Mercurial > sdl-ios-xcode
view src/video/SDL_sysvideo.h @ 4139:568c9b3c0167 SDL-1.2
* Added configure option --enable-screensaver, to allow enabling the screensaver by default.
* Use XResetScreenSaver() instead of disabling screensaver entirely.
Full discussion summary from Erik on the SDL mailing list:
Current behaviour
=================
SDL changes the user's display power management settings without
permission from the user and without telling the user.
The interface that it uses to do so is DPMSDisable/DPMSEnable, which
should only ever be used by configuration utilities like KControl, never
by normal application programs, let alone by the libraries that they
use. Using an interface that is not at all intended for what SDL tries
to achieve means that it will not work as it should. Firstly, the power
management is completely disabled during the whole lifetime of the SDL
program, not only when it should be. Secondly, it makes SDL
non-reentrant, meaning that things will break when multiple SDL programs
are clients of the same X server simultaneously. Thirdly, no cleanup
mechanism ensures that the setting is restored if the client does not do
that (for example if it crashes).
In addition to that, this interface is broken on xorg,
[http://bugs.freedesktop.org/show_bug.cgi?id=13962], so what SDL tries
to do does not work at all on that implementation of the X Window
System. (The reason that the DPMSEnable works in KControl is that it
calls DPMSSetTimeout immediately after,
[http://websvn.kde.org/tags/KDE/3.5.9/kdebase/kcontrol/energy/energy.cpp?annotate=774532#l343]).
The problems that the current behaviour causes
==============================================
1. Information leak. When the user is away, someone might see what the
user has on the display when the user counts on the screensaver
preventing this. This does not even require physical access to the
workstation, it is enough to see it from a distance.
2. Draining battery. An SDL program that runs on a laptop will quickly
drain the battery while the user is away. The system will soon shut down
and require recharging before being usable again, while it should in
fact have consumed very little energy if the user's settings would have
been obeyed.
3. Wasting energy. Even if battery issues are not considered, energy as
such is wasted.
4. Display wear. The display may be worn out.
The problems that the current behaviour tries to solve
======================================================
1. Preventing screensaver while playing movies.
Many SDL applications are media players. They have reasons to prevent
screensavers from being activated while a movie is being played. When a
user clicks on the play button it can be interpreted as saying "play
this movie, but do not turn off the display while playing it, because I
will watch it even though I do not interact with the system".
2. Preventing screensaver when some input bypasses X.
Sometimes SDL uses input from another source than the X server, so
that the X server is bypassed. This obviously breaks the screensaver
handling. SDL tries to work around that.
3. Preventing screensaver when all input bypasses X.
There is something called Direct Graphics Access mode, where a
program takes control of both the display and the input devices from the
X server. This obviously means that the X server can not handle the
screensaver alone, since screensaver handling depends on input handling.
SDL does not do what it should to help the X server to handle the
screensaver. Nor does SDL take care of screeensaver handling itself. SDL
simply disables the screensaver completely.
How the problems should be solved
=================================
The correct way for an application program to prevent the screensaver
under X is to call XResetScreenSaver. This was recently discovered and
implemented by the mplayer developers,
[http://svn.mplayerhq.hu/mplayer?view=rev&revision=25637]. SDL needs to
wrap this in an API call (SDL_ResetScreenSaver) and implement it for the
other video targets (if they do not have a corresponding call, SDL
should do what it takes on that particular target, for example sending
fake key events).
1. When a movie is played, the player should reset the screensaver when
the animation is advanced to a new frame. The same applies to anything
similar, like slideshows.
2. When the X server is handling input, it must handle all input
(keyboards, mice, gamepads, ...). This is necessary, not only to be able
to handle the screensaver, but also so that it can send the events to
the correct (the currently active) client. If there is an input device
that the X server can not handle for some reason (such as lack of Plug
and Play capability), the program that handles the device as a
workaround must simulate what would happen if the X server would have
handled the device, by calling XResetScreenSaver when input is received
from the device.
3. When the X server is not handling the input, it depends on the
program that does to call XResetScreenSaver whenever an input event
occurs. Alternatively the program must handle the screensaver countdown
internally and call XActivateScreenSaver.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 29 Feb 2008 13:55:44 +0000 |
| parents | 8582c6a5ca16 |
| children | a1b03ba2fcd0 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" #ifndef _SDL_sysvideo_h #define _SDL_sysvideo_h #include "SDL_mouse.h" #define SDL_PROTOTYPES_ONLY #include "SDL_syswm.h" #undef SDL_PROTOTYPES_ONLY /* This file prototypes the video driver implementation. This is designed to be easily converted to C++ in the future. */ #if SDL_VIDEO_OPENGL #include "SDL_opengl.h" #endif /* SDL_VIDEO_OPENGL */ /* The SDL video driver */ typedef struct SDL_VideoDevice SDL_VideoDevice; /* Define the SDL video driver structure */ #define _THIS SDL_VideoDevice *_this #ifndef _STATUS #define _STATUS SDL_status *status #endif struct SDL_VideoDevice { /* * * */ /* The name of this video driver */ const char *name; /* * * */ /* Initialization/Query functions */ /* Initialize the native video subsystem, filling 'vformat' with the "best" display pixel format, returning 0 or -1 if there's an error. */ int (*VideoInit)(_THIS, SDL_PixelFormat *vformat); /* List the available video modes for the given pixel format, sorted from largest to smallest. */ SDL_Rect **(*ListModes)(_THIS, SDL_PixelFormat *format, Uint32 flags); /* Set the requested video mode, returning a surface which will be set to the SDL_VideoSurface. The width and height will already be verified by ListModes(), and the video subsystem is free to set the mode to a supported bit depth different from the one specified -- the desired bpp will be emulated with a shadow surface if necessary. If a new mode is returned, this function should take care of cleaning up the current mode. */ SDL_Surface *(*SetVideoMode)(_THIS, SDL_Surface *current, int width, int height, int bpp, Uint32 flags); /* Toggle the fullscreen mode */ int (*ToggleFullScreen)(_THIS, int on); /* This is called after the video mode has been set, to get the initial mouse state. It should queue events as necessary to properly represent the current mouse focus and position. */ void (*UpdateMouse)(_THIS); /* Create a YUV video surface (possibly overlay) of the given format. The hardware should be able to perform at least 2x scaling on display. */ SDL_Overlay *(*CreateYUVOverlay)(_THIS, int width, int height, Uint32 format, SDL_Surface *display); /* Sets the color entries { firstcolor .. (firstcolor+ncolors-1) } of the physical palette to those in 'colors'. If the device is using a software palette (SDL_HWPALETTE not set), then the changes are reflected in the logical palette of the screen as well. The return value is 1 if all entries could be set properly or 0 otherwise. */ int (*SetColors)(_THIS, int firstcolor, int ncolors, SDL_Color *colors); /* This pointer should exist in the native video subsystem and should point to an appropriate update function for the current video mode */ void (*UpdateRects)(_THIS, int numrects, SDL_Rect *rects); /* Reverse the effects VideoInit() -- called if VideoInit() fails or if the application is shutting down the video subsystem. */ void (*VideoQuit)(_THIS); /* * * */ /* Hardware acceleration functions */ /* Information about the video hardware */ SDL_VideoInfo info; /* The pixel format used when SDL_CreateRGBSurface creates SDL_HWSURFACEs with alpha */ SDL_PixelFormat* displayformatalphapixel; /* Allocates a surface in video memory */ int (*AllocHWSurface)(_THIS, SDL_Surface *surface); /* Sets the hardware accelerated blit function, if any, based on the current flags of the surface (colorkey, alpha, etc.) */ int (*CheckHWBlit)(_THIS, SDL_Surface *src, SDL_Surface *dst); /* Fills a surface rectangle with the given color */ int (*FillHWRect)(_THIS, SDL_Surface *dst, SDL_Rect *rect, Uint32 color); /* Sets video mem colorkey and accelerated blit function */ int (*SetHWColorKey)(_THIS, SDL_Surface *surface, Uint32 key); /* Sets per surface hardware alpha value */ int (*SetHWAlpha)(_THIS, SDL_Surface *surface, Uint8 value); /* Returns a readable/writable surface */ int (*LockHWSurface)(_THIS, SDL_Surface *surface); void (*UnlockHWSurface)(_THIS, SDL_Surface *surface); /* Performs hardware flipping */ int (*FlipHWSurface)(_THIS, SDL_Surface *surface); /* Frees a previously allocated video surface */ void (*FreeHWSurface)(_THIS, SDL_Surface *surface); /* * * */ /* Gamma support */ Uint16 *gamma; /* Set the gamma correction directly (emulated with gamma ramps) */ int (*SetGamma)(_THIS, float red, float green, float blue); /* Get the gamma correction directly (emulated with gamma ramps) */ int (*GetGamma)(_THIS, float *red, float *green, float *blue); /* Set the gamma ramp */ int (*SetGammaRamp)(_THIS, Uint16 *ramp); /* Get the gamma ramp */ int (*GetGammaRamp)(_THIS, Uint16 *ramp); /* * * */ /* OpenGL support */ /* Sets the dll to use for OpenGL and loads it */ int (*GL_LoadLibrary)(_THIS, const char *path); /* Retrieves the address of a function in the gl library */ void* (*GL_GetProcAddress)(_THIS, const char *proc); /* Get attribute information from the windowing system. */ int (*GL_GetAttribute)(_THIS, SDL_GLattr attrib, int* value); /* Make the context associated with this driver current */ int (*GL_MakeCurrent)(_THIS); /* Swap the current buffers in double buffer mode. */ void (*GL_SwapBuffers)(_THIS); /* OpenGL functions for SDL_OPENGLBLIT */ #if SDL_VIDEO_OPENGL #if !defined(__WIN32__) #define WINAPI #endif #define SDL_PROC(ret,func,params) ret (WINAPI *func) params; #include "SDL_glfuncs.h" #undef SDL_PROC /* Texture id */ GLuint texture; #endif int is_32bit; /* * * */ /* Window manager functions */ /* Set the title and icon text */ void (*SetCaption)(_THIS, const char *title, const char *icon); /* Set the window icon image */ void (*SetIcon)(_THIS, SDL_Surface *icon, Uint8 *mask); /* Iconify the window. This function returns 1 if there is a window manager and the window was actually iconified, it returns 0 otherwise. */ int (*IconifyWindow)(_THIS); /* Grab or ungrab keyboard and mouse input */ SDL_GrabMode (*GrabInput)(_THIS, SDL_GrabMode mode); /* Get some platform dependent window information */ int (*GetWMInfo)(_THIS, SDL_SysWMinfo *info); /* * * */ /* Cursor manager functions */ /* Free a window manager cursor This function can be NULL if CreateWMCursor is also NULL. */ void (*FreeWMCursor)(_THIS, WMcursor *cursor); /* If not NULL, create a black/white window manager cursor */ WMcursor *(*CreateWMCursor)(_THIS, Uint8 *data, Uint8 *mask, int w, int h, int hot_x, int hot_y); /* Show the specified cursor, or hide if cursor is NULL */ int (*ShowWMCursor)(_THIS, WMcursor *cursor); /* Warp the window manager cursor to (x,y) If NULL, a mouse motion event is posted internally. */ void (*WarpWMCursor)(_THIS, Uint16 x, Uint16 y); /* If not NULL, this is called when a mouse motion event occurs */ void (*MoveWMCursor)(_THIS, int x, int y); /* Determine whether the mouse should be in relative mode or not. This function is called when the input grab state or cursor visibility state changes. If the cursor is not visible, and the input is grabbed, the driver can place the mouse in relative mode, which may result in higher accuracy sampling of the pointer motion. */ void (*CheckMouseMode)(_THIS); /* * * */ /* Event manager functions */ /* Initialize keyboard mapping for this driver */ void (*InitOSKeymap)(_THIS); /* Handle any queued OS events */ void (*PumpEvents)(_THIS); /* * * */ /* Data common to all drivers */ SDL_Surface *screen; SDL_Surface *shadow; SDL_Surface *visible; SDL_Palette *physpal; /* physical palette, if != logical palette */ SDL_Color *gammacols; /* gamma-corrected colours, or NULL */ char *wm_title; char *wm_icon; int offset_x; int offset_y; SDL_GrabMode input_grab; /* Driver information flags */ int handles_any_size; /* Driver handles any size video mode */ /* * * */ /* Data used by the GL drivers */ struct { int red_size; int green_size; int blue_size; int alpha_size; int depth_size; int buffer_size; int stencil_size; int double_buffer; int accum_red_size; int accum_green_size; int accum_blue_size; int accum_alpha_size; int stereo; int multisamplebuffers; int multisamplesamples; int accelerated; int swap_control; int driver_loaded; char driver_path[256]; void* dll_handle; } gl_config; /* * * */ /* Data private to this driver */ struct SDL_PrivateVideoData *hidden; struct SDL_PrivateGLData *gl_data; /* * * */ /* The function used to dispose of this structure */ void (*free)(_THIS); }; #undef _THIS typedef struct VideoBootStrap { const char *name; const char *desc; int (*available)(void); SDL_VideoDevice *(*create)(int devindex); } VideoBootStrap; #if SDL_VIDEO_DRIVER_QUARTZ extern VideoBootStrap QZ_bootstrap; #endif #if SDL_VIDEO_DRIVER_X11 extern VideoBootStrap X11_bootstrap; #endif #if SDL_VIDEO_DRIVER_DGA extern VideoBootStrap DGA_bootstrap; #endif #if SDL_VIDEO_DRIVER_NANOX extern VideoBootStrap NX_bootstrap; #endif #if SDL_VIDEO_DRIVER_IPOD extern VideoBootStrap iPod_bootstrap; #endif #if SDL_VIDEO_DRIVER_QTOPIA extern VideoBootStrap Qtopia_bootstrap; #endif #if SDL_VIDEO_DRIVER_WSCONS extern VideoBootStrap WSCONS_bootstrap; #endif #if SDL_VIDEO_DRIVER_FBCON extern VideoBootStrap FBCON_bootstrap; #endif #if SDL_VIDEO_DRIVER_DIRECTFB extern VideoBootStrap DirectFB_bootstrap; #endif #if SDL_VIDEO_DRIVER_PS2GS extern VideoBootStrap PS2GS_bootstrap; #endif #if SDL_VIDEO_DRIVER_GGI extern VideoBootStrap GGI_bootstrap; #endif #if SDL_VIDEO_DRIVER_VGL extern VideoBootStrap VGL_bootstrap; #endif #if SDL_VIDEO_DRIVER_SVGALIB extern VideoBootStrap SVGALIB_bootstrap; #endif #if SDL_VIDEO_DRIVER_GAPI extern VideoBootStrap GAPI_bootstrap; #endif #if SDL_VIDEO_DRIVER_WINDIB extern VideoBootStrap WINDIB_bootstrap; #endif #if SDL_VIDEO_DRIVER_DDRAW extern VideoBootStrap DIRECTX_bootstrap; #endif #if SDL_VIDEO_DRIVER_BWINDOW extern VideoBootStrap BWINDOW_bootstrap; #endif #if SDL_VIDEO_DRIVER_TOOLBOX extern VideoBootStrap TOOLBOX_bootstrap; #endif #if SDL_VIDEO_DRIVER_DRAWSPROCKET extern VideoBootStrap DSp_bootstrap; #endif #if SDL_VIDEO_DRIVER_PHOTON extern VideoBootStrap ph_bootstrap; #endif #if SDL_VIDEO_DRIVER_EPOC extern VideoBootStrap EPOC_bootstrap; #endif #if SDL_VIDEO_DRIVER_XBIOS extern VideoBootStrap XBIOS_bootstrap; #endif #if SDL_VIDEO_DRIVER_GEM extern VideoBootStrap GEM_bootstrap; #endif #if SDL_VIDEO_DRIVER_PICOGUI extern VideoBootStrap PG_bootstrap; #endif #if SDL_VIDEO_DRIVER_DC extern VideoBootStrap DC_bootstrap; #endif #if SDL_VIDEO_DRIVER_NDS extern VideoBootStrap NDS_bootstrap; #endif #if SDL_VIDEO_DRIVER_RISCOS extern VideoBootStrap RISCOS_bootstrap; #endif #if SDL_VIDEO_DRIVER_OS2FS extern VideoBootStrap OS2FSLib_bootstrap; #endif #if SDL_VIDEO_DRIVER_AALIB extern VideoBootStrap AALIB_bootstrap; #endif #if SDL_VIDEO_DRIVER_DUMMY extern VideoBootStrap DUMMY_bootstrap; #endif /* This is the current video device */ extern SDL_VideoDevice *current_video; #define SDL_VideoSurface (current_video->screen) #define SDL_ShadowSurface (current_video->shadow) #define SDL_PublicSurface (current_video->visible) #endif /* _SDL_sysvideo_h */