    ImGui_ImplWin32_Init(void* hwnd)
     81 {
     82     if (!::QueryPerformanceFrequency((LARGE_INTEGER*)&g_TicksPerSecond))
     83         return false;
     84     if (!::QueryPerformanceCounter((LARGE_INTEGER*)&g_Time))
     85         return false;
     86 
     87     // Setup backend capabilities flags
     88     g_hWnd = (HWND)hwnd;
     89     ImGuiIO& io = ImGui::GetIO();
     90     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     91     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
     92     io.BackendPlatformName = "imgui_impl_win32";
     93     io.ImeWindowHandle = hwnd;
     94 
     95     // Keyboard mapping. Dear ImGui will use those indices to peek into the io.KeysDown[] array that we will update during the application lifetime.
     96     io.KeyMap[ImGuiKey_Tab] = VK_TAB;
     97     io.KeyMap[ImGuiKey_LeftArrow] = VK_LEFT;
     98     io.KeyMap[ImGuiKey_RightArrow] = VK_RIGHT;
     99     io.KeyMap[ImGuiKey_UpArrow] = VK_UP;
    100     io.KeyMap[ImGuiKey_DownArrow] = VK_DOWN;
    101     io.KeyMap[ImGuiKey_PageUp] = VK_PRIOR;
    102     io.KeyMap[ImGuiKey_PageDown] = VK_NEXT;
    103     io.KeyMap[ImGuiKey_Home] = VK_HOME;
    104     io.KeyMap[ImGuiKey_End] = VK_END;
    105     io.KeyMap[ImGuiKey_Insert] = VK_INSERT;
    106     io.KeyMap[ImGuiKey_Delete] = VK_DELETE;
    107     io.KeyMap[ImGuiKey_Backspace] = VK_BACK;
    108     io.KeyMap[ImGuiKey_Space] = VK_SPACE;
    109     io.KeyMap[ImGuiKey_Enter] = VK_RETURN;
    110     io.KeyMap[ImGuiKey_Escape] = VK_ESCAPE;
    111     io.KeyMap[ImGuiKey_KeyPadEnter] = VK_RETURN;
    112     io.KeyMap[ImGuiKey_A] = 'A';
    113     io.KeyMap[ImGuiKey_C] = 'C';
    114     io.KeyMap[ImGuiKey_V] = 'V';
    115     io.KeyMap[ImGuiKey_X] = 'X';
    116     io.KeyMap[ImGuiKey_Y] = 'Y';
    117     io.KeyMap[ImGuiKey_Z] = 'Z';
    118 
    119     // Dynamically load XInput library
    120 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
    121     const char* xinput_dll_names[] =
    122     {
    123         "xinput1_4.dll",   // Windows 8+
    124         "xinput1_3.dll",   // DirectX SDK
    125         "xinput9_1_0.dll", // Windows Vista, Windows 7
    126         "xinput1_2.dll",   // DirectX SDK
    127         "xinput1_1.dll"    // DirectX SDK
    128     };
    129     for (int n = 0; n < IM_ARRAYSIZE(xinput_dll_names); n++)
    130         if (HMODULE dll = ::LoadLibraryA(xinput_dll_names[n]))
    131         {
    132             g_XInputDLL = dll;
    133             g_XInputGetCapabilities = (PFN_XInputGetCapabilities)::GetProcAddress(dll, "XInputGetCapabilities");
    134             g_XInputGetState = (PFN_XInputGetState)::GetProcAddress(dll, "XInputGetState");
    135             break;
    136         }
    137 #endif // IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
    138 
    139     return true;
    140 }
    141 
    142 void    ImGui_ImplWin32_Shutdown()
    143 {
    144     // Unload XInput library
    145 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
    146     if (g_XInputDLL)
    147         ::FreeLibrary(g_XInputDLL);
    148     g_XInputDLL = NULL;
    149     g_XInputGetCapabilities = NULL;
    150     g_XInputGetState = NULL;
    151 #endif // IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
    152 
    153     g_hWnd = NULL;
    154     g_Time = 0;
    155     g_TicksPerSecond = 0;
    156     g_LastMouseCursor = ImGuiMouseCursor_COUNT;
    157     g_HasGamepad = false;
    158     g_WantUpdateHasGamepad = true;
    159 }
    160 
    161 static bool ImGui_ImplWin32_UpdateMouseCursor()
    162 {
    163     ImGuiIO& io = ImGui::GetIO();
    164     if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
    165         return false;
    166 
    167     ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
    168     if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
    169     {
    170         // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
    171         ::SetCursor(NULL);
    172     }
    173     else
    174     {
    175         // Show OS mouse cursor
    176         LPTSTR win32_cursor = IDC_ARROW;
    177         switch (imgui_cursor)
    178         {
    179         case ImGuiMouseCursor_Arrow:        win32_cursor = IDC_ARROW; break;
    180         case ImGuiMouseCursor_TextInput:    win32_cursor = IDC_IBEAM; break;
    181         case ImGuiMouseCursor_ResizeAll:    win32_cursor = IDC_SIZEALL; break;
    182         case ImGuiMouseCursor_ResizeEW:     win32_cursor = IDC_SIZEWE; break;
    183         case ImGuiMouseCursor_ResizeNS:     win32_cursor = IDC_SIZENS; break;
    184         case ImGuiMouseCursor_ResizeNESW:   win32_cursor = IDC_SIZENESW; break;
    185         case ImGuiMouseCursor_ResizeNWSE:   win32_cursor = IDC_SIZENWSE; break;
    186         case ImGuiMouseCursor_Hand:         win32_cursor = IDC_HAND; break;
    187         case ImGuiMouseCursor_NotAllowed:   win32_cursor = IDC_NO; break;
    188         }
    189         ::SetCursor(::LoadCursor(NULL, win32_cursor));
    190     }
    191     return true;
    192 }
    193 
    194 static void ImGui_ImplWin32_UpdateMousePos()
    195 {
    196     ImGuiIO& io = ImGui::GetIO();
    197     IM_ASSERT(g_hWnd != 0);
    198 
    199     // Set OS mouse position if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
    200     if (io.WantSetMousePos)
    201     {
    202         POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
    203         if (::ClientToScreen(g_hWnd, &pos))
    204             ::SetCursorPos(pos.x, pos.y);
    205     }
    206 
    207     // Set mouse position
    208     io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
    209     POINT pos;
    210     if (HWND active_window = ::GetForegroundWindow())
    211         if (active_window == g_hWnd || ::IsChild(active_window, g_hWnd))
    212             if (::GetCursorPos(&pos) && ::ScreenToClient(g_hWnd, &pos))
    213                 io.MousePos = ImVec2((float)pos.x, (float)pos.y);
    214 }
    215 
    216 // Gamepad navigation mapping
    217 static void ImGui_ImplWin32_UpdateGamepads()
    218 {
    219 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
    220     ImGuiIO& io = ImGui::GetIO();
    221     memset(io.NavInputs, 0, sizeof(io.NavInputs));
    222     if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0)
    223         return;
    224 
    225     // Calling XInputGetState() every frame on disconnected gamepads is unfortunately too slow.
    226     // Instead we refresh gamepad availability by calling XInputGetCapabilities() _only_ after receiving WM_DEVICECHANGE.
    227     if (g_WantUpdateHasGamepad)
    228     {
    229         XINPUT_CAPABILITIES caps;
    230         g_HasGamepad = g_XInputGetCapabilities ? (g_XInputGetCapabilities(0, XINPUT_FLAG_GAMEPAD, &caps) == ERROR_SUCCESS) : false;
    231         g_WantUpdateHasGamepad = false;
    232     }
    233 
    234     io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
    235     XINPUT_STATE xinput_state;
    236     if (g_HasGamepad && g_XInputGetState && g_XInputGetState(0, &xinput_state) == ERROR_SUCCESS)
    237     {
    238         const XINPUT_GAMEPAD& gamepad = xinput_state.Gamepad;
    239         io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
    240 
    241         #define MAP_BUTTON(NAV_NO, BUTTON_ENUM)     { io.NavInputs[NAV_NO] = (gamepad.wButtons & BUTTON_ENUM) ? 1.0f : 0.0f; }
    242         #define MAP_ANALOG(NAV_NO, VALUE, V0, V1)   { float vn = (float)(VALUE - V0) / (float)(V1 - V0); if (vn > 1.0f) vn = 1.0f; if (vn > 0.0f && io.NavInputs[NAV_NO] < vn) io.NavInputs[NAV_NO] = vn; }
    243         MAP_BUTTON(ImGuiNavInput_Activate,      XINPUT_GAMEPAD_A);              // Cross / A
    244         MAP_BUTTON(ImGuiNavInput_Cancel,        XINPUT_GAMEPAD_B);              // Circle / B
    245         MAP_BUTTON(ImGuiNavInput_Menu,          XINPUT_GAMEPAD_X);              // Square / X
    246         MAP_BUTTON(ImGuiNavInput_Input,         XINPUT_GAMEPAD_Y);              // Triangle / Y
    247         MAP_BUTTON(ImGuiNavInput_DpadLeft,      XINPUT_GAMEPAD_DPAD_LEFT);      // D-Pad Left
    248         MAP_BUTTON(ImGuiNavInput_DpadRight,     XINPUT_GAMEPAD_DPAD_RIGHT);     // D-Pad Right
    249         MAP_BUTTON(ImGuiNavInput_DpadUp,        XINPUT_GAMEPAD_DPAD_UP);        // D-Pad Up
    250         MAP_BUTTON(ImGuiNavInput_DpadDown,      XINPUT_GAMEPAD_DPAD_DOWN);      // D-Pad Down
    251         MAP_BUTTON(ImGuiNavInput_FocusPrev,     XINPUT_GAMEPAD_LEFT_SHOULDER);  // L1 / LB
    252         MAP_BUTTON(ImGuiNavInput_FocusNext,     XINPUT_GAMEPAD_RIGHT_SHOULDER); // R1 / RB
    253         MAP_BUTTON(ImGuiNavInput_TweakSlow,     XINPUT_GAMEPAD_LEFT_SHOULDER);  // L1 / LB
    254         MAP_BUTTON(ImGuiNavInput_TweakFast,     XINPUT_GAMEPAD_RIGHT_SHOULDER); // R1 / RB
    255         MAP_ANALOG(ImGuiNavInput_LStickLeft,    gamepad.sThumbLX,  -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
    256         MAP_ANALOG(ImGuiNavInput_LStickRight,   gamepad.sThumbLX,  +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
    257         MAP_ANALOG(ImGuiNavInput_LStickUp,      gamepad.sThumbLY,  +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
    258         MAP_ANALOG(ImGuiNavInput_LStickDown,    gamepad.sThumbLY,  -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32767);
    259         #undef MAP_BUTTON
    260         #undef MAP_ANALOG
    261     }
    262 #endif // #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
    263 }
    264 
    265 void    ImGui_ImplWin32_NewFrame()
    266 {
    267     ImGuiIO& io = ImGui::GetIO();
    268     IM_ASSERT(io.Fonts->IsBuilt() && "Font atlas not built! It is generally built by the renderer backend. Missing call to renderer _NewFrame() function? e.g. ImGui_ImplOpenGL3_NewFrame().");
    269 
    270     // Setup display size (every frame to accommodate for window resizing)
    271     RECT rect = { 0, 0, 0, 0 };
    272     ::GetClientRect(g_hWnd, &rect);
    273     io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
    274 
    275     // Setup time step
    276     INT64 current_time = 0;
    277     ::QueryPerformanceCounter((LARGE_INTEGER*)&current_time);
    278     io.DeltaTime = (float)(current_time - g_Time) / g_TicksPerSecond;
    279     g_Time = current_time;
    280 
    281     // Read keyboard modifiers inputs
    282     io.KeyCtrl = (::GetKeyState(VK_CONTROL) & 0x8000) != 0;
    283     io.KeyShift = (::GetKeyState(VK_SHIFT) & 0x8000) != 0;
    284     io.KeyAlt = (::GetKeyState(VK_MENU) & 0x8000) != 0;
    285     io.KeySuper = false;
    286     // io.KeysDown[], io.MousePos, io.MouseDown[], io.MouseWheel: filled by the WndProc handler below.
    287 
    288     // Update OS mouse position
    289     ImGui_ImplWin32_UpdateMousePos();
    290 
    291     // Update OS mouse cursor with the cursor requested by imgui
    292     ImGuiMouseCursor mouse_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor();
    293     if (g_LastMouseCursor != mouse_cursor)
    294     {
    295         g_LastMouseCursor = mouse_cursor;
    296         ImGui_ImplWin32_UpdateMouseCursor();
    297     }
    298 
    299     // Update game controllers (if enabled and available)
    300     ImGui_ImplWin32_UpdateGamepads();
    301 }
    302 
    303 // Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
    304 #ifndef WM_MOUSEHWHEEL
    305 #define WM_MOUSEHWHEEL 0x020E
    306 #endif
    307 #ifndef DBT_DEVNODES_CHANGED
    308 #define DBT_DEVNODES_CHANGED 0x0007
    309 #endif
    310 
    311 // Win32 message handler (process Win32 mouse/keyboard inputs, etc.)
    312 // Call from your application's message handler.
    313 // When implementing your own backend, you can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if Dear ImGui wants to use your inputs.
    314 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
    315 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
    316 // Generally you may always pass all inputs to Dear ImGui, and hide them from your application based on those two flags.
    317 // PS: In this Win32 handler, we use the capture API (GetCapture/SetCapture/ReleaseCapture) to be able to read mouse coordinates when dragging mouse outside of our window bounds.
    318 // PS: We treat DBLCLK messages as regular mouse down messages, so this code will work on windows classes that have the CS_DBLCLKS flag set. Our own example app code doesn't set this flag.
    319 #if 0
    320 // Copy this line into your .cpp file to forward declare the function.
    321 extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
    322 #endif
    323 IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
    324 {
    325     if (ImGui::GetCurrentContext() == NULL)
    326         return 0;
    327 
    328     ImGuiIO& io = ImGui::GetIO();
    329     switch (msg)
    330     {
    331     case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK:
    332     case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK:
    333     case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK:
    334     case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK:
    335     {
    336         int button = 0;
    337         if (msg == WM_LBUTTONDOWN || msg == WM_LBUTTONDBLCLK) { button = 0; }
    338         if (msg == WM_RBUTTONDOWN || msg == WM_RBUTTONDBLCLK) { button = 1; }
    339         if (msg == WM_MBUTTONDOWN || msg == WM_MBUTTONDBLCLK) { button = 2; }
    340         if (msg == WM_XBUTTONDOWN || msg == WM_XBUTTONDBLCLK) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
    341         if (!ImGui::IsAnyMouseDown() && ::GetCapture() == NULL)
    342             ::SetCapture(hwnd);
    343         io.MouseDown[button] = true;
    344         return 0;
    345     }
    346     case WM_LBUTTONUP:
    347     case WM_RBUTTONUP:
    348     case WM_MBUTTONUP:
    349     case WM_XBUTTONUP:
    350     {
    351         int button = 0;
    352         if (msg == WM_LBUTTONUP) { button = 0; }
    353         if (msg == WM_RBUTTONUP) { button = 1; }
    354         if (msg == WM_MBUTTONUP) { button = 2; }
    355         if (msg == WM_XBUTTONUP) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
    356         io.MouseDown[button] = false;
    357         if (!ImGui::IsAnyMouseDown() && ::GetCapture() == hwnd)
    358             ::ReleaseCapture();
    359         return 0;
    360     }
    361     case WM_MOUSEWHEEL:
    362         io.MouseWheel += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
    363         return 0;
    364     case WM_MOUSEHWHEEL:
    365         io.MouseWheelH += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
    366         return 0;
    367     case WM_KEYDOWN:
    368     case WM_SYSKEYDOWN:
    369         if (wParam < 256)
    370             io.KeysDown[wParam] = 1;
    371         return 0;
    372     case WM_KEYUP:
    373     case WM_SYSKEYUP:
    374         if (wParam < 256)
    375             io.KeysDown[wParam] = 0;
    376         return 0;
    377     case WM_KILLFOCUS:
    378         memset(io.KeysDown, 0, sizeof(io.KeysDown));
    379         return 0;
    380     case WM_CHAR:
    381         // You can also use ToAscii()+GetKeyboardState() to retrieve characters.
    382         if (wParam > 0 && wParam < 0x10000)
    383             io.AddInputCharacterUTF16((unsigned short)wParam);
    384         return 0;
    385     case WM_SETCURSOR:
    386         if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor())
    387             return 1;
    388         return 0;
    389     case WM_DEVICECHANGE:
    390         if ((UINT)wParam == DBT_DEVNODES_CHANGED)
    391             g_WantUpdateHasGamepad = true;
    392         return 0;
    393     }
    394     return 0;
    395 }
    396 
    397 
    398 //--------------------------------------------------------------------------------------------------------
    399 // DPI-related helpers (optional)
    400 //--------------------------------------------------------------------------------------------------------
    401 // - Use to enable DPI awareness without having to create an application manifest.
    402 // - Your own app may already do this via a manifest or explicit calls. This is mostly useful for our examples/ apps.
    403 // - In theory we could call simple functions from Windows SDK such as SetProcessDPIAware(), SetProcessDpiAwareness(), etc.
    404 //   but most of the functions provided by Microsoft require Windows 8.1/10+ SDK at compile time and Windows 8/10+ at runtime,
    405 //   neither we want to require the user to have. So we dynamically select and load those functions to avoid dependencies.
    406 //---------------------------------------------------------------------------------------------------------
    407 // This is the scheme successfully used by GLFW (from which we borrowed some of the code) and other apps aiming to be highly portable.
    408 // ImGui_ImplWin32_EnableDpiAwareness() is just a helper called by main.cpp, we don't call it automatically.
    409 // If you are trying to implement your own backend for your own engine, you may ignore that noise.
    410 //---------------------------------------------------------------------------------------------------------
    411 
    412 // Implement some of the functions and types normally declared in recent Windows SDK.
    413 #if !defined(_versionhelpers_H_INCLUDED_) && !defined(_INC_VERSIONHELPERS)
    414 static BOOL IsWindowsVersionOrGreater(WORD major, WORD minor, WORD sp)
    415 {
    416     OSVERSIONINFOEXW osvi = { sizeof(osvi), major, minor, 0, 0, { 0 }, sp, 0, 0, 0, 0 };
    417     DWORD mask = VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR;
    418     ULONGLONG cond = ::VerSetConditionMask(0, VER_MAJORVERSION, VER_GREATER_EQUAL);
    419     cond = ::VerSetConditionMask(cond, VER_MINORVERSION, VER_GREATER_EQUAL);
    420     cond = ::VerSetConditionMask(cond, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);
    421     return ::VerifyVersionInfoW(&osvi, mask, cond);
    422 }
    423 #define IsWindowsVistaOrGreater()   IsWindowsVersionOrGreater(HIBYTE(0x0600), LOBYTE(0x0600), 0) // _WIN32_WINNT_VISTA
    424 #define IsWindows8OrGreater()       IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WIN8
    425 #define IsWindows8Point1OrGreater() IsWindowsVersionOrGreater(HIBYTE(0x0603), LOBYTE(0x0603), 0) // _WIN32_WINNT_WINBLUE
    426 #endif
    427 
    428 #ifndef DPI_ENUMS_DECLARED
    429 typedef enum { PROCESS_DPI_UNAWARE = 0, PROCESS_SYSTEM_DPI_AWARE = 1, PROCESS_PER_MONITOR_DPI_AWARE = 2 } PROCESS_DPI_AWARENESS;
    430 typedef enum { MDT_EFFECTIVE_DPI = 0, MDT_ANGULAR_DPI = 1, MDT_RAW_DPI = 2, MDT_DEFAULT = MDT_EFFECTIVE_DPI } MONITOR_DPI_TYPE;
    431 #endif
    432 #ifndef _DPI_AWARENESS_CONTEXTS_
    433 DECLARE_HANDLE(DPI_AWARENESS_CONTEXT);
    434 #define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE    (DPI_AWARENESS_CONTEXT)-3
    435 #endif
    436 #ifndef DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
    437 #define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 (DPI_AWARENESS_CONTEXT)-4
    438 #endif
    439 typedef HRESULT(WINAPI* PFN_SetProcessDpiAwareness)(PROCESS_DPI_AWARENESS);                     // Shcore.lib + dll, Windows 8.1+
    440 typedef HRESULT(WINAPI* PFN_GetDpiForMonitor)(HMONITOR, MONITOR_DPI_TYPE, UINT*, UINT*);        // Shcore.lib + dll, Windows 8.1+
    441 typedef DPI_AWARENESS_CONTEXT(WINAPI* PFN_SetThreadDpiAwarenessContext)(DPI_AWARENESS_CONTEXT); // User32.lib + dll, Windows 10 v1607+ (Creators Update)
    442 
    443 // Helper function to enable DPI awareness without setting up a manifest
    444 void ImGui_ImplWin32_EnableDpiAwareness()
    445 {
    446     // if (IsWindows10OrGreater()) // This needs a manifest to succeed. Instead we try to grab the function pointer!
    447     {
    448         static HINSTANCE user32_dll = ::LoadLibraryA("user32.dll"); // Reference counted per-process
    449         if (PFN_SetThreadDpiAwarenessContext SetThreadDpiAwarenessContextFn = (PFN_SetThreadDpiAwarenessContext)::GetProcAddress(user32_dll, "SetThreadDpiAwarenessContext"))
    450         {
    451             SetThreadDpiAwarenessContextFn(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
    452             return;
    453         }
    454     }
    455     if (IsWindows8Point1OrGreater())
    456     {
    457         static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
    458         if (PFN_SetProcessDpiAwareness SetProcessDpiAwarenessFn = (PFN_SetProcessDpiAwareness)::GetProcAddress(shcore_dll, "SetProcessDpiAwareness"))
    459         {
    460             SetProcessDpiAwarenessFn(PROCESS_PER_MONITOR_DPI_AWARE);
    461             return;
    462         }
    463     }
    464 #if _WIN32_WINNT >= 0x0600
    465     ::SetProcessDPIAware();
    466 #endif
    467 }
    468 
    469 #if defined(_MSC_VER) && !defined(NOGDI)
    470 #pragma comment(lib, "gdi32")   // Link with gdi32.lib for GetDeviceCaps(). MinGW will require linking with '-lgdi32'
    471 #endif
    472 
    473 float ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor)
    474 {
    475     UINT xdpi = 96, ydpi = 96;
    476     static BOOL bIsWindows8Point1OrGreater = IsWindows8Point1OrGreater();
    477     if (bIsWindows8Point1OrGreater)
    478     {
    479         static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
    480         if (PFN_GetDpiForMonitor GetDpiForMonitorFn = (PFN_GetDpiForMonitor)::GetProcAddress(shcore_dll, "GetDpiForMonitor"))
    481             GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi);
    482     }
    483 #ifndef NOGDI
    484     else
    485     {
    486         const HDC dc = ::GetDC(NULL);
    487         xdpi = ::GetDeviceCaps(dc, LOGPIXELSX);
    488         ydpi = ::GetDeviceCaps(dc, LOGPIXELSY);
    489         ::ReleaseDC(NULL, dc);
    490     }
    491 #endif
    492     IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
    493     return xdpi / 96.0f;
    494 }
    495 
    496 float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd)
    497 {
    498     HMONITOR monitor = ::MonitorFromWindow((HWND)hwnd, MONITOR_DEFAULTTONEAREST);
    499     return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
    500 }
    501 
    502 //---------------------------------------------------------------------------------------------------------
    503 // Transparency related helpers (optional)
    504 //--------------------------------------------------------------------------------------------------------
    505 
    506 #if defined(_MSC_VER)
    507 #pragma comment(lib, "dwmapi")  // Link with dwmapi.lib. MinGW will require linking with '-ldwmapi'
    508 #endif
    509 
    510 // [experimental]
    511 // Borrowed from GLFW's function updateFramebufferTransparency() in src/win32_window.c
    512 // (the Dwm* functions are Vista era functions but we are borrowing logic from GLFW)
    513 void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd)
    514 {
    515     if (!IsWindowsVistaOrGreater())
    516         return;
    517 
    518     BOOL composition;
    519     if (FAILED(::DwmIsCompositionEnabled(&composition)) || !composition)
    520         return;
    521 
    522     BOOL opaque;
    523     DWORD color;
    524     if (IsWindows8OrGreater() || (SUCCEEDED(::DwmGetColorizationColor(&color, &opaque)) && !opaque))
    525     {
    526         HRGN region = ::CreateRectRgn(0, 0, -1, -1);
    527         DWM_BLURBEHIND bb = {};
    528         bb.dwFlags = DWM_BB_ENABLE | DWM_BB_BLURREGION;
    529         bb.hRgnBlur = region;
    530         bb.fEnable = TRUE;
    531         ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
    532         ::DeleteObject(region);
    533     }
    534     else
    535     {
    536         DWM_BLURBEHIND bb = {};
    537         bb.dwFlags = DWM_BB_ENABLE;
    538         ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
    539     }
    540 }
    541 
    542 //---------------------------------------------------------------------------------------------------------