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diff --git a/krita/doc/DESIGN.obsolete b/krita/doc/DESIGN.obsolete new file mode 100644 index 00000000..f3fd1631 --- /dev/null +++ b/krita/doc/DESIGN.obsolete @@ -0,0 +1,179 @@ +A Perspective on Krita's Design + + Krita's codebase has been through as many changes as the app's name + itself. It started with KImageShop (hence the 'kis' prefix one finds + everwhere, and which would have been unnessary had Krita used + namespaces, one fancies), then became Krayon to end up as Krita. The + stated design goal was to create a application geared towards the + more artistic user; the kind of user who settles down with his + tablet to create a spot of Art. It ended up as a Gimp-clone, a Kimp, + so to say. + + This document was the basis for a discussion on the krita mailinglist: + http://lists.kde.org/?l=kde-kimageshop&m=106530035202770&w=2. See the + answer for some answers to the questions at the end. + +Design Patterns + + Patrick Julien restructured Krita to use a lot design patterns. Krita + appears to have a very solid base for blasting pixels to the screen, + zooming, selecting and moving. These are what I recognize as his + changes: + + * Change brushes handling to a generic Mediator pattern + (kis_resource_mediator). Resources are brush shapes, + patterns (and colours, too?) Patrick intended a Flyweight + here. + + * The composite pattern is used in paint devices, layers, channels, + etc. (What about masks?) + + * Change colourspace handling to a Strategy pattern + (strategy/kis_strategy_color) + + * Change moving chunks of painting to a Strategy pattern + (strategy/kis_strategy_move) + + * kis_factory points towards a Factory pattern Creates the + pluginserver and resourceserver. + + * Tools are created by a Factory pattern (but it isn't + dynamic yet): kis_tool_factory. Tools are intended to + become kparts. + + * There's the start of a Memento pattern for tools, but it + doesn't seem to be used (kis_tool_memento). It was an + experiment that didn't pan out. + + * The Builder pattern is used to do conversion to and/or + from ImageMagick. I guess this is used for importing + images in other file-formats than .krita. An idea at one + was to use Koffice filters, but that didn't work because + images are rather different from other office documents. + + * Flyweight pattern used for background tiles. + kis_background. + + * Nameserver. Perhaps not a pattern -- at least not one + with an obvious GOF name. Appears to be computing a + number for new layers and new documents. + + * kis_render. Interface implemented by kis_paint_device + and kis_image. + + * Rename kisTool to kisToolInterface -- but the file is + still called kis_tool. (This is intentional, and should + be kept in the style guide.) + + * Addition of kis_types. Defines shared pointer pointers + to core krita objects: image, paintdevice, channel, + mask, layer etc. + + * Tile architecture. There's Mediator and a Singleton + pattern here at least. This stuff seems to work, doesn't + need hacking at the moment. + + * Visitor pattern used to flatten an image or merge + layers. Merging exposes a funny bug where the tiles + are re-arranged in an interesting mosaic pattern. + + +User interface + + Krita uses a fairly ugly side-panel to collect what are palettes + in other applications. I would prefer dockable, attachable + palettes myself. Doesn't KDE have a lib for that already? + + + ui/labels + + These classes are used in the statusbar. + + ui + + The dialogs appear to be created by hand, not with Qt + Designer. Besides, many are inoperational. + + other + + The canvas, rules and sidebar panels are defined here, too, + nicely separated. + +Tools + + Working: select_rectangular, test, zoom, colorpicker, paste, move + + Not working: airbrush, brush, colorchanger (no idea what it should + do), ellipse, eraser, fill, line, pen, polygon, polyline, + rectangle, select_contiguous, select_elliptical, select_freehand, + select_polygonal, stamp + + Missing tools: convolve, smear, smudge, whirl, charcoal, chalk, + oils, clone, select_by_colour + +Plugins + + The single plugin example has been present in krita since about day + one, as far as I can see. It doesn't show anything about what one + can do with plugins. + + To judge from the code in kis_plugin_server, it never got beyond + an idea. (kdDebug() << "hallo\n"...) + + (This code should be removed.) + +ImageMagick + + There still appear to be some dependencies upon ImageMagick (builder + subdir). What are these for, and should they stay? Is it for + importing/exporting foreign file formats? + +Undo/Redo + + Undo and Redo make use of the standard KDE mechanism, which I don't + really understand either. + + +Obsolete files + + The following files appear to be unused: + + core/helper/kis_timer + core/helper/kis_scopedlock (Replaced with QMutexlocker) + core/kis_krayon (was predecessor of kis_resource) + core/kis_mask + core/kis_util + ui/kis_krayon_widget + +Random head-scratchings + + + - Why the QUANTUM redefinition: the number of bits per channel, + 8 for 32-bit colour, 16 for 64-bit colour. + + - is_mask unimplemented? What was it meant to do, or is it an + interface? + + - nameserver presents unique numbers for new layers and images. + + - what does 'upscale' do? in 8 bit/channel color mode, upscale + doesn't do anything. However, downscale and upscale in > 8 bit, + this is needed to covert the color for the actual display + rendering, i.e. X, etc, only do 8 bit color. Using this + everywhere you work on color will keep krita color channel + bit depth independent. + + + - Is KisVector only used in obsolete tools? + + - I take it that the two tests that are present in krita/test + are obsolete? + + - what with the dummmmmy.cc? + + - which bits of the krita/ui files are still relevant? + + - kis_selection.h needs to be included to compile code that + uses kis_paint_device, and I wonder why. + + - what is paint-offset? |