Class | Rubygame::Screen
In: | lib/rubygame/screen.rb
Parent: | Rubygame::Surface

Screen represents the display window for the game. The Screen is a special Surface that is displayed to the user. By changing and then updating the Screen many times per second, you can create the illusion of continous motion.

Screen inherits most of the Surface methods, and can be passed to methods which expect a Surface, including Surface#blit. However, the Screen cannot have an alpha channel or a colorkey, so Surface#alpha=, Surface#set_alpha, Surface#colorkey=, and Surface#set_colorkey are not inherited.

Please note that only one Screen can exist at a time, per application; this is a limitation of SDL. Use Screen.new (or its alias, Screen.open) to create or modify the Screen.

Also note that no changes to the Screen will be seen until it is refreshed. See update, update_rects, and flip for ways to refresh all or part of the Screen.

### Methods

close flip get_resolution get_surface icon= instance new open? set_mode show_cursor= show_cursor? title title= update update_rects

### External Aliases

new | -> | open

### Public Class methods

close()

Close the Screen, making the Rubygame window disappear. This method also exits from fullscreen mode, if needed.

After calling this method, you should discard any references to the old Screen surface, as it is no longer valid, even if you call Screen.new again.

(Note: You do not need to close the Screen to change its size or flags, you can simply call Screen.new while already open.)

get_resolution()

Returns the pixel dimensions of the user‘s display (i.e. monitor). (That is not the same as Screen#size, which only measures the Rubygame window.) You can use this information to detect how large of a Screen can fit on the user‘s display.

This method can only be used when there is no open Screen instance. This method raises SDLError if there is a Screen instance (i.e. you have done Screen.new before). This is a limitation of the SDL function SDL_GetVideoInfo, which behaves differently when a Screen is open than when it is closed.

This method will also raise SDLError if it cannot get the display size for some other reason.

get_surface()

Returns the currently open Screen, or raises SDLError if it fails to get it (for example, if it doesn‘t exist yet).

instance( size, depth=0, flags=[Rubygame::SWSURFACE] )

Deprecated alias for Screen.new. This method will be REMOVED in Rubygame 3.0. You should use Screen.new (or its alias, Screen.open) instead.

new( size, depth=0, flags=[Rubygame::SWSURFACE] )

Create a new Rubygame window if there is none, or modify the existing one. You cannot create more than one Screen; the existing one will be replaced. (This is a limitation of SDL.)

Returns the resulting Screen.

size: | requested window size (in pixels), in the form [width,height]
depth: | requested color depth (in bits per pixel). If 0 (default), the current system color depth.

flags:

an Array of zero or more of the following flags (located under the Rubygame module).

SWSURFACE: | Create the video surface in system memory.
HWSURFACE: | Create the video surface in video memory.
ASYNCBLIT: | Enables the use of asynchronous updates of the display surface. This will usually slow down blitting on single CPU machines, but may provide a speed increase on SMP systems.
ANYFORMAT: | Normally, if a video surface of the requested bits-per-pixel (bpp) is not available, Rubygame will emulate one with a shadow surface. Passing `ANYFORMAT` prevents this and causes Rubygame to use the video surface regardless of its depth.
DOUBLEBUF: | Enable hardware double buffering; only valid with `HWSURFACE`. Calling flip will flip the buffers and update the screen. All drawing will take place on the surface that is not displayed at the moment. If double buffering could not be enabled then flip will just update the entire screen.
FULLSCREEN: | Rubygame will attempt to use a fullscreen mode. If a hardware resolution change is not possible (for whatever reason), the next higher resolution will be used and the display window centered on a black background.
OPENGL: | Create an OpenGL rendering context. You must set proper OpenGL video attributes with GL#set_attrib before calling this method with this flag. You can then use separate opengl libraries (for example rbogl) to do all OpenGL-related functions. Please note that you can‘t blit or draw regular SDL Surfaces onto an OpenGL-mode screen; you must use OpenGL functions.
RESIZABLE: | Create a resizable window. When the window is resized by the user, a ResizeEvent is generated and this method can be called again with the new size.
NOFRAME: | If possible, create a window with no title bar or frame decoration. Fullscreen modes automatically have this flag set.

open?()

True if there is an open Rubygame window. See Screen.new and Screen.close.

set_mode( size, depth=0, flags=[Rubygame::SWSURFACE] )

Deprecated alias for Screen.new. This method will be REMOVED in Rubygame 3.0. You should use Screen.new (or its alias, Screen.open) instead.

### Public Instance methods

flip()

If the Rubygame display is double-buffered (see Screen.new), flips the buffers and updates the whole screen. Otherwise, just updates the whole screen.

icon=( surface )

Sets the window icon for the Screen.

icon: | a Rubygame::Surface to be displayed at the top of the Rubygame window (when not in fullscreen mode), and in other OS-specific areas (like the taskbar entry). If omitted or `nil`, no icon will be shown at all.

NOTE: The SDL docs state that icons on Win32 systems must be 32x32 pixels. That may or may not be true anymore, but you might want to consider it when creating games to run on Windows.

show_cursor=( value )

Set whether the mouse cursor is displayed or not. If `value` is true, the cursor will be shown; if false, it will be hidden. See also show_cursor?

show_cursor?()

Returns true if the mouse cursor is shown, or false if hidden. See also show_cursor=

title()

Returns the current window title for the Screen. The default is an empty string.

title=( newtitle )

Sets the window title for the Screen.

newtitle: | a string, (usually) displayed at the top of the Rubygame window (when not in fullscreen mode). If omitted or `nil`, `title` will be an empty string. How this string is displayed (if at all) is system-dependent.

update
update( rect )
update( x,y,w,h )

Updates (refreshes) all or part of the Rubygame window, revealing to the user any changes that have been made since the last update. If you‘re using a double-buffered display (see Screen.new), you should use Screen#flip instead.

rect: | a Rubygame::Rect representing the area of the screen to update. Can also be an length-4 Array, or given as 4 separate arguments. If omitted or nil, the entire screen is updated.

update_rects( rects )

Updates (as Screen#update does) several areas of the screen.

rects: | an Array containing any number of Rect objects, each rect representing a portion of the screen to update.

[Validate]