Regarding rendering regions, the first job is collecting, and scaling of X/Z coordinates (X/Y provides a side-on view of the universe). After these have been scaled to the width/height of your output image (if you are rendering a single region), you would take a center point of the image as a reference, or starting point. From that reference point you would project a ‘line of detection’.

This ‘line’, is in fact a moving point in X/Y coordinates of the image. The only reason I use the term line is because the point itself moves from the outer constraint of the region (starting point + 50% region width), back to the starting point, looking for nearby Solar Systems as it goes. This is all done using Trigonometry, examples of which I would be happy to give.

This process is repeated through a 360 degree rotation from the starting point, in 5 degree increments. Once a Solar System is found on an increment, a line is drawn from the previously found Solar System, to the newly found. Increased smoothness can be gained by reducing the increment at the expense of increased CPU time. These coordinates are all stored in an array, for which we will need in a second once the outer border has been completed.

Once we have our border, we can use the PHP function ‘imagefilledpolygon’ to create a polygon to overlap the region, to make it a bit more distinct. Of course, unless you draw the stars first you would want to assign a color with an alpha value, so as to give transparency.

When we have got everything together, simply dump to a PNG file or stream. This process can be repeated on all regions, simply by taking the starting point from the area of the MIN/MAX X/Y coordinates of a region, after the entire universe has been scaled down to the size of your destination image, and using them as an offset in your calculations.

I hope this has helped! If you have any questions, please feel free to post again. I’d be very interested in seeing the progress you make, or different approaches you have to solving the problem of calculating region constraints, as I know there is a faster solution out there..I’ve simply not put the time in to hack it out yet.

Take it easy!
Psilocybeing