view src/video/win32/SDL_win32events.c @ 3168:6338b7f2d024

Hi, I have prepared a set of patches to readd WindowsCE support to SDL 1.3. I've created a new GAPI/Rawframebuffer and a DirectDraw renderer. Both renderers are work in progress and there are several unimplemented cases. (Notably RenderLine/RenderPoint/RenderFill/QueryTexturePixels/UpdateTexture and texture blending ) Nevertheless I am successfully using these renderers together with the SDL software renderer. (On most devices the SDL software renderer will be much faster as there are only badly optimized vendor drivers available) I send these patches now in this unpolished state because there seems to be some interest in win ce and someone has to start supporting SDL 1.3 Now on to the patches: wince_events_window_fixes.patch fixes some wince incompatibilities and adds fullscreen support via SHFullScreen. NOTE: This patch shouldn't have any side effects on Windows, but I have NOT tested it on Windows, so please double-check. This patch doesn't dependent on the following ones. wince_renderers_system.patch This patch does all necessary modifications to the SDL system. - it adds the renderers to the configure system - it adds the renderers to win32video SDL_ceddrawrender.c SDL_ceddrawrender.h SDL_gapirender_c.h SDL_gapirender.c SDL_gapirender.h these files add the new render drivers and should be placed in src/video/win32 Some notes to people who want to test this: - I have only compiled sdl with ming32ce, so the VisualC files are not up to date - As mingw32ce has no ddraw.h this file must be taken from the MS SDK and modified to work with gcc - I had to modify line 2611 in configure.in to EXTRA_LDFLAGS="$EXTRA_LDFLAGS -lcoredll -lcommctrl -lmmtimer -Wl,--image-base -Wl,0x10000" otherwise GetCPinfo wouldn't link. If someone knows whats causing this I'd be happy to hear about it. It would be great if these patches could make their way into SVN as this would make collaboration much much easier. I'm out of office for the next week and therefore will be unavailable via email. Regards Stefan
author Sam Lantinga <slouken@libsdl.org>
date Sun, 07 Jun 2009 02:44:46 +0000
parents 7f684f249ec9
children 5d7ef5970073
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#if (_WIN32_WINNT < 0x0501)
#undef _WIN32_WINNT
#define _WIN32_WINNT 0x0501
#endif

#include "SDL_config.h"

#include "SDL_win32video.h"
#include "SDL_syswm.h"
#include "SDL_vkeys.h"
#include "../../events/SDL_events_c.h"

/*#define WMMSG_DEBUG*/
#ifdef WMMSG_DEBUG
#include <stdio.h>
#include "wmmsg.h"
#endif

/* Masks for processing the windows KEYDOWN and KEYUP messages */
#define REPEATED_KEYMASK    (1<<30)
#define EXTENDED_KEYMASK    (1<<24)

#define VK_ENTER    10          /* Keypad Enter ... no VKEY defined? */

/* Make sure XBUTTON stuff is defined that isn't in older Platform SDKs... */
#ifndef WM_XBUTTONDOWN
#define WM_XBUTTONDOWN 0x020B
#endif
#ifndef WM_XBUTTONUP
#define WM_XBUTTONUP 0x020C
#endif
#ifndef GET_XBUTTON_WPARAM
#define GET_XBUTTON_WPARAM(w) (HIWORD(w))
#endif
#ifndef WM_INPUT
#define WM_INPUT 0x00ff
#endif

extern HCTX *g_hCtx;
extern HANDLE *mice;
extern int total_mice;
extern int tablet;
int pressure = 0;               /* the pressure reported by the tablet */

static WPARAM
RemapVKEY(WPARAM wParam, LPARAM lParam)
{
    int i;
    BYTE scancode = (BYTE) ((lParam >> 16) & 0xFF);

    /* Windows remaps alphabetic keys based on current layout.
       We try to provide USB scancodes, so undo this mapping.
     */
    if (wParam >= 'A' && wParam <= 'Z') {
        if (scancode != alpha_scancodes[wParam - 'A']) {
            for (i = 0; i < SDL_arraysize(alpha_scancodes); ++i) {
                if (scancode == alpha_scancodes[i]) {
                    wParam = 'A' + i;
                    break;
                }
            }
        }
    }

    /* Keypad keys are a little trickier, we always scan for them. */
    for (i = 0; i < SDL_arraysize(keypad_scancodes); ++i) {
        if (scancode == keypad_scancodes[i]) {
            wParam = VK_NUMPAD0 + i;
            break;
        }
    }

    return wParam;
}

LRESULT CALLBACK
WIN_WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    SDL_WindowData *data;
    RAWINPUT *raw;
    PACKET packet;

    /* Send a SDL_SYSWMEVENT if the application wants them */
    if (SDL_ProcessEvents[SDL_SYSWMEVENT] == SDL_ENABLE) {
        SDL_SysWMmsg wmmsg;

        SDL_VERSION(&wmmsg.version);
        wmmsg.hwnd = hwnd;
        wmmsg.msg = msg;
        wmmsg.wParam = wParam;
        wmmsg.lParam = lParam;
        SDL_SendSysWMEvent(&wmmsg);
    }

    /* Get the window data for the window */
    data = (SDL_WindowData *) GetProp(hwnd, TEXT("SDL_WindowData"));
    if (!data) {
        return CallWindowProc(DefWindowProc, hwnd, msg, wParam, lParam);
    }
#ifdef WMMSG_DEBUG
    {
        FILE *log = fopen("wmmsg.txt", "a");
        fprintf(log, "Received windows message: %p ", hwnd);
        if (msg > MAX_WMMSG) {
            fprintf(log, "%d", msg);
        } else {
            fprintf(log, "%s", wmtab[msg]);
        }
        fprintf(log, " -- 0x%X, 0x%X\n", wParam, lParam);
        fclose(log);
    }

#endif

    switch (msg) {

    case WT_PACKET:
        {
            /* if we receive such data we need to update the pressure */
            SDL_VideoData *videodata = data->videodata;
            if (videodata->wintabDLL
                && videodata->WTPacket((HCTX) lParam, wParam, &packet)) {
                SDL_ChangeEnd(tablet, (int) packet.pkCursor);
                pressure = (int) packet.pkNormalPressure;
            }
        }
        break;

    case WT_PROXIMITY:
        {
            /* checking where the proximity message showed up */
            int h_context = LOWORD(lParam);
            POINT point;
            GetCursorPos(&point);
            ScreenToClient(hwnd, &point);

            /* are we in proximity or out of proximity */
            if (h_context == 0) {
                SDL_SendProximity(tablet, point.x, point.y, SDL_PROXIMITYOUT);
            } else {
                SDL_SendProximity(tablet, point.x, point.y, SDL_PROXIMITYIN);
            }
        }
        break;

    case WM_SHOWWINDOW:
        {
            if (wParam) {
                SDL_SendWindowEvent(data->windowID, SDL_WINDOWEVENT_SHOWN, 0,
                                    0);
            } else {
                SDL_SendWindowEvent(data->windowID, SDL_WINDOWEVENT_HIDDEN, 0,
                                    0);
            }
        }
        break;

    case WM_ACTIVATE:
        {
            int index;
            SDL_Keyboard *keyboard;
            BOOL minimized;

            minimized = HIWORD(wParam);
            index = data->videodata->keyboard;
            keyboard = SDL_GetKeyboard(index);
            if (!minimized && (LOWORD(wParam) != WA_INACTIVE)) {
                SDL_SendWindowEvent(data->windowID, SDL_WINDOWEVENT_SHOWN,
                                    0, 0);
                SDL_SendWindowEvent(data->windowID,
                                    SDL_WINDOWEVENT_RESTORED, 0, 0);
#ifndef _WIN32_WCE              /* WinCE misses IsZoomed() */
                if (IsZoomed(hwnd)) {
                    SDL_SendWindowEvent(data->windowID,
                                        SDL_WINDOWEVENT_MAXIMIZED, 0, 0);
                }
#endif
                if (keyboard && keyboard->focus != data->windowID) {
                    SDL_SetKeyboardFocus(index, data->windowID);
                }
                /* FIXME: Update keyboard state */
            } else {
                if (keyboard && keyboard->focus == data->windowID) {
                    SDL_SetKeyboardFocus(index, 0);
                }
                if (minimized) {
                    SDL_SendWindowEvent(data->windowID,
                                        SDL_WINDOWEVENT_MINIMIZED, 0, 0);
                }
            }
        }
        return (0);

/* WinCE has no RawInput, so we use the classic mouse events.
   In classic Win32 this is done by WM_INPUT
 */
#ifdef _WIN32_WCE
    case WM_MOUSEMOVE:
        SDL_SendMouseMotion(0, 0, LOWORD(lParam), HIWORD(lParam), 0);
        break;

    case WM_LBUTTONDOWN:
        SDL_SendMouseMotion(0, 0, LOWORD(lParam), HIWORD(lParam), 0);
        SDL_SendMouseButton(0, SDL_PRESSED, SDL_BUTTON_LEFT);
        break;

    case WM_LBUTTONUP:
        SDL_SendMouseMotion(0, 0, LOWORD(lParam), HIWORD(lParam), 0);
        SDL_SendMouseButton(0, SDL_RELEASED, SDL_BUTTON_LEFT);
        break;
#else /* _WIN32_WCE */

    case WM_INPUT:             /* mouse events */
        {
            LPBYTE lpb;
            const RAWINPUTHEADER *header;
            int index;
            int i;
            int size = 0;
            const RAWMOUSE *raw_mouse = NULL;
            POINT point;
            USHORT flags;
            int w, h;

            /* we're collecting raw data to be able to identify the mouse (if there are several) */
            GetRawInputData((HRAWINPUT) lParam, RID_INPUT, NULL, &size,
                            sizeof(RAWINPUTHEADER));
            lpb = SDL_stack_alloc(BYTE, size);
            GetRawInputData((HRAWINPUT) lParam, RID_INPUT, lpb, &size,
                            sizeof(RAWINPUTHEADER));
            raw = (RAWINPUT *) lpb;
            header = &raw->header;
            flags = raw->data.mouse.usButtonFlags;

            /* we're checking which mouse generated the event */
            for (i = 0; i < total_mice; ++i) {
                if (mice[i] == header->hDevice) {
                    index = i;
                    break;
                }
            }

            GetCursorPos(&point);
            ScreenToClient(hwnd, &point);

            SDL_GetWindowSize(data->windowID, &w, &h);
            if (point.x >= 0 && point.y >= 0 && point.x < w && point.y < h) {
                SDL_SetMouseFocus(index, data->windowID);
            } else {
                SDL_SetMouseFocus(index, 0);
                /* FIXME: Should we be doing anything else here? */
                break;
            }

            /* if the message was sent by a tablet we have to send also pressure */
            if (index == tablet) {
                SDL_SendMouseMotion(index, 0, point.x, point.y, pressure);
            } else {
                SDL_SendMouseMotion(index, 0, point.x, point.y, 0);
            }
            /* we're sending mouse buttons messages to check up if sth changed */
            if (flags & RI_MOUSE_LEFT_BUTTON_DOWN) {
                SDL_SendMouseButton(index, SDL_PRESSED, SDL_BUTTON_LEFT);
            } else if (flags & RI_MOUSE_LEFT_BUTTON_UP) {
                SDL_SendMouseButton(index, SDL_RELEASED, SDL_BUTTON_LEFT);
            }
            if (flags & RI_MOUSE_MIDDLE_BUTTON_DOWN) {
                SDL_SendMouseButton(index, SDL_PRESSED, SDL_BUTTON_MIDDLE);
            } else if (flags & RI_MOUSE_MIDDLE_BUTTON_UP) {
                SDL_SendMouseButton(index, SDL_RELEASED, SDL_BUTTON_MIDDLE);
            }
            if (flags & RI_MOUSE_RIGHT_BUTTON_DOWN) {
                SDL_SendMouseButton(index, SDL_PRESSED, SDL_BUTTON_RIGHT);
            } else if (flags & RI_MOUSE_RIGHT_BUTTON_UP) {
                SDL_SendMouseButton(index, SDL_RELEASED, SDL_BUTTON_RIGHT);
            }
            if (flags & RI_MOUSE_BUTTON_4_DOWN) {
                SDL_SendMouseButton(index, SDL_PRESSED, SDL_BUTTON_X1);
            } else if (flags & RI_MOUSE_BUTTON_4_UP) {
                SDL_SendMouseButton(index, SDL_RELEASED, SDL_BUTTON_X1);
            }
            if (flags & RI_MOUSE_BUTTON_5_DOWN) {
                SDL_SendMouseButton(index, SDL_PRESSED, SDL_BUTTON_X2);
            } else if (flags & RI_MOUSE_BUTTON_5_UP) {
                SDL_SendMouseButton(index, SDL_RELEASED, SDL_BUTTON_X2);
            }
            if (flags & RI_MOUSE_WHEEL) {
                SDL_SendMouseWheel(index, 0,
                                   (short) raw->data.mouse.usButtonData);
            }
            SDL_stack_free(lpb);
        }
        return (0);
#endif /* _WIN32_WCE */

    case WM_MOUSELEAVE:
        {
            int i;

            for (i = 0; i < SDL_GetNumMice(); ++i) {
                SDL_Mouse *mouse = SDL_GetMouse(i);

                if (mouse->focus == data->windowID) {
                    SDL_SetMouseFocus(i, 0);
                }
            }
        }
        return (0);

    case WM_SYSKEYDOWN:
    case WM_KEYDOWN:
        {
            int index;

            /* Ignore repeated keys */
            if (lParam & REPEATED_KEYMASK) {
                return (0);
            }

            index = data->videodata->keyboard;
            wParam = RemapVKEY(wParam, lParam);
            switch (wParam) {
            case VK_CONTROL:
                if (lParam & EXTENDED_KEYMASK)
                    wParam = VK_RCONTROL;
                else
                    wParam = VK_LCONTROL;
                break;
            case VK_SHIFT:
                /* EXTENDED trick doesn't work here */
                {
                    Uint8 *state = SDL_GetKeyboardState(NULL);
                    if (state[SDL_SCANCODE_LSHIFT] == SDL_RELEASED
                        && (GetKeyState(VK_LSHIFT) & 0x8000)) {
                        wParam = VK_LSHIFT;
                    } else if (state[SDL_SCANCODE_RSHIFT] == SDL_RELEASED
                               && (GetKeyState(VK_RSHIFT) & 0x8000)) {
                        wParam = VK_RSHIFT;
                    } else {
                        /* Probably a key repeat */
                        return (0);
                    }
                }
                break;
            case VK_MENU:
                if (lParam & EXTENDED_KEYMASK)
                    wParam = VK_RMENU;
                else
                    wParam = VK_LMENU;
                break;
            case VK_RETURN:
                if (lParam & EXTENDED_KEYMASK)
                    wParam = VK_ENTER;
                break;
            }
            if (wParam < 256) {
                SDL_SendKeyboardKey(index, SDL_PRESSED,
                                    data->videodata->key_layout[wParam]);
            }
        }
        return (0);

    case WM_SYSKEYUP:
    case WM_KEYUP:
        {
            int index;

            index = data->videodata->keyboard;
            wParam = RemapVKEY(wParam, lParam);
            switch (wParam) {
            case VK_CONTROL:
                if (lParam & EXTENDED_KEYMASK)
                    wParam = VK_RCONTROL;
                else
                    wParam = VK_LCONTROL;
                break;
            case VK_SHIFT:
                /* EXTENDED trick doesn't work here */
                {
                    Uint8 *state = SDL_GetKeyboardState(NULL);
                    if (state[SDL_SCANCODE_LSHIFT] == SDL_PRESSED
                        && !(GetKeyState(VK_LSHIFT) & 0x8000)) {
                        wParam = VK_LSHIFT;
                    } else if (state[SDL_SCANCODE_RSHIFT] == SDL_PRESSED
                               && !(GetKeyState(VK_RSHIFT) & 0x8000)) {
                        wParam = VK_RSHIFT;
                    } else {
                        /* Probably a key repeat */
                        return (0);
                    }
                }
                break;
            case VK_MENU:
                if (lParam & EXTENDED_KEYMASK)
                    wParam = VK_RMENU;
                else
                    wParam = VK_LMENU;
                break;
            case VK_RETURN:
                if (lParam & EXTENDED_KEYMASK)
                    wParam = VK_ENTER;
                break;
            }

            /* Windows only reports keyup for print screen */
            if (wParam == VK_SNAPSHOT
                && SDL_GetKeyboardState(NULL)[SDL_SCANCODE_PRINTSCREEN] ==
                SDL_RELEASED) {
                SDL_SendKeyboardKey(index, SDL_PRESSED,
                                    data->videodata->key_layout[wParam]);
            }
            if (wParam < 256) {
                SDL_SendKeyboardKey(index, SDL_RELEASED,
                                    data->videodata->key_layout[wParam]);
            }
        }
        return (0);

    case WM_CHAR:
        {
            char text[4];

            /* Convert to UTF-8 and send it on... */
            if (wParam <= 0x7F) {
                text[0] = (char) wParam;
                text[1] = '\0';
            } else if (wParam <= 0x7FF) {
                text[0] = 0xC0 | (char) ((wParam >> 6) & 0x1F);
                text[1] = 0x80 | (char) (wParam & 0x3F);
                text[2] = '\0';
            } else {
                text[0] = 0xE0 | (char) ((wParam >> 12) & 0x0F);
                text[1] = 0x80 | (char) ((wParam >> 6) & 0x3F);
                text[2] = 0x80 | (char) (wParam & 0x3F);
                text[3] = '\0';
            }
            SDL_SendKeyboardText(data->videodata->keyboard, text);
        }
        return (0);

    case WM_INPUTLANGCHANGE:
        {
            WIN_UpdateKeymap(data->videodata->keyboard);
        }
        return (1);

    case WM_GETMINMAXINFO:
        {
            MINMAXINFO *info;
            RECT size;
            int x, y;
            int w, h;
            int style;
            BOOL menu;

            /* If we allow resizing, let the resize happen naturally */
            if (SDL_GetWindowFlags(data->windowID) & SDL_WINDOW_RESIZABLE) {
                return (0);
            }

            /* Get the current position of our window */
            GetWindowRect(hwnd, &size);
            x = size.left;
            y = size.top;

            /* Calculate current size of our window */
            SDL_GetWindowSize(data->windowID, &w, &h);
            size.top = 0;
            size.left = 0;
            size.bottom = h;
            size.right = w;


            style = GetWindowLong(hwnd, GWL_STYLE);
#ifdef _WIN32_WCE
            menu = FALSE;
#else
            /* DJM - according to the docs for GetMenu(), the
               return value is undefined if hwnd is a child window.
               Aparently it's too difficult for MS to check
               inside their function, so I have to do it here.
             */
            menu = (style & WS_CHILDWINDOW) ? FALSE : (GetMenu(hwnd) != NULL);
#endif
            AdjustWindowRectEx(&size, style, menu, 0);
            w = size.right - size.left;
            h = size.bottom - size.top;

            /* Fix our size to the current size */
            info = (MINMAXINFO *) lParam;
            info->ptMaxSize.x = w;
            info->ptMaxSize.y = h;
            info->ptMaxPosition.x = x;
            info->ptMaxPosition.y = y;
            info->ptMinTrackSize.x = w;
            info->ptMinTrackSize.y = h;
            info->ptMaxTrackSize.x = w;
            info->ptMaxTrackSize.y = h;
        }
        return (0);

    case WM_WINDOWPOSCHANGED:
        {
            RECT rect;
            int x, y;
            int w, h;
            Uint32 window_flags;

            GetClientRect(hwnd, &rect);
            ClientToScreen(hwnd, (LPPOINT) & rect);
            ClientToScreen(hwnd, (LPPOINT) & rect + 1);

            window_flags = SDL_GetWindowFlags(data->windowID);
            if ((window_flags & SDL_WINDOW_INPUT_GRABBED) &&
                (window_flags & SDL_WINDOW_INPUT_FOCUS)) {
                ClipCursor(&rect);
            }

            x = rect.left;
            y = rect.top;
            SDL_SendWindowEvent(data->windowID, SDL_WINDOWEVENT_MOVED, x, y);

            w = rect.right - rect.left;
            h = rect.bottom - rect.top;
            SDL_SendWindowEvent(data->windowID, SDL_WINDOWEVENT_RESIZED, w,
                                h);
        }
        break;

    case WM_SETCURSOR:
        {
            Uint16 hittest;

            hittest = LOWORD(lParam);
            if (hittest == HTCLIENT) {
                /* FIXME: Implement the cursor API */
                static HCURSOR cursor;
                if (!cursor) {
                    cursor = LoadCursor(NULL, IDC_ARROW);
                }
                SetCursor(cursor);
                return (TRUE);
            }
        }
        break;

        /* We are about to get palette focus! */
    case WM_QUERYNEWPALETTE:
        {
            /*
               WIN_RealizePalette(current_video);
               return (TRUE);
             */
        }
        break;

        /* Another application changed the palette */
    case WM_PALETTECHANGED:
        {
            /*
               WIN_PaletteChanged(current_video, (HWND) wParam);
             */
        }
        break;

        /* We were occluded, refresh our display */
    case WM_PAINT:
        {
            RECT rect;
            if (GetUpdateRect(hwnd, &rect, FALSE)) {
                ValidateRect(hwnd, &rect);
                SDL_SendWindowEvent(data->windowID, SDL_WINDOWEVENT_EXPOSED,
                                    0, 0);
            }
        }
        return (0);

        /* If this isn't our window, we don't need to repaint the frame.
           This fixes a reentrancy issue that can cause stack overflows with foreign windows.
           3/21/09 Mason Wheeler */
    case WM_NCPAINT:
        {
            if (SDL_GetWindowFlags(data->windowID) & SDL_WINDOW_FOREIGN) {
                return (0);
            }
            break;
        }

        /* We'll do our own drawing, prevent flicker */
    case WM_ERASEBKGND:
        {
        }
        return (1);

    case WM_SYSCOMMAND:
        {
            /* Don't start the screensaver or blank the monitor in fullscreen apps */
            if ((wParam & 0xFFF0) == SC_SCREENSAVE ||
                (wParam & 0xFFF0) == SC_MONITORPOWER) {
                if (SDL_GetVideoDevice()->suspend_screensaver) {
                    return (0);
                }
            }
        }
        break;

    case WM_CLOSE:
        {
            SDL_SendWindowEvent(data->windowID, SDL_WINDOWEVENT_CLOSE, 0, 0);
        }
        return (0);
    }
    return CallWindowProc(data->wndproc, hwnd, msg, wParam, lParam);
}

void
WIN_PumpEvents(_THIS)
{
    MSG msg;
    while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

static int app_registered = 0;
LPTSTR SDL_Appname = NULL;
Uint32 SDL_Appstyle = 0;
HINSTANCE SDL_Instance = NULL;

/* Register the class for this application */
int
SDL_RegisterApp(char *name, Uint32 style, void *hInst)
{
    WNDCLASS class;

    /* Only do this once... */
    if (app_registered) {
        ++app_registered;
        return (0);
    }
    if (!name && !SDL_Appname) {
        name = "SDL_app";
        SDL_Appstyle = (CS_BYTEALIGNCLIENT | CS_OWNDC);
        SDL_Instance = hInst ? hInst : GetModuleHandle(NULL);
    }

    if (name) {
        SDL_Appname = WIN_UTF8ToString(name);
        SDL_Appstyle = style;
        SDL_Instance = hInst ? hInst : GetModuleHandle(NULL);
    }

    /* Register the application class */
    class.hCursor = NULL;
    class.hIcon =
        LoadImage(SDL_Instance, SDL_Appname, IMAGE_ICON, 0, 0,
                  LR_DEFAULTCOLOR);
    class.lpszMenuName = NULL;
    class.lpszClassName = SDL_Appname;
    class.hbrBackground = NULL;
    class.hInstance = SDL_Instance;
    class.style = SDL_Appstyle;
    class.lpfnWndProc = DefWindowProc;
    class.cbWndExtra = 0;
    class.cbClsExtra = 0;
    if (!RegisterClass(&class)) {
        SDL_SetError("Couldn't register application class");
        return (-1);
    }

    app_registered = 1;
    return (0);
}

/* Unregisters the windowclass registered in SDL_RegisterApp above. */
void
SDL_UnregisterApp()
{
    WNDCLASS class;

    /* SDL_RegisterApp might not have been called before */
    if (!app_registered) {
        return;
    }
    --app_registered;
    if (app_registered == 0) {
        /* Check for any registered window classes. */
        if (GetClassInfo(SDL_Instance, SDL_Appname, &class)) {
            UnregisterClass(SDL_Appname, SDL_Instance);
        }
        SDL_free(SDL_Appname);
        SDL_Appname = NULL;
    }
}

/* Sets an error message based on GetLastError() */
void
WIN_SetError(const char *prefix)
{
    TCHAR buffer[1024];
    char *message;
    FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(), 0,
                  buffer, SDL_arraysize(buffer), NULL);
    message = WIN_StringToUTF8(buffer);
    SDL_SetError("%s%s%s", prefix ? prefix : "", prefix ? ":" : "", message);
    SDL_free(message);
}

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