src/video/windows/SDL_windowswindow.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_config.h"

#include "../SDL_sysvideo.h"
#include "../SDL_pixels_c.h"
#include "../../events/SDL_keyboard_c.h"

#include "SDL_windowsvideo.h"
#include "SDL_windowswindow.h"

/* This is included after SDL_windowsvideo.h, which includes windows.h */
#include "SDL_syswm.h"

/* Windows CE compatibility */
#ifndef SWP_NOCOPYBITS
#define SWP_NOCOPYBITS 0
#endif

/* Fake window to help with DirectInput events. */
HWND SDL_HelperWindow = NULL;
static WCHAR *SDL_HelperWindowClassName = TEXT("SDLHelperWindowInputCatcher");
static WCHAR *SDL_HelperWindowName = TEXT("SDLHelperWindowInputMsgWindow");
static ATOM SDL_HelperWindowClass = 0;

#define STYLE_BASIC         (WS_CLIPSIBLINGS | WS_CLIPCHILDREN)
#define STYLE_FULLSCREEN    (WS_POPUP)
#define STYLE_BORDERLESS    (WS_POPUP)
#define STYLE_NORMAL        (WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX)
#define STYLE_RESIZABLE     (WS_THICKFRAME | WS_MAXIMIZEBOX)
#define STYLE_MASK          (STYLE_FULLSCREEN | STYLE_BORDERLESS | STYLE_NORMAL | STYLE_RESIZABLE)

static DWORD
GetWindowStyle(SDL_Window * window)
{
    DWORD style = 0;

	if (window->flags & SDL_WINDOW_FULLSCREEN) {
        style |= STYLE_FULLSCREEN;
	} else {
		if (window->flags & SDL_WINDOW_BORDERLESS) {
            style |= STYLE_BORDERLESS;
		} else {
            style |= STYLE_NORMAL;
		}
		if (window->flags & SDL_WINDOW_RESIZABLE) {
            style |= STYLE_RESIZABLE;
		}
	}
    return style;
}

static int
SetupWindowData(_THIS, SDL_Window * window, HWND hwnd, SDL_bool created)
{
    SDL_VideoData *videodata = (SDL_VideoData *) _this->driverdata;
    SDL_VideoDisplay *display = SDL_GetDisplayForWindow(window);
    SDL_WindowData *data;

    /* Allocate the window data */
    data = (SDL_WindowData *) SDL_malloc(sizeof(*data));
    if (!data) {
        SDL_OutOfMemory();
        return -1;
    }
    data->window = window;
    data->hwnd = hwnd;
    data->hdc = GetDC(hwnd);
    data->created = created;
    data->mouse_pressed = SDL_FALSE;
    data->videodata = videodata;

    window->driverdata = data;

    /* Associate the data with the window */
    if (!SetProp(hwnd, TEXT("SDL_WindowData"), data)) {
        ReleaseDC(hwnd, data->hdc);
        SDL_free(data);
        WIN_SetError("SetProp() failed");
        return -1;
    }

    /* Set up the window proc function */
#ifdef GWLP_WNDPROC
    data->wndproc = (WNDPROC) GetWindowLongPtr(hwnd, GWLP_WNDPROC);
    if (data->wndproc == WIN_WindowProc) {
        data->wndproc = NULL;
    } else {
        SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR) WIN_WindowProc);
    }
#else
    data->wndproc = (WNDPROC) GetWindowLong(hwnd, GWL_WNDPROC);
    if (data->wndproc == WIN_WindowProc) {
        data->wndproc = NULL;
    } else {
        SetWindowLong(hwnd, GWL_WNDPROC, (LONG_PTR) WIN_WindowProc);
    }
#endif

    /* Fill in the SDL window with the window data */
    {
        POINT point;
        point.x = 0;
        point.y = 0;
        if (ClientToScreen(hwnd, &point)) {
            window->x = point.x;
            window->y = point.y;
        }
    }
    {
        RECT rect;
        if (GetClientRect(hwnd, &rect)) {
            window->w = rect.right;
            window->h = rect.bottom;
        }
    }
    {
        DWORD style = GetWindowLong(hwnd, GWL_STYLE);
        if (style & WS_VISIBLE) {
            window->flags |= SDL_WINDOW_SHOWN;
        } else {
            window->flags &= ~SDL_WINDOW_SHOWN;
        }
        if (style & (WS_BORDER | WS_THICKFRAME)) {
            window->flags &= ~SDL_WINDOW_BORDERLESS;
        } else {
            window->flags |= SDL_WINDOW_BORDERLESS;
        }
        if (style & WS_THICKFRAME) {
            window->flags |= SDL_WINDOW_RESIZABLE;
        } else {
            window->flags &= ~SDL_WINDOW_RESIZABLE;
        }
#ifdef WS_MAXIMIZE
        if (style & WS_MAXIMIZE) {
            window->flags |= SDL_WINDOW_MAXIMIZED;
        } else
#endif
        {
            window->flags &= ~SDL_WINDOW_MAXIMIZED;
        }
#ifdef WS_MINIMIZE
        if (style & WS_MINIMIZE) {
            window->flags |= SDL_WINDOW_MINIMIZED;
        } else
#endif
        {
            window->flags &= ~SDL_WINDOW_MINIMIZED;
        }
    }
    if (GetFocus() == hwnd) {
        window->flags |= SDL_WINDOW_INPUT_FOCUS;
        SDL_SetKeyboardFocus(data->window);

        if (window->flags & SDL_WINDOW_INPUT_GRABBED) {
            RECT rect;
            GetClientRect(hwnd, &rect);
            ClientToScreen(hwnd, (LPPOINT) & rect);
            ClientToScreen(hwnd, (LPPOINT) & rect + 1);
            ClipCursor(&rect);
        }
    }

	/* Enable multi-touch */
    if (videodata->RegisterTouchWindow) {
        videodata->RegisterTouchWindow(hwnd, (TWF_FINETOUCH|TWF_WANTPALM));
    }

    /* All done! */
    return 0;
}

int
WIN_CreateWindow(_THIS, SDL_Window * window)
{
    SDL_VideoDisplay *display = SDL_GetDisplayForWindow(window);
    HWND hwnd;
    RECT rect;
    DWORD style = STYLE_BASIC;
    int x, y;
    int w, h;
    
    style |= GetWindowStyle(window);

    /* Figure out what the window area will be */
    rect.left = window->x;
    rect.top = window->y;
    rect.right = window->x + window->w;
    rect.bottom = window->y + window->h;
    AdjustWindowRectEx(&rect, style, FALSE, 0);
    x = rect.left;
    y = rect.top;
    w = (rect.right - rect.left);
    h = (rect.bottom - rect.top);

    hwnd =
        CreateWindow(SDL_Appname, TEXT(""), style, x, y, w, h, NULL, NULL,
                     SDL_Instance, NULL);
    if (!hwnd) {
        WIN_SetError("Couldn't create window");
        return -1;
    }

    WIN_PumpEvents(_this);

    if (SetupWindowData(_this, window, hwnd, SDL_TRUE) < 0) {
        DestroyWindow(hwnd);
        return -1;
    }
#if SDL_VIDEO_OPENGL_WGL
    if (window->flags & SDL_WINDOW_OPENGL) {
        if (WIN_GL_SetupWindow(_this, window) < 0) {
            WIN_DestroyWindow(_this, window);
            return -1;
        }
    }
#endif
    return 0;
}

int
WIN_CreateWindowFrom(_THIS, SDL_Window * window, const void *data)
{
    HWND hwnd = (HWND) data;
    LPTSTR title;
    int titleLen;

    /* Query the title from the existing window */
    titleLen = GetWindowTextLength(hwnd);
    title = SDL_stack_alloc(TCHAR, titleLen + 1);
    if (title) {
        titleLen = GetWindowText(hwnd, title, titleLen);
    } else {
        titleLen = 0;
    }
    if (titleLen > 0) {
        window->title = WIN_StringToUTF8(title);
    }
    if (title) {
        SDL_stack_free(title);
    }

    if (SetupWindowData(_this, window, hwnd, SDL_FALSE) < 0) {
        return -1;
    }
    return 0;
}

void
WIN_SetWindowTitle(_THIS, SDL_Window * window)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    LPTSTR title;

    if (window->title) {
        title = WIN_UTF8ToString(window->title);
    } else {
        title = NULL;
    }
    SetWindowText(hwnd, title ? title : TEXT(""));
    if (title) {
        SDL_free(title);
    }
}

void
WIN_SetWindowIcon(_THIS, SDL_Window * window, SDL_Surface * icon)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    HICON hicon = NULL;
    BYTE *icon_bmp;
    int icon_len;
    SDL_RWops *dst;
    SDL_Surface *surface;

    /* Create temporary bitmap buffer */
    icon_len = 40 + icon->h * icon->w * 4;
    icon_bmp = SDL_stack_alloc(BYTE, icon_len);
    dst = SDL_RWFromMem(icon_bmp, icon_len);
    if (!dst) {
        SDL_stack_free(icon_bmp);
        return;
    }

    /* Write the BITMAPINFO header */
    SDL_WriteLE32(dst, 40);
    SDL_WriteLE32(dst, icon->w);
    SDL_WriteLE32(dst, icon->h * 2);
    SDL_WriteLE16(dst, 1);
    SDL_WriteLE16(dst, 32);
    SDL_WriteLE32(dst, BI_RGB);
    SDL_WriteLE32(dst, icon->h * icon->w * 4);
    SDL_WriteLE32(dst, 0);
    SDL_WriteLE32(dst, 0);
    SDL_WriteLE32(dst, 0);
    SDL_WriteLE32(dst, 0);

    /* Convert the icon to a 32-bit surface with alpha channel */
    surface = SDL_ConvertSurfaceFormat(icon, SDL_PIXELFORMAT_ARGB8888, 0);
    if (surface) {
        /* Write the pixels upside down into the bitmap buffer */
        int y = surface->h;
        while (y--) {
            Uint8 *src = (Uint8 *) surface->pixels + y * surface->pitch;
            SDL_RWwrite(dst, src, surface->pitch, 1);
        }
        SDL_FreeSurface(surface);

/* TODO: create the icon in WinCE (CreateIconFromResource isn't available) */
#ifndef _WIN32_WCE
        hicon = CreateIconFromResource(icon_bmp, icon_len, TRUE, 0x00030000);
#endif
    }
    SDL_RWclose(dst);
    SDL_stack_free(icon_bmp);

    /* Set the icon for the window */
    SendMessage(hwnd, WM_SETICON, ICON_SMALL, (LPARAM) hicon);

    /* Set the icon in the task manager (should we do this?) */
    SendMessage(hwnd, WM_SETICON, ICON_BIG, (LPARAM) hicon);
}

void
WIN_SetWindowPosition(_THIS, SDL_Window * window)
{
    SDL_VideoDisplay *display = SDL_GetDisplayForWindow(window);
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    RECT rect;
    DWORD style;
    HWND top;
    BOOL menu;
    int x, y;
    int w, h;

    /* Figure out what the window area will be */
    if (window->flags & SDL_WINDOW_FULLSCREEN) {
        top = HWND_TOPMOST;
    } else {
        top = HWND_NOTOPMOST;
    }
    style = GetWindowLong(hwnd, GWL_STYLE);
    rect.left = 0;
    rect.top = 0;
    rect.right = window->w;
    rect.bottom = window->h;
#ifdef _WIN32_WCE
    menu = FALSE;
#else
    menu = (style & WS_CHILDWINDOW) ? FALSE : (GetMenu(hwnd) != NULL);
#endif
    AdjustWindowRectEx(&rect, style, menu, 0);
    w = (rect.right - rect.left);
    h = (rect.bottom - rect.top);
    x = window->x + rect.left;
    y = window->y + rect.top;

    SetWindowPos(hwnd, top, x, y, 0, 0, (SWP_NOCOPYBITS | SWP_NOSIZE));
}

void
WIN_SetWindowSize(_THIS, SDL_Window * window)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    RECT rect;
    DWORD style;
    HWND top;
    BOOL menu;
    int w, h;

    /* Figure out what the window area will be */
    if (window->flags & SDL_WINDOW_FULLSCREEN) {
        top = HWND_TOPMOST;
    } else {
        top = HWND_NOTOPMOST;
    }
    style = GetWindowLong(hwnd, GWL_STYLE);
    rect.left = 0;
    rect.top = 0;
    rect.right = window->w;
    rect.bottom = window->h;
#ifdef _WIN32_WCE
    menu = FALSE;
#else
    menu = (style & WS_CHILDWINDOW) ? FALSE : (GetMenu(hwnd) != NULL);
#endif
    AdjustWindowRectEx(&rect, style, menu, 0);
    w = (rect.right - rect.left);
    h = (rect.bottom - rect.top);

    SetWindowPos(hwnd, top, 0, 0, w, h, (SWP_NOCOPYBITS | SWP_NOMOVE));
}

#ifdef _WIN32_WCE
void WINCE_ShowWindow(_THIS, SDL_Window* window, int visible)
{
    SDL_WindowData* windowdata = (SDL_WindowData*) window->driverdata;
    SDL_VideoData *videodata = (SDL_VideoData *) _this->driverdata;

    if(visible) {
        if(window->flags & SDL_WINDOW_FULLSCREEN) {
            if(videodata->SHFullScreen)
                videodata->SHFullScreen(windowdata->hwnd, SHFS_HIDETASKBAR | SHFS_HIDESTARTICON | SHFS_HIDESIPBUTTON);

            ShowWindow(FindWindow(TEXT("HHTaskBar"), NULL), SW_HIDE);
        }

        ShowWindow(windowdata->hwnd, SW_SHOW);
        SetForegroundWindow(windowdata->hwnd);
    } else {
        ShowWindow(windowdata->hwnd, SW_HIDE);

        if(window->flags & SDL_WINDOW_FULLSCREEN) {
            if(videodata->SHFullScreen)
                videodata->SHFullScreen(windowdata->hwnd, SHFS_SHOWTASKBAR | SHFS_SHOWSTARTICON | SHFS_SHOWSIPBUTTON);

            ShowWindow(FindWindow(TEXT("HHTaskBar"), NULL), SW_SHOW);

        }
    }
}
#endif /* _WIN32_WCE */

void
WIN_ShowWindow(_THIS, SDL_Window * window)
{
#ifdef _WIN32_WCE
    WINCE_ShowWindow(_this, window, 1);
#else
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    ShowWindow(hwnd, SW_SHOW);
#endif
}

void
WIN_HideWindow(_THIS, SDL_Window * window)
{
#ifdef _WIN32_WCE
    WINCE_ShowWindow(_this, window, 0);
#else
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    ShowWindow(hwnd, SW_HIDE);
#endif
}

void
WIN_RaiseWindow(_THIS, SDL_Window * window)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    HWND top;

    if (window->flags & SDL_WINDOW_FULLSCREEN) {
        top = HWND_TOPMOST;
    } else {
        top = HWND_NOTOPMOST;
    }
    SetWindowPos(hwnd, top, 0, 0, 0, 0, (SWP_NOMOVE | SWP_NOSIZE));
}

void
WIN_MaximizeWindow(_THIS, SDL_Window * window)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    SDL_VideoData *videodata = (SDL_VideoData *) _this->driverdata;

#ifdef _WIN32_WCE
    if((window->flags & SDL_WINDOW_FULLSCREEN) && videodata->SHFullScreen)
        videodata->SHFullScreen(hwnd, SHFS_HIDETASKBAR | SHFS_HIDESTARTICON | SHFS_HIDESIPBUTTON);
#endif

    ShowWindow(hwnd, SW_MAXIMIZE);
}

void
WIN_MinimizeWindow(_THIS, SDL_Window * window)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    SDL_VideoData *videodata = (SDL_VideoData *) _this->driverdata;

    ShowWindow(hwnd, SW_MINIMIZE);

#ifdef _WIN32_WCE
    if((window->flags & SDL_WINDOW_FULLSCREEN) && videodata->SHFullScreen)
        videodata->SHFullScreen(hwnd, SHFS_SHOWTASKBAR | SHFS_SHOWSTARTICON | SHFS_SHOWSIPBUTTON);
#endif
}

void
WIN_RestoreWindow(_THIS, SDL_Window * window)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;

    ShowWindow(hwnd, SW_RESTORE);
}

void
WIN_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen)
{
    SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
    HWND hwnd = data->hwnd;
    RECT rect;
    SDL_Rect bounds;
    DWORD style;
    HWND top;
    BOOL menu;
    int x, y;
    int w, h;

    if (fullscreen) {
        top = HWND_TOPMOST;
    } else {
        top = HWND_NOTOPMOST;
    }
    style = GetWindowLong(hwnd, GWL_STYLE);
    style &= ~STYLE_MASK;
    style |= GetWindowStyle(window);

    WIN_GetDisplayBounds(_this, display, &bounds);

    if (fullscreen) {
        x = bounds.x;
        y = bounds.y;
        w = bounds.w;
        h = bounds.h;
    } else {
        rect.left = 0;
        rect.top = 0;
        rect.right = window->windowed.w;
        rect.bottom = window->windowed.h;
#ifdef _WIN32_WCE
        menu = FALSE;
#else
        menu = (style & WS_CHILDWINDOW) ? FALSE : (GetMenu(hwnd) != NULL);
#endif
        AdjustWindowRectEx(&rect, style, menu, 0);
        w = (rect.right - rect.left);
        h = (rect.bottom - rect.top);
        x = window->windowed.x + rect.left;
        y = window->windowed.y + rect.top;
    }
    SetWindowLong(hwnd, GWL_STYLE, style);
    SetWindowPos(hwnd, top, x, y, w, h, SWP_NOCOPYBITS);
}

int
WIN_SetWindowGammaRamp(_THIS, SDL_Window * window, const Uint16 * ramp)
{
#ifdef _WIN32_WCE
    SDL_Unsupported();
    return -1;
#else
    SDL_VideoDisplay *display = SDL_GetDisplayForWindow(window);
    SDL_DisplayData *data = (SDL_DisplayData *) display->driverdata;
    HDC hdc;
    BOOL succeeded = FALSE;

    hdc = CreateDC(data->DeviceName, NULL, NULL, NULL);
    if (hdc) {
        succeeded = SetDeviceGammaRamp(hdc, (LPVOID)ramp);
        if (!succeeded) {
            WIN_SetError("SetDeviceGammaRamp()");
        }
        DeleteDC(hdc);
    }
    return succeeded ? 0 : -1;
#endif
}

int
WIN_GetWindowGammaRamp(_THIS, SDL_Window * window, Uint16 * ramp)
{
#ifdef _WIN32_WCE
    SDL_Unsupported();
    return -1;
#else
    SDL_VideoDisplay *display = SDL_GetDisplayForWindow(window);
    SDL_DisplayData *data = (SDL_DisplayData *) display->driverdata;
    HDC hdc;
    BOOL succeeded = FALSE;

    hdc = CreateDC(data->DeviceName, NULL, NULL, NULL);
    if (hdc) {
        succeeded = GetDeviceGammaRamp(hdc, (LPVOID)ramp);
        if (!succeeded) {
            WIN_SetError("GetDeviceGammaRamp()");
        }
        DeleteDC(hdc);
    }
    return succeeded ? 0 : -1;
#endif
}

void
WIN_SetWindowGrab(_THIS, SDL_Window * window)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;

    if ((window->flags & SDL_WINDOW_INPUT_GRABBED) &&
        (window->flags & SDL_WINDOW_INPUT_FOCUS)) {
        RECT rect;
        GetClientRect(hwnd, &rect);
        ClientToScreen(hwnd, (LPPOINT) & rect);
        ClientToScreen(hwnd, (LPPOINT) & rect + 1);
        ClipCursor(&rect);
    } else {
        ClipCursor(NULL);
    }
}

void
WIN_DestroyWindow(_THIS, SDL_Window * window)
{
    SDL_WindowData *data = (SDL_WindowData *) window->driverdata;

    if (data) {
#ifdef _WIN32_WCE
	WINCE_ShowWindow(_this, window, 0);
#endif
        ReleaseDC(data->hwnd, data->hdc);
        if (data->created) {
            DestroyWindow(data->hwnd);
        } else {
            /* Restore any original event handler... */
            if (data->wndproc != NULL) {
#ifdef GWLP_WNDPROC
                SetWindowLongPtr(data->hwnd, GWLP_WNDPROC,
                                 (LONG_PTR) data->wndproc);
#else
                SetWindowLong(data->hwnd, GWL_WNDPROC,
                              (LONG_PTR) data->wndproc);
#endif
            }
        }
        SDL_free(data);
    }
}

SDL_bool
WIN_GetWindowWMInfo(_THIS, SDL_Window * window, SDL_SysWMinfo * info)
{
    HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
    if (info->version.major <= SDL_MAJOR_VERSION) {
        info->subsystem = SDL_SYSWM_WINDOWS;
        info->info.win.window = hwnd;
        return SDL_TRUE;
    } else {
        SDL_SetError("Application not compiled with SDL %d.%d\n",
                     SDL_MAJOR_VERSION, SDL_MINOR_VERSION);
        return SDL_FALSE;
    }
}


/*
 * Creates a HelperWindow used for DirectInput events.
 */
int
SDL_HelperWindowCreate(void)
{
    HINSTANCE hInstance = GetModuleHandle(NULL);
    WNDCLASS wce;
    HWND hWndParent = NULL;

    /* Make sure window isn't created twice. */
    if (SDL_HelperWindow != NULL) {
        return 0;
    }

    /* Create the class. */
    SDL_zero(wce);
    wce.lpfnWndProc = DefWindowProc;
    wce.lpszClassName = (LPCWSTR) SDL_HelperWindowClassName;
    wce.hInstance = hInstance;

    /* Register the class. */
    SDL_HelperWindowClass = RegisterClass(&wce);
    if (SDL_HelperWindowClass == 0) {
        WIN_SetError("Unable to create Helper Window Class");
        return -1;
    }

#ifndef _WIN32_WCE
    /* WinCE doesn't have HWND_MESSAGE */
    hWndParent = HWND_MESSAGE;
#endif

    /* Create the window. */
    SDL_HelperWindow = CreateWindowEx(0, SDL_HelperWindowClassName,
                                      SDL_HelperWindowName,
                                      WS_OVERLAPPED, CW_USEDEFAULT,
                                      CW_USEDEFAULT, CW_USEDEFAULT,
                                      CW_USEDEFAULT, hWndParent, NULL,
                                      hInstance, NULL);
    if (SDL_HelperWindow == NULL) {
        UnregisterClass(SDL_HelperWindowClassName, hInstance);
        WIN_SetError("Unable to create Helper Window");
        return -1;
    }

    return 0;
}


/*
 * Destroys the HelperWindow previously created with SDL_HelperWindowCreate.
 */
void
SDL_HelperWindowDestroy(void)
{
    HINSTANCE hInstance = GetModuleHandle(NULL);

    /* Destroy the window. */
    if (SDL_HelperWindow != NULL) {
        if (DestroyWindow(SDL_HelperWindow) == 0) {
            WIN_SetError("Unable to destroy Helper Window");
            return;
        }
        SDL_HelperWindow = NULL;
    }

    /* Unregister the class. */
    if (SDL_HelperWindowClass != 0) {
        if ((UnregisterClass(SDL_HelperWindowClassName, hInstance)) == 0) {
            WIN_SetError("Unable to destroy Helper Window Class");
            return;
        }
        SDL_HelperWindowClass = 0;
    }
}

/* vi: set ts=4 sw=4 expandtab: */