This file lists TODO items for the compositing code. See file COMPOSITE_HOWTO for setting up kwin_composite. See file HACKING for details on developing KWin, including building the kwin_composite branch. See effects/howto.* for a HOWTO on writting effects. See documentation in source (mainly in scene.cpp) for description of the design of the compositing framework. TODO ================================= * = not done, will be either done by me, or should be at least discussed first with me + = not done, I don't plan on doing it that soon - in other words, these should be the best ones for you if you want to help ! = like +, but they should be relatively simple - in other words, these should be the best if you want to get started with the code / = work in progress ? = should it be done? % = should be probably done later, during cleanups and preparations for being stable KDE 4.0 TODO ================================= - effects (to do) - add generic support to use effect only for certain window types [Seli] - window-specific rules need to apply to unmanaged windows as well (where applicable) - some window-specific rules also related to compositing - opacity / handling of window pixmaps for unmapped windows [Seli] - config option? - shm mode needs support for more data formats than GL_BGRA - check what works with XRender - documentation - disable application effects when kwin can provide them, e.g. shadow/transparency General TODO ================================= + suspend repaints if not visible or dpms is active - there is already 'overlay_visible', but it still polls the mouse in such case - it should turn off the timer ? wait for decoration repaints - it is sometimes visible that the window contents are painted first and the decoration only afterwards with a small delay ? - this has been already greatly improved by r632378, so it's maybe not worth it anymore - maybe posted paint events need to be processed immediatelly, or maybe the compositing code should not update the window until the decoration is finished painting % paint throttling - there's 5ms grace period per repaint to avoid overloading the system with just compositing and not letting the system do anything else - check and evaluate * handle properly stacking order of deleted windows for showing in effects * handle properly deleted windows that reappear (windowReadded() function?) % during screensaving, do no let non-screensaver windows show above screensaver - kdesktop_lock watches for such things and raises again, but there's a small gap % nvidia drivers by default use fake refresh rates as a workaround for some X limitations - see the DynamicTwinView section in nvidia README - this makes KWin repaint at a different rate than it should / handling of window pixmap for unmapped windows - currently it's kept around after a window is unmapped * - but it's still discarded on e.g. resize - how to solve this? * - windows could be unmapped but quickly mapped back when a live thumbnail is needed * window grouping is not implemented for unmanaged windows (used e.g. by DimInactive) % clean up and sort out shortcuts so that they don't conflict and make sense ? hidden previews currently needs input shape extension, otherwise the window can possibly interfere - not very likely though, so is this worth bothering at all? OpenGL TODO ================================= / Check/make it work with other gfx cards % Xgl support - should work - in SceneGL::Texture::findTarget() there is a hack that makes KWin work with XGL without requiring KWin to be built against the libGL version that Compiz is built against % - that may not be necessary somewhen later - interesting observation: normally run glxgears performs somewhat poorly compared to normal nvidia mode, changing glxgears to be override-redirect (i.e. no reparenting) however makes glxgears to be even faster than without any compositing at all, in this case however kwin's redrawing speed drops somewhat % AIGLX support - should work / GL_ARB_texture_rectangle vs GL_ARB_texture_non_power_of_two % - works; bugs in tfp_mode with power_of_two textures - ati (others?): power_of_two windows are drawn white unless non-tfp_mode is forced in findTextureTarget() % bindTexture() optimize copied areas - right now bindTexture() updates every damaged area and resets the window damage - it might make things faster to update only areas that need to be repainted and keep the rest damaged until needed % clipping optimization - like XRender code has paintTransformedScreen(), avoid painting parts that are obscured (makes a difference with many windows open) - http://lists.kde.org/?l=kwin&m=116585618111882&w=2 ! shm mode needs support for more data formats than GL_BGRA - http://www.xfree86.org/current/glTexImage2D.3.html - this now works for 16bpp, but maybe not 15bpp or less - endian issues? + support for __GL_YIELD=NOTHING and LIBGL_ALWAYS_INDIRECT should be possibly less hacky - or at least not hardcoded (although, does that matter?) - (http://lists.kde.org/?l=kwin&m=116439615124838&w=2) - (http://lists.freedesktop.org/archives/xorg/2006-December/020323.html) XRender TODO ============================== + SceneXrender::paintTransformedScreen() doesn't handle properly extending of painted area in window's pre-paint - see the transformedShape() comment - and currently seems to be generally broken Effects framework TODO ============================== * more notification functions for effects are needed - currently there are only very few notification functions (windowAdded, windowActivated,...) ! - window state changes ? more / support for grabbing input - during some more complicated effects, input (at least mouse) should be disabled, because currently there is no way to do input redirection + EffectWindow should be completely opaque when kept as the only API for effects - no inlines, etc. + EffectsHandler should not have virtuals but should instead use an internal object for communication with KWin core, so that adding new functions doesn't break BC all the time + API for tabbox for effects should be cleaned up * check Scene::updateTimeDiff() - should the time be 0 or 1? % post calls are probably not necessary by now (http://lists.kde.org/?t=117770818100003&r=1&w=2) % consider using http://lists.kde.org/?l=kwin&m=118094888517415&w=2 for notification functions % API cleanups and making sure it will stay backwards compatible Effects TODO =============================== ! add reloadConfig() to effects - currently changing the global animation speed in the kcm does not change effect + minimize/shade effects - to replace the ones from KWin core / - minimizing - check support for it and the avoid_animation flag + - shading - shading will probably need special support / zoom effect - enlarge a portion of the screen - Should it react to meta+wheel? + logout effect * - should be triggered by ksmserver somehow + effects to replace widget effects (the ones in the Effects tab in "kcmshell style") / showfps effect - should also detect kwin being idle - it probably should detect in pre-paint that the only damage is its own area and avoid damaging for the next round in post-paint / scalein + - should scale in from e.g. 80%, not 0%, to just "pop up" + effect for drawing attention to windows demanding attention - Rays? Ripples? * DimInactive flickers when switching between windows (temporarily no window becomes active) - focus effect (windows waves a little when it gets focus) + shadow + - follow the shape of the window (currently is disabled completely using the hasOwnShadow() hack) + window thumbnails directly in panel - i.e. the panel (taskbar?) could show window previews directly, without tooltips Performance ================== + various caching - there are many things that usually don't change and could gain few fps (is it worth it?) - Workspace::performCompositing() - WindowQuadList could perhaps cache quads split by contents/decoration (for select()) + avoiding X roundtrips each compositing pass - right now it at least always polls the mouse position and the current stacking order