From 3744281b9ae8aa0ab86ceaee1afe8a603e3aeb2c Mon Sep 17 00:00:00 2001 From: marha Date: Mon, 19 Nov 2012 10:16:38 +0100 Subject: dos -> unix --- xorg-server/miext/rootless/README.txt | 668 +++++++++++++++++----------------- 1 file changed, 334 insertions(+), 334 deletions(-) (limited to 'xorg-server/miext/rootless') diff --git a/xorg-server/miext/rootless/README.txt b/xorg-server/miext/rootless/README.txt index 1beabda38..754715d33 100644 --- a/xorg-server/miext/rootless/README.txt +++ b/xorg-server/miext/rootless/README.txt @@ -1,334 +1,334 @@ - Generic Rootless Layer - Version 1.0 - July 13, 2004 - - Torrey T. Lyons - torrey@xfree86.org - - -Introduction - - The generic rootless layer allows an X server to be implemented -on top of another window server in a cooperative manner. This allows the -X11 windows and native windows of the underlying window server to -coexist on the same screen. The layer is called "rootless" because the root -window of the X server is generally not drawn. Instead, each top-level -child of the root window is represented as a separate on-screen window by -the underlying window server. The layer is referred to as "generic" -because it abstracts away the details of the underlying window system and -contains code that is useful for any rootless X server. The code for the -generic rootless layer is located in xc/programs/Xserver/miext/rootless. To -build a complete rootless X server requires a specific rootless -implementation, which provides functions that allow the generic rootless -layer to interact with the underlying window system. - - -Concepts - - In the context of a rootless X server the term window is used to -mean many fundamentally different things. For X11 a window is a DDX -resource that describes a visible, or potentially visible, rectangle on the -screen. A top-level window is a direct child of the root window. To avoid -confusion, an on-screen native window of the underlying window system -is referred to as a "frame". The generic rootless layer associates each -mapped top-level X11 window with a frame. An X11 window may be said -to be "framed" if it or its top-level parent is represented by a frame. - - The generic rootless layer models each frame as being backed at -all times by a backing buffer, which is periodically flushed to the screen. -If the underlying window system does not provide a backing buffer for -frames, this must be done by the rootless implementation. The generic -rootless layer model does not assume it always has access to the frames' -backing buffers. Any drawing to the buffer will be proceeded by a call to -the rootless implementation's StartDrawing() function and StopDrawing() -will be called when the drawing is concluded. The address of the frame's -backing buffer is returned by the StartDrawing() function and it can -change between successive calls. - - Because each frame is assumed to have a backing buffer, the -generic rootless layer will stop Expose events being generated when the -regions of visibility of a frame change on screen. This is similar to backing -store, but backing buffers are different in that they always store a copy of -the entire window contents, not just the obscured portions. The price paid -in increased memory consumption is made up by the greatly decreased -complexity in not having to track and record regions as they are obscured. - - -Rootless Implementation - - The specifics of the underlying window system are provided to the -generic rootless layer through rootless implementation functions, compile- -time options, and runtime parameters. The rootless implementation -functions are a list of functions that allow the generic rootless layer to -perform operations such as creating, destroying, moving, and resizing -frames. Some of the implementation functions are optional. A detailed -description of the rootless implementation functions is provided in -Appendix A. - - By design, a rootless implementation should only have to include -the rootless.h header file. The rootlessCommon.h file contains definitions -internal to the generic rootless layer. (If you find you need to use -rootlessCommon.h in your implementation, let the generic rootless layer -maintainers know. This could be an area where the generic rootless layer -should be generalized.) A rootless implementation should also modify -rootlessConfig.h to specify compile time options for its platform. - - The following compile-time options are defined in -rootlessConfig.h: - - o ROOTLESS_PROTECT_ALPHA: By default for a color bit depth of 24 and - 32 bits per pixel, fb will overwrite the "unused" 8 bits to optimize - drawing speed. If this is true, the alpha channel of frames is - protected and is not modified when drawing to them. The bits - containing the alpha channel are defined by the macro - RootlessAlphaMask(bpp), which should return a bit mask for - various bits per pixel. - - o ROOTLESS_REDISPLAY_DELAY: Time in milliseconds between updates to - the underlying window server. Most operations will be buffered until - this time has expired. - - o ROOTLESS_RESIZE_GRAVITY: If the underlying window system supports it, - some frame resizes can be optimized by relying on the frame contents - maintaining a particular gravity during the resize. In this way less - of the frame contents need to be preserved by the generic rootless - layer. If true, the generic rootless layer will pass gravity hints - during resizing and rely on the frame contents being preserved - accordingly. - - The following runtime options are defined in rootless.h: - - o rootlessGlobalOffsetX, rootlessGlobalOffsetY: These specify the global - offset that is applied to all screens when converting from - screen-local to global coordinates. - - o rootless_CopyBytes_threshold, rootless_CopyWindow_threshold: - The minimum number of bytes or pixels for which to use the rootless - implementation's respective acceleration function. The rootless - acceleration functions are all optional so these will only be used - if the respective acceleration function pointer is not NULL. - - -Accelerated Drawing - - The rootless implementation typically does not have direct access -to the hardware. Its access to the graphics hardware is generally through -the API of the underlying window system. This underlying API may not -overlap well with the X11 drawing primitives. The generic rootless layer -falls back to using fb for all its 2-D drawing. Providing optional rootless -implementation acceleration functions can accelerate some graphics -primitives and some window functions. Typically calling through to the -underlying window systems API will not speed up these operations for -small enough areas. The rootless_*_threshold runtime options allow the -rootless implementation to provide hints for when the acceleration -functions should be used instead of fb. - - -Alpha Channel Protection - - If the bits per pixel is greater then the color bit depth, the contents -of the extra bits are undefined by the X11 protocol. Some window systems -will use these extra bits as an alpha channel. The generic rootless layer can -be configured to protect these bits and make sure they are not modified by -other parts of the X server. To protect the alpha channel -ROOTLESS_PROTECT_ALPHA and RootlessAlphaMask(bpp) must be -set appropriately as described under the compile time options. This -ensures that the X11 graphics primitives do not overwrite the alpha -channel in an attempt to optimize drawing. In addition, the window -functions PaintWindow() and Composite() must be replaced by alpha -channel safe variants. These are provided in rootless/safeAlpha. - - -Credits - - The generic rootless layer was originally conceived and developed -by Greg Parker as part of the XDarwin X server on Mac OS X. John -Harper made later optimizations to this code but removed its generic -independence of the underlying window system. Torrey T. Lyons -reintroduced the generic abstractions and made the rootless code suitable -for use by other X servers. - - -Appendix A: Rootless Implementation Functions - - The rootless implementation functions are defined in rootless.h. It -is intended that rootless.h contains the complete interface that is needed by -rootless implementations. The definitions contained in rootlessCommon.h -are intended for internal use by the generic rootless layer and are more -likely to change. - - Most of these functions take a RootlessFrameID as a parameter. -The RootlessFrameID is an opaque object that is returned by the -implementation's CreateFrame() function. The generic rootless layer does -not use this frame id other than to pass it back to the rootless -implementation to indicate the frame to operate on. - -/* - * Create a new frame. - * The frame is created unmapped. - * - * pFrame RootlessWindowPtr for this frame should be completely - * initialized before calling except for pFrame->wid, which - * is set by this function. - * pScreen Screen on which to place the new frame - * newX, newY Position of the frame. - * pNewShape Shape for the frame (in frame-local coordinates). NULL for - * unshaped frames. - */ -typedef Bool (*RootlessCreateFrameProc) - (RootlessWindowPtr pFrame, ScreenPtr pScreen, int newX, int newY, - RegionPtr pNewShape); - -/* - * Destroy a frame. - * Drawing is stopped and all updates are flushed before this is called. - * - * wid Frame id - */ -typedef void (*RootlessDestroyFrameProc) - (RootlessFrameID wid); - -/* - * Move a frame on screen. - * Drawing is stopped and all updates are flushed before this is called. - * - * wid Frame id - * pScreen Screen to move the new frame to - * newX, newY New position of the frame - */ -typedef void (*RootlessMoveFrameProc) - (RootlessFrameID wid, ScreenPtr pScreen, int newX, int newY); - -/* - * Resize and move a frame. - * Drawing is stopped and all updates are flushed before this is called. - * - * wid Frame id - * pScreen Screen to move the new frame to - * newX, newY New position of the frame - * newW, newH New size of the frame - * gravity Gravity for window contents (rl_gravity_enum). This is always - * RL_GRAVITY_NONE unless ROOTLESS_RESIZE_GRAVITY is set. - */ -typedef void (*RootlessResizeFrameProc) - (RootlessFrameID wid, ScreenPtr pScreen, - int newX, int newY, unsigned int newW, unsigned int newH, - unsigned int gravity); - -/* - * Change frame ordering (AKA stacking, layering). - * Drawing is stopped before this is called. Unmapped frames are mapped by - * setting their ordering. - * - * wid Frame id - * nextWid Frame id of frame that is now above this one or NULL if this - * frame is at the top. - */ -typedef void (*RootlessRestackFrameProc) - (RootlessFrameID wid, RootlessFrameID nextWid); - -/* - * Change frame's shape. - * Drawing is stopped before this is called. - * - * wid Frame id - * pNewShape New shape for the frame (in frame-local coordinates) - * or NULL if now unshaped. - */ -typedef void (*RootlessReshapeFrameProc) - (RootlessFrameID wid, RegionPtr pNewShape); - -/* - * Unmap a frame. - * - * wid Frame id - */ -typedef void (*RootlessUnmapFrameProc) - (RootlessFrameID wid); - -/* - * Start drawing to a frame. - * Prepare a frame for direct access to its backing buffer. - * - * wid Frame id - * pixelData Address of the backing buffer (returned) - * bytesPerRow Width in bytes of the backing buffer (returned) - */ -typedef void (*RootlessStartDrawingProc) - (RootlessFrameID wid, char **pixelData, int *bytesPerRow); - -/* - * Stop drawing to a frame. - * No drawing to the frame's backing buffer will occur until drawing - * is started again. - * - * wid Frame id - * flush Flush drawing updates for this frame to the screen. - */ -typedef void (*RootlessStopDrawingProc) - (RootlessFrameID wid, Bool flush); - -/* - * Flush drawing updates to the screen. - * Drawing is stopped before this is called. - * - * wid Frame id - * pDamage Region containing all the changed pixels in frame-local - * coordinates. This is clipped to the window's clip. - */ -typedef void (*RootlessUpdateRegionProc) - (RootlessFrameID wid, RegionPtr pDamage); - -/* - * Mark damaged rectangles as requiring redisplay to screen. - * - * wid Frame id - * nrects Number of damaged rectangles - * rects Array of damaged rectangles in frame-local coordinates - * shift_x, Vector to shift rectangles by - * shift_y - */ -typedef void (*RootlessDamageRectsProc) - (RootlessFrameID wid, int nrects, const BoxRec *rects, - int shift_x, int shift_y); - -/* - * Switch the window associated with a frame. (Optional) - * When a framed window is reparented, the frame is resized and set to - * use the new top-level parent. If defined this function will be called - * afterwards for implementation specific bookkeeping. - * - * pFrame Frame whose window has switched - * oldWin Previous window wrapped by this frame - */ -typedef void (*RootlessSwitchWindowProc) - (RootlessWindowPtr pFrame, WindowPtr oldWin); - -/* - * Copy bytes. (Optional) - * Source and destinate may overlap and the right thing should happen. - * - * width Bytes to copy per row - * height Number of rows - * src Source data - * srcRowBytes Width of source in bytes - * dst Destination data - * dstRowBytes Width of destination in bytes - */ -typedef void (*RootlessCopyBytesProc) - (unsigned int width, unsigned int height, - const void *src, unsigned int srcRowBytes, - void *dst, unsigned int dstRowBytes); - -/* - * Copy area in frame to another part of frame. (Optional) - * - * wid Frame id - * dstNrects Number of rectangles to copy - * dstRects Array of rectangles to copy - * dx, dy Number of pixels away to copy area - */ -typedef void (*RootlessCopyWindowProc) - (RootlessFrameID wid, int dstNrects, const BoxRec *dstRects, - int dx, int dy); - + Generic Rootless Layer + Version 1.0 + July 13, 2004 + + Torrey T. Lyons + torrey@xfree86.org + + +Introduction + + The generic rootless layer allows an X server to be implemented +on top of another window server in a cooperative manner. This allows the +X11 windows and native windows of the underlying window server to +coexist on the same screen. The layer is called "rootless" because the root +window of the X server is generally not drawn. Instead, each top-level +child of the root window is represented as a separate on-screen window by +the underlying window server. The layer is referred to as "generic" +because it abstracts away the details of the underlying window system and +contains code that is useful for any rootless X server. The code for the +generic rootless layer is located in xc/programs/Xserver/miext/rootless. To +build a complete rootless X server requires a specific rootless +implementation, which provides functions that allow the generic rootless +layer to interact with the underlying window system. + + +Concepts + + In the context of a rootless X server the term window is used to +mean many fundamentally different things. For X11 a window is a DDX +resource that describes a visible, or potentially visible, rectangle on the +screen. A top-level window is a direct child of the root window. To avoid +confusion, an on-screen native window of the underlying window system +is referred to as a "frame". The generic rootless layer associates each +mapped top-level X11 window with a frame. An X11 window may be said +to be "framed" if it or its top-level parent is represented by a frame. + + The generic rootless layer models each frame as being backed at +all times by a backing buffer, which is periodically flushed to the screen. +If the underlying window system does not provide a backing buffer for +frames, this must be done by the rootless implementation. The generic +rootless layer model does not assume it always has access to the frames' +backing buffers. Any drawing to the buffer will be proceeded by a call to +the rootless implementation's StartDrawing() function and StopDrawing() +will be called when the drawing is concluded. The address of the frame's +backing buffer is returned by the StartDrawing() function and it can +change between successive calls. + + Because each frame is assumed to have a backing buffer, the +generic rootless layer will stop Expose events being generated when the +regions of visibility of a frame change on screen. This is similar to backing +store, but backing buffers are different in that they always store a copy of +the entire window contents, not just the obscured portions. The price paid +in increased memory consumption is made up by the greatly decreased +complexity in not having to track and record regions as they are obscured. + + +Rootless Implementation + + The specifics of the underlying window system are provided to the +generic rootless layer through rootless implementation functions, compile- +time options, and runtime parameters. The rootless implementation +functions are a list of functions that allow the generic rootless layer to +perform operations such as creating, destroying, moving, and resizing +frames. Some of the implementation functions are optional. A detailed +description of the rootless implementation functions is provided in +Appendix A. + + By design, a rootless implementation should only have to include +the rootless.h header file. The rootlessCommon.h file contains definitions +internal to the generic rootless layer. (If you find you need to use +rootlessCommon.h in your implementation, let the generic rootless layer +maintainers know. This could be an area where the generic rootless layer +should be generalized.) A rootless implementation should also modify +rootlessConfig.h to specify compile time options for its platform. + + The following compile-time options are defined in +rootlessConfig.h: + + o ROOTLESS_PROTECT_ALPHA: By default for a color bit depth of 24 and + 32 bits per pixel, fb will overwrite the "unused" 8 bits to optimize + drawing speed. If this is true, the alpha channel of frames is + protected and is not modified when drawing to them. The bits + containing the alpha channel are defined by the macro + RootlessAlphaMask(bpp), which should return a bit mask for + various bits per pixel. + + o ROOTLESS_REDISPLAY_DELAY: Time in milliseconds between updates to + the underlying window server. Most operations will be buffered until + this time has expired. + + o ROOTLESS_RESIZE_GRAVITY: If the underlying window system supports it, + some frame resizes can be optimized by relying on the frame contents + maintaining a particular gravity during the resize. In this way less + of the frame contents need to be preserved by the generic rootless + layer. If true, the generic rootless layer will pass gravity hints + during resizing and rely on the frame contents being preserved + accordingly. + + The following runtime options are defined in rootless.h: + + o rootlessGlobalOffsetX, rootlessGlobalOffsetY: These specify the global + offset that is applied to all screens when converting from + screen-local to global coordinates. + + o rootless_CopyBytes_threshold, rootless_CopyWindow_threshold: + The minimum number of bytes or pixels for which to use the rootless + implementation's respective acceleration function. The rootless + acceleration functions are all optional so these will only be used + if the respective acceleration function pointer is not NULL. + + +Accelerated Drawing + + The rootless implementation typically does not have direct access +to the hardware. Its access to the graphics hardware is generally through +the API of the underlying window system. This underlying API may not +overlap well with the X11 drawing primitives. The generic rootless layer +falls back to using fb for all its 2-D drawing. Providing optional rootless +implementation acceleration functions can accelerate some graphics +primitives and some window functions. Typically calling through to the +underlying window systems API will not speed up these operations for +small enough areas. The rootless_*_threshold runtime options allow the +rootless implementation to provide hints for when the acceleration +functions should be used instead of fb. + + +Alpha Channel Protection + + If the bits per pixel is greater then the color bit depth, the contents +of the extra bits are undefined by the X11 protocol. Some window systems +will use these extra bits as an alpha channel. The generic rootless layer can +be configured to protect these bits and make sure they are not modified by +other parts of the X server. To protect the alpha channel +ROOTLESS_PROTECT_ALPHA and RootlessAlphaMask(bpp) must be +set appropriately as described under the compile time options. This +ensures that the X11 graphics primitives do not overwrite the alpha +channel in an attempt to optimize drawing. In addition, the window +functions PaintWindow() and Composite() must be replaced by alpha +channel safe variants. These are provided in rootless/safeAlpha. + + +Credits + + The generic rootless layer was originally conceived and developed +by Greg Parker as part of the XDarwin X server on Mac OS X. John +Harper made later optimizations to this code but removed its generic +independence of the underlying window system. Torrey T. Lyons +reintroduced the generic abstractions and made the rootless code suitable +for use by other X servers. + + +Appendix A: Rootless Implementation Functions + + The rootless implementation functions are defined in rootless.h. It +is intended that rootless.h contains the complete interface that is needed by +rootless implementations. The definitions contained in rootlessCommon.h +are intended for internal use by the generic rootless layer and are more +likely to change. + + Most of these functions take a RootlessFrameID as a parameter. +The RootlessFrameID is an opaque object that is returned by the +implementation's CreateFrame() function. The generic rootless layer does +not use this frame id other than to pass it back to the rootless +implementation to indicate the frame to operate on. + +/* + * Create a new frame. + * The frame is created unmapped. + * + * pFrame RootlessWindowPtr for this frame should be completely + * initialized before calling except for pFrame->wid, which + * is set by this function. + * pScreen Screen on which to place the new frame + * newX, newY Position of the frame. + * pNewShape Shape for the frame (in frame-local coordinates). NULL for + * unshaped frames. + */ +typedef Bool (*RootlessCreateFrameProc) + (RootlessWindowPtr pFrame, ScreenPtr pScreen, int newX, int newY, + RegionPtr pNewShape); + +/* + * Destroy a frame. + * Drawing is stopped and all updates are flushed before this is called. + * + * wid Frame id + */ +typedef void (*RootlessDestroyFrameProc) + (RootlessFrameID wid); + +/* + * Move a frame on screen. + * Drawing is stopped and all updates are flushed before this is called. + * + * wid Frame id + * pScreen Screen to move the new frame to + * newX, newY New position of the frame + */ +typedef void (*RootlessMoveFrameProc) + (RootlessFrameID wid, ScreenPtr pScreen, int newX, int newY); + +/* + * Resize and move a frame. + * Drawing is stopped and all updates are flushed before this is called. + * + * wid Frame id + * pScreen Screen to move the new frame to + * newX, newY New position of the frame + * newW, newH New size of the frame + * gravity Gravity for window contents (rl_gravity_enum). This is always + * RL_GRAVITY_NONE unless ROOTLESS_RESIZE_GRAVITY is set. + */ +typedef void (*RootlessResizeFrameProc) + (RootlessFrameID wid, ScreenPtr pScreen, + int newX, int newY, unsigned int newW, unsigned int newH, + unsigned int gravity); + +/* + * Change frame ordering (AKA stacking, layering). + * Drawing is stopped before this is called. Unmapped frames are mapped by + * setting their ordering. + * + * wid Frame id + * nextWid Frame id of frame that is now above this one or NULL if this + * frame is at the top. + */ +typedef void (*RootlessRestackFrameProc) + (RootlessFrameID wid, RootlessFrameID nextWid); + +/* + * Change frame's shape. + * Drawing is stopped before this is called. + * + * wid Frame id + * pNewShape New shape for the frame (in frame-local coordinates) + * or NULL if now unshaped. + */ +typedef void (*RootlessReshapeFrameProc) + (RootlessFrameID wid, RegionPtr pNewShape); + +/* + * Unmap a frame. + * + * wid Frame id + */ +typedef void (*RootlessUnmapFrameProc) + (RootlessFrameID wid); + +/* + * Start drawing to a frame. + * Prepare a frame for direct access to its backing buffer. + * + * wid Frame id + * pixelData Address of the backing buffer (returned) + * bytesPerRow Width in bytes of the backing buffer (returned) + */ +typedef void (*RootlessStartDrawingProc) + (RootlessFrameID wid, char **pixelData, int *bytesPerRow); + +/* + * Stop drawing to a frame. + * No drawing to the frame's backing buffer will occur until drawing + * is started again. + * + * wid Frame id + * flush Flush drawing updates for this frame to the screen. + */ +typedef void (*RootlessStopDrawingProc) + (RootlessFrameID wid, Bool flush); + +/* + * Flush drawing updates to the screen. + * Drawing is stopped before this is called. + * + * wid Frame id + * pDamage Region containing all the changed pixels in frame-local + * coordinates. This is clipped to the window's clip. + */ +typedef void (*RootlessUpdateRegionProc) + (RootlessFrameID wid, RegionPtr pDamage); + +/* + * Mark damaged rectangles as requiring redisplay to screen. + * + * wid Frame id + * nrects Number of damaged rectangles + * rects Array of damaged rectangles in frame-local coordinates + * shift_x, Vector to shift rectangles by + * shift_y + */ +typedef void (*RootlessDamageRectsProc) + (RootlessFrameID wid, int nrects, const BoxRec *rects, + int shift_x, int shift_y); + +/* + * Switch the window associated with a frame. (Optional) + * When a framed window is reparented, the frame is resized and set to + * use the new top-level parent. If defined this function will be called + * afterwards for implementation specific bookkeeping. + * + * pFrame Frame whose window has switched + * oldWin Previous window wrapped by this frame + */ +typedef void (*RootlessSwitchWindowProc) + (RootlessWindowPtr pFrame, WindowPtr oldWin); + +/* + * Copy bytes. (Optional) + * Source and destinate may overlap and the right thing should happen. + * + * width Bytes to copy per row + * height Number of rows + * src Source data + * srcRowBytes Width of source in bytes + * dst Destination data + * dstRowBytes Width of destination in bytes + */ +typedef void (*RootlessCopyBytesProc) + (unsigned int width, unsigned int height, + const void *src, unsigned int srcRowBytes, + void *dst, unsigned int dstRowBytes); + +/* + * Copy area in frame to another part of frame. (Optional) + * + * wid Frame id + * dstNrects Number of rectangles to copy + * dstRects Array of rectangles to copy + * dx, dy Number of pixels away to copy area + */ +typedef void (*RootlessCopyWindowProc) + (RootlessFrameID wid, int dstNrects, const BoxRec *dstRects, + int dx, int dy); + -- cgit v1.2.3