ShapeRenderer | simple yet powerful tool for creating vector graphics | Game Engine library

Normalize before you scale. By normalizing you are making the directional vector 1 unit in length, and by scaling it after by 25 you get a vector that is 25 units every time, regardless of how far apart thw current and previous positions are.

Your render is not being called with the same delta(time interval) between frames causing the perceived speed to judder. Normally with LibGDX the render method is called with the delta i.e. the time since the last render, however, you are using the ApplicationAdapter. You can compensate though by just getting the delta time yourself and changing your increment from

For anyone wanting to do attempt the same, the error comes from me copying the wrong list of vectors. Instead of copying:

I just compared your code and the sample code you provided on bl.ocks.org

Your issue is that you moved the data in flare.json into the javascript section, causing d3.json not to find any data. Try removing this large json portion in javascript and add a file called flare.json in the same directory as your HTML file, and copy the JSON there.

The directory tree:

The exception means that snakeBody.first() is called without any elements in the queue.

This is because snakeBody in Buttons is another Queue than snakeBody in GameState.

In the Buttons-class:

Your update approach in StellarTest1 looks conceptually fine to me (I assume this 1000f factor is way to adjust the gravitational constant/mass of the bigger body). However, of you want some extra decay of the orbit, you need to add some fictitious velocity-dependent drag term to the acceleration. There is no need of StellarTest2, because you should get a comparable results while the calculation of cos and sin is slower and expensive, while the same components in StellarTest1 are calculated in a purely algebraic way (multiplication and division) which are much faster.

But to achieve some interesting orbit you need not only the two coordinates of the initial position of the smaller object, but also the two coordinates of the initial velocity of the smaller object! Without specifying the initial velocity or assuming it is zero you are not going to get a nice curved orbit. You need to choose initial velocity. Also, the orbits should not get nowhere near the center of the big object, because the Newtonian gravitational force-field has a singularity at the center of the bigger body, so the closer the smaller body gets to that singularity, the worse the orbit will look (and the numerical errors will blow out of proportion) and it is not surprising you are getting the smaller body shot out of the center of the bigger one.

In general there is a way to choose a velocity that will send the smaller body on an elliptic orbit with predefined orbital parameters: the length of the semi-major axis a, orbital eccentricity e, the angle omega between the semi-major axis and the horizontal x-axis and the angle f (called true anomaly) between the position vector from the bigger to the smaller body and the the semi-major axis.

Converting Cartesian coordinates to isometric is (sort of) done like this:

I figured it out. All I had to do was begin another batch after I inserted the Filled Rectangles. This is what I did:

A few quick and superficial pointers:

You seem to have multiple challenges and problems. Focus on them one at a time if you can, dividing and conquering them one by one.

If you are doing this for the sake of learning and you are very new to programming, be very careful about not having a large scope for the project. Set a very modest goal for what you want to be able to do with the project, and once you have accomplished that, you can add an additional goal. Iteratively continuing. This is very risk-resilient, because you start from a relatively easy point and go from there. The drawback with this is that you may have to do a fair amount of work, because one design early one that was suitable then may not be suitable for later work, and this may require a rewrite and redesign to a smaller or larger degree. Once you get more experienced, planning and seeking to design early on can be very, very helpful, especially if you know that some important aspects are going to be important later and the design you choose early on will impact these - but again, this is once you are more experienced.

Consider what things you would like the game to be able to have, like AI (state-space-search), graphics, saving/loading, the player using a GUI to move around, etc. And then pick the few things that you consider both easy and most nice to have. If you are new, don't require it to be a cohesive whole, you can always take that on later as a more ambitious goal once you have more experience, have learned more, thought more about things, etc. Again, be very, very modest with your goals and scope, and get some experience and just learn.