On Jun 12, 2013, at 9:58 PM, Mark <mark...@gmail.com> wrote: > 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 ;)
Targeted at 5.1.1 now, it is by no means a showstopper :) > > 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
