Hi everyone, Thanks for the feedback on my idea. Based on the feedback and the tests I made the past few days, I wrote a GSoC application.
http://www.google-melange.com/gsoc/proposal/public/google/gsoc2015/michaelz/5750085036015616 Feel free to leave feedback/your thoughts on this. Regards, Michael Am 09.03.2015 um 18:19 schrieb Michael Zangl: > Hi, > > I'm also posting this on the JOSM-List in hope to get feedback on the > technical parts here. > > Regards, > Michael > > -------- Weitergeleitete Nachricht -------- > Betreff: [OSM-dev] GSoC: OpenGL view for JOSM > Datum: Mon, 09 Mar 2015 13:58:41 +0100 > Von: Michael Zangl <openstreet...@michael.fam-zangl.net> > An: d...@openstreetmap.org > > Hello, > > This is a thing that annoyed me for a long time: JOSM is slow when > zooming out. I would like to improve this and have enough spare time > this summer to work on this as GSoC project. > > I am currently studying computer science at the KIT (Karlsruhe, > Germany). My OSM name is "michael2402". > > Motivation > Currently, JOSM uses the default Java 2D framework. While this is > portable (it just works) and also supports 2d graphic acceleration using > OpenGL, it is not as fast as a plain OpenGL implementation would be. > This is why I would suggest adding a second render mode to JOSM which > would then use OpenGL and all it's modern features like VBOs to > accelerate rendering and allow a smooth moving of a zoomed-out map. > > The idea: > I would like to add a second rendering mode that only uses OpenGL. Users > are then able to chose between classic rendering and the new OpenGL > render styles. > > The basic idea is that this interface can be used if you want to work in > an urban area with a lot of details and change e.g. the public transport > system so you need to zoom out a lot. The current renderer is pretty > slow as soon as there are many objects in the view. Therefore, even a > not-fully-featured Renderer can be beneficial for users to get an > overview over the area. > > I would then add a new rendering interface that exposes the new features > required/provided by OpenGL. That interface should be prepared to accept > 3D-Positions (although I don't plan on using them, but maybe someone > might want to add shadows or even a real 3D building view in the > future). We have to discuss how this works, but currently I am in favor > of offsetting all nodes to the ground elevation (so a barrier=wall might > be from 0 to 1 meter), then adding the elevation we got from elevation > tags (ele, NASA data, ...) > > That rendering interface can then be used by plugins to add their own > styles. This would be necessary if one wanted to add real 3D objects, > like trees. This is more like a bonus feature, so I will be writing a > test plugin to test the interface. We also need a way to add "ground" > (=> Background) images for background layers. > > I would then create one plugin that can uses MapCSS to render a style in > the view. That way, many existing styles can be used with the new > interface. This will be the most part of the work on this project. > > As library I would currently prefer JOGL, since I already have > experience with it and it contains some additional features we would > need (like text rendering support and the ability to be added as swing > panel). > > Current status: > - Currently, each layer draws it self to the Java Graphics. Most layers > are not really extensible (like the GPX-Track feature), which makes it > hard to modify them using plugins (like adding non-standard accuracy > info to GPX and drawing the accuracy area instead of the line). > - Layers are drawn the way they are ordered in the side view. > - There are basically two types of layers: Background layers > (ImageryLayer.java, TMSLayer.java, ...) and data layers (GpxLayer.java, > OsmDataLayer.java, ...) > > Implementation details/ideas (so far): > - JOSM create a list of "Drawer" objects for each layer. > - I would like to use a 2D plane (which can then be offsetted using > shaders) to be the background for all of the map. There is only one > background pane with the textures of background layers added to it. I > will have to look more into shaders (like supporting an unlimited number > of textures on a single area) but I hope this is possible. > -- Fallback: Just render the images as rectangle, one over the other, > using opacity settings and disabling the depth buffer (the way it is > done currently). Cache using VBOs. This is not as modern as shaders > would be, but it is simple. > - Layers make heavy use of VBOs. I would like to provide a nice > interface to draw and cache VBO structures. This will also speed up > drawing of the map a lot, since the map does not change. Thinks it > should do include: > -- Draw a point at the given lat/lon > -- Draw a line of width x with given (lat/lon/width) point pairs and > color, closed or open. > -- Draw a filled area (without contour) > -- Add text at a given position. > -- MapCSS properties this basically supports: width, color (rgba), > dashes, linecap, linejoin, fill-color (rgba), font-size, text-color, > text-offset, text. > -- What we won't support: z-index (but we could order the elements > before drawing), casing, extrude, icons, text-position. > - Each VBO is tied to map objects that it depends on. That way, it only > needs to be updated if those objects change. Doing this is done by the > renderer (which also has knowledge of all MapCSS styles). > -- The MapCSS renderer needs to be adjusted to keep track of object > changes and re-create a VBO as soon as it's rules change. > > Implementation schedule (12 weeks until "pencils down") > 2 Weeks: Getting to know JOSM and adding the OpenGL view to the core > (and an interface to use it). > 2 Weeks: Adding the OpenGL interfaces we need (like computing the > OpenGL-Coordinates for a point on earth and the objects it should render). > 3 Weeks: Create a VBO drawing library. > 3 Weeks: Add a mappaint style renderer (hopefully being able to use as > much of an existing renderer as possible). Make objects clickable. Bonus > (I can't tell if I have time, but basically this should be the same as > any other observed object changes): Support hover and active. > 2 Weeks: (to be discussed which): Add a new render layer for background > images. It should then be possible to draw a GeorefImage list and e.g. > the Bing map. > > Main challenges: > - Prevent code-duplication as much as possible. > - Get the OpenGL-Part as stable as possible (not fully featured, but > non-crashing), so that it can be included in trunk after GSoC is over. > > To be discussed: > - How much of this can be a plugin? Is it possible to use a plugin for > all of this or should as much of it be in core? I would suggest adding > the basic OpenGL stuff to Core and implementing the layer renderers as > plugins. That way, each of them can be improved independently. > - Should the layer Painters be a private for to each layer (and provided > by it) or should they be provided by a central system (get me the > Painter for ...) > - Use shaders for the background images. > - I did not find an OpenGL MapCSS renderer. This could be a nice project > to have (for other editors, smartphones, ...). Are there any efforts > currently? We don't need to do things twice... > - Should we support multiple renderers? I really opt for this, we could > e.g. add a mini-map to the sidebar to show where you are on the map or > even support opening multiple Edit-Windows (imagine having the official > Map with house numbers on one screen and the map with Bing sattelite on > the other, house number mapping would just get so much easier ;-)) > > What are your thoughts on this? > > In hope of a lot of feedback, > Michael Zangl > > _______________________________________________ > dev mailing list > d...@openstreetmap.org > https://lists.openstreetmap.org/listinfo/dev > > > > _______________________________________________ > josm-dev mailing list > josm-dev@openstreetmap.org > https://lists.openstreetmap.org/listinfo/josm-dev > _______________________________________________ josm-dev mailing list josm-dev@openstreetmap.org https://lists.openstreetmap.org/listinfo/josm-dev
