I am looking for a very simple and efficient way to draw arrows in JavaFX 8, what is the best way to achieve that (performance-wise if let's say I'm willing to draw hundreds or thousands of them)?
I've heard using a Canvas to draw on it is quite efficient.
However, I do not know whether the best implementation is to go with:
Inheriting from the class Shape [https://docs.oracle.com/javase/8/javafx/api/javafx/scene/shape/Shape.html]
Inheriting from the class Line? [https://docs.oracle.com/javase/8/javafx/api/javafx/scene/shape/Line.html]
Bothering myself every now and then with the GraphicContext class in order to create the arrow manually? Does not sound like the good idea.
Other strategy?
The best method depends on various factors which we don't know so it's difficult to give a clear answer here. I will try to give a few general hints though and you will have to decide yourself if these are applicable to your problem.
For mass drawings using the canvas sounds like a good idea.
Simple lines and rectangles are much faster than paths (also polylines and polygons).
Some line joins/caps are faster than others.
Avoid transparency.
It may be helpfull to consider specialized approaches like, e.g. creating images of your arrows and then just painting these images.
Michael
Related
I want to display two circles, with different colors (might change them dynamically) and let both circle. There is a different range of ways to get animation going. Animating objects, using canvas, etc. and I am still confused which one would be the right approach.
I was thinking of extending View and overwriting onDraw(Canvas) is that right?
Really you should look at using some existing frameworks rather than re-inventing the wheel. Depending on just what you are doing look for android animation and/or graphics/games libraries and find one with the facilities you need.
I'm doing a project to implement virtual chemistry laboratory system. I tried to do this by using java2D. I have come across a big issue here. that is how to show some kind of filling effect to a beaker or to a flask (beaker is an image). I tried out this with setPixel() method in WritableRaster(java.awt.image) class. but it is not much useful.
I need a help to show something filling to a beaker and to show color change when mixing two chemicals. please remember that beaker is an image. thanks in advance if anyone can give me a solution with sample code.
Conveniently, many classes implement the Shape interface. Implementing classes work well with fill(), as shown here. To display color transitions, consider AlphaComposite, shown here.
I'd advise using a dynamic SVG canvas using Batik, and then you can use advanced high-level features like masks and blending and such. It's not the most efficient solution, but who cares? It's flexible for the future. Also, it'd take a lot of optimisation to work out what parts of the image have actually changed and pass that through for efficiency. I expect Batik does that as standard. Also, you'll have something that looks really very nice.
Anyway, then you just need to use Inkscape to create the SVG, and then modify the DOM (Document Object Model) accordingly. It's just like messing with HTML. Here is some SVG beaker clipart.
I'm coding a programm, that will produce 3d coordinates for a rocket and I would like to do a rudimentally graphic output for this.
it just has to be scaleable and rotationable, so that you can change the view manually.
the postions should be connected by lines and
it ould be nice to have spheres for earth and moon ( and perhaps addtional celestial objects).
I think, there should be some ready stuff for this kind of plott already available, but I couldn't find one.
So that's why I'm here to ask you, if you know such a thing.
and if there isn't I would kike to ask you how a bignner like me should start this?
I ust coded for console apllications, because there was no need for a real graphics output.
thank you in advance for any tip! :)
Andreas
I don't think there are sand-box ready things you can use to draw customizable 3d objects in Java, if you can live without strange things you can you just a graph library able to draw 3d graphs like for example jMathTools (link).. otherwise you should go into J3D with opengl and similar things.
I don't think they exist just because doing simple things is trivial if you work with OpenGL or similar APIs..
Doing what you need with OpenGL is not complex at all, just a GL_LINE_STRIP to draw the trajectory and some primitives if you need earth, moon and so on.. rotating and scaling come implicitly moving the camera of your viewport..
Take a look at: Java3D or JOGL
I can't believe nobody has mentioned this yet, but the NASA WorldWind project seems like exactly what you need: http://worldwind.arc.nasa.gov/java/ You can extend it with JOGL if needed, or you can use some of the vast modeling objects already available to mark trajectory and location in 3D coordinates, complete with zooming/rotating and the like. Having accurate Earth layers is nice as well =)
Use JOGL! It is easy to install, and if you know Java it should be easy. There are a few things in JOGL that require you to be decent in trigonometry. This tutorial might help you get started: http://www.youtube.com/watch?v=rT02jFYrXv0
Using Java 2D I've patched several Bezier curves (CubicCurve2D) together to create a "blob". The problem I now face is how to:
Efficiently fill the blob with a given colour.
Efficiently determine whether a given point lies inside the blob.
I noticed thst CubicCurve2D implements Shape which provides numerous contains methods for determining "insideness" and that Graphics2D is able to fill a Shape via the fill(Shape) (which I believe uses Shape's getPathIterator methods to do this).
Given this I was hoping I could create a composite Shape, whereby my getPathIterator(AffineTransform) method would simply link the underlying PathIterators together. However, this is producing a NoSuchElementException once my shape contains more than one CubicCurve2D. Even if I do manage to achieve this I'm not convinced it will work as expected because a CubicCurve2D is always filled on the convex side, and my "blob" is composed of concave and convex curves. The "contains" problem is even harder as a point can legitimately lie within the blob but not within any of the individual curves.
Am I approaching this problem in the correct way (trying to implement Shape?) or is there an idiomatic way to do this that I'm unaware of? I would have thought that the problem of compositing geometric shapes would be fairly common.
Does anyone have any suggestions regarding how to solve this problem?
Thanks in advance.
I'm not sure I understand your question but composite shapes can be created with the class java/awt/geom/Area.
Looking to Shape for a solution is the right way to go about this. If you have a collection of curves that you are trying to assemble into a shape, I would suggest that you use a GeneralPath. Simply add your curves, or straight line segments, as required. Look to the interface to see the various append methods. Also note that you can 'complete' the shape by joining the last point to the starting point.
Once the path is closed, there are a number of different versions of contains() that can be used, please take the time to read each of their descriptions, as there are trade-offs in terms of speed and accuracy, depends on your application.
Also it is easy to get a shape from the path, and fill it, transform it, etc.
I have recently been developing a sim game in java, as many of my questions show, and it's come a long way! Graphically, it is somewhat lacking, and at current I'm using shapes for items, people, rooms etc.
I was looking at other similar projects, and noticed that one was using OpenGL. I have been reading CokeAndCode "space invaders 103 - refactoring and OpenGL", and I still don't know if it is something I need in my game or not.
Here is a video that I used for a previous question, but it still shows basically what I have so far (http://www.screenjelly.com/watch/Bd7d7pObyFo), although I have done a lot of refactoring and re coding over the last few weeks, but graphically, nothing has changed. As I understand it, I'm currently using java2D to do this.
I really don't know how I should continue graphically with this game. This is my first project I have done outside of learning for my own enjoyment, and so I'm still rather new to this.
Thanks in advance!
This could turn into a long subjective conversation quickly but I want to state the fact that you don't need openGL. Your application doesn't need to be the best looking one out there. Nethack still attracts people and between you and me : the graphics sucks.
Do you want to learn about 2D and 3D graphics and textures and so on ? Then try stuff... best way to learn. Then you can add this to your resume.
There are a lot of tutorial to do your first steps in OpenGL or some other graphic library. You can even try Qt Jambi. But once you start, you're in for a ride ;)
According to this, it's still largely possible to implement a working graphical game in Java2D with decent performance, as long as you make sure not to do a certain number of bad things.
It might help you to check and see how your approach is, compared to this.
I have no idea how far along Java has come with OpenGL support, so were I in your place I would probably just see how much refactoring of the Java2D code I could do, and figure out what to do from there.
Hope this helps, at least a bit.
One good side of using opengl (even for 2D graphics) is that you will get (if properly done) hardware graphics acceleration for your scenes.
Also, you can use orthogonal projection and keep one of the axis (Z) as zero to do your 2D graphics. It will be easy if you want to add a 3D effect (like lightning or something) if you use OpenGL.
However it all depends on how much you want to improve the graphics, since adding OpenGL might make things a little more complicated than plain Java2D.
How to continue graphically: use textures, more interesting animations (implement a simple physics engine and/or collision detection, that always looks nice).
When you go 3d (for example using opengl) you can add lighting effects to the equation, that usually does a lot to the aesthetics of the whole. For example if the moving circle was a sphere with a nice texture (marble or something), then you could make it really role over the board, and you could specify diffuse and specular reflection values to vary the lighting like for example here.
Camera movement can also beef up the graphics.