improved virtual buttons for touch devices (Android)
[rocksndiamonds.git] / src / libgame / sdl.c
index 4c484243934102774e2670d626f967495d87ef53..7221c7afeede8e9655e005b63d98bb8c4e1b51e0 100644 (file)
@@ -1,15 +1,13 @@
-/***********************************************************
-* Artsoft Retro-Game Library                               *
-*----------------------------------------------------------*
-* (c) 1994-2006 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 "misc.h"
 #include "setup.h"
 
+#define ENABLE_UNUSED_CODE     0       /* currently unused functions */
 
-#if defined(TARGET_SDL)
 
 /* ========================================================================= */
 /* video functions                                                           */
 /* ========================================================================= */
 
+/* SDL internal variables */
+#if defined(TARGET_SDL2)
+static SDL_Window *sdl_window = NULL;
+static SDL_Renderer *sdl_renderer = NULL;
+static SDL_Texture *sdl_texture_stream = NULL;
+static SDL_Texture *sdl_texture_target = NULL;
+static boolean fullscreen_enabled = FALSE;
+#endif
+
+static boolean limit_screen_updates = FALSE;
+
+
 /* functions from SGE library */
 void sge_Line(SDL_Surface *, Sint16, Sint16, Sint16, Sint16, Uint32);
 
-/* 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;
+/* functions to draw overlay graphics for touch device input */
+static void DrawTouchInputOverlay();
 
-static void setFullscreenParameters(char *fullscreen_mode_string)
+void SDLLimitScreenUpdates(boolean enable)
 {
-  struct ScreenModeInfo *fullscreen_mode;
-  int i;
+  limit_screen_updates = enable;
+}
+
+static void FinalizeScreen(int draw_target)
+{
+  // copy global animations to render target buffer, if defined (below border)
+  if (gfx.draw_global_anim_function != NULL)
+    gfx.draw_global_anim_function(draw_target, DRAW_GLOBAL_ANIM_STAGE_1);
+
+  // copy global masked border to render target buffer, if defined
+  if (gfx.draw_global_border_function != NULL)
+    gfx.draw_global_border_function(draw_target);
+
+  // copy global animations to render target buffer, if defined (above border)
+  if (gfx.draw_global_anim_function != NULL)
+    gfx.draw_global_anim_function(draw_target, DRAW_GLOBAL_ANIM_STAGE_2);
+}
 
-  fullscreen_mode = get_screen_mode_from_string(fullscreen_mode_string);
+static void UpdateScreenExt(SDL_Rect *rect, boolean with_frame_delay)
+{
+  static unsigned int update_screen_delay = 0;
+  unsigned int update_screen_delay_value = 50;         /* (milliseconds) */
+  SDL_Surface *screen = backbuffer->surface;
 
-  if (fullscreen_mode == NULL)
+  if (limit_screen_updates &&
+      !DelayReached(&update_screen_delay, update_screen_delay_value))
     return;
 
-  for (i = 0; video.fullscreen_modes[i].width != -1; i++)
+  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 (video.screen_rendering_mode == SPECIAL_RENDERING_BITMAP &&
+      gfx.final_screen_bitmap != NULL) // may not be initialized yet
   {
-    if (fullscreen_mode->width  == video.fullscreen_modes[i].width &&
-       fullscreen_mode->height == video.fullscreen_modes[i].height)
+    // draw global animations using bitmaps instead of using textures
+    // to prevent texture scaling artefacts (this is potentially slower)
+
+    BlitBitmap(backbuffer, gfx.final_screen_bitmap, 0, 0,
+              gfx.win_xsize, gfx.win_ysize, 0, 0);
+
+    FinalizeScreen(DRAW_TO_SCREEN);
+
+    screen = gfx.final_screen_bitmap->surface;
+
+    // force full window redraw
+    rect = NULL;
+  }
+
+#if defined(TARGET_SDL2)
+  SDL_Texture *sdl_texture = sdl_texture_stream;
+
+  // deactivate use of target texture if render targets are not supported
+  if ((video.screen_rendering_mode == SPECIAL_RENDERING_TARGET ||
+       video.screen_rendering_mode == SPECIAL_RENDERING_DOUBLE) &&
+      sdl_texture_target == NULL)
+    video.screen_rendering_mode = SPECIAL_RENDERING_OFF;
+
+  if (video.screen_rendering_mode == SPECIAL_RENDERING_TARGET)
+    sdl_texture = sdl_texture_target;
+
+  if (rect)
+  {
+    int bytes_x = screen->pitch / video.width;
+    int bytes_y = screen->pitch;
+
+    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);
+  }
+
+  int xoff = video.screen_xoffset;
+  int yoff = video.screen_yoffset;
+  SDL_Rect dst_rect_screen = { xoff, yoff, video.width, video.height };
+  SDL_Rect *src_rect1 = NULL, *dst_rect1 = NULL;
+  SDL_Rect *src_rect2 = NULL, *dst_rect2 = NULL;
+
+  if (video.screen_rendering_mode == SPECIAL_RENDERING_TARGET ||
+      video.screen_rendering_mode == SPECIAL_RENDERING_DOUBLE)
+    dst_rect2 = &dst_rect_screen;
+  else
+    dst_rect1 = &dst_rect_screen;
+
+#if defined(HAS_SCREEN_KEYBOARD)
+  if (video.shifted_up || video.shifted_up_delay)
+  {
+    int time_current = SDL_GetTicks();
+    int pos = video.shifted_up_pos;
+    int pos_last = video.shifted_up_pos_last;
+
+    if (!DelayReachedExt(&video.shifted_up_delay, video.shifted_up_delay_value,
+                        time_current))
     {
-      fullscreen_width  = fullscreen_mode->width;
-      fullscreen_height = fullscreen_mode->height;
+      int delay = time_current - video.shifted_up_delay;
+      int delay_value = video.shifted_up_delay_value;
 
-      fullscreen_xoffset = (fullscreen_width  - video.width)  / 2;
-      fullscreen_yoffset = (fullscreen_height - video.height) / 2;
+      pos = pos_last + (pos - pos_last) * delay / delay_value;
+    }
+    else
+    {
+      video.shifted_up_pos_last = pos;
+      video.shifted_up_delay = 0;
+    }
 
-      break;
+    SDL_Rect src_rect_up = { 0,    pos,  video.width, video.height - pos };
+    SDL_Rect dst_rect_up = { xoff, yoff, video.width, video.height - pos };
+
+    if (video.screen_rendering_mode == SPECIAL_RENDERING_TARGET ||
+       video.screen_rendering_mode == SPECIAL_RENDERING_DOUBLE)
+    {
+      src_rect2 = &src_rect_up;
+      dst_rect2 = &dst_rect_up;
     }
+    else
+    {
+      src_rect1 = &src_rect_up;
+      dst_rect1 = &dst_rect_up;
+    }
+  }
+#endif
+
+  // clear render target buffer
+  SDL_RenderClear(sdl_renderer);
+
+  // set renderer to use target texture for rendering
+  if (video.screen_rendering_mode == SPECIAL_RENDERING_TARGET ||
+      video.screen_rendering_mode == SPECIAL_RENDERING_DOUBLE)
+    SDL_SetRenderTarget(sdl_renderer, sdl_texture_target);
+
+  // copy backbuffer texture to render target buffer
+  if (video.screen_rendering_mode != SPECIAL_RENDERING_TARGET)
+    SDL_RenderCopy(sdl_renderer, sdl_texture_stream, src_rect1, dst_rect1);
+
+  if (video.screen_rendering_mode != SPECIAL_RENDERING_BITMAP)
+    FinalizeScreen(DRAW_TO_SCREEN);
+
+  // when using target texture, copy it to screen buffer
+  if (video.screen_rendering_mode == SPECIAL_RENDERING_TARGET ||
+      video.screen_rendering_mode == SPECIAL_RENDERING_DOUBLE)
+  {
+    SDL_SetRenderTarget(sdl_renderer, NULL);
+    SDL_RenderCopy(sdl_renderer, sdl_texture_target, src_rect2, dst_rect2);
   }
+
+  // draw overlay graphics for touch device input, if needed
+  DrawTouchInputOverlay();
+#endif
+
+  // global synchronization point of the game to align video frame delay
+  if (with_frame_delay)
+    WaitUntilDelayReached(&video.frame_delay, video.frame_delay_value);
+
+#if defined(TARGET_SDL2)
+ // show render target buffer on screen
+  SDL_RenderPresent(sdl_renderer);
+#else  // TARGET_SDL
+  if (rect)
+    SDL_UpdateRects(screen, 1, rect);
+  else
+    SDL_UpdateRect(screen, 0, 0, 0, 0);
+#endif
+}
+
+static void UpdateScreen_WithFrameDelay(SDL_Rect *rect)
+{
+  UpdateScreenExt(rect, TRUE);
+}
+
+static void UpdateScreen_WithoutFrameDelay(SDL_Rect *rect)
+{
+  UpdateScreenExt(rect, FALSE);
 }
 
 static void SDLSetWindowIcon(char *basename)
@@ -85,271 +258,735 @@ static void SDLSetWindowIcon(char *basename)
   }
 
   /* set transparent color */
-  SDL_SetColorKey(surface, SDL_SRCCOLORKEY,
+  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);
+}
+
+static Pixel SDLGetColorKey(SDL_Surface *surface)
+{
+  Pixel color_key;
+
+  if (SDL_GetColorKey(surface, &color_key) != 0)
+    return -1;
+
+  return color_key;
+}
+
+static boolean SDLHasColorKey(SDL_Surface *surface)
+{
+  return (SDLGetColorKey(surface) != -1);
+}
+
+static boolean SDLHasAlpha(SDL_Surface *surface)
+{
+  SDL_BlendMode blend_mode;
+
+  if (SDL_GetSurfaceBlendMode(surface, &blend_mode) != 0)
+    return FALSE;
+
+  return (blend_mode == SDL_BLENDMODE_BLEND);
+}
+
+static void SDLSetAlpha(SDL_Surface *surface, boolean set, int alpha)
+{
+  SDL_BlendMode blend_mode = (set ? SDL_BLENDMODE_BLEND : SDL_BLENDMODE_NONE);
+
+  SDL_SetSurfaceBlendMode(surface, blend_mode);
+  SDL_SetSurfaceAlphaMod(surface, alpha);
+}
+
+SDL_Surface *SDLGetNativeSurface(SDL_Surface *surface)
+{
+  SDL_PixelFormat format;
+  SDL_Surface *new_surface;
+
+  if (surface == NULL)
+    return NULL;
+
+  if (backbuffer && backbuffer->surface)
+  {
+    format = *backbuffer->surface->format;
+    format.Amask = surface->format->Amask;     // keep alpha channel
+  }
+  else
+  {
+    format = *surface->format;
+  }
+
+  new_surface = SDL_ConvertSurface(surface, &format, 0);
+
+  if (new_surface == NULL)
+    Error(ERR_EXIT, "SDL_ConvertSurface() failed: %s", SDL_GetError());
+
+  return new_surface;
+}
+
+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 = SDLGetNativeSurface(*surface);
+
+  SDL_FreeSurface(*surface);
+
+  *surface = new_surface;
+
+  return TRUE;
+}
+
+#else
+
+static Pixel SDLGetColorKey(SDL_Surface *surface)
+{
+  if ((surface->flags & SDL_SRCCOLORKEY) == 0)
+    return -1;
+
+  return surface->format->colorkey;
+}
+
+static boolean SDLHasColorKey(SDL_Surface *surface)
+{
+  return (SDLGetColorKey(surface) != -1);
+}
+
+static boolean SDLHasAlpha(SDL_Surface *surface)
+{
+  return ((surface->flags & SDL_SRCALPHA) != 0);
+}
+
+static void SDLSetAlpha(SDL_Surface *surface, boolean set, int alpha)
+{
+  SDL_SetAlpha(surface, (set ? SDL_SRCALPHA : 0), alpha);
+}
+
+SDL_Surface *SDLGetNativeSurface(SDL_Surface *surface)
+{
+  SDL_Surface *new_surface;
+
+  if (surface == NULL)
+    return NULL;
+
+  if (!video.initialized)
+    new_surface = SDL_ConvertSurface(surface, surface->format, SURFACE_FLAGS);
+  else if (SDLHasAlpha(surface))
+    new_surface = SDL_DisplayFormatAlpha(surface);
+  else
+    new_surface = SDL_DisplayFormat(surface);
+
+  if (new_surface == NULL)
+    Error(ERR_EXIT, "%s() failed: %s",
+         (video.initialized ? "SDL_DisplayFormat" : "SDL_ConvertSurface"),
+         SDL_GetError());
+
+  return new_surface;
+}
+
+boolean SDLSetNativeSurface(SDL_Surface **surface)
+{
+  SDL_Surface *new_surface;
+
+  if (surface == NULL ||
+      *surface == NULL ||
+      !video.initialized)
+    return FALSE;
+
+  new_surface = SDLGetNativeSurface(*surface);
+
+  SDL_FreeSurface(*surface);
+
+  *surface = new_surface;
+
+  return TRUE;
+}
+
+#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;
+
+  if (bitmap->texture)
+    SDL_DestroyTexture(bitmap->texture);
+  if (bitmap->texture_masked)
+    SDL_DestroyTexture(bitmap->texture_masked);
+
+  bitmap->texture        = SDLCreateTextureFromSurface(bitmap->surface);
+  bitmap->texture_masked = SDLCreateTextureFromSurface(bitmap->surface_masked);
+#endif
+}
+
+void SDLFreeBitmapTextures(Bitmap *bitmap)
+{
+#if defined(TARGET_SDL2)
+  if (bitmap == NULL)
+    return;
+
+  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 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 */
+#if !defined(TARGET_SDL2)
   video.default_depth = SDL_GetVideoInfo()->vfmt->BitsPerPixel;
+#else
+  video.default_depth = 32;    // (how to determine video depth in SDL2?)
+#endif
+}
+
+void SDLInitVideoBuffer(boolean fullscreen)
+{
+  video.window_scaling_percent = setup.window_scaling_percent;
+  video.window_scaling_quality = setup.window_scaling_quality;
+
+  SDLSetScreenRenderingMode(setup.screen_rendering_mode);
+
+#if defined(TARGET_SDL2)
+  // SDL 2.0: support for (desktop) fullscreen mode available
+  video.fullscreen_available = TRUE;
+#else
+  // SDL 1.2: no support for fullscreen mode in R'n'D anymore
+  video.fullscreen_available = FALSE;
+#endif
+
+  /* open SDL video output device (window or fullscreen mode) */
+  if (!SDLSetVideoMode(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 */
+#if defined(TARGET_SDL2)
+  SDL_SetWindowTitle(sdl_window, program.window_title);
+#else
+  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
+     video framebuffer with 'SDL_UpdateRect' (or replaced with the current
+     visible video framebuffer with 'SDL_Flip', if the hardware supports
+     this). Therefore do not use an additional backbuffer for drawing, but
+     use a symbolic buffer (distinguishable from the SDL backbuffer) called
+     '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. */
+
+  /* create additional (symbolic) buffer for double-buffering */
+  ReCreateBitmap(&window, video.width, video.height);
 }
 
-void SDLInitVideoBuffer(DrawBuffer **backbuffer, DrawWindow **window,
-                       boolean fullscreen)
+static boolean SDLCreateScreen(boolean fullscreen)
 {
-  static int screen_xy[][2] =
+  SDL_Surface *new_surface = NULL;
+
+#if defined(TARGET_SDL2)
+  int surface_flags_window     = SURFACE_FLAGS | SDL_WINDOW_RESIZABLE;
+  int surface_flags_fullscreen = SURFACE_FLAGS | SDL_WINDOW_FULLSCREEN_DESKTOP;
+#else
+  int surface_flags_window     = SURFACE_FLAGS;
+  int surface_flags_fullscreen = SURFACE_FLAGS;        // (no fullscreen in SDL 1.2)
+#endif
+
+#if defined(TARGET_SDL2)
+#if 1
+  int renderer_flags = SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE;
+#else
+  /* 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) */
+  int renderer_flags = SDL_RENDERER_SOFTWARE;
+#endif
+#endif
+
+  SDLSetScreenSizeAndOffsets(video.width, video.height);
+
+  int width  = video.width;
+  int height = video.height;
+  int screen_width  = video.screen_width;
+  int screen_height = video.screen_height;
+  int surface_flags = (fullscreen ? surface_flags_fullscreen :
+                      surface_flags_window);
+
+  // default window size is unscaled
+  video.window_width  = screen_width;
+  video.window_height = screen_height;
+
+#if defined(TARGET_SDL2)
+
+  // store if initial screen mode is fullscreen mode when changing screen size
+  video.fullscreen_initial = fullscreen;
+
+  float window_scaling_factor = (float)setup.window_scaling_percent / 100;
+
+  video.window_width  = window_scaling_factor * screen_width;
+  video.window_height = window_scaling_factor * screen_height;
+
+  if (sdl_texture_stream)
   {
-    {  640, 480 },
-    {  800, 600 },
-    { 1024, 768 },
-    {   -1,  -1 }
-  };
-  SDL_Rect **modes;
-  int i, j;
+    SDL_DestroyTexture(sdl_texture_stream);
+    sdl_texture_stream = NULL;
+  }
 
-  /* default: normal game window size */
-  fullscreen_width = video.width;
-  fullscreen_height = video.height;
-  fullscreen_xoffset = 0;
-  fullscreen_yoffset = 0;
+  if (sdl_texture_target)
+  {
+    SDL_DestroyTexture(sdl_texture_target);
+    sdl_texture_target = NULL;
+  }
 
-  for (i = 0; screen_xy[i][0] != -1; i++)
+  if (!(fullscreen && fullscreen_enabled))
   {
-    if (screen_xy[i][0] >= video.width && screen_xy[i][1] >= video.height)
+    if (sdl_renderer)
     {
-      fullscreen_width  = screen_xy[i][0];
-      fullscreen_height = screen_xy[i][1];
+      SDL_DestroyRenderer(sdl_renderer);
+      sdl_renderer = NULL;
+    }
 
-      break;
+    if (sdl_window)
+    {
+      SDL_DestroyWindow(sdl_window);
+      sdl_window = NULL;
     }
   }
 
-  fullscreen_xoffset = (fullscreen_width  - video.width)  / 2;
-  fullscreen_yoffset = (fullscreen_height - video.height) / 2;
+  if (sdl_window == NULL)
+    sdl_window = SDL_CreateWindow(program.window_title,
+                                 SDL_WINDOWPOS_CENTERED,
+                                 SDL_WINDOWPOS_CENTERED,
+                                 video.window_width,
+                                 video.window_height,
+                                 surface_flags);
 
-#if 1
-  checked_free(video.fullscreen_modes);
-
-  video.fullscreen_modes = NULL;
-  video.fullscreen_mode_current = NULL;
-#endif
+  if (sdl_window != NULL)
+  {
+    if (sdl_renderer == NULL)
+      sdl_renderer = SDL_CreateRenderer(sdl_window, -1, renderer_flags);
 
-  /* get available hardware supported fullscreen modes */
-  modes = SDL_ListModes(NULL, SDL_FULLSCREEN | SDL_HWSURFACE);
+    if (sdl_renderer != NULL)
+    {
+      SDL_RenderSetLogicalSize(sdl_renderer, screen_width, screen_height);
+      // SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
+      SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, setup.window_scaling_quality);
+
+      sdl_texture_stream = SDL_CreateTexture(sdl_renderer,
+                                            SDL_PIXELFORMAT_ARGB8888,
+                                            SDL_TEXTUREACCESS_STREAMING,
+                                            width, height);
+
+      if (SDL_RenderTargetSupported(sdl_renderer))
+       sdl_texture_target = SDL_CreateTexture(sdl_renderer,
+                                              SDL_PIXELFORMAT_ARGB8888,
+                                              SDL_TEXTUREACCESS_TARGET,
+                                              width, height);
+
+      if (sdl_texture_stream != 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 (modes == NULL)
+       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
   {
-    /* no screen modes available => no fullscreen mode support */
-    video.fullscreen_available = FALSE;
+    Error(ERR_WARN, "SDL_CreateWindow() failed: %s", SDL_GetError());
   }
-  else if (modes == (SDL_Rect **)-1)
+
+#else  // TARGET_SDL
+
+  if (gfx.final_screen_bitmap == NULL)
+    gfx.final_screen_bitmap = CreateBitmapStruct();
+
+  gfx.final_screen_bitmap->width = width;
+  gfx.final_screen_bitmap->height = height;
+
+  gfx.final_screen_bitmap->surface =
+    SDL_SetVideoMode(width, height, video.depth, surface_flags);
+
+  if (gfx.final_screen_bitmap->surface != NULL)
   {
-    /* fullscreen resolution is not restricted -- all resolutions available */
-    video.fullscreen_modes = checked_calloc(2 * sizeof(struct ScreenModeInfo));
+    new_surface =
+      SDL_CreateRGBSurface(surface_flags, width, height, video.depth, 0,0,0, 0);
+
+    if (new_surface == NULL)
+      Error(ERR_WARN, "SDL_CreateRGBSurface() failed: %s", SDL_GetError());
 
-    /* use native video buffer size for fullscreen mode */
-    video.fullscreen_modes[0].width  = video.width;
-    video.fullscreen_modes[0].height = video.height;
+#if 0
+    new_surface = gfx.final_screen_bitmap->surface;
+    gfx.final_screen_bitmap = NULL;
+#endif
 
-    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;
+    Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+  }
+#endif
 
-    for(i = 0; modes[i] != NULL; i++)
-    {
-      boolean found_mode = FALSE;
+#if defined(TARGET_SDL2)
+  // store fullscreen state ("video.fullscreen_enabled" may not reflect this!)
+  if (new_surface != NULL)
+    fullscreen_enabled = fullscreen;
+#endif
 
-      /* screen mode is smaller than video buffer size -- skip it */
-      if (modes[i]->w < video.width || modes[i]->h < video.height)
-       continue;
+  if (backbuffer == NULL)
+    backbuffer = CreateBitmapStruct();
 
-      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;
+  backbuffer->width  = video.width;
+  backbuffer->height = video.height;
 
-      if (found_mode)          /* screen mode already stored -- skip it */
-       continue;
+  if (backbuffer->surface)
+    SDL_FreeSurface(backbuffer->surface);
 
-      /* new mode found; add it to list of available fullscreen modes */
+  backbuffer->surface = new_surface;
 
-      num_modes++;
+  return (new_surface != NULL);
+}
 
-      video.fullscreen_modes = checked_realloc(video.fullscreen_modes,
-                                              (num_modes + 1) *
-                                              sizeof(struct ScreenModeInfo));
+boolean SDLSetVideoMode(boolean fullscreen)
+{
+  boolean success = FALSE;
 
-      video.fullscreen_modes[num_modes - 1].width  = modes[i]->w;
-      video.fullscreen_modes[num_modes - 1].height = modes[i]->h;
+  SetWindowTitle();
 
-      video.fullscreen_modes[num_modes].width  = -1;
-      video.fullscreen_modes[num_modes].height = -1;
-    }
+  if (fullscreen && !video.fullscreen_enabled && video.fullscreen_available)
+  {
+    /* switch display to fullscreen mode, if available */
+    success = SDLCreateScreen(TRUE);
 
-    if (num_modes == 0)
+    if (!success)
     {
-      /* no appropriate screen modes available => no fullscreen mode support */
+      /* switching display to fullscreen mode failed -- do not try it again */
       video.fullscreen_available = FALSE;
     }
+    else
+    {
+      video.fullscreen_enabled = TRUE;
+    }
   }
 
-  /* set window icon */
-  SDLSetWindowIcon(program.sdl_icon_filename);
+  if ((!fullscreen && video.fullscreen_enabled) || !success)
+  {
+    /* switch display to window mode */
+    success = SDLCreateScreen(FALSE);
 
-  /* open SDL video output device (window or fullscreen mode) */
-  if (!SDLSetVideoMode(backbuffer, fullscreen))
-    Error(ERR_EXIT, "setting video mode failed");
+    if (!success)
+    {
+      /* switching display to window mode failed -- should not happen */
+    }
+    else
+    {
+      video.fullscreen_enabled = FALSE;
+      video.window_scaling_percent = setup.window_scaling_percent;
+      video.window_scaling_quality = setup.window_scaling_quality;
 
-  /* set window and icon title */
-  SDL_WM_SetCaption(program.window_title, program.window_title);
+      SDLSetScreenRenderingMode(setup.screen_rendering_mode);
+    }
+  }
 
-  /* SDL cannot directly draw to the visible video framebuffer like X11,
-     but always uses a backbuffer, which is then blitted to the visible
-     video framebuffer with 'SDL_UpdateRect' (or replaced with the current
-     visible video framebuffer with 'SDL_Flip', if the hardware supports
-     this). Therefore do not use an additional backbuffer for drawing, but
-     use a symbolic buffer (distinguishable from the SDL backbuffer) called
-     'window', which indicates that the SDL backbuffer should be updated to
-     the visible video framebuffer when attempting to blit to it.
+#if defined(TARGET_SDL2)
+  SDLRedrawWindow();                   // map window
+#endif
 
-     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. */
+#ifdef DEBUG
+#if defined(PLATFORM_WIN32)
+  // experimental drag and drop code
 
-  /* create additional (symbolic) buffer for double-buffering */
-#if 1
-  ReCreateBitmap(window, video.width, video.height, video.depth);
+  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
-  *window = CreateBitmap(video.width, video.height, video.depth);
+      hwnd = wminfo.window;
 #endif
+
+      DragAcceptFiles(hwnd, TRUE);
+    }
+  }
+#endif
+#endif
+
+  return success;
 }
 
-boolean SDLSetVideoMode(DrawBuffer **backbuffer, boolean fullscreen)
+void SDLSetWindowTitle()
 {
-  boolean success = TRUE;
-  int surface_flags_fullscreen = SURFACE_FLAGS | SDL_FULLSCREEN;
-  int surface_flags_window = SURFACE_FLAGS;
-  SDL_Surface *new_surface = NULL;
+#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.screen_width);
+  int new_window_height = (int)(window_scaling_factor * video.screen_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)
+{
+  SDL_Texture *new_texture;
+
+  if (sdl_texture_stream == NULL)
+    return;
+
+  SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, window_scaling_quality);
+
+  new_texture = SDL_CreateTexture(sdl_renderer,
+                                 SDL_PIXELFORMAT_ARGB8888,
+                                 SDL_TEXTUREACCESS_STREAMING,
+                                 video.width, video.height);
+
+  if (new_texture != NULL)
+  {
+    SDL_DestroyTexture(sdl_texture_stream);
+
+    sdl_texture_stream = new_texture;
+  }
+
+  if (SDL_RenderTargetSupported(sdl_renderer))
+    new_texture = SDL_CreateTexture(sdl_renderer,
+                                   SDL_PIXELFORMAT_ARGB8888,
+                                   SDL_TEXTUREACCESS_TARGET,
+                                   video.width, video.height);
+  else
+    new_texture = NULL;
 
-  if (*backbuffer == NULL)
-    *backbuffer = CreateBitmapStruct();
+  if (new_texture != NULL)
+  {
+    SDL_DestroyTexture(sdl_texture_target);
 
-  /* (real bitmap might be larger in fullscreen mode with video offsets) */
-  (*backbuffer)->width  = video.width;
-  (*backbuffer)->height = video.height;
+    sdl_texture_target = new_texture;
+  }
 
-  if (fullscreen && !video.fullscreen_enabled && video.fullscreen_available)
-  {
-    setFullscreenParameters(setup.fullscreen_mode);
+  SDLRedrawWindow();
 
-    video_xoffset = fullscreen_xoffset;
-    video_yoffset = fullscreen_yoffset;
+  video.window_scaling_quality = window_scaling_quality;
+}
 
-    /* switch display to fullscreen mode, if available */
-    if ((new_surface = SDL_SetVideoMode(fullscreen_width, fullscreen_height,
-                                       video.depth, surface_flags_fullscreen))
-       == NULL)
-    {
-      /* switching display to fullscreen mode failed */
-      Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+void SDLSetWindowFullscreen(boolean fullscreen)
+{
+  if (sdl_window == NULL)
+    return;
 
-      /* do not try it again */
-      video.fullscreen_available = FALSE;
+  int flags = (fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
 
-      success = FALSE;
-    }
-    else
-    {
-      (*backbuffer)->surface = new_surface;
+  if (SDL_SetWindowFullscreen(sdl_window, flags) == 0)
+    video.fullscreen_enabled = fullscreen_enabled = fullscreen;
 
-      video.fullscreen_enabled = TRUE;
-      video.fullscreen_mode_current = setup.fullscreen_mode;
+  // 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);
 
-      success = TRUE;
-    }
+    video.fullscreen_initial = FALSE;
   }
+}
 
-  if ((!fullscreen && video.fullscreen_enabled) || new_surface == NULL)
-  {
-    video_xoffset = 0;
-    video_yoffset = 0;
+void SDLSetDisplaySize()
+{
+  SDL_Rect display_bounds;
 
-    /* switch display to window mode */
-    if ((new_surface = SDL_SetVideoMode(video.width, video.height,
-                                       video.depth, surface_flags_window))
-       == NULL)
-    {
-      /* switching display to window mode failed -- should not happen */
-      Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+  SDL_GetDisplayBounds(0, &display_bounds);
 
-      success = FALSE;
-    }
-    else
-    {
-      (*backbuffer)->surface = new_surface;
+  video.display_width  = display_bounds.w;
+  video.display_height = display_bounds.h;
 
-      video.fullscreen_enabled = FALSE;
+#if 0
+  Error(ERR_DEBUG, "SDL real screen size: %d x %d",
+       video.display_width, video.display_height);
+#endif
+}
 
-      success = TRUE;
-    }
-  }
+void SDLSetScreenSizeAndOffsets(int width, int height)
+{
+  // set default video screen size and offsets
+  video.screen_width = width;
+  video.screen_height = height;
+  video.screen_xoffset = 0;
+  video.screen_yoffset = 0;
 
-#if 1
-  SDL_EventState(SDL_SYSWMEVENT, SDL_ENABLE);
+#if defined(USE_COMPLETE_DISPLAY)
+  float ratio_video   = (float) width / height;
+  float ratio_display = (float) video.display_width / video.display_height;
 
-#if defined(PLATFORM_WIN32)
+  if (ratio_video != ratio_display)
   {
-    SDL_SysWMinfo wminfo;
-    HWND hwnd;
+    // adjust drawable screen size to cover the whole device display
 
-    SDL_VERSION(&wminfo.version);
-    SDL_GetWMInfo(&wminfo);
+    if (ratio_video < ratio_display)
+      video.screen_width  *= ratio_display / ratio_video;
+    else
+      video.screen_height *= ratio_video / ratio_display;
 
-    hwnd = wminfo.window;
+    video.screen_xoffset = (video.screen_width  - width)  / 2;
+    video.screen_yoffset = (video.screen_height - height) / 2;
 
-    DragAcceptFiles(hwnd, TRUE);
+#if 0
+    Error(ERR_DEBUG, "Changing screen from %dx%d to %dx%d (%.2f to %.2f)",
+         width, height,
+         video.screen_width, video.screen_height,
+         ratio_video, ratio_display);
+#endif
   }
 #endif
+}
+
+void SDLSetScreenSizeForRenderer(int width, int height)
+{
+  SDL_RenderSetLogicalSize(sdl_renderer, width, height);
+}
+
+void SDLSetScreenProperties()
+{
+  SDLSetScreenSizeAndOffsets(video.width, video.height);
+  SDLSetScreenSizeForRenderer(video.screen_width, video.screen_height);
+}
+
 #endif
 
+void SDLSetScreenRenderingMode(char *screen_rendering_mode)
+{
+#if defined(TARGET_SDL2)
+  video.screen_rendering_mode =
+    (strEqual(screen_rendering_mode, STR_SPECIAL_RENDERING_BITMAP) ?
+     SPECIAL_RENDERING_BITMAP :
+     strEqual(screen_rendering_mode, STR_SPECIAL_RENDERING_TARGET) ?
+     SPECIAL_RENDERING_TARGET:
+     strEqual(screen_rendering_mode, STR_SPECIAL_RENDERING_DOUBLE) ?
+     SPECIAL_RENDERING_DOUBLE : SPECIAL_RENDERING_OFF);
+#else
+  video.screen_rendering_mode = SPECIAL_RENDERING_BITMAP;
+#endif
+}
 
-  return success;
+void SDLRedrawWindow()
+{
+  UpdateScreen_WithoutFrameDelay(NULL);
 }
 
-void SDLCreateBitmapContent(Bitmap *new_bitmap, int width, int height,
+void SDLCreateBitmapContent(Bitmap *bitmap, int width, int height,
                            int depth)
 {
-  SDL_Surface *surface_tmp, *surface_native;
+  SDL_Surface *surface =
+    SDL_CreateRGBSurface(SURFACE_FLAGS, width, height, depth, 0,0,0, 0);
 
-  if ((surface_tmp = SDL_CreateRGBSurface(SURFACE_FLAGS, width, height, depth,
-                                         0, 0, 0, 0))
-      == NULL)
+  if (surface == NULL)
     Error(ERR_EXIT, "SDL_CreateRGBSurface() failed: %s", SDL_GetError());
 
-  if ((surface_native = SDL_DisplayFormat(surface_tmp)) == NULL)
-    Error(ERR_EXIT, "SDL_DisplayFormat() failed: %s", SDL_GetError());
-
-  SDL_FreeSurface(surface_tmp);
+  SDLSetNativeSurface(&surface);
 
-  new_bitmap->surface = surface_native;
+  bitmap->surface = surface;
 }
 
 void SDLFreeBitmapPointers(Bitmap *bitmap)
@@ -358,8 +995,19 @@ void SDLFreeBitmapPointers(Bitmap *bitmap)
     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,
@@ -369,35 +1017,53 @@ void SDLCopyArea(Bitmap *src_bitmap, Bitmap *dst_bitmap,
   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)
+  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 (dst_bitmap == window)
-    SDL_UpdateRect(backbuffer->surface, dst_x, dst_y, width, height);
+    UpdateScreen_WithFrameDelay(&dst_rect);
+}
+
+void SDLBlitTexture(Bitmap *bitmap,
+                   int src_x, int src_y, int width, int height,
+                   int dst_x, int dst_y, int mask_mode)
+{
+#if defined(TARGET_SDL2)
+  SDL_Texture *texture;
+  SDL_Rect src_rect;
+  SDL_Rect dst_rect;
+
+  texture =
+    (mask_mode == BLIT_MASKED ? bitmap->texture_masked : bitmap->texture);
+
+  if (texture == NULL)
+    return;
+
+  src_rect.x = src_x;
+  src_rect.y = src_y;
+  src_rect.w = width;
+  src_rect.h = height;
+
+  dst_rect.x = dst_x;
+  dst_rect.y = dst_y;
+  dst_rect.w = width;
+  dst_rect.h = height;
+
+  SDL_RenderCopy(sdl_renderer, texture, &src_rect, &dst_rect);
+#endif
 }
 
 void SDLFillRectangle(Bitmap *dst_bitmap, int x, int y, int width, int height,
@@ -406,12 +1072,6 @@ void SDLFillRectangle(Bitmap *dst_bitmap, int x, int y, int width, int height,
   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;
@@ -420,115 +1080,76 @@ void SDLFillRectangle(Bitmap *dst_bitmap, int x, int y, int width, int height,
   SDL_FillRect(real_dst_bitmap->surface, &rect, color);
 
   if (dst_bitmap == window)
-    SDL_UpdateRect(backbuffer->surface, x, y, width, height);
+    UpdateScreen_WithFrameDelay(&rect);
+}
+
+void PrepareFadeBitmap(int draw_target)
+{
+  Bitmap *fade_bitmap =
+    (draw_target == DRAW_TO_FADE_SOURCE ? gfx.fade_bitmap_source :
+     draw_target == DRAW_TO_FADE_TARGET ? gfx.fade_bitmap_target : NULL);
+
+  if (fade_bitmap == NULL)
+    return;
+
+  // copy backbuffer to fading buffer
+  BlitBitmap(backbuffer, fade_bitmap, 0, 0, gfx.win_xsize, gfx.win_ysize, 0, 0);
+
+  // add border and animations to fading buffer
+  FinalizeScreen(draw_target);
 }
 
-void SDLFadeRectangle(Bitmap *bitmap_cross, int x, int y, int width, int height,
+void SDLFadeRectangle(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_backup = gfx.fade_bitmap_backup->surface;
+  SDL_Surface *surface_source = gfx.fade_bitmap_source->surface;
+  SDL_Surface *surface_target = gfx.fade_bitmap_target->surface;
+  SDL_Surface *surface_black  = gfx.fade_bitmap_black->surface;
   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);
+  // store function for drawing global masked border
+  void (*draw_global_border_function)(int) = gfx.draw_global_border_function;
 
-    initialization_needed = TRUE;
-  }
+  // deactivate drawing of global border while fading, if needed
+  if (draw_border_function == NULL)
+    gfx.draw_global_border_function = NULL;
 
   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) */
 
-  if (initialization_needed)
-  {
-    unsigned int flags = SDL_SRCALPHA;
+  dst_rect2 = dst_rect;
 
-    /* use same surface type as screen surface */
-    if ((surface_screen->flags & SDL_HWSURFACE))
-      flags |= SDL_HWSURFACE;
-    else
-      flags |= SDL_SWSURFACE;
-
-    /* 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;
-  }
+  // before fading in, store backbuffer (without animation graphics)
+  if (fade_mode & (FADE_TYPE_FADE_IN | FADE_TYPE_TRANSFORM))
+    SDL_BlitSurface(surface_screen, &dst_rect, surface_backup, &src_rect);
 
   /* 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);
+    // (source and target fading buffer already prepared)
   }
   else if (fade_mode & FADE_TYPE_FADE_IN)
   {
+    // (target fading buffer already prepared)
     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);
+    // (source fading buffer already prepared)
     SDL_BlitSurface(surface_black,  &src_rect, surface_target, &src_rect);
   }
 
@@ -546,7 +1167,8 @@ void SDLFadeRectangle(Bitmap *bitmap_cross, int x, int y, int width, int height,
     int i;
 
     SDL_BlitSurface(surface_source, &src_rect, surface_screen, &dst_rect);
-    SDL_SetAlpha(surface_target, 0, 0);                /* disable alpha blending */
+
+    SDLSetAlpha(surface_target, FALSE, 0);     /* disable alpha blending */
 
     ypos[0] = -GetSimpleRandom(16);
 
@@ -648,11 +1270,66 @@ void SDLFadeRectangle(Bitmap *bitmap_cross, int x, int y, int width, int height,
        if (draw_border_function != NULL)
          draw_border_function();
 
-       SDL_UpdateRect(surface_screen, dst_x, dst_y, width, height);
+       UpdateScreen_WithFrameDelay(&dst_rect2);
       }
     }
   }
-  else
+  else if (fade_mode == FADE_MODE_CURTAIN)
+  {
+    float xx;
+    int xx_final;
+    int xx_size = width / 2;
+
+    SDL_BlitSurface(surface_target, &src_rect, surface_screen, &dst_rect);
+
+    SDLSetAlpha(surface_source, FALSE, 0);     /* disable alpha blending */
+
+    for (xx = 0; xx < xx_size;)
+    {
+      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);
+
+      src_rect.x = src_x;
+      src_rect.y = src_y;
+      src_rect.w = width;
+      src_rect.h = height;
+
+      dst_rect.x = dst_x;
+      dst_rect.y = dst_y;
+
+      /* draw new (target) image to screen buffer */
+      SDL_BlitSurface(surface_target, &src_rect, surface_screen, &dst_rect);
+
+      if (xx_final < xx_size)
+      {
+       src_rect.w = xx_size - xx_final;
+       src_rect.h = height;
+
+       /* draw old (source) image to screen buffer (left side) */
+
+       src_rect.x = src_x + xx_final;
+       dst_rect.x = dst_x;
+
+       SDL_BlitSurface(surface_source, &src_rect, surface_screen, &dst_rect);
+
+       /* draw old (source) image to screen buffer (right side) */
+
+       src_rect.x = src_x + xx_size;
+       dst_rect.x = dst_x + xx_size + xx_final;
+
+       SDL_BlitSurface(surface_source, &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_WithFrameDelay(&dst_rect2);
+    }
+  }
+  else         /* fading in, fading out or cross-fading */
   {
     float alpha;
     int alpha_final;
@@ -668,22 +1345,39 @@ void SDLFadeRectangle(Bitmap *bitmap_cross, int x, int y, int width, int height,
       SDL_BlitSurface(surface_source, &src_rect, surface_screen, &dst_rect);
 
       /* draw new (target) image to screen buffer using alpha blending */
-      SDL_SetAlpha(surface_target, SDL_SRCALPHA, alpha_final);
+      SDLSetAlpha(surface_target, TRUE, alpha_final);
       SDL_BlitSurface(surface_target, &src_rect, surface_screen, &dst_rect);
 
       if (draw_border_function != NULL)
        draw_border_function();
 
-#if 1
       /* only update the region of the screen that is affected from fading */
-      SDL_UpdateRect(surface_screen, dst_x, dst_y, width, height);
-#else
-      SDL_Flip(surface_screen);
-#endif
+      UpdateScreen_WithFrameDelay(&dst_rect);
+    }
+  }
+
+  if (post_delay > 0)
+  {
+    unsigned int time_post_delay;
+
+    time_current = SDL_GetTicks();
+    time_post_delay = time_current + post_delay;
+
+    while (time_current < time_post_delay)
+    {
+      // updating the screen contains waiting for frame delay (non-busy)
+      UpdateScreen_WithFrameDelay(NULL);
+
+      time_current = SDL_GetTicks();
     }
   }
 
-  Delay(post_delay);
+  // restore function for drawing global masked border
+  gfx.draw_global_border_function = draw_global_border_function;
+
+  // after fading in, restore backbuffer (without animation graphics)
+  if (fade_mode & (FADE_TYPE_FADE_IN | FADE_TYPE_TRANSFORM))
+    SDL_BlitSurface(surface_backup, &dst_rect, surface_screen, &src_rect);
 }
 
 void SDLDrawSimpleLine(Bitmap *dst_bitmap, int from_x, int from_y,
@@ -703,30 +1397,16 @@ void SDLDrawSimpleLine(Bitmap *dst_bitmap, int from_x, int from_y,
   rect.w = (to_x - from_x + 1);
   rect.h = (to_y - from_y + 1);
 
-  if (dst_bitmap == backbuffer || dst_bitmap == window)
-  {
-    rect.x += video_xoffset;
-    rect.y += video_yoffset;
-  }
-
   SDL_FillRect(surface, &rect, color);
 }
 
 void SDLDrawLine(Bitmap *dst_bitmap, int from_x, int from_y,
                 int to_x, int to_y, Uint32 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
+#if ENABLE_UNUSED_CODE
 void SDLDrawLines(SDL_Surface *surface, struct XY *points,
                  int num_points, Uint32 color)
 {
@@ -760,12 +1440,6 @@ 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 */
@@ -811,7 +1485,7 @@ Pixel SDLGetPixel(Bitmap *src_bitmap, int x, int y)
 
 /* ========================================================================= */
 /* The following functions were taken from the SGE library                   */
-/* (SDL Graphics Extension Library) by Anders Lindström                      */
+/* (SDL Graphics Extension Library) by Anders Lindström                      */
 /* http://www.etek.chalmers.se/~e8cal1/sge/index.html                        */
 /* ========================================================================= */
 
@@ -1257,12 +1931,6 @@ void sge_LineRGB(SDL_Surface *Surface, Sint16 x1, Sint16 y1, Sint16 x2,
 
 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);
 }
 
@@ -1334,12 +2002,11 @@ int zoomSurfaceRGBA_scaleDownBy2(SDL_Surface *src, SDL_Surface *dst)
 {
   int x, y;
   tColorRGBA *sp, *csp, *dp;
-  int sgap, dgap;
+  int dgap;
 
   /* pointer setup */
   sp = csp = (tColorRGBA *) src->pixels;
   dp = (tColorRGBA *) dst->pixels;
-  sgap = src->pitch - src->w * 4;
   dgap = dst->pitch - dst->w * 4;
 
   for (y = 0; y < dst->h; y++)
@@ -1384,9 +2051,10 @@ int zoomSurfaceRGBA_scaleDownBy2(SDL_Surface *src, SDL_Surface *dst)
 
 int zoomSurfaceRGBA(SDL_Surface *src, SDL_Surface *dst)
 {
-  int x, y, sx, sy, *sax, *say, *csax, *csay, csx, csy;
-  tColorRGBA *sp, *csp, *dp;
-  int sgap, dgap;
+  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 &&
@@ -1394,38 +2062,23 @@ int zoomSurfaceRGBA(SDL_Surface *src, SDL_Surface *dst)
     return zoomSurfaceRGBA_scaleDownBy2(src, dst);
 
   /* variable setup */
-  sx = (int) (65536.0 * (float) src->w / (float) dst->w);
-  sy = (int) (65536.0 * (float) src->h / (float) dst->h);
+  sx = (float) src->w / (float) dst->w;
+  sy = (float) src->h / (float) dst->h;
 
   /* allocate memory for row increments */
-  sax = (int *)checked_malloc((dst->w + 1) * sizeof(Uint32));
-  say = (int *)checked_malloc((dst->h + 1) * sizeof(Uint32));
+  csax = sax = (int *)checked_malloc((dst->w + 1) * sizeof(Uint32));
+  csay = say = (int *)checked_malloc((dst->h + 1) * sizeof(Uint32));
 
   /* precalculate row increments */
-  csx = 0;
-  csax = sax;
   for (x = 0; x <= dst->w; x++)
-  {
-    *csax = csx;
-    csax++;
-    csx &= 0xffff;
-    csx += sx;
-  }
+    *csax++ = (int)(sx * x);
 
-  csy = 0;
-  csay = say;
   for (y = 0; y <= dst->h; y++)
-  {
-    *csay = csy;
-    csay++;
-    csy &= 0xffff;
-    csy += sy;
-  }
+    *csay++ = (int)(sy * y);
 
   /* pointer setup */
-  sp = csp = (tColorRGBA *) src->pixels;
+  sp = csp = csp0 = (tColorRGBA *) src->pixels;
   dp = (tColorRGBA *) dst->pixels;
-  sgap = src->pitch - src->w * 4;
   dgap = dst->pitch - dst->w * 4;
 
   csay = say;
@@ -1441,7 +2094,7 @@ int zoomSurfaceRGBA(SDL_Surface *src, SDL_Surface *dst)
 
       /* advance source pointers */
       csax++;
-      sp += (*csax >> 16);
+      sp = csp + *csax;
 
       /* advance destination pointer */
       dp++;
@@ -1449,7 +2102,7 @@ int zoomSurfaceRGBA(SDL_Surface *src, SDL_Surface *dst)
 
     /* advance source pointer */
     csay++;
-    csp = (tColorRGBA *) ((Uint8 *) csp + (*csay >> 16) * src->pitch);
+    csp = (tColorRGBA *) ((Uint8 *) csp0 + *csay * src->pitch);
 
     /* advance destination pointers */
     dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
@@ -1591,8 +2244,9 @@ SDL_Surface *zoomSurface(SDL_Surface *src, int dst_width, int dst_height)
   else
   {
     /* new source surface is 32 bit with a defined RGB ordering */
-    zoom_src = SDL_CreateRGBSurface(SDL_SWSURFACE, src->w, src->h, 32,
-                                   0x000000ff, 0x0000ff00, 0x00ff0000, 0);
+    zoom_src = SDL_CreateRGBSurface(SURFACE_FLAGS, src->w, src->h, 32,
+                                   0x000000ff, 0x0000ff00, 0x00ff0000,
+                                   (src->format->Amask ? 0xff000000 : 0));
     SDL_BlitSurface(src, NULL, zoom_src, NULL);
     is_32bit = TRUE;
     is_converted = TRUE;
@@ -1602,15 +2256,16 @@ SDL_Surface *zoomSurface(SDL_Surface *src, int dst_width, int dst_height)
   if (is_32bit)
   {
     /* target surface is 32 bit with source RGBA/ABGR ordering */
-    zoom_dst = SDL_CreateRGBSurface(SDL_SWSURFACE, dst_width, dst_height, 32,
+    zoom_dst = SDL_CreateRGBSurface(SURFACE_FLAGS, dst_width, dst_height, 32,
                                    zoom_src->format->Rmask,
                                    zoom_src->format->Gmask,
-                                   zoom_src->format->Bmask, 0);
+                                   zoom_src->format->Bmask,
+                                   zoom_src->format->Amask);
   }
   else
   {
     /* target surface is 8 bit */
-    zoom_dst = SDL_CreateRGBSurface(SDL_SWSURFACE, dst_width, dst_height, 8,
+    zoom_dst = SDL_CreateRGBSurface(SURFACE_FLAGS, dst_width, dst_height, 8,
                                    0, 0, 0, 0);
   }
 
@@ -1646,23 +2301,55 @@ SDL_Surface *zoomSurface(SDL_Surface *src, int dst_width, int dst_height)
   return zoom_dst;
 }
 
-void SDLZoomBitmap(Bitmap *src_bitmap, Bitmap *dst_bitmap)
+static SDL_Surface *SDLGetOpaqueSurface(SDL_Surface *surface)
+{
+  SDL_Surface *new_surface;
+
+  if (surface == NULL)
+    return NULL;
+
+  if ((new_surface = SDLGetNativeSurface(surface)) == NULL)
+    Error(ERR_EXIT, "SDLGetNativeSurface() failed");
+
+  /* remove alpha channel from native non-transparent surface, if defined */
+  SDLSetAlpha(new_surface, FALSE, 0);
+
+  /* remove transparent color from native non-transparent surface, if defined */
+  SDL_SetColorKey(new_surface, UNSET_TRANSPARENT_PIXEL, 0);
+
+  return new_surface;
+}
+
+Bitmap *SDLZoomBitmap(Bitmap *src_bitmap, int dst_width, int dst_height)
 {
-  SDL_Surface *sdl_surface_tmp;
-  int dst_width = dst_bitmap->width;
-  int dst_height = dst_bitmap->height;
+  Bitmap *dst_bitmap = CreateBitmapStruct();
+  SDL_Surface *src_surface = src_bitmap->surface_masked;
+  SDL_Surface *dst_surface;
 
-  /* throw away old destination surface */
-  SDL_FreeSurface(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 */
-  sdl_surface_tmp = zoomSurface(src_bitmap->surface, dst_width, dst_height);
+  dst_surface = zoomSurface(src_surface, dst_width, dst_height);
 
   /* create native format destination surface from zoomed temporary surface */
-  dst_bitmap->surface = SDL_DisplayFormat(sdl_surface_tmp);
+  SDLSetNativeSurface(&dst_surface);
 
-  /* free temporary surface */
-  SDL_FreeSurface(sdl_surface_tmp);
+  /* set color key for zoomed surface from source surface, if defined */
+  if (SDLHasColorKey(src_surface))
+    SDL_SetColorKey(dst_surface, SET_TRANSPARENT_PIXEL,
+                   SDLGetColorKey(src_surface));
+
+  /* create native non-transparent surface for opaque blitting */
+  dst_bitmap->surface = SDLGetOpaqueSurface(dst_surface);
+
+  /* set native transparent surface for masked blitting */
+  dst_bitmap->surface_masked = dst_surface;
+
+  return dst_bitmap;
 }
 
 
@@ -1675,35 +2362,37 @@ 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)
-  {
-    SetError("IMG_Load(): %s", SDL_GetError());
+    Error(ERR_EXIT, "IMG_Load() failed: %s", SDL_GetError());
 
-    return NULL;
-  }
+  print_timestamp_time("IMG_Load");
 
   UPDATE_BUSY_STATE();
 
   /* create native non-transparent surface for current image */
-  if ((new_bitmap->surface = SDL_DisplayFormat(sdl_image_tmp)) == NULL)
-  {
-    SetError("SDL_DisplayFormat(): %s", SDL_GetError());
+  if ((new_bitmap->surface = SDLGetOpaqueSurface(sdl_image_tmp)) == NULL)
+    Error(ERR_EXIT, "SDLGetOpaqueSurface() failed");
 
-    return NULL;
-  }
+  print_timestamp_time("SDLGetNativeSurface (opaque)");
 
   UPDATE_BUSY_STATE();
 
+  /* set black pixel to transparent if no alpha channel / transparent color */
+  if (!SDLHasAlpha(sdl_image_tmp) &&
+      !SDLHasColorKey(sdl_image_tmp))
+    SDL_SetColorKey(sdl_image_tmp, SET_TRANSPARENT_PIXEL,
+                   SDL_MapRGB(sdl_image_tmp->format, 0x00, 0x00, 0x00));
+
   /* create native transparent surface for current image */
-  SDL_SetColorKey(sdl_image_tmp, SDL_SRCCOLORKEY,
-                 SDL_MapRGB(sdl_image_tmp->format, 0x00, 0x00, 0x00));
-  if ((new_bitmap->surface_masked = SDL_DisplayFormat(sdl_image_tmp)) == NULL)
-  {
-    SetError("SDL_DisplayFormat(): %s", SDL_GetError());
+  if ((new_bitmap->surface_masked = SDLGetNativeSurface(sdl_image_tmp)) == NULL)
+    Error(ERR_EXIT, "SDLGetNativeSurface() failed");
 
-    return NULL;
-  }
+  print_timestamp_time("SDLGetNativeSurface (masked)");
 
   UPDATE_BUSY_STATE();
 
@@ -1713,6 +2402,8 @@ Bitmap *SDLLoadImage(char *filename)
   new_bitmap->width = new_bitmap->surface->w;
   new_bitmap->height = new_bitmap->surface->h;
 
+  print_timestamp_done("SDLLoadImage");
+
   return new_bitmap;
 }
 
@@ -1760,8 +2451,10 @@ void SDLSetMouseCursor(struct MouseCursorInfo *cursor_info)
 
 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)
   {
@@ -1807,41 +2500,28 @@ void SDLCloseAudio(void)
 void SDLNextEvent(Event *event)
 {
   SDL_WaitEvent(event);
-
-  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 (((MotionEvent *)event)->x > video_xoffset)
-      ((MotionEvent *)event)->x -= video_xoffset;
-    else
-      ((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");
@@ -1858,9 +2538,14 @@ void SDLHandleWindowManagerEvent(Event *event)
       printf("::: - '%s'\n", buffer);
     }
 
+#if defined(TARGET_SDL2)
+    DragFinish((HDROP)syswmmsg->msg.win.wParam);
+#else
     DragFinish((HDROP)syswmmsg->wParam);
+#endif
   }
 #endif
+#endif
 }
 
 
@@ -1886,6 +2571,8 @@ static void SDLCloseJoystick(int nr)
     return;
 
   SDL_JoystickClose(sdl_joystick[nr]);
+
+  sdl_joystick[nr] = NULL;
 }
 
 static boolean SDLCheckJoystickOpened(int nr)
@@ -1893,7 +2580,11 @@ 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)
@@ -1930,7 +2621,7 @@ void SDLInitJoysticks()
   {
     sdl_joystick_subsystem_initialized = TRUE;
 
-    if (SDL_Init(SDL_INIT_JOYSTICK) < 0)
+    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) < 0)
     {
       Error(ERR_EXIT, "SDL_Init() failed: %s", SDL_GetError());
       return;
@@ -1994,4 +2685,97 @@ boolean SDLReadJoystick(int nr, int *x, int *y, boolean *b1, boolean *b2)
   return TRUE;
 }
 
-#endif /* TARGET_SDL */
+static void DrawTouchInputOverlay()
+{
+#if defined(USE_TOUCH_INPUT_OVERLAY)
+  static SDL_Texture *texture = NULL;
+  static boolean initialized = FALSE;
+  static boolean deactivated = TRUE;
+  static int width = 0, height = 0;
+  static int alpha_max = SDL_ALPHA_OPAQUE / 2;
+  static int alpha_step = 5;
+  static int alpha_last = 0;
+  static int alpha = 0;
+
+  if (!overlay.active && deactivated)
+    return;
+
+  if (overlay.active)
+  {
+    if (alpha < alpha_max)
+      alpha = MIN(alpha + alpha_step, alpha_max);
+
+    deactivated = FALSE;
+  }
+  else
+  {
+    alpha = MAX(0, alpha - alpha_step);
+
+    if (alpha == 0)
+      deactivated = TRUE;
+  }
+
+  if (!initialized)
+  {
+    char *basename = "overlay/VirtualButtons.png";
+    char *filename = getCustomImageFilename(basename);
+
+    if (filename == NULL)
+      Error(ERR_EXIT, "LoadCustomImage(): cannot find file '%s'", basename);
+
+    SDL_Surface *surface;
+
+    if ((surface = IMG_Load(filename)) == NULL)
+      Error(ERR_EXIT, "IMG_Load() failed: %s", SDL_GetError());
+
+    width  = surface->w;
+    height = surface->h;
+
+    /* set black pixel to transparent if no alpha channel / transparent color */
+    if (!SDLHasAlpha(surface) &&
+       !SDLHasColorKey(surface))
+      SDL_SetColorKey(surface, SET_TRANSPARENT_PIXEL,
+                     SDL_MapRGB(surface->format, 0x00, 0x00, 0x00));
+
+    if ((texture = SDLCreateTextureFromSurface(surface)) == NULL)
+      Error(ERR_EXIT, "SDLCreateTextureFromSurface() failed");
+
+    SDL_FreeSurface(surface);
+
+    SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
+    SDL_SetTextureAlphaMod(texture, alpha_max);
+
+    initialized = TRUE;
+  }
+
+  if (alpha != alpha_last)
+    SDL_SetTextureAlphaMod(texture, alpha);
+
+  alpha_last = alpha;
+
+  float ratio_overlay = (float) width / height;
+  float ratio_screen = (float) video.screen_width / video.screen_height;
+  int width_scaled, height_scaled;
+  int xpos, ypos;
+
+  if (ratio_overlay > ratio_screen)
+  {
+    width_scaled = video.screen_width;
+    height_scaled = video.screen_height * ratio_screen / ratio_overlay;
+    xpos = 0;
+    ypos = video.screen_height - height_scaled;
+  }
+  else
+  {
+    width_scaled = video.screen_width * ratio_overlay / ratio_screen;
+    height_scaled = video.screen_height;
+    xpos = (video.screen_width - width_scaled) / 2;
+    ypos = 0;
+  }
+
+  SDL_Rect src_rect = { 0, 0, width, height };
+  SDL_Rect dst_rect = { xpos, ypos, width_scaled, height_scaled };
+
+  SDL_RenderCopy(sdl_renderer, texture, &src_rect, &dst_rect);
+#endif
+}