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diff --git a/nx-X11/programs/Xserver/miext/rootless/README.txt b/nx-X11/programs/Xserver/miext/rootless/README.txt deleted file mode 100644 index ffd17902f..000000000 --- a/nx-X11/programs/Xserver/miext/rootless/README.txt +++ /dev/null @@ -1,403 +0,0 @@ - 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_ACCEL: If true, use the optional rootless acceleration - functions where possible to a accelerate X11 drawing primitives. - If false, all drawing will be done with fb. - - o ROOTLESS_GLOBAL_COORDS: This option controls the way that frame - coordinates are passed to the rootless implementation. If false, - the coordinates are passed per screen relative to the origin of - the screen the frame is currently on. Some implementations may - prefer to work in a single global coordinate space that spans all - screens. If this option is true, the coordinates are passed after - adding the coordinates of the screen origin and an overall offset of - (rootlessGlobalOffsetX, rootlessGlobalOffsetY). - - 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. - - o ROOTLESS_TRACK_DAMAGE: The generic rootless layer draws to the - frames' backing buffers and periodically flushes the modified - regions to the underlying window server. If this option is true, - the generic rootless layer will track these damaged regions. - Currently it uses the miRegion code and will not simplify damaged - regions even when updating a bounding region would be more - efficient. Some window systems provide a more efficient way to - track damaged regions. If this option is false, the rootless - implementation function DamageRects() is called whenever a - backing buffer is modified and the rootless implementation is - expected to track the damaged regions itself. - - The following runtime options are defined in rootless.h: - - o rootlessGlobalOffsetX, rootlessGlobalOffsetY: These are only - used if ROOTLESS_GLOBAL_COORDS is true. They specify the global - offset that is applied to all screens when converting from - screen-local to global coordinates. - - o rootless_CopyBytes_threshold, rootless_FillBytes_threshold, - rootless_CompositePixels_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. These will be identical to pFrame-x, - * pFrame->y unless ROOTLESS_GLOBAL_COORDS is set. - * 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. This - * will always be FALSE if ROOTLESS_TRACK_DAMAGE is set. - */ -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. This - * will be NULL if ROOTLESS_TRACK_DAMAGE is not set. - */ -typedef void (*RootlessUpdateRegionProc) - (RootlessFrameID wid, RegionPtr pDamage); - -/* - * Mark damaged rectangles as requiring redisplay to screen. - * This will only be called if ROOTLESS_TRACK_DAMAGE is not set. - * - * 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); - -/* - * Fill memory with 32-bit pattern. (Optional) - * - * width Bytes to fill per row - * height Number of rows - * value 32-bit pattern to fill with - * dst Destination data - * dstRowBytes Width of destination in bytes - */ -typedef void (*RootlessFillBytesProc) - (unsigned int width, unsigned int height, unsigned int value, - void *dst, unsigned int dstRowBytes); - -/* - * Composite pixels from source and mask to destination. (Optional) - * - * width, height Size of area to composite to in pizels - * function Composite function built with RL_COMPOSITE_FUNCTION - * src Source data - * srcRowBytes Width of source in bytes (Passing NULL means source - * is a single pixel. - * mask Mask data - * maskRowBytes Width of mask in bytes - * dst Destination data - * dstRowBytes Width of destination in bytes - * - * For src and dst, the first element of the array is the color data. If - * the second element is non-null it implies there is alpha data (which - * may be meshed or planar). Data without alpha is assumed to be opaque. - * - * An X11 error code is returned. - */ -typedef int (*RootlessCompositePixelsProc) - (unsigned int width, unsigned int height, unsigned int function, - void *src[2], unsigned int srcRowBytes[2], - void *mask, unsigned int maskRowBytes, - void *dst[2], unsigned int dstRowBytes[2]); - -/* - * 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); - |