Draw grid lines in vtkXYPlotActor - c++

I want to show the grid lines in a graph created using vtkXYPlotActor.
Can you suggest me how?
Thanks.

With the vtkXYPlotActor class it is difficult modify the underlying (generated) plot data and settings.
You are better off using the vtkChartXY class , which allows this easily using something like
vtkSmartPointer<vtkChartXY> chart = vtkSmartPointer<vtkChartXY>::New();
chart->GetAxis(0)->SetGridVisible(true);
chart->GetAxis(0)->SetGridVisible(true);
If you don't have access to the vtkChartXY class you have two options both of which are more work than upgrading.
Attempt to make your own version of vtkXYPlotActor that uses
vtkAxisActor instead of vtkAxisActor2D, either through
subclassing or from creating from scratch.
vtkAxisActor has the 2 relevant modifiers for gridlines vtkAxisActor::SetDrawGridlines and vtkAxisActor::SetGridlinesProperty, whilst vtkAxisActor2D doesn't have these.
This is non trivial.
Make a 3D plot and move the camera so the plot looks like it is 2D.
Further VTK references include
VTK Plotting Examples
vtkChartXY Class Reference
vtkXYPlotActor Class Reference

Related

Qt | creating a dynamic object in a customized scene

Good day to all!
I would like to learn from the respected community how it is possible using Qt Designer to create a simple GUI that performs what is shown in the attached image. Namely: after a single click of the LMB, a marker is placed at the place of the click, indicating the beginning of the polygon, and a temporary polygon of the desired type (but of different sizes) begins to follow the mouse cursor until we click on the LMB again, after which the final polygon will be built from the point of the first click of the LMB to the point of the second click. Such a ready-made polygon will have to be stored somewhere in memory for further work with it.
As a polygon here, I show a complex sector built on some calculated points, but as a simple example, you can take a straight line - I don't think that the essence of the program changes much.
I have already looked at many examples of different implementations of different things on QGraphicsScene, but I could not figure out exactly how to create an object in the way I needed. That is, I know that we need a separate class describing the polygon and calculating the coordinates of which it consists, but I don't quite understand how to implement the dynamics - with each mousemoveivent, delete the temporary polygon and draw a new one for the new coordinates, or how?
P.S. If it won't be so difficult, could someone also show how to implement what was conceived through the redefined paintScene class, replacing the standard QGraphicsScene class and inheriting from it? I am faced with the fact that when creating a custom class of the scene object, clicking on the objects attached to it is ignored by the program, and instead of, for example, dragging an object on the scene when clicking on it, the mousePressEvent of the scene, not the object, is triggered, and I do not understand what the problem is.
P.P.S. I apologize for my English and thank everyone for any help!

Qt Qml: Dynamic number of moving axis aligned bounding boxes

I am writing a video display software capable of displaying multiple video streams. For this I have a GridView holding VideoOutputs in QML connected to a QAbstractListModel derived class in c++ which provides instances of an object with a QAbstractVideoSurface Q_PROPERTY. It's working quite beautifully so far.
The video frames I am displaying come with metadata, however, containing data for axis aligned bounding boxes. I don't know beforehand how many boxes there are, the number could even change on a frame by frame basis, their position and size is also not set.
Ultimately, it should look something like this:
As I need to be able to display a few video streams at once, and preferably at 30+ fps, I need a fast method of drawing these boxes. Using QPainter on the QImage on which the QVideoFrame is based is rather slow so I was considering a few other approaches:
Using the QML object Rectangle in a Repeater with a c++ provided model (Was hoping to simply provide a QVariantList::fromVector() ): Could work, however I would need a lot of models which in turn I need to provide to QML with a model, and I would likely need to call begin/endResetModel every frame that the boxes change to cause QML to update - this is also very slow.
Using a Shader to draw the boxes: This is a rather difficult approach. I'm no stranger to shaders, but in Qt/Qml I don't know how to provide the shader with the information necessary.
Using OpenGL directly to draw the boxes: Again, I have no clue how to do this, but I think I could work it out if I googled.
My question: Which one, if any, of these approaches is the best? If none of these, which other approach could I use?
Thank you so much for taking the time to read my rather long question!

Combine different parts of sprites to form a single sprite in cocos2d-x in ios game using c++

I am starter in cocos2d-x.I have multiple sprites of arms legs eyes etc.i want to create a single sprite ,suppose a human out of it who has arms,legs,eyes,head,body etc.How to do it..As i have to animate them and make the human walking and also i have to kill it on touch.Any one here please tell me the logic in cocos2d-x using c++
CocosBuilder can be used for assembling the body parts. By laying down each sprite to its own layer, you can also animate them, create different animations for walking, dying.
Tutorials :
http://www.raywenderlich.com/23996/introduction-to-cocosbuilder
http://www.plungeinteractive.com/blog/2012/10/29/using-cocosbuilder-on-cocos2d-x-games/
There is another way of using it.We can use cocostudio also and export the file as JSON
Refer to this link
http://upyun.cocimg.com/CocoStudio/helpdoc/v1.0.0.0/en/index.html

How to draw a line (or arrow) from one object to another in run time using Qt

I have to design a GUI using Qt. I would like to draw multiple lines depicting relationships between two objects. It's the same idea as matching a word with a definition by drawing a straight line (which might be a diagonal) between the two.
In my case it is an a label (with image inside of it) that needs to be matched with another label.
So we have something like this - http://dl.dropbox.com/u/46437808/DrawLines.png
And I want to add lines to make it look something like this http://dl.dropbox.com/u/46437808/DrawLines2.png
I need to do this in run time because the relationship will be changing based on different factors.
Thanks!
Do you need interaction or is this just an image that the user needs to see based on other information? If it's just a static image, I would simply draw it onto a QImage and show it. That way you have complete control over how things are drawn. So you can either cache the relationship diagrams you need ahead of time, or just draw them on the fly onto the QImage based on the relationship that needs to be displayed at the time. You can look at Qt's painting example for some ideas on how to accomplish what you need.
If you need interactivity, I would probably go with the Graphics View Framework. This way if you need push buttons, check boxes, etc. for any reason you can use the QGraphicsProxyWidget to get them, or you can just make your own from QGraphicsItem subclasses.

QT Creator c++ writing Kakuro puzzle and unsure of what widget to use

I'm using QT creator and have all my methods etc designed and trying to design a UI and I'm not sure what widget I should be using to reference my puzzle layout.
I've been reading over the documentation for a while and I still am nowhere closer to finding a solution to what I should be using to display my values. I know what I should like but all I seem to find information on is various layouts of entry boxes that are in no way linked. I have no problem with coding it myself to communicate with my classes if I just knew what to use to start off with.
I need something that can help me create a layout that has up to two numbers with positions specific to the type of hint it is with a slash between the hints, black blocks that are neither hints nor stored values and squares that have values that can take up the whole square.
Layout is something similar to http://www.nikoli.co.jp/en/puzzles/kakuro/
I wish I knew what to pick >.<
Personally I'd use QGraphicsView and handle the drawing myself.
It can draw rectangles, triangles, circles and text without much effort, and that's pretty much everything you need as far as I can see. You just need to add the objects to a QGraphicsScene and you get them on the screen. You can also interact with the objects (you can find which object you're pointing at etc.)