added initialization of config and textures for global animations
[rocksndiamonds.git] / src / libgame / sdl.c
index 18de01b3425b9c109224e28773cd38e506820910..71f6cf171ec796583b48dd40e09ddf05728cdc20 100644 (file)
-/***********************************************************
-* Artsoft Retro-Game Library                               *
-*----------------------------------------------------------*
-* (c) 1994-2000 Artsoft Entertainment                      *
-*               Holger Schemel                             *
-*               Detmolder Strasse 189                      *
-*               33604 Bielefeld                            *
-*               Germany                                    *
-*               e-mail: info@artsoft.org                   *
-*----------------------------------------------------------*
-* sdl.c                                                    *
-***********************************************************/
+// ============================================================================
+// Artsoft Retro-Game Library
+// ----------------------------------------------------------------------------
+// (c) 1995-2014 by Artsoft Entertainment
+//                         Holger Schemel
+//                 info@artsoft.org
+//                 http://www.artsoft.org/
+// ----------------------------------------------------------------------------
+// sdl.c
+// ============================================================================
 
 #include "system.h"
 #include "sound.h"
 
 #include "system.h"
 #include "sound.h"
+#include "joystick.h"
 #include "misc.h"
 #include "misc.h"
+#include "setup.h"
 
 
+#define ENABLE_UNUSED_CODE     0       /* currently unused functions */
 
 
-#if defined(TARGET_SDL)
 
 /* ========================================================================= */
 /* video functions                                                           */
 /* ========================================================================= */
 
 
 /* ========================================================================= */
 /* video functions                                                           */
 /* ========================================================================= */
 
-inline void SDLInitVideoDisplay(void)
+/* SDL internal variables */
+#if defined(TARGET_SDL2)
+static SDL_Window *sdl_window = NULL;
+static SDL_Renderer *sdl_renderer = NULL;
+static SDL_Texture *sdl_texture = NULL;
+static boolean fullscreen_enabled = FALSE;
+
+#define USE_RENDERER   TRUE
+#endif
+
+/* stuff needed to work around SDL/Windows fullscreen drawing bug */
+static int fullscreen_width;
+static int fullscreen_height;
+static int fullscreen_xoffset;
+static int fullscreen_yoffset;
+static int video_xoffset;
+static int video_yoffset;
+static boolean limit_screen_updates = FALSE;
+
+
+/* functions from SGE library */
+void sge_Line(SDL_Surface *, Sint16, Sint16, Sint16, Sint16, Uint32);
+
+void SDLLimitScreenUpdates(boolean enable)
+{
+  limit_screen_updates = enable;
+}
+
+static void UpdateScreen(SDL_Rect *rect)
+{
+  static unsigned int update_screen_delay = 0;
+  unsigned int update_screen_delay_value = 20;         /* (milliseconds) */
+
+  if (limit_screen_updates &&
+      !DelayReached(&update_screen_delay, update_screen_delay_value))
+    return;
+
+  LimitScreenUpdates(FALSE);
+
+#if 0
+  {
+    static int LastFrameCounter = 0;
+    boolean changed = (FrameCounter != LastFrameCounter);
+
+    printf("::: FrameCounter == %d [%s]\n", FrameCounter,
+          (changed ? "-" : "SAME FRAME UPDATED"));
+
+    LastFrameCounter = FrameCounter;
+
+    /*
+    if (FrameCounter % 2)
+      return;
+    */
+  }
+#endif
+
+#if defined(TARGET_SDL2)
+#if USE_RENDERER
+  SDL_Surface *screen = backbuffer->surface;
+
+  if (rect)
+  {
+    int bytes_x = screen->pitch / video.width;
+    int bytes_y = screen->pitch;
+
+    if (video.fullscreen_enabled)
+      bytes_x = screen->pitch / fullscreen_width;
+
+    SDL_UpdateTexture(sdl_texture, rect,
+                     screen->pixels + rect->x * bytes_x + rect->y * bytes_y,
+                     screen->pitch);
+  }
+  else
+  {
+    SDL_UpdateTexture(sdl_texture, NULL, screen->pixels, screen->pitch);
+  }
+  SDL_RenderClear(sdl_renderer);
+  SDL_RenderCopy(sdl_renderer, sdl_texture, NULL, NULL);
+  SDL_RenderPresent(sdl_renderer);
+#else
+  if (rect)
+    SDL_UpdateWindowSurfaceRects(sdl_window, rect, 1);
+  else
+    SDL_UpdateWindowSurface(sdl_window);
+#endif
+
+#else  // TARGET_SDL
+  if (rect)
+    SDL_UpdateRects(backbuffer->surface, 1, rect);
+  else
+    SDL_UpdateRect(backbuffer->surface, 0, 0, 0, 0);
+#endif
+}
+
+static void setFullscreenParameters(char *fullscreen_mode_string)
+{
+#if defined(TARGET_SDL2)
+  fullscreen_width = video.width;
+  fullscreen_height = video.height;
+  fullscreen_xoffset = 0;
+  fullscreen_yoffset = 0;  
+
+#else
+
+  struct ScreenModeInfo *fullscreen_mode;
+  int i;
+
+  fullscreen_mode = get_screen_mode_from_string(fullscreen_mode_string);
+
+  if (fullscreen_mode == NULL)
+    return;
+
+  for (i = 0; video.fullscreen_modes[i].width != -1; i++)
+  {
+    if (fullscreen_mode->width  == video.fullscreen_modes[i].width &&
+       fullscreen_mode->height == video.fullscreen_modes[i].height)
+    {
+      fullscreen_width  = fullscreen_mode->width;
+      fullscreen_height = fullscreen_mode->height;
+
+      fullscreen_xoffset = (fullscreen_width  - video.width)  / 2;
+      fullscreen_yoffset = (fullscreen_height - video.height) / 2;
+
+      break;
+    }
+  }
+#endif
+}
+
+static void SDLSetWindowIcon(char *basename)
+{
+  /* (setting the window icon on Mac OS X would replace the high-quality
+     dock icon with the currently smaller (and uglier) icon from file) */
+
+#if !defined(PLATFORM_MACOSX)
+  char *filename = getCustomImageFilename(basename);
+  SDL_Surface *surface;
+
+  if (filename == NULL)
+  {
+    Error(ERR_WARN, "SDLSetWindowIcon(): cannot find file '%s'", basename);
+
+    return;
+  }
+
+  if ((surface = IMG_Load(filename)) == NULL)
+  {
+    Error(ERR_WARN, "IMG_Load() failed: %s", SDL_GetError());
+
+    return;
+  }
+
+  /* set transparent color */
+  SDL_SetColorKey(surface, SET_TRANSPARENT_PIXEL,
+                 SDL_MapRGB(surface->format, 0x00, 0x00, 0x00));
+
+#if defined(TARGET_SDL2)
+  SDL_SetWindowIcon(sdl_window, surface);
+#else
+  SDL_WM_SetIcon(surface, NULL);
+#endif
+#endif
+}
+
+#if defined(TARGET_SDL2)
+
+static boolean equalSDLPixelFormat(SDL_PixelFormat *format1,
+                                  SDL_PixelFormat *format2)
+{
+  return (format1->format       == format2->format &&
+         format1->BitsPerPixel  == format2->BitsPerPixel &&
+         format1->BytesPerPixel == format2->BytesPerPixel &&
+         format1->Rmask         == format2->Rmask &&
+         format1->Gmask         == format2->Gmask &&
+         format1->Bmask         == format2->Bmask &&
+         format1->Amask         == format2->Amask);
+}
+
+boolean SDLSetNativeSurface(SDL_Surface **surface)
+{
+  SDL_Surface *new_surface;
+
+  if (surface == NULL ||
+      *surface == NULL ||
+      backbuffer == NULL ||
+      backbuffer->surface == NULL)
+    return FALSE;
+
+  // if pixel format already optimized for destination surface, do nothing
+  if (equalSDLPixelFormat((*surface)->format, backbuffer->surface->format))
+    return FALSE;
+
+  new_surface = SDL_ConvertSurface(*surface, backbuffer->surface->format, 0);
+
+  if (new_surface == NULL)
+    Error(ERR_EXIT, "SDL_ConvertSurface() failed: %s", SDL_GetError());
+
+  SDL_FreeSurface(*surface);
+
+  *surface = new_surface;
+
+  return TRUE;
+}
+
+SDL_Surface *SDLGetNativeSurface(SDL_Surface *surface)
+{
+  SDL_Surface *new_surface;
+
+  if (surface == NULL)
+    return NULL;
+
+  if (backbuffer && backbuffer->surface)
+    new_surface = SDL_ConvertSurface(surface, backbuffer->surface->format, 0);
+  else
+    new_surface = SDL_ConvertSurface(surface, surface->format, 0);
+
+  if (new_surface == NULL)
+    Error(ERR_EXIT, "SDL_ConvertSurface() failed: %s", SDL_GetError());
+
+  return new_surface;
+}
+
+#else
+
+boolean SDLSetNativeSurface(SDL_Surface **surface)
+{
+  SDL_Surface *new_surface;
+
+  if (surface == NULL ||
+      *surface == NULL ||
+      !video.initialized)
+    return FALSE;
+
+  new_surface = SDL_DisplayFormat(*surface);
+
+  if (new_surface == NULL)
+    Error(ERR_EXIT, "SDL_DisplayFormat() failed: %s", SDL_GetError());
+
+  SDL_FreeSurface(*surface);
+
+  *surface = new_surface;
+
+  return TRUE;
+}
+
+SDL_Surface *SDLGetNativeSurface(SDL_Surface *surface)
+{
+  SDL_Surface *new_surface;
+
+  if (video.initialized)
+    new_surface = SDL_DisplayFormat(surface);
+  else
+    new_surface = SDL_ConvertSurface(surface, surface->format, SURFACE_FLAGS);
+
+  if (new_surface == NULL)
+    Error(ERR_EXIT, "%s() failed: %s",
+         (video.initialized ? "SDL_DisplayFormat" : "SDL_ConvertSurface"),
+         SDL_GetError());
+
+  return new_surface;
+}
+
+#endif
+
+#if defined(TARGET_SDL2)
+static SDL_Texture *SDLCreateTextureFromSurface(SDL_Surface *surface)
+{
+  SDL_Texture *texture = SDL_CreateTextureFromSurface(sdl_renderer, surface);
+
+  if (texture == NULL)
+    Error(ERR_EXIT, "SDL_CreateTextureFromSurface() failed: %s",
+         SDL_GetError());
+
+  return texture;
+}
+#endif
+
+void SDLCreateBitmapTextures(Bitmap *bitmap)
+{
+#if defined(TARGET_SDL2)
+  if (bitmap == NULL)
+    return;
+
+  bitmap->texture        = SDLCreateTextureFromSurface(bitmap->surface);
+  bitmap->texture_masked = SDLCreateTextureFromSurface(bitmap->surface_masked);
+#endif
+}
+
+void SDLInitVideoDisplay(void)
 {
 {
+#if !defined(TARGET_SDL2)
+  if (!strEqual(setup.system.sdl_videodriver, ARG_DEFAULT))
+    SDL_putenv(getStringCat2("SDL_VIDEODRIVER=", setup.system.sdl_videodriver));
+
+  SDL_putenv("SDL_VIDEO_CENTERED=1");
+#endif
+
   /* initialize SDL video */
   if (SDL_InitSubSystem(SDL_INIT_VIDEO) < 0)
     Error(ERR_EXIT, "SDL_InitSubSystem() failed: %s", SDL_GetError());
 
   /* set default SDL depth */
   /* initialize SDL video */
   if (SDL_InitSubSystem(SDL_INIT_VIDEO) < 0)
     Error(ERR_EXIT, "SDL_InitSubSystem() failed: %s", SDL_GetError());
 
   /* set default SDL depth */
+#if !defined(TARGET_SDL2)
   video.default_depth = SDL_GetVideoInfo()->vfmt->BitsPerPixel;
   video.default_depth = SDL_GetVideoInfo()->vfmt->BitsPerPixel;
+#else
+  video.default_depth = 32;    // (how to determine video depth in SDL2?)
+#endif
 }
 
 }
 
-inline void SDLInitVideoBuffer(DrawBuffer **backbuffer, DrawWindow **window,
-                              boolean fullscreen)
+void SDLInitVideoBuffer(DrawBuffer **backbuffer, DrawWindow **window,
+                       boolean fullscreen)
 {
 {
+#if !defined(TARGET_SDL2)
+  static int screen_xy[][2] =
+  {
+    {  640, 480 },
+    {  800, 600 },
+    { 1024, 768 },
+    {   -1,  -1 }
+  };
+#endif
+  SDL_Rect **modes = NULL;
+  boolean hardware_fullscreen_available = TRUE;
+  int i, j;
+
+  /* default: normal game window size */
+  fullscreen_width = video.width;
+  fullscreen_height = video.height;
+  fullscreen_xoffset = 0;
+  fullscreen_yoffset = 0;
+
+#if !defined(TARGET_SDL2)
+  /* determine required standard fullscreen mode for game screen size */
+  for (i = 0; screen_xy[i][0] != -1; i++)
+  {
+    if (screen_xy[i][0] >= video.width && screen_xy[i][1] >= video.height)
+    {
+      fullscreen_width  = screen_xy[i][0];
+      fullscreen_height = screen_xy[i][1];
+
+      break;
+    }
+  }
+
+  fullscreen_xoffset = (fullscreen_width  - video.width)  / 2;
+  fullscreen_yoffset = (fullscreen_height - video.height) / 2;
+#endif
+
+  checked_free(video.fullscreen_modes);
+
+  video.fullscreen_modes = NULL;
+  video.fullscreen_mode_current = NULL;
+
+  video.window_scaling_percent = setup.window_scaling_percent;
+  video.window_scaling_quality = setup.window_scaling_quality;
+
+#if defined(TARGET_SDL2)
+  int num_displays = SDL_GetNumVideoDisplays();
+
+  if (num_displays > 0)
+  {
+    // currently only display modes of first display supported
+    int num_modes = SDL_GetNumDisplayModes(0);
+
+    if (num_modes > 0)
+    {
+      modes = checked_calloc((num_modes + 1) * sizeof(SDL_Rect *));
+
+      for (i = 0; i < num_modes; i++)
+      {
+       SDL_DisplayMode mode;
+
+       if (SDL_GetDisplayMode(0, i, &mode) < 0)
+         break;
+
+       modes[i] = checked_calloc(sizeof(SDL_Rect));
+
+       modes[i]->w = mode.w;
+       modes[i]->h = mode.h;
+      }
+    }
+  }
+#else
+  /* get available hardware supported fullscreen modes */
+  modes = SDL_ListModes(NULL, SDL_FULLSCREEN | SDL_HWSURFACE);
+#endif
+
+  if (modes == NULL)
+  {
+    /* no hardware screen modes available => no fullscreen mode support */
+    // video.fullscreen_available = FALSE;
+    hardware_fullscreen_available = FALSE;
+  }
+  else if (modes == (SDL_Rect **)-1)
+  {
+    /* fullscreen resolution is not restricted -- all resolutions available */
+    video.fullscreen_modes = checked_calloc(2 * sizeof(struct ScreenModeInfo));
+
+    /* use native video buffer size for fullscreen mode */
+    video.fullscreen_modes[0].width  = video.width;
+    video.fullscreen_modes[0].height = video.height;
+
+    video.fullscreen_modes[1].width  = -1;
+    video.fullscreen_modes[1].height = -1;
+  }
+  else
+  {
+    /* in this case, a certain number of screen modes is available */
+    int num_modes = 0;
+
+    for (i = 0; modes[i] != NULL; i++)
+    {
+      boolean found_mode = FALSE;
+
+      /* screen mode is smaller than video buffer size -- skip it */
+      if (modes[i]->w < video.width || modes[i]->h < video.height)
+       continue;
+
+      if (video.fullscreen_modes != NULL)
+       for (j = 0; video.fullscreen_modes[j].width != -1; j++)
+         if (modes[i]->w == video.fullscreen_modes[j].width &&
+             modes[i]->h == video.fullscreen_modes[j].height)
+           found_mode = TRUE;
+
+      if (found_mode)          /* screen mode already stored -- skip it */
+       continue;
+
+      /* new mode found; add it to list of available fullscreen modes */
+
+      num_modes++;
+
+      video.fullscreen_modes = checked_realloc(video.fullscreen_modes,
+                                              (num_modes + 1) *
+                                              sizeof(struct ScreenModeInfo));
+
+      video.fullscreen_modes[num_modes - 1].width  = modes[i]->w;
+      video.fullscreen_modes[num_modes - 1].height = modes[i]->h;
+
+      video.fullscreen_modes[num_modes].width  = -1;
+      video.fullscreen_modes[num_modes].height = -1;
+    }
+
+    if (num_modes == 0)
+    {
+      /* no appropriate screen modes available => no fullscreen mode support */
+      // video.fullscreen_available = FALSE;
+      hardware_fullscreen_available = FALSE;
+    }
+  }
+
+  video.fullscreen_available = hardware_fullscreen_available;
+
+#if USE_DESKTOP_FULLSCREEN
+  // in SDL 2.0, there is always support for desktop fullscreen mode
+  // (in SDL 1.2, there is only support for "real" fullscreen mode)
+  video.fullscreen_available = TRUE;
+#endif
+
+#if defined(TARGET_SDL2)
+  if (modes)
+  {
+    for (i = 0; modes[i] != NULL; i++)
+      checked_free(modes[i]);
+
+    checked_free(modes);
+  }
+#endif
+
   /* open SDL video output device (window or fullscreen mode) */
   if (!SDLSetVideoMode(backbuffer, fullscreen))
     Error(ERR_EXIT, "setting video mode failed");
 
   /* open SDL video output device (window or fullscreen mode) */
   if (!SDLSetVideoMode(backbuffer, fullscreen))
     Error(ERR_EXIT, "setting video mode failed");
 
+  /* !!! SDL2 can only set the window icon if the window already exists !!! */
+  /* set window icon */
+  SDLSetWindowIcon(program.icon_filename);
+
   /* set window and icon title */
   /* set window and icon title */
+#if defined(TARGET_SDL2)
+  SDL_SetWindowTitle(sdl_window, program.window_title);
+#else
   SDL_WM_SetCaption(program.window_title, program.window_title);
   SDL_WM_SetCaption(program.window_title, program.window_title);
+#endif
 
   /* SDL cannot directly draw to the visible video framebuffer like X11,
      but always uses a backbuffer, which is then blitted to the visible
 
   /* SDL cannot directly draw to the visible video framebuffer like X11,
      but always uses a backbuffer, which is then blitted to the visible
@@ -51,132 +514,826 @@ inline void SDLInitVideoBuffer(DrawBuffer **backbuffer, DrawWindow **window,
      'window', which indicates that the SDL backbuffer should be updated to
      the visible video framebuffer when attempting to blit to it.
 
      'window', which indicates that the SDL backbuffer should be updated to
      the visible video framebuffer when attempting to blit to it.
 
-     For convenience, it seems to be a good idea to create this symbolic
-     buffer 'window' at the same size as the SDL backbuffer. Although it
-     should never be drawn to directly, it would do no harm nevertheless. */
+     For convenience, it seems to be a good idea to create this symbolic
+     buffer 'window' at the same size as the SDL backbuffer. Although it
+     should never be drawn to directly, it would do no harm nevertheless. */
+
+  /* create additional (symbolic) buffer for double-buffering */
+  ReCreateBitmap(window, video.width, video.height, video.depth);
+}
+
+static SDL_Surface *SDLCreateScreen(DrawBuffer **backbuffer,
+                                   boolean fullscreen)
+{
+  SDL_Surface *new_surface = NULL;
+
+#if defined(TARGET_SDL2)
+  int surface_flags_window = SURFACE_FLAGS | SDL_WINDOW_RESIZABLE;
+#if USE_DESKTOP_FULLSCREEN
+  int surface_flags_fullscreen = SURFACE_FLAGS | SDL_WINDOW_FULLSCREEN_DESKTOP;
+#else
+  int surface_flags_fullscreen = SURFACE_FLAGS | SDL_WINDOW_FULLSCREEN;
+#endif
+
+#else
+  int surface_flags_window = SURFACE_FLAGS;
+  int surface_flags_fullscreen = SURFACE_FLAGS | SDL_FULLSCREEN;
+#endif
+
+  int width  = (fullscreen ? fullscreen_width  : video.width);
+  int height = (fullscreen ? fullscreen_height : video.height);
+  int surface_flags = (fullscreen ? surface_flags_fullscreen :
+                      surface_flags_window);
+
+  // default window size is unscaled
+  video.window_width  = video.width;
+  video.window_height = video.height;
+
+#if defined(TARGET_SDL2)
+
+  // store if initial screen mode is fullscreen mode when changing screen size
+  video.fullscreen_initial = fullscreen;
+
+#if USE_RENDERER
+  float window_scaling_factor = (float)setup.window_scaling_percent / 100;
+#if !USE_DESKTOP_FULLSCREEN
+  float screen_scaling_factor = (fullscreen ? 1 : window_scaling_factor);
+#endif
+
+  video.window_width  = window_scaling_factor * width;
+  video.window_height = window_scaling_factor * height;
+
+  if ((*backbuffer)->surface)
+  {
+    SDL_FreeSurface((*backbuffer)->surface);
+    (*backbuffer)->surface = NULL;
+  }
+
+  if (sdl_texture)
+  {
+    SDL_DestroyTexture(sdl_texture);
+    sdl_texture = NULL;
+  }
+
+  if (!(fullscreen && fullscreen_enabled))
+  {
+    if (sdl_renderer)
+    {
+      SDL_DestroyRenderer(sdl_renderer);
+      sdl_renderer = NULL;
+    }
+
+    if (sdl_window)
+    {
+      SDL_DestroyWindow(sdl_window);
+      sdl_window = NULL;
+    }
+  }
+
+  if (sdl_window == NULL)
+    sdl_window = SDL_CreateWindow(program.window_title,
+                                 SDL_WINDOWPOS_CENTERED,
+                                 SDL_WINDOWPOS_CENTERED,
+#if USE_DESKTOP_FULLSCREEN
+                                 video.window_width,
+                                 video.window_height,
+#else
+                                 (int)(screen_scaling_factor * width),
+                                 (int)(screen_scaling_factor * height),
+#endif
+                                 surface_flags);
+
+  if (sdl_window != NULL)
+  {
+#if 0
+    /* if SDL_CreateRenderer() is called from within a VirtualBox Windows VM
+     *without* enabling 2D/3D acceleration and/or guest additions installed,
+     it will crash if flags are *not* set to SDL_RENDERER_SOFTWARE (because
+     it will try to use accelerated graphics and apparently fails miserably) */
+    if (sdl_renderer == NULL)
+      sdl_renderer = SDL_CreateRenderer(sdl_window, -1, SDL_RENDERER_SOFTWARE);
+#else
+    if (sdl_renderer == NULL)
+      sdl_renderer = SDL_CreateRenderer(sdl_window, -1, 0);
+#endif
+
+    if (sdl_renderer != NULL)
+    {
+      SDL_RenderSetLogicalSize(sdl_renderer, width, height);
+      // SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
+      SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, setup.window_scaling_quality);
+
+      sdl_texture = SDL_CreateTexture(sdl_renderer,
+                                     SDL_PIXELFORMAT_ARGB8888,
+                                     SDL_TEXTUREACCESS_STREAMING,
+                                     width, height);
+
+      if (sdl_texture != NULL)
+      {
+       // use SDL default values for RGB masks and no alpha channel
+       new_surface = SDL_CreateRGBSurface(0, width, height, 32, 0,0,0, 0);
+
+       if (new_surface == NULL)
+         Error(ERR_WARN, "SDL_CreateRGBSurface() failed: %s",
+               SDL_GetError());
+      }
+      else
+      {
+       Error(ERR_WARN, "SDL_CreateTexture() failed: %s", SDL_GetError());
+      }
+    }
+    else
+    {
+      Error(ERR_WARN, "SDL_CreateRenderer() failed: %s", SDL_GetError());
+    }
+  }
+  else
+  {
+    Error(ERR_WARN, "SDL_CreateWindow() failed: %s", SDL_GetError());
+  }
+
+#else
+
+  if (sdl_window)
+    SDL_DestroyWindow(sdl_window);
+
+  sdl_window = SDL_CreateWindow(program.window_title,
+                               SDL_WINDOWPOS_CENTERED,
+                               SDL_WINDOWPOS_CENTERED,
+                               width, height,
+                               surface_flags);
+
+  if (sdl_window != NULL)
+    new_surface = SDL_GetWindowSurface(sdl_window);
+#endif
+
+#else
+  new_surface = SDL_SetVideoMode(width, height, video.depth, surface_flags);
+#endif
+
+#if defined(TARGET_SDL2)
+  // store fullscreen state ("video.fullscreen_enabled" may not reflect this!)
+  if (new_surface != NULL)
+    fullscreen_enabled = fullscreen;
+#endif
+
+  return new_surface;
+}
+
+boolean SDLSetVideoMode(DrawBuffer **backbuffer, boolean fullscreen)
+{
+  boolean success = TRUE;
+  SDL_Surface *new_surface = NULL;
+
+  SetWindowTitle();
+
+  if (*backbuffer == NULL)
+    *backbuffer = CreateBitmapStruct();
+
+  /* (real bitmap might be larger in fullscreen mode with video offsets) */
+  (*backbuffer)->width  = video.width;
+  (*backbuffer)->height = video.height;
+
+  if (fullscreen && !video.fullscreen_enabled && video.fullscreen_available)
+  {
+    setFullscreenParameters(setup.fullscreen_mode);
+
+    video_xoffset = fullscreen_xoffset;
+    video_yoffset = fullscreen_yoffset;
+
+    /* switch display to fullscreen mode, if available */
+    new_surface = SDLCreateScreen(backbuffer, TRUE);
+
+    if (new_surface == NULL)
+    {
+      /* switching display to fullscreen mode failed */
+      Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+
+      /* do not try it again */
+      video.fullscreen_available = FALSE;
+
+      success = FALSE;
+    }
+    else
+    {
+      (*backbuffer)->surface = new_surface;
+
+      video.fullscreen_enabled = TRUE;
+      video.fullscreen_mode_current = setup.fullscreen_mode;
+
+      success = TRUE;
+    }
+  }
+
+  if ((!fullscreen && video.fullscreen_enabled) || new_surface == NULL)
+  {
+    video_xoffset = 0;
+    video_yoffset = 0;
+
+    /* switch display to window mode */
+    new_surface = SDLCreateScreen(backbuffer, FALSE);
+
+    if (new_surface == NULL)
+    {
+      /* switching display to window mode failed -- should not happen */
+      Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+
+      success = FALSE;
+    }
+    else
+    {
+      (*backbuffer)->surface = new_surface;
+
+      video.fullscreen_enabled = FALSE;
+      video.window_scaling_percent = setup.window_scaling_percent;
+      video.window_scaling_quality = setup.window_scaling_quality;
+
+      success = TRUE;
+    }
+  }
+
+#if defined(TARGET_SDL2)
+  SDLRedrawWindow();                   // map window
+#endif
+
+#ifdef DEBUG
+#if defined(PLATFORM_WIN32)
+  // experimental drag and drop code
+
+  SDL_EventState(SDL_SYSWMEVENT, SDL_ENABLE);
+
+  {
+    SDL_SysWMinfo wminfo;
+    HWND hwnd;
+    boolean wminfo_success = FALSE;
+
+    SDL_VERSION(&wminfo.version);
+#if defined(TARGET_SDL2)
+    if (sdl_window)
+      wminfo_success = SDL_GetWindowWMInfo(sdl_window, &wminfo);
+#else
+    wminfo_success = (SDL_GetWMInfo(&wminfo) == 1);
+#endif
+
+    if (wminfo_success)
+    {
+#if defined(TARGET_SDL2)
+      hwnd = wminfo.info.win.window;
+#else
+      hwnd = wminfo.window;
+#endif
+
+      DragAcceptFiles(hwnd, TRUE);
+    }
+  }
+#endif
+#endif
+
+  return success;
+}
+
+void SDLSetWindowTitle()
+{
+#if defined(TARGET_SDL2)
+  SDL_SetWindowTitle(sdl_window, program.window_title);
+#else
+  SDL_WM_SetCaption(program.window_title, program.window_title);
+#endif
+}
+
+#if defined(TARGET_SDL2)
+void SDLSetWindowScaling(int window_scaling_percent)
+{
+  if (sdl_window == NULL)
+    return;
+
+  float window_scaling_factor = (float)window_scaling_percent / 100;
+  int new_window_width  = (int)(window_scaling_factor * video.width);
+  int new_window_height = (int)(window_scaling_factor * video.height);
+
+  SDL_SetWindowSize(sdl_window, new_window_width, new_window_height);
+
+  video.window_scaling_percent = window_scaling_percent;
+  video.window_width  = new_window_width;
+  video.window_height = new_window_height;
+
+  SetWindowTitle();
+}
+
+void SDLSetWindowScalingQuality(char *window_scaling_quality)
+{
+  if (sdl_texture == NULL)
+    return;
+
+  SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, window_scaling_quality);
+
+  SDL_Texture *new_texture = SDL_CreateTexture(sdl_renderer,
+                                              SDL_PIXELFORMAT_ARGB8888,
+                                              SDL_TEXTUREACCESS_STREAMING,
+                                              video.width, video.height);
+
+  if (new_texture != NULL)
+  {
+    SDL_DestroyTexture(sdl_texture);
+
+    sdl_texture = new_texture;
+
+    SDLRedrawWindow();
+  }
+
+  video.window_scaling_quality = window_scaling_quality;
+}
+
+void SDLSetWindowFullscreen(boolean fullscreen)
+{
+  if (sdl_window == NULL)
+    return;
+
+#if USE_DESKTOP_FULLSCREEN
+  int flags = (fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
+#else
+  int flags = (fullscreen ? SDL_WINDOW_FULLSCREEN : 0);
+#endif
+
+  if (SDL_SetWindowFullscreen(sdl_window, flags) == 0)
+    video.fullscreen_enabled = fullscreen_enabled = fullscreen;
+
+  // if screen size was changed in fullscreen mode, correct desktop window size
+  if (!fullscreen && video.fullscreen_initial)
+  {
+    SDLSetWindowScaling(setup.window_scaling_percent);
+    SDL_SetWindowPosition(sdl_window,
+                         SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
+
+    video.fullscreen_initial = FALSE;
+  }
+}
+
+void SDLRedrawWindow()
+{
+  UpdateScreen(NULL);
+}
+#endif
+
+void SDLCreateBitmapContent(Bitmap *bitmap, int width, int height,
+                           int depth)
+{
+  SDL_Surface *surface =
+    SDL_CreateRGBSurface(SURFACE_FLAGS, width, height, depth, 0,0,0, 0);
+
+  if (surface == NULL)
+    Error(ERR_EXIT, "SDL_CreateRGBSurface() failed: %s", SDL_GetError());
+
+  SDLSetNativeSurface(&surface);
+
+  bitmap->surface = surface;
+}
+
+void SDLFreeBitmapPointers(Bitmap *bitmap)
+{
+  if (bitmap->surface)
+    SDL_FreeSurface(bitmap->surface);
+  if (bitmap->surface_masked)
+    SDL_FreeSurface(bitmap->surface_masked);
+
+  bitmap->surface = NULL;
+  bitmap->surface_masked = NULL;
+
+#if defined(TARGET_SDL2)
+  if (bitmap->texture)
+    SDL_DestroyTexture(bitmap->texture);
+  if (bitmap->texture_masked)
+    SDL_DestroyTexture(bitmap->texture_masked);
+
+  bitmap->texture = NULL;
+  bitmap->texture_masked = NULL;
+#endif
+}
+
+void SDLCopyArea(Bitmap *src_bitmap, Bitmap *dst_bitmap,
+                int src_x, int src_y, int width, int height,
+                int dst_x, int dst_y, int mask_mode)
+{
+  Bitmap *real_dst_bitmap = (dst_bitmap == window ? backbuffer : dst_bitmap);
+  SDL_Rect src_rect, dst_rect;
+
+  if (src_bitmap == backbuffer)
+  {
+    src_x += video_xoffset;
+    src_y += video_yoffset;
+  }
+
+  src_rect.x = src_x;
+  src_rect.y = src_y;
+  src_rect.w = width;
+  src_rect.h = height;
+
+  if (dst_bitmap == backbuffer || dst_bitmap == window)
+  {
+    dst_x += video_xoffset;
+    dst_y += video_yoffset;
+  }
+
+  dst_rect.x = dst_x;
+  dst_rect.y = dst_y;
+  dst_rect.w = width;
+  dst_rect.h = height;
+
+  // if (src_bitmap != backbuffer || dst_bitmap != window)
+  if (!(src_bitmap == backbuffer && dst_bitmap == window))
+    SDL_BlitSurface((mask_mode == BLIT_MASKED ?
+                    src_bitmap->surface_masked : src_bitmap->surface),
+                   &src_rect, real_dst_bitmap->surface, &dst_rect);
+
+#if defined(TARGET_SDL2)
+  if (dst_bitmap == window)
+  {
+    // SDL_UpdateWindowSurface(sdl_window);
+    // SDL_UpdateWindowSurfaceRects(sdl_window, &dst_rect, 1);
+    UpdateScreen(&dst_rect);
+  }
+#else
+  if (dst_bitmap == window)
+  {
+    // SDL_UpdateRect(backbuffer->surface, dst_x, dst_y, width, height);
+    UpdateScreen(&dst_rect);
+  }
+#endif
+}
+
+void SDLFillRectangle(Bitmap *dst_bitmap, int x, int y, int width, int height,
+                     Uint32 color)
+{
+  Bitmap *real_dst_bitmap = (dst_bitmap == window ? backbuffer : dst_bitmap);
+  SDL_Rect rect;
+
+  if (dst_bitmap == backbuffer || dst_bitmap == window)
+  {
+    x += video_xoffset;
+    y += video_yoffset;
+  }
+
+  rect.x = x;
+  rect.y = y;
+  rect.w = width;
+  rect.h = height;
+
+  SDL_FillRect(real_dst_bitmap->surface, &rect, color);
+
+#if defined(TARGET_SDL2)
+  if (dst_bitmap == window)
+  {
+    // SDL_UpdateWindowSurface(sdl_window);
+    // SDL_UpdateWindowSurfaceRects(sdl_window, &rect, 1);
+    UpdateScreen(&rect);
+  }
+#else
+  if (dst_bitmap == window)
+  {
+    // SDL_UpdateRect(backbuffer->surface, x, y, width, height);
+    UpdateScreen(&rect);
+  }
+#endif
+}
+
+void SDLFadeRectangle(Bitmap *bitmap_cross, int x, int y, int width, int height,
+                     int fade_mode, int fade_delay, int post_delay,
+                     void (*draw_border_function)(void))
+{
+  static boolean initialization_needed = TRUE;
+  static SDL_Surface *surface_source = NULL;
+  static SDL_Surface *surface_target = NULL;
+  static SDL_Surface *surface_black = NULL;
+  SDL_Surface *surface_screen = backbuffer->surface;
+  SDL_Surface *surface_cross = (bitmap_cross ? bitmap_cross->surface : NULL);
+  SDL_Rect src_rect, dst_rect;
+  SDL_Rect dst_rect2;
+  int src_x = x, src_y = y;
+  int dst_x = x, dst_y = y;
+  unsigned int time_last, time_current;
+
+  /* check if screen size has changed */
+  if (surface_source != NULL && (video.width  != surface_source->w ||
+                                video.height != surface_source->h))
+  {
+    SDL_FreeSurface(surface_source);
+    SDL_FreeSurface(surface_target);
+    SDL_FreeSurface(surface_black);
+
+    initialization_needed = TRUE;
+  }
+
+  src_rect.x = src_x;
+  src_rect.y = src_y;
+  src_rect.w = width;
+  src_rect.h = height;
+
+  dst_x += video_xoffset;
+  dst_y += video_yoffset;
+
+  dst_rect.x = dst_x;
+  dst_rect.y = dst_y;
+  dst_rect.w = width;          /* (ignored) */
+  dst_rect.h = height;         /* (ignored) */
+
+  dst_rect2 = dst_rect;
+
+  if (initialization_needed)
+  {
+#if defined(TARGET_SDL2)
+    unsigned int flags = 0;
+#else
+    unsigned int flags = SDL_SRCALPHA;
+
+    /* use same surface type as screen surface */
+    if ((surface_screen->flags & SDL_HWSURFACE))
+      flags |= SDL_HWSURFACE;
+    else
+      flags |= SDL_SWSURFACE;
+#endif
+
+    /* create surface for temporary copy of screen buffer (source) */
+    if ((surface_source =
+        SDL_CreateRGBSurface(flags,
+                             video.width,
+                             video.height,
+                             surface_screen->format->BitsPerPixel,
+                             surface_screen->format->Rmask,
+                             surface_screen->format->Gmask,
+                             surface_screen->format->Bmask,
+                             surface_screen->format->Amask)) == NULL)
+      Error(ERR_EXIT, "SDL_CreateRGBSurface() failed: %s", SDL_GetError());
+
+    /* create surface for cross-fading screen buffer (target) */
+    if ((surface_target =
+        SDL_CreateRGBSurface(flags,
+                             video.width,
+                             video.height,
+                             surface_screen->format->BitsPerPixel,
+                             surface_screen->format->Rmask,
+                             surface_screen->format->Gmask,
+                             surface_screen->format->Bmask,
+                             surface_screen->format->Amask)) == NULL)
+      Error(ERR_EXIT, "SDL_CreateRGBSurface() failed: %s", SDL_GetError());
+
+    /* create black surface for fading from/to black */
+    if ((surface_black =
+        SDL_CreateRGBSurface(flags,
+                             video.width,
+                             video.height,
+                             surface_screen->format->BitsPerPixel,
+                             surface_screen->format->Rmask,
+                             surface_screen->format->Gmask,
+                             surface_screen->format->Bmask,
+                             surface_screen->format->Amask)) == NULL)
+      Error(ERR_EXIT, "SDL_CreateRGBSurface() failed: %s", SDL_GetError());
+
+    /* completely fill the surface with black color pixels */
+    SDL_FillRect(surface_black, NULL,
+                SDL_MapRGB(surface_screen->format, 0, 0, 0));
+
+    initialization_needed = FALSE;
+  }
 
 
-  /* create additional (symbolic) buffer for double-buffering */
-  *window = CreateBitmap(video.width, video.height, video.depth);
-}
+  /* copy source and target surfaces to temporary surfaces for fading */
+  if (fade_mode & FADE_TYPE_TRANSFORM)
+  {
+    SDL_BlitSurface(surface_cross,  &src_rect, surface_source, &src_rect);
+    SDL_BlitSurface(surface_screen, &dst_rect, surface_target, &src_rect);
+  }
+  else if (fade_mode & FADE_TYPE_FADE_IN)
+  {
+    SDL_BlitSurface(surface_black,  &src_rect, surface_source, &src_rect);
+    SDL_BlitSurface(surface_screen, &dst_rect, surface_target, &src_rect);
+  }
+  else         /* FADE_TYPE_FADE_OUT */
+  {
+    SDL_BlitSurface(surface_screen, &dst_rect, surface_source, &src_rect);
+    SDL_BlitSurface(surface_black,  &src_rect, surface_target, &src_rect);
+  }
 
 
-inline boolean SDLSetVideoMode(DrawBuffer **backbuffer, boolean fullscreen)
-{
-  boolean success = TRUE;
-  int surface_flags = SDL_HWSURFACE | (fullscreen ? SDL_FULLSCREEN : 0);
+  time_current = SDL_GetTicks();
 
 
-  if (fullscreen && !video.fullscreen_enabled && video.fullscreen_available)
+  if (fade_mode == FADE_MODE_MELT)
   {
   {
-    /* switch display to fullscreen mode, if available */
-    DrawWindow *window_old = *backbuffer;
-    DrawWindow *window_new = CreateBitmapStruct();
+    boolean done = FALSE;
+    int melt_pixels = 2;
+    int melt_columns = width / melt_pixels;
+    int ypos[melt_columns];
+    int max_steps = height / 8 + 32;
+    int steps_done = 0;
+    float steps = 0;
+    int i;
+
+    SDL_BlitSurface(surface_source, &src_rect, surface_screen, &dst_rect);
+#if defined(TARGET_SDL2)
+    SDL_SetSurfaceBlendMode(surface_target, SDL_BLENDMODE_NONE);
+#else
+    SDL_SetAlpha(surface_target, 0, 0);                /* disable alpha blending */
+#endif
 
 
-    if ((window_new->surface = SDL_SetVideoMode(video.width, video.height,
-                                               video.depth, surface_flags))
-       == NULL)
+    ypos[0] = -GetSimpleRandom(16);
+
+    for (i = 1 ; i < melt_columns; i++)
     {
     {
-      /* switching display to fullscreen mode failed */
-      Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+      int r = GetSimpleRandom(3) - 1;  /* randomly choose from { -1, 0, -1 } */
 
 
-      /* do not try it again */
-      video.fullscreen_available = FALSE;
-      success = FALSE;
+      ypos[i] = ypos[i - 1] + r;
+
+      if (ypos[i] > 0)
+        ypos[i] = 0;
+      else
+        if (ypos[i] == -16)
+          ypos[i] = -15;
     }
     }
-    else
+
+    while (!done)
     {
     {
-      if (window_old)
-       FreeBitmap(window_old);
-      *backbuffer = window_new;
+      int steps_final;
 
 
-      video.fullscreen_enabled = TRUE;
-      success = TRUE;
+      time_last = time_current;
+      time_current = SDL_GetTicks();
+      steps += max_steps * ((float)(time_current - time_last) / fade_delay);
+      steps_final = MIN(MAX(0, steps), max_steps);
+
+      steps_done++;
+
+      done = (steps_done >= steps_final);
+
+      for (i = 0 ; i < melt_columns; i++)
+      {
+       if (ypos[i] < 0)
+        {
+          ypos[i]++;
+
+          done = FALSE;
+        }
+       else if (ypos[i] < height)
+       {
+         int y1 = 16;
+         int y2 = 8;
+         int y3 = 8;
+         int dy = (ypos[i] < y1) ? ypos[i] + 1 : y2 + GetSimpleRandom(y3);
+
+         if (ypos[i] + dy >= height)
+           dy = height - ypos[i];
+
+         /* copy part of (appearing) target surface to upper area */
+         src_rect.x = src_x + i * melt_pixels;
+         // src_rect.y = src_y + ypos[i];
+         src_rect.y = src_y;
+         src_rect.w = melt_pixels;
+         // src_rect.h = dy;
+         src_rect.h = ypos[i] + dy;
+
+         dst_rect.x = dst_x + i * melt_pixels;
+         // dst_rect.y = dst_y + ypos[i];
+         dst_rect.y = dst_y;
+
+         if (steps_done >= steps_final)
+           SDL_BlitSurface(surface_target, &src_rect,
+                           surface_screen, &dst_rect);
+
+         ypos[i] += dy;
+
+         /* copy part of (disappearing) source surface to lower area */
+         src_rect.x = src_x + i * melt_pixels;
+         src_rect.y = src_y;
+         src_rect.w = melt_pixels;
+         src_rect.h = height - ypos[i];
+
+         dst_rect.x = dst_x + i * melt_pixels;
+         dst_rect.y = dst_y + ypos[i];
+
+         if (steps_done >= steps_final)
+           SDL_BlitSurface(surface_source, &src_rect,
+                           surface_screen, &dst_rect);
+
+         done = FALSE;
+       }
+       else
+       {
+         src_rect.x = src_x + i * melt_pixels;
+         src_rect.y = src_y;
+         src_rect.w = melt_pixels;
+         src_rect.h = height;
+
+         dst_rect.x = dst_x + i * melt_pixels;
+         dst_rect.y = dst_y;
+
+         if (steps_done >= steps_final)
+           SDL_BlitSurface(surface_target, &src_rect,
+                           surface_screen, &dst_rect);
+       }
+      }
+
+      if (steps_done >= steps_final)
+      {
+       if (draw_border_function != NULL)
+         draw_border_function();
+
+       UpdateScreen(&dst_rect2);
+      }
     }
   }
     }
   }
-
-  if ((!fullscreen && video.fullscreen_enabled) || !*backbuffer)
+  else if (fade_mode == FADE_MODE_CURTAIN)
   {
   {
-    /* switch display to window mode */
-    DrawWindow *window_old = *backbuffer;
-    DrawWindow *window_new = CreateBitmapStruct();
+    float xx;
+    int xx_final;
+    int xx_size = width / 2;
+
+    SDL_BlitSurface(surface_target, &src_rect, surface_screen, &dst_rect);
+#if defined(TARGET_SDL2)
+    SDL_SetSurfaceBlendMode(surface_source, SDL_BLENDMODE_NONE);
+#else
+    SDL_SetAlpha(surface_source, 0, 0);                /* disable alpha blending */
+#endif
 
 
-    if ((window_new->surface = SDL_SetVideoMode(video.width, video.height,
-                                               video.depth, surface_flags))
-       == NULL)
+    for (xx = 0; xx < xx_size;)
     {
     {
-      /* switching display to window mode failed -- should not happen */
-      Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+      time_last = time_current;
+      time_current = SDL_GetTicks();
+      xx += xx_size * ((float)(time_current - time_last) / fade_delay);
+      xx_final = MIN(MAX(0, xx), xx_size);
 
 
-      success = FALSE;
-    }
-    else
-    {
-      if (window_old)
-       FreeBitmap(window_old);
-      *backbuffer = window_new;
+      src_rect.x = src_x;
+      src_rect.y = src_y;
+      src_rect.w = width;
+      src_rect.h = height;
 
 
-      video.fullscreen_enabled = FALSE;
-      success = TRUE;
-    }
-  }
+      dst_rect.x = dst_x;
+      dst_rect.y = dst_y;
 
 
-  return success;
-}
+      /* draw new (target) image to screen buffer */
+      SDL_BlitSurface(surface_target, &src_rect, surface_screen, &dst_rect);
 
 
-inline void SDLCopyArea(Bitmap *src_bitmap, Bitmap *dst_bitmap,
-                       int src_x, int src_y,
-                       int width, int height,
-                       int dst_x, int dst_y, int copy_mode)
-{
-  Bitmap *real_dst_bitmap = (dst_bitmap == window ? backbuffer : dst_bitmap);
-  SDL_Rect src_rect, dst_rect;
+      if (xx_final < xx_size)
+      {
+       src_rect.w = xx_size - xx_final;
+       src_rect.h = height;
 
 
-  src_rect.x = src_x;
-  src_rect.y = src_y;
-  src_rect.w = width;
-  src_rect.h = height;
+       /* draw old (source) image to screen buffer (left side) */
 
 
-  dst_rect.x = dst_x;
-  dst_rect.y = dst_y;
-  dst_rect.w = width;
-  dst_rect.h = height;
+       src_rect.x = src_x + xx_final;
+       dst_rect.x = dst_x;
 
 
-  if (src_bitmap != backbuffer || dst_bitmap != window)
-    SDL_BlitSurface((copy_mode == SDLCOPYAREA_MASKED ?
-                    src_bitmap->surface_masked : src_bitmap->surface),
-                   &src_rect, real_dst_bitmap->surface, &dst_rect);
+       SDL_BlitSurface(surface_source, &src_rect, surface_screen, &dst_rect);
 
 
-  if (dst_bitmap == window)
-    SDL_UpdateRect(backbuffer->surface, dst_x, dst_y, width, height);
-}
+       /* draw old (source) image to screen buffer (right side) */
 
 
-inline void SDLFillRectangle(Bitmap *dst_bitmap, int x, int y,
-                            int width, int height, unsigned int color)
-{
-  Bitmap *real_dst_bitmap = (dst_bitmap == window ? backbuffer : dst_bitmap);
-  SDL_Rect rect;
-  unsigned int color_r = (color >> 16) && 0xff;
-  unsigned int color_g = (color >>  8) && 0xff;
-  unsigned int color_b = (color >>  0) && 0xff;
+       src_rect.x = src_x + xx_size;
+       dst_rect.x = dst_x + xx_size + xx_final;
 
 
-  rect.x = x;
-  rect.y = y;
-  rect.w = width;
-  rect.h = height;
+       SDL_BlitSurface(surface_source, &src_rect, surface_screen, &dst_rect);
+      }
 
 
-  SDL_FillRect(real_dst_bitmap->surface, &rect,
-              SDL_MapRGB(real_dst_bitmap->surface->format,
-                         color_r, color_g, color_b));
+      if (draw_border_function != NULL)
+       draw_border_function();
 
 
-  if (dst_bitmap == window)
-    SDL_UpdateRect(backbuffer->surface, x, y, width, height);
+      /* only update the region of the screen that is affected from fading */
+      UpdateScreen(&dst_rect2);
+    }
+  }
+  else         /* fading in, fading out or cross-fading */
+  {
+    float alpha;
+    int alpha_final;
+
+    for (alpha = 0.0; alpha < 255.0;)
+    {
+      time_last = time_current;
+      time_current = SDL_GetTicks();
+      alpha += 255 * ((float)(time_current - time_last) / fade_delay);
+      alpha_final = MIN(MAX(0, alpha), 255);
+
+      /* draw existing (source) image to screen buffer */
+      SDL_BlitSurface(surface_source, &src_rect, surface_screen, &dst_rect);
+
+      /* draw new (target) image to screen buffer using alpha blending */
+#if defined(TARGET_SDL2)
+      SDL_SetSurfaceAlphaMod(surface_target, alpha_final);
+      SDL_SetSurfaceBlendMode(surface_target, SDL_BLENDMODE_BLEND);
+#else
+      SDL_SetAlpha(surface_target, SDL_SRCALPHA, alpha_final);
+#endif
+      SDL_BlitSurface(surface_target, &src_rect, surface_screen, &dst_rect);
+
+      if (draw_border_function != NULL)
+       draw_border_function();
+
+      /* only update the region of the screen that is affected from fading */
+      UpdateScreen(&dst_rect);
+    }
+  }
+
+  Delay(post_delay);
 }
 
 }
 
-inline void SDLDrawSimpleLine(SDL_Surface *surface, int from_x, int from_y,
-                             int to_x, int to_y, unsigned int color)
+void SDLDrawSimpleLine(Bitmap *dst_bitmap, int from_x, int from_y,
+                      int to_x, int to_y, Uint32 color)
 {
 {
+  SDL_Surface *surface = dst_bitmap->surface;
   SDL_Rect rect;
   SDL_Rect rect;
-  unsigned int color_r = (color >> 16) & 0xff;
-  unsigned int color_g = (color >>  8) & 0xff;
-  unsigned int color_b = (color >>  0) & 0xff;
 
   if (from_x > to_x)
     swap_numbers(&from_x, &to_x);
 
   if (from_x > to_x)
     swap_numbers(&from_x, &to_x);
@@ -189,28 +1346,41 @@ inline void SDLDrawSimpleLine(SDL_Surface *surface, int from_x, int from_y,
   rect.w = (to_x - from_x + 1);
   rect.h = (to_y - from_y + 1);
 
   rect.w = (to_x - from_x + 1);
   rect.h = (to_y - from_y + 1);
 
-  SDL_FillRect(surface, &rect,
-               SDL_MapRGB(surface->format, color_r, color_g, color_b));
+  if (dst_bitmap == backbuffer || dst_bitmap == window)
+  {
+    rect.x += video_xoffset;
+    rect.y += video_yoffset;
+  }
+
+  SDL_FillRect(surface, &rect, color);
 }
 
 }
 
-inline void SDLDrawLine(SDL_Surface *surface, int from_x, int from_y,
-                       int to_x, int to_y, Uint32 color)
+void SDLDrawLine(Bitmap *dst_bitmap, int from_x, int from_y,
+                int to_x, int to_y, Uint32 color)
 {
 {
-  sge_Line(surface, from_x, from_y, to_x, to_y, color);
+  if (dst_bitmap == backbuffer || dst_bitmap == window)
+  {
+    from_x += video_xoffset;
+    from_y += video_yoffset;
+    to_x += video_xoffset;
+    to_y += video_yoffset;
+  }
+
+  sge_Line(dst_bitmap->surface, from_x, from_y, to_x, to_y, color);
 }
 
 }
 
-#if 0
-inline void SDLDrawLines(SDL_Surface *surface, struct XY *points,
-                        int num_points, Uint32 color)
+#if ENABLE_UNUSED_CODE
+void SDLDrawLines(SDL_Surface *surface, struct XY *points,
+                 int num_points, Uint32 color)
 {
   int i, x, y;
   int line_width = 4;
 
 {
   int i, x, y;
   int line_width = 4;
 
-  for (i=0; i<num_points - 1; i++)
+  for (i = 0; i < num_points - 1; i++)
   {
   {
-    for (x=0; x<line_width; x++)
+    for (x = 0; x < line_width; x++)
     {
     {
-      for (y=0; y<line_width; y++)
+      for (y = 0; y < line_width; y++)
       {
        int dx = x - line_width / 2;
        int dy = y - line_width / 2;
       {
        int dx = x - line_width / 2;
        int dy = y - line_width / 2;
@@ -229,10 +1399,62 @@ inline void SDLDrawLines(SDL_Surface *surface, struct XY *points,
 }
 #endif
 
 }
 #endif
 
+Pixel SDLGetPixel(Bitmap *src_bitmap, int x, int y)
+{
+  SDL_Surface *surface = src_bitmap->surface;
+
+  if (src_bitmap == backbuffer || src_bitmap == window)
+  {
+    x += video_xoffset;
+    y += video_yoffset;
+  }
+
+  switch (surface->format->BytesPerPixel)
+  {
+    case 1:            /* assuming 8-bpp */
+    {
+      return *((Uint8 *)surface->pixels + y * surface->pitch + x);
+    }
+    break;
+
+    case 2:            /* probably 15-bpp or 16-bpp */
+    {
+      return *((Uint16 *)surface->pixels + y * surface->pitch / 2 + x);
+    }
+    break;
+
+  case 3:              /* slow 24-bpp mode; usually not used */
+    {
+      /* does this work? */
+      Uint8 *pix = (Uint8 *)surface->pixels + y * surface->pitch + x * 3;
+      Uint32 color = 0;
+      int shift;
+
+      shift = surface->format->Rshift;
+      color |= *(pix + shift / 8) >> shift;
+      shift = surface->format->Gshift;
+      color |= *(pix + shift / 8) >> shift;
+      shift = surface->format->Bshift;
+      color |= *(pix + shift / 8) >> shift;
+
+      return color;
+    }
+    break;
+
+  case 4:              /* probably 32-bpp */
+    {
+      return *((Uint32 *)surface->pixels + y * surface->pitch / 4 + x);
+    }
+    break;
+  }
+
+  return 0;
+}
+
 
 /* ========================================================================= */
 
 /* ========================================================================= */
-/* The following functions have been taken from the SGE library              */
-/* (SDL Graphics Extension Library) by Anders Lindström                      */
+/* The following functions were taken from the SGE library                   */
+/* (SDL Graphics Extension Library) by Anders Lindström                      */
 /* http://www.etek.chalmers.se/~e8cal1/sge/index.html                        */
 /* ========================================================================= */
 
 /* http://www.etek.chalmers.se/~e8cal1/sge/index.html                        */
 /* ========================================================================= */
 
@@ -360,9 +1582,9 @@ void sge_PutPixel(SDL_Surface *surface, Sint16 x, Sint16 y, Uint32 color)
 }
 
 void sge_PutPixelRGB(SDL_Surface *surface, Sint16 x, Sint16 y,
 }
 
 void sge_PutPixelRGB(SDL_Surface *surface, Sint16 x, Sint16 y,
-                 Uint8 R, Uint8 G, Uint8 B)
+                 Uint8 r, Uint8 g, Uint8 b)
 {
 {
-  sge_PutPixel(surface, x, y, SDL_MapRGB(surface->format, R, G, B));
+  sge_PutPixel(surface, x, y, SDL_MapRGB(surface->format, r, g, b));
 }
 
 Sint32 sge_CalcYPitch(SDL_Surface *dest, Sint16 y)
 }
 
 Sint32 sge_CalcYPitch(SDL_Surface *dest, Sint16 y)
@@ -584,139 +1806,616 @@ void _VLine(SDL_Surface *Surface, Sint16 x, Sint16 y1, Sint16 y2, Uint32 Color)
   l.w = 1;
   l.h = y2 - y1 + 1;
 
   l.w = 1;
   l.h = y2 - y1 + 1;
 
-  SDL_FillRect(Surface, &l, Color);
+  SDL_FillRect(Surface, &l, Color);
+}
+
+void sge_DoLine(SDL_Surface *Surface, Sint16 x1, Sint16 y1,
+               Sint16 x2, Sint16 y2, Uint32 Color,
+               void Callback(SDL_Surface *Surf, Sint16 X, Sint16 Y,
+                             Uint32 Color))
+{
+  Sint16 dx, dy, sdx, sdy, x, y, px, py;
+
+  dx = x2 - x1;
+  dy = y2 - y1;
+
+  sdx = (dx < 0) ? -1 : 1;
+  sdy = (dy < 0) ? -1 : 1;
+
+  dx = sdx * dx + 1;
+  dy = sdy * dy + 1;
+
+  x = y = 0;
+
+  px = x1;
+  py = y1;
+
+  if (dx >= dy)
+  {
+    for (x = 0; x < dx; x++)
+    {
+      Callback(Surface, px, py, Color);
+
+      y += dy;
+      if (y >= dx)
+      {
+       y -= dx;
+       py += sdy;
+      }
+
+      px += sdx;
+    }
+  }
+  else
+  {
+    for (y = 0; y < dy; y++)
+    {
+      Callback(Surface, px, py, Color);
+
+      x += dx;
+      if (x >= dy)
+      {
+       x -= dy;
+       px += sdx;
+      }
+
+      py += sdy;
+    }
+  }
+}
+
+void sge_DoLineRGB(SDL_Surface *Surface, Sint16 X1, Sint16 Y1,
+                  Sint16 X2, Sint16 Y2, Uint8 R, Uint8 G, Uint8 B,
+                  void Callback(SDL_Surface *Surf, Sint16 X, Sint16 Y,
+                                Uint32 Color))
+{
+  sge_DoLine(Surface, X1, Y1, X2, Y2,
+            SDL_MapRGB(Surface->format, R, G, B), Callback);
+}
+
+void sge_Line(SDL_Surface *Surface, Sint16 x1, Sint16 y1, Sint16 x2, Sint16 y2,
+             Uint32 Color)
+{
+  if (SDL_MUSTLOCK(Surface))
+  {
+    if (SDL_LockSurface(Surface) < 0)
+      return;
+   }
+
+   /* Draw the line */
+   sge_DoLine(Surface, x1, y1, x2, y2, Color, _PutPixel);
+
+   /* unlock the display */
+   if (SDL_MUSTLOCK(Surface))
+   {
+      SDL_UnlockSurface(Surface);
+   }
+}
+
+void sge_LineRGB(SDL_Surface *Surface, Sint16 x1, Sint16 y1, Sint16 x2,
+                Sint16 y2, Uint8 R, Uint8 G, Uint8 B)
+{
+  sge_Line(Surface, x1, y1, x2, y2, SDL_MapRGB(Surface->format, R, G, B));
+}
+
+void SDLPutPixel(Bitmap *dst_bitmap, int x, int y, Pixel pixel)
+{
+  if (dst_bitmap == backbuffer || dst_bitmap == window)
+  {
+    x += video_xoffset;
+    y += video_yoffset;
+  }
+
+  sge_PutPixel(dst_bitmap->surface, x, y, pixel);
+}
+
+
+/*
+  -----------------------------------------------------------------------------
+  quick (no, it's slow) and dirty hack to "invert" rectangle inside SDL surface
+  -----------------------------------------------------------------------------
+*/
+
+void SDLInvertArea(Bitmap *bitmap, int src_x, int src_y,
+                  int width, int height, Uint32 color)
+{
+  int x, y;
+
+  for (y = src_y; y < src_y + height; y++)
+  {
+    for (x = src_x; x < src_x + width; x++)
+    {
+      Uint32 pixel = SDLGetPixel(bitmap, x, y);
+
+      SDLPutPixel(bitmap, x, y, pixel == BLACK_PIXEL ? color : BLACK_PIXEL);
+    }
+  }
+}
+
+void SDLCopyInverseMasked(Bitmap *src_bitmap, Bitmap *dst_bitmap,
+                         int src_x, int src_y, int width, int height,
+                         int dst_x, int dst_y)
+{
+  int x, y;
+
+  for (y = 0; y < height; y++)
+  {
+    for (x = 0; x < width; x++)
+    {
+      Uint32 pixel = SDLGetPixel(src_bitmap, src_x + x, src_y + y);
+
+      if (pixel != BLACK_PIXEL)
+       SDLPutPixel(dst_bitmap, dst_x + x, dst_y + y, BLACK_PIXEL);
+    }
+  }
+}
+
+
+/* ========================================================================= */
+/* The following functions were taken from the SDL_gfx library version 2.0.3 */
+/* (Rotozoomer) by Andreas Schiffler                                         */
+/* http://www.ferzkopp.net/Software/SDL_gfx-2.0/index.html                   */
+/* ========================================================================= */
+
+/*
+  -----------------------------------------------------------------------------
+  32 bit zoomer
+
+  zoomes 32bit RGBA/ABGR 'src' surface to 'dst' surface.
+  -----------------------------------------------------------------------------
+*/
+
+typedef struct
+{
+  Uint8 r;
+  Uint8 g;
+  Uint8 b;
+  Uint8 a;
+} tColorRGBA;
+
+int zoomSurfaceRGBA_scaleDownBy2(SDL_Surface *src, SDL_Surface *dst)
+{
+  int x, y;
+  tColorRGBA *sp, *csp, *dp;
+  int dgap;
+
+  /* pointer setup */
+  sp = csp = (tColorRGBA *) src->pixels;
+  dp = (tColorRGBA *) dst->pixels;
+  dgap = dst->pitch - dst->w * 4;
+
+  for (y = 0; y < dst->h; y++)
+  {
+    sp = csp;
+
+    for (x = 0; x < dst->w; x++)
+    {
+      tColorRGBA *sp0 = sp;
+      tColorRGBA *sp1 = (tColorRGBA *) ((Uint8 *) sp + src->pitch);
+      tColorRGBA *sp00 = &sp0[0];
+      tColorRGBA *sp01 = &sp0[1];
+      tColorRGBA *sp10 = &sp1[0];
+      tColorRGBA *sp11 = &sp1[1];
+      tColorRGBA new;
+
+      /* create new color pixel from all four source color pixels */
+      new.r = (sp00->r + sp01->r + sp10->r + sp11->r) / 4;
+      new.g = (sp00->g + sp01->g + sp10->g + sp11->g) / 4;
+      new.b = (sp00->b + sp01->b + sp10->b + sp11->b) / 4;
+      new.a = (sp00->a + sp01->a + sp10->a + sp11->a) / 4;
+
+      /* draw */
+      *dp = new;
+
+      /* advance source pointers */
+      sp += 2;
+
+      /* advance destination pointer */
+      dp++;
+    }
+
+    /* advance source pointer */
+    csp = (tColorRGBA *) ((Uint8 *) csp + 2 * src->pitch);
+
+    /* advance destination pointers */
+    dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
+  }
+
+  return 0;
 }
 
 }
 
-void sge_DoLine(SDL_Surface *Surface, Sint16 x1, Sint16 y1,
-               Sint16 x2, Sint16 y2, Uint32 Color,
-               void Callback(SDL_Surface *Surf, Sint16 X, Sint16 Y,
-                             Uint32 Color))
+int zoomSurfaceRGBA(SDL_Surface *src, SDL_Surface *dst)
 {
 {
-  Sint16 dx, dy, sdx, sdy, x, y, px, py;
+  int x, y, *sax, *say, *csax, *csay;
+  float sx, sy;
+  tColorRGBA *sp, *csp, *csp0, *dp;
+  int dgap;
+
+  /* use specialized zoom function when scaling down to exactly half size */
+  if (src->w == 2 * dst->w &&
+      src->h == 2 * dst->h)
+    return zoomSurfaceRGBA_scaleDownBy2(src, dst);
+
+  /* variable setup */
+  sx = (float) src->w / (float) dst->w;
+  sy = (float) src->h / (float) dst->h;
+
+  /* allocate memory for row increments */
+  csax = sax = (int *)checked_malloc((dst->w + 1) * sizeof(Uint32));
+  csay = say = (int *)checked_malloc((dst->h + 1) * sizeof(Uint32));
+
+  /* precalculate row increments */
+  for (x = 0; x <= dst->w; x++)
+    *csax++ = (int)(sx * x);
+
+  for (y = 0; y <= dst->h; y++)
+    *csay++ = (int)(sy * y);
+
+  /* pointer setup */
+  sp = csp = csp0 = (tColorRGBA *) src->pixels;
+  dp = (tColorRGBA *) dst->pixels;
+  dgap = dst->pitch - dst->w * 4;
+
+  csay = say;
+  for (y = 0; y < dst->h; y++)
+  {
+    sp = csp;
+    csax = sax;
 
 
-  dx = x2 - x1;
-  dy = y2 - y1;
+    for (x = 0; x < dst->w; x++)
+    {
+      /* draw */
+      *dp = *sp;
 
 
-  sdx = (dx < 0) ? -1 : 1;
-  sdy = (dy < 0) ? -1 : 1;
+      /* advance source pointers */
+      csax++;
+      sp = csp + *csax;
 
 
-  dx = sdx * dx + 1;
-  dy = sdy * dy + 1;
+      /* advance destination pointer */
+      dp++;
+    }
 
 
-  x = y = 0;
+    /* advance source pointer */
+    csay++;
+    csp = (tColorRGBA *) ((Uint8 *) csp0 + *csay * src->pitch);
 
 
-  px = x1;
-  py = y1;
+    /* advance destination pointers */
+    dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
+  }
 
 
-  if (dx >= dy)
+  free(sax);
+  free(say);
+
+  return 0;
+}
+
+/*
+  -----------------------------------------------------------------------------
+  8 bit zoomer
+
+  zoomes 8 bit palette/Y 'src' surface to 'dst' surface
+  -----------------------------------------------------------------------------
+*/
+
+int zoomSurfaceY(SDL_Surface * src, SDL_Surface * dst)
+{
+  Uint32 x, y, sx, sy, *sax, *say, *csax, *csay, csx, csy;
+  Uint8 *sp, *dp, *csp;
+  int dgap;
+
+  /* variable setup */
+  sx = (Uint32) (65536.0 * (float) src->w / (float) dst->w);
+  sy = (Uint32) (65536.0 * (float) src->h / (float) dst->h);
+
+  /* allocate memory for row increments */
+  sax = (Uint32 *)checked_malloc(dst->w * sizeof(Uint32));
+  say = (Uint32 *)checked_malloc(dst->h * sizeof(Uint32));
+
+  /* precalculate row increments */
+  csx = 0;
+  csax = sax;
+  for (x = 0; x < dst->w; x++)
   {
   {
-    for (x = 0; x < dx; x++)
-    {
-      Callback(Surface, px, py, Color);
+    csx += sx;
+    *csax = (csx >> 16);
+    csx &= 0xffff;
+    csax++;
+  }
 
 
-      y += dy;
-      if (y >= dx)
-      {
-       y -= dx;
-       py += sdy;
-      }
+  csy = 0;
+  csay = say;
+  for (y = 0; y < dst->h; y++)
+  {
+    csy += sy;
+    *csay = (csy >> 16);
+    csy &= 0xffff;
+    csay++;
+  }
 
 
-      px += sdx;
-    }
+  csx = 0;
+  csax = sax;
+  for (x = 0; x < dst->w; x++)
+  {
+    csx += (*csax);
+    csax++;
   }
   }
-  else
+
+  csy = 0;
+  csay = say;
+  for (y = 0; y < dst->h; y++)
   {
   {
-    for (y = 0; y < dy; y++)
+    csy += (*csay);
+    csay++;
+  }
+
+  /* pointer setup */
+  sp = csp = (Uint8 *) src->pixels;
+  dp = (Uint8 *) dst->pixels;
+  dgap = dst->pitch - dst->w;
+
+  /* draw */
+  csay = say;
+  for (y = 0; y < dst->h; y++)
+  {
+    csax = sax;
+    sp = csp;
+    for (x = 0; x < dst->w; x++)
     {
     {
-      Callback(Surface, px, py, Color);
+      /* draw */
+      *dp = *sp;
 
 
-      x += dx;
-      if (x >= dy)
-      {
-       x -= dy;
-       px += sdx;
-      }
+      /* advance source pointers */
+      sp += (*csax);
+      csax++;
 
 
-      py += sdy;
+      /* advance destination pointer */
+      dp++;
     }
     }
+
+    /* advance source pointer (for row) */
+    csp += ((*csay) * src->pitch);
+    csay++;
+
+    /* advance destination pointers */
+    dp += dgap;
   }
   }
-}
 
 
-void sge_DoLineRGB(SDL_Surface *Surface, Sint16 X1, Sint16 Y1,
-                  Sint16 X2, Sint16 Y2, Uint8 R, Uint8 G, Uint8 B,
-                  void Callback(SDL_Surface *Surf, Sint16 X, Sint16 Y,
-                                Uint32 Color))
-{
-  sge_DoLine(Surface, X1, Y1, X2, Y2,
-            SDL_MapRGB(Surface->format, R, G, B), Callback);
+  free(sax);
+  free(say);
+
+  return 0;
 }
 
 }
 
-void sge_Line(SDL_Surface *Surface, Sint16 x1, Sint16 y1, Sint16 x2, Sint16 y2,
-             Uint32 Color)
+/*
+  -----------------------------------------------------------------------------
+  zoomSurface()
+
+  Zooms a 32bit or 8bit 'src' surface to newly created 'dst' surface.
+  'zoomx' and 'zoomy' are scaling factors for width and height.
+  If the surface is not 8bit or 32bit RGBA/ABGR it will be converted
+  into a 32bit RGBA format on the fly.
+  -----------------------------------------------------------------------------
+*/
+
+SDL_Surface *zoomSurface(SDL_Surface *src, int dst_width, int dst_height)
 {
 {
-  if (SDL_MUSTLOCK(Surface))
+  SDL_Surface *zoom_src = NULL;
+  SDL_Surface *zoom_dst = NULL;
+  boolean is_converted = FALSE;
+  boolean is_32bit;
+  int i;
+
+  if (src == NULL)
+    return NULL;
+
+  /* determine if source surface is 32 bit or 8 bit */
+  is_32bit = (src->format->BitsPerPixel == 32);
+
+  if (is_32bit || src->format->BitsPerPixel == 8)
   {
   {
-    if (SDL_LockSurface(Surface) < 0)
-      return;
-   }
+    /* use source surface 'as is' */
+    zoom_src = src;
+  }
+  else
+  {
+    /* new source surface is 32 bit with a defined RGB ordering */
+    zoom_src = SDL_CreateRGBSurface(SURFACE_FLAGS, src->w, src->h, 32,
+                                   0x000000ff, 0x0000ff00, 0x00ff0000, 0);
+    SDL_BlitSurface(src, NULL, zoom_src, NULL);
+    is_32bit = TRUE;
+    is_converted = TRUE;
+  }
 
 
-   /* Draw the line */
-   sge_DoLine(Surface, x1, y1, x2, y2, Color, _PutPixel);
+  /* allocate surface to completely contain the zoomed surface */
+  if (is_32bit)
+  {
+    /* target surface is 32 bit with source RGBA/ABGR ordering */
+    zoom_dst = SDL_CreateRGBSurface(SURFACE_FLAGS, dst_width, dst_height, 32,
+                                   zoom_src->format->Rmask,
+                                   zoom_src->format->Gmask,
+                                   zoom_src->format->Bmask, 0);
+  }
+  else
+  {
+    /* target surface is 8 bit */
+    zoom_dst = SDL_CreateRGBSurface(SURFACE_FLAGS, dst_width, dst_height, 8,
+                                   0, 0, 0, 0);
+  }
 
 
-   /* unlock the display */
-   if (SDL_MUSTLOCK(Surface))
-   {
-      SDL_UnlockSurface(Surface);
-   }
+  /* lock source surface */
+  SDL_LockSurface(zoom_src);
+
+  /* check which kind of surface we have */
+  if (is_32bit)
+  {
+    /* call the 32 bit transformation routine to do the zooming */
+    zoomSurfaceRGBA(zoom_src, zoom_dst);
+  }
+  else
+  {
+    /* copy palette */
+    for (i = 0; i < zoom_src->format->palette->ncolors; i++)
+      zoom_dst->format->palette->colors[i] =
+       zoom_src->format->palette->colors[i];
+    zoom_dst->format->palette->ncolors = zoom_src->format->palette->ncolors;
+
+    /* call the 8 bit transformation routine to do the zooming */
+    zoomSurfaceY(zoom_src, zoom_dst);
+  }
+
+  /* unlock source surface */
+  SDL_UnlockSurface(zoom_src);
+
+  /* free temporary surface */
+  if (is_converted)
+    SDL_FreeSurface(zoom_src);
+
+  /* return destination surface */
+  return zoom_dst;
 }
 
 }
 
-void sge_LineRGB(SDL_Surface *Surface, Sint16 x1, Sint16 y1, Sint16 x2,
-                Sint16 y2, Uint8 R, Uint8 G, Uint8 B)
+Bitmap *SDLZoomBitmap(Bitmap *src_bitmap, int dst_width, int dst_height)
 {
 {
-  sge_Line(Surface, x1, y1, x2, y2, SDL_MapRGB(Surface->format, R, G, B));
+  Bitmap *dst_bitmap = CreateBitmapStruct();
+  SDL_Surface **dst_surface = &dst_bitmap->surface;
+
+  dst_width  = MAX(1, dst_width);      /* prevent zero bitmap width */
+  dst_height = MAX(1, dst_height);     /* prevent zero bitmap height */
+
+  dst_bitmap->width  = dst_width;
+  dst_bitmap->height = dst_height;
+
+  /* create zoomed temporary surface from source surface */
+  *dst_surface = zoomSurface(src_bitmap->surface, dst_width, dst_height);
+
+  /* create native format destination surface from zoomed temporary surface */
+  SDLSetNativeSurface(dst_surface);
+
+  return dst_bitmap;
 }
 
 }
 
+
+/* ========================================================================= */
+/* load image to bitmap                                                      */
+/* ========================================================================= */
+
 Bitmap *SDLLoadImage(char *filename)
 {
   Bitmap *new_bitmap = CreateBitmapStruct();
   SDL_Surface *sdl_image_tmp;
 
 Bitmap *SDLLoadImage(char *filename)
 {
   Bitmap *new_bitmap = CreateBitmapStruct();
   SDL_Surface *sdl_image_tmp;
 
+  print_timestamp_init("SDLLoadImage");
+
+  print_timestamp_time(getBaseNamePtr(filename));
+
   /* load image to temporary surface */
   if ((sdl_image_tmp = IMG_Load(filename)) == NULL)
   /* load image to temporary surface */
   if ((sdl_image_tmp = IMG_Load(filename)) == NULL)
-    Error(ERR_EXIT, "IMG_Load() failed: %s", SDL_GetError());
+  {
+    SetError("IMG_Load(): %s", SDL_GetError());
+
+    return NULL;
+  }
+
+  print_timestamp_time("IMG_Load");
+
+  UPDATE_BUSY_STATE();
 
   /* create native non-transparent surface for current image */
 
   /* create native non-transparent surface for current image */
-  if ((new_bitmap->surface = SDL_DisplayFormat(sdl_image_tmp)) == NULL)
-    Error(ERR_EXIT, "SDL_DisplayFormat() failed: %s", SDL_GetError());
+  if ((new_bitmap->surface = SDLGetNativeSurface(sdl_image_tmp)) == NULL)
+  {
+    SetError("SDL_DisplayFormat(): %s", SDL_GetError());
+
+    return NULL;
+  }
+
+  print_timestamp_time("SDL_DisplayFormat (opaque)");
+
+  UPDATE_BUSY_STATE();
 
   /* create native transparent surface for current image */
 
   /* create native transparent surface for current image */
-  SDL_SetColorKey(sdl_image_tmp, SDL_SRCCOLORKEY,
+  SDL_SetColorKey(sdl_image_tmp, SET_TRANSPARENT_PIXEL,
                  SDL_MapRGB(sdl_image_tmp->format, 0x00, 0x00, 0x00));
                  SDL_MapRGB(sdl_image_tmp->format, 0x00, 0x00, 0x00));
-  if ((new_bitmap->surface_masked = SDL_DisplayFormat(sdl_image_tmp)) == NULL)
-    Error(ERR_EXIT, "SDL_DisplayFormat() failed: %s", SDL_GetError());
+
+  if ((new_bitmap->surface_masked = SDLGetNativeSurface(sdl_image_tmp)) == NULL)
+  {
+    SetError("SDL_DisplayFormat(): %s", SDL_GetError());
+
+    return NULL;
+  }
+
+  print_timestamp_time("SDL_DisplayFormat (masked)");
+
+  UPDATE_BUSY_STATE();
 
   /* free temporary surface */
   SDL_FreeSurface(sdl_image_tmp);
 
 
   /* free temporary surface */
   SDL_FreeSurface(sdl_image_tmp);
 
+  new_bitmap->width = new_bitmap->surface->w;
+  new_bitmap->height = new_bitmap->surface->h;
+
+  print_timestamp_done("SDLLoadImage");
+
   return new_bitmap;
 }
 
 
   return new_bitmap;
 }
 
 
+/* ------------------------------------------------------------------------- */
+/* custom cursor fuctions                                                    */
+/* ------------------------------------------------------------------------- */
+
+static SDL_Cursor *create_cursor(struct MouseCursorInfo *cursor_info)
+{
+  return SDL_CreateCursor(cursor_info->data, cursor_info->mask,
+                         cursor_info->width, cursor_info->height,
+                         cursor_info->hot_x, cursor_info->hot_y);
+}
+
+void SDLSetMouseCursor(struct MouseCursorInfo *cursor_info)
+{
+  static struct MouseCursorInfo *last_cursor_info = NULL;
+  static struct MouseCursorInfo *last_cursor_info2 = NULL;
+  static SDL_Cursor *cursor_default = NULL;
+  static SDL_Cursor *cursor_current = NULL;
+
+  /* if invoked for the first time, store the SDL default cursor */
+  if (cursor_default == NULL)
+    cursor_default = SDL_GetCursor();
+
+  /* only create new cursor if cursor info (custom only) has changed */
+  if (cursor_info != NULL && cursor_info != last_cursor_info)
+  {
+    cursor_current = create_cursor(cursor_info);
+    last_cursor_info = cursor_info;
+  }
+
+  /* only set new cursor if cursor info (custom or NULL) has changed */
+  if (cursor_info != last_cursor_info2)
+    SDL_SetCursor(cursor_info ? cursor_current : cursor_default);
+
+  last_cursor_info2 = cursor_info;
+}
+
+
 /* ========================================================================= */
 /* audio functions                                                           */
 /* ========================================================================= */
 
 /* ========================================================================= */
 /* audio functions                                                           */
 /* ========================================================================= */
 
-inline void SDLOpenAudio(void)
+void SDLOpenAudio(void)
 {
 {
+#if !defined(TARGET_SDL2)
+  if (!strEqual(setup.system.sdl_audiodriver, ARG_DEFAULT))
+    SDL_putenv(getStringCat2("SDL_AUDIODRIVER=", setup.system.sdl_audiodriver));
+#endif
+
   if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0)
   {
     Error(ERR_WARN, "SDL_InitSubSystem() failed: %s", SDL_GetError());
     return;
   }
 
   if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0)
   {
     Error(ERR_WARN, "SDL_InitSubSystem() failed: %s", SDL_GetError());
     return;
   }
 
-  if (Mix_OpenAudio(DEFAULT_AUDIO_SAMPLE_RATE, AUDIO_S16,
-                   AUDIO_STEREO_CHANNELS,
-                   DEFAULT_AUDIO_FRAGMENT_SIZE) < 0)
+  if (Mix_OpenAudio(DEFAULT_AUDIO_SAMPLE_RATE, MIX_DEFAULT_FORMAT,
+                   AUDIO_NUM_CHANNELS_STEREO,
+                   setup.system.audio_fragment_size) < 0)
   {
     Error(ERR_WARN, "Mix_OpenAudio() failed: %s", SDL_GetError());
     return;
   {
     Error(ERR_WARN, "Mix_OpenAudio() failed: %s", SDL_GetError());
     return;
@@ -727,27 +2426,236 @@ inline void SDLOpenAudio(void)
   audio.loops_available = TRUE;
   audio.sound_enabled = TRUE;
 
   audio.loops_available = TRUE;
   audio.sound_enabled = TRUE;
 
-  /* determine number of available channels */
-  audio.channels = Mix_AllocateChannels(MIX_CHANNELS);
+  /* set number of available mixer channels */
+  audio.num_channels = Mix_AllocateChannels(NUM_MIXER_CHANNELS);
+  audio.music_channel = MUSIC_CHANNEL;
+  audio.first_sound_channel = FIRST_SOUND_CHANNEL;
+
+  Mixer_InitChannels();
+}
+
+void SDLCloseAudio(void)
+{
+  Mix_HaltMusic();
+  Mix_HaltChannel(-1);
+
+  Mix_CloseAudio();
+  SDL_QuitSubSystem(SDL_INIT_AUDIO);
+}
+
+
+/* ========================================================================= */
+/* event functions                                                           */
+/* ========================================================================= */
+
+void SDLNextEvent(Event *event)
+{
+  SDL_WaitEvent(event);
 
 
-  if (!audio.mods_available)   /* reserve first channel for music loops */
+  if (event->type == EVENT_BUTTONPRESS ||
+      event->type == EVENT_BUTTONRELEASE)
+  {
+    if (((ButtonEvent *)event)->x > video_xoffset)
+      ((ButtonEvent *)event)->x -= video_xoffset;
+    else
+      ((ButtonEvent *)event)->x = 0;
+    if (((ButtonEvent *)event)->y > video_yoffset)
+      ((ButtonEvent *)event)->y -= video_yoffset;
+    else
+      ((ButtonEvent *)event)->y = 0;
+  }
+  else if (event->type == EVENT_MOTIONNOTIFY)
   {
   {
-    if (Mix_ReserveChannels(1) == 1)
-      audio.music_channel = 0;
+    if (((MotionEvent *)event)->x > video_xoffset)
+      ((MotionEvent *)event)->x -= video_xoffset;
     else
     else
-      audio.music_available = FALSE;
+      ((MotionEvent *)event)->x = 0;
+    if (((MotionEvent *)event)->y > video_yoffset)
+      ((MotionEvent *)event)->y -= video_yoffset;
+    else
+      ((MotionEvent *)event)->y = 0;
+  }
+}
+
+void SDLHandleWindowManagerEvent(Event *event)
+{
+#ifdef DEBUG
+#if defined(PLATFORM_WIN32)
+  // experimental drag and drop code
+
+  SDL_SysWMEvent *syswmevent = (SDL_SysWMEvent *)event;
+  SDL_SysWMmsg *syswmmsg = (SDL_SysWMmsg *)(syswmevent->msg);
+
+#if defined(TARGET_SDL2)
+  if (syswmmsg->msg.win.msg == WM_DROPFILES)
+#else
+  if (syswmmsg->msg == WM_DROPFILES)
+#endif
+  {
+#if defined(TARGET_SDL2)
+    HDROP hdrop = (HDROP)syswmmsg->msg.win.wParam;
+#else
+    HDROP hdrop = (HDROP)syswmmsg->wParam;
+#endif
+    int i, num_files;
+
+    printf("::: SDL_SYSWMEVENT:\n");
+
+    num_files = DragQueryFile(hdrop, 0xffffffff, NULL, 0);
+
+    for (i = 0; i < num_files; i++)
+    {
+      int buffer_len = DragQueryFile(hdrop, i, NULL, 0);
+      char buffer[buffer_len + 1];
+
+      DragQueryFile(hdrop, i, buffer, buffer_len + 1);
+
+      printf("::: - '%s'\n", buffer);
+    }
+
+#if defined(TARGET_SDL2)
+    DragFinish((HDROP)syswmmsg->msg.win.wParam);
+#else
+    DragFinish((HDROP)syswmmsg->wParam);
+#endif
   }
   }
+#endif
+#endif
+}
+
+
+/* ========================================================================= */
+/* joystick functions                                                        */
+/* ========================================================================= */
 
 
-  Mix_Volume(-1, SOUND_MAX_VOLUME);
-  Mix_VolumeMusic(SOUND_MAX_VOLUME);
+static SDL_Joystick *sdl_joystick[MAX_PLAYERS] = { NULL, NULL, NULL, NULL };
+static int sdl_js_axis[MAX_PLAYERS][2]   = { {0, 0}, {0, 0}, {0, 0}, {0, 0} };
+static int sdl_js_button[MAX_PLAYERS][2] = { {0, 0}, {0, 0}, {0, 0}, {0, 0} };
+
+static boolean SDLOpenJoystick(int nr)
+{
+  if (nr < 0 || nr > MAX_PLAYERS)
+    return FALSE;
+
+  return ((sdl_joystick[nr] = SDL_JoystickOpen(nr)) == NULL ? FALSE : TRUE);
 }
 
 }
 
-inline void SDLCloseAudio(void)
+static void SDLCloseJoystick(int nr)
 {
 {
-  Mix_HaltMusic();
-  Mix_HaltChannel(-1);
+  if (nr < 0 || nr > MAX_PLAYERS)
+    return;
 
 
-  Mix_CloseAudio();
+  SDL_JoystickClose(sdl_joystick[nr]);
+
+  sdl_joystick[nr] = NULL;
+}
+
+static boolean SDLCheckJoystickOpened(int nr)
+{
+  if (nr < 0 || nr > MAX_PLAYERS)
+    return FALSE;
+
+#if defined(TARGET_SDL2)
+  return (sdl_joystick[nr] != NULL ? TRUE : FALSE);
+#else
+  return (SDL_JoystickOpened(nr) ? TRUE : FALSE);
+#endif
+}
+
+void HandleJoystickEvent(Event *event)
+{
+  switch(event->type)
+  {
+    case SDL_JOYAXISMOTION:
+      if (event->jaxis.axis < 2)
+       sdl_js_axis[event->jaxis.which][event->jaxis.axis]= event->jaxis.value;
+      break;
+
+    case SDL_JOYBUTTONDOWN:
+      if (event->jbutton.button < 2)
+       sdl_js_button[event->jbutton.which][event->jbutton.button] = TRUE;
+      break;
+
+    case SDL_JOYBUTTONUP:
+      if (event->jbutton.button < 2)
+       sdl_js_button[event->jbutton.which][event->jbutton.button] = FALSE;
+      break;
+
+    default:
+      break;
+  }
+}
+
+void SDLInitJoysticks()
+{
+  static boolean sdl_joystick_subsystem_initialized = FALSE;
+  boolean print_warning = !sdl_joystick_subsystem_initialized;
+  int i;
+
+  if (!sdl_joystick_subsystem_initialized)
+  {
+    sdl_joystick_subsystem_initialized = TRUE;
+
+    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) < 0)
+    {
+      Error(ERR_EXIT, "SDL_Init() failed: %s", SDL_GetError());
+      return;
+    }
+  }
+
+  for (i = 0; i < MAX_PLAYERS; i++)
+  {
+    /* get configured joystick for this player */
+    char *device_name = setup.input[i].joy.device_name;
+    int joystick_nr = getJoystickNrFromDeviceName(device_name);
+
+    if (joystick_nr >= SDL_NumJoysticks())
+    {
+      if (setup.input[i].use_joystick && print_warning)
+       Error(ERR_WARN, "cannot find joystick %d", joystick_nr);
+
+      joystick_nr = -1;
+    }
+
+    /* misuse joystick file descriptor variable to store joystick number */
+    joystick.fd[i] = joystick_nr;
+
+    if (joystick_nr == -1)
+      continue;
+
+    /* this allows subsequent calls to 'InitJoysticks' for re-initialization */
+    if (SDLCheckJoystickOpened(joystick_nr))
+      SDLCloseJoystick(joystick_nr);
+
+    if (!setup.input[i].use_joystick)
+      continue;
+
+    if (!SDLOpenJoystick(joystick_nr))
+    {
+      if (print_warning)
+       Error(ERR_WARN, "cannot open joystick %d", joystick_nr);
+
+      continue;
+    }
+
+    joystick.status = JOYSTICK_ACTIVATED;
+  }
 }
 
 }
 
-#endif /* TARGET_SDL */
+boolean SDLReadJoystick(int nr, int *x, int *y, boolean *b1, boolean *b2)
+{
+  if (nr < 0 || nr >= MAX_PLAYERS)
+    return FALSE;
+
+  if (x != NULL)
+    *x = sdl_js_axis[nr][0];
+  if (y != NULL)
+    *y = sdl_js_axis[nr][1];
+
+  if (b1 != NULL)
+    *b1 = sdl_js_button[nr][0];
+  if (b2 != NULL)
+    *b2 = sdl_js_button[nr][1];
+
+  return TRUE;
+}