Hi Gunnar, I just tried your example out (from the new review link [1]) and you've truly done a amazing job! + you saved my days of fiddling around :) Big pros! It runs well on Qt with OpenGL on Windows. I haven't tried other instances.
Again, an awesome job! Will this be added as an example to 5.1.0 or 5.1.1? It's not like it's blocking anything ;) Cheers, Mark [1] https://codereview.qt-project.org/#change,58714 On Wed, Jun 12, 2013 at 8:54 AM, Mark <mark...@gmail.com> wrote: > On Wed, Jun 12, 2013 at 8:29 AM, Sletta Gunnar <gunnar.sle...@digia.com> > wrote: >>> > This graph concept might be a good usecase for a more complex example >>> > down the line though.. I'll keep it in mind and maybe it will be included >>> > in Qt in the future :) >>> >>> Oh... that sucks. >> >> I think so too, so I spent some time yesterday evening to put it together: >> https://codereview.qt-project.org/#change,58589 >> >> It does the background, grid, line and dropshadow as 4 separate geometry >> nodes and shows several new sides of the scene graph API. >> >> The line stroking is a bit crude as it doesn't account for the line angle so >> steep slopes will come out thinner, but it should be a good starting point. > > Oh wow! You're trying to do everything i tried in just a couple of > hours where i would spend several nights and not even get close to > what you just made. Thank you very much for this! >> >> cheers, >> Gunnar >> >>> Well, i guess i'm just gonna have to play with this >>> and see how it turns out. If (assuming i can figure it out) i get it >>> working i will certainly share my code in here or on this list. >> >>> >>>> >>>>> - for the dropshadow, do exactly the same as for the line, except you can >>>>> use the custom vertex shader to expand it a little bit more and change >>>>> the opacity to make it a more blurry. >>>> Here i really do wonder if it isn't easier to just make a simple line >>>> component and use QtGraphicalEffects for the shadowing... I guess >>>> experimenting with both will tell which option works best. >>>> >>>> >>>>> - for the gradient under the line, create a trianglestrip and colorize it >>>>> according based on the y position in the fragment shader. >>>> Yeah, figured it would be something like that. Will do. >>>>> >>>>>> >>>>>> 2. Another way i see is taking the OpenGL direct approach following >>>>>> the "OpenGLunderQML example [1]. I can probably work of that example, >>>>>> but i really try to stay away from doing direct opengl interaction.. >>>>> >>>>> Raw OpenGL has its benefits, which is why the example and the feature is >>>>> there, but I've been thinking that the primary usecase for OpenGLUnderQML >>>>> is when you have a game/cad app running and QML is just the HUD controls. >>>>> Using raw opengl for UI elements has the downside that you don't get any >>>>> inherited clipping, transformation, nor opacity so things might be quite >>>>> a bit more complicated to manage inside your UI. >>>> Exactly my opinion as well. I try to stay away from raw opengl calls. >>>>> >>>>>> >>>>>> 3. A third possible way that i can think of is by throwing everything >>>>>> out and starting over in a very abstract manner. Making a bunch of >>>>>> small components (in C++) like: >>>>>> (note: this is still for the charting stuff [0]) >>>>>> - 1 component to draw the background with a little more power then a >>>>>> Rectangle. However, if i choose this route i might as well use the >>>>>> QtGraphicalEffects for the added power (gradients) since that provides >>>>>> it. >>>>>> - 1 component for drawing a grid on top of the gradient. >>>>>> - 1 component for drawing a line where i probably only provide the >>>>>> data indicating where the line should be. Again i can use >>>>>> QtGraphicalEffects on top of this to add additional shadow. However, i >>>>>> find the default OpenGL line drawing stuff (even with multisampling) >>>>>> of a very very very poor rendering quality. I'm really thinking of >>>>>> using the "vase renderer" for drawing a way sharper line [2] Another >>>>>> note, this might also be very interesting for you to draw way sharper >>>>>> "scene graph fonts" which at the moment still look quite blurry at >>>>>> it's best under desktop environments. >>>>> >>>>> The distancefield fonts are unhinted and this is why they look more >>>>> blurry than native fonts (at least on windows and potentially linux). You >>>>> can enable native rendering by sacrificing font scalability: >>>>> http://blog.qt.digia.com/blog/2012/08/08/native-looking-text-in-qml-2/ >>>>> >>>>>> - I'm stuck at how to animate the line as more data flows in.. >>>>>> >>>>>> I hope you can advice me here in picking an option to go for. It's all >>>>>> quite a bit of work and all likely has the same end result. Right now >>>>>> i'm leaning towards option 3 where i was trying to go for option 1 >>>>>> till this very moment. >>>>>> >>>>>> >>>>>> [0] http://i.stack.imgur.com/Zk2RG.png -- i try to make it look as >>>>>> crisp as this one >>>>> >>>>> >>>>>> [1] >>>>>> https://qt.gitorious.org/qt/qtdeclarative/trees/stable/examples/quick/scenegraph/openglunderqml >>>>>> [2] >>>>>> http://www.codeproject.com/Articles/226569/Drawing-polylines-by-tessellation >>>>>> >>>>>> >>>>>> On Mon, Jun 10, 2013 at 10:07 AM, Sletta Gunnar >>>>>> <gunnar.sle...@digia.com> wrote: >>>>>>> >>>>>>> On Jun 8, 2013, at 11:33 PM, Mark <mark...@gmail.com> wrote: >>>>>>> >>>>>>>> Hi, >>>>>>>> >>>>>>>> Back when the graphical effects where first showcased in a blog i was >>>>>>>> already kinda scared that there would be no C++ interface to use them >>>>>>>> from the C++ side. Now i find myself in the position where i want to >>>>>>>> use the DropShadow element from that very same module in custom QML >>>>>>>> Scene Graph module and give a line a shadow. >>>>>>>> >>>>>>>> I kinda - very much - dislike copying the relavant parts of the >>>>>>>> DropShadow code and re-create that in C++.. >>>>>>>> >>>>>>>> Is there a way that i can use DropShadow from the C++ side? >>>>>>> >>>>>>> There is no way to do this using pure C++ API. You could construct it >>>>>>> from c++ using QQmlComponent and set the source property by passing it >>>>>>> the item that creates the geometry node. >>>>>>> >>>>>>> cheers, >>>>>>> Gunnar >>>>>>> >>>>>>>> >>>>>>>> Regards, >>>>>>>> Mark >>>>>>>> _______________________________________________ >>>>>>>> Interest mailing list >>>>>>>> Interest@qt-project.org >>>>>>>> http://lists.qt-project.org/mailman/listinfo/interest >>>>>>> >>>>> >>> _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
