četvrtak, 16. ožujka 2017.

Preview release v0.5.4

It's been a while since the last release and a lot of new stuff was added and polished.

Download Stareater v0.5.4

As usual details are covered in previous posts and here is a brief summary:
  • Refit cost from one design to another factors in component difference. More similar designs cost less to refit.
  • Missiles were introduced. They are basically an instant hit weapon like laser but with limited ammunition.
  • Damage on ships persists after battle and can be repaired.
  • Improved graphics engine. It's a bit more powerful and a lot less prone to human error.
  • Last game map settings are remembered.
  • Fixed a crash on when loading invalid settings file.
  • Improved starlane distribution when generating a "galaxy" map.
There are two known issues. First one is crash on startup on Nvidia GPU with recent drivers. There is no easy way to fix it so it will stay for a while. If you do observe this crash, try to run Stareater on different GPU or on no GPU at all. Second one is occasional crash on new turn. I'm still figuring out how to solve it, it a though case of concurrency issue where a piece of data is used after expiry. But don't let it ruin your fun!

subota, 11. ožujka 2017.

Map generator 2/3: starlanes

It's been cooking for some time and it's finally out, starlane distribution algorithm in map generator has got some actual implementation instead of stub. The algorithm could use some tweaking but it already produces good results.

The algorithm has three subalgorithms: maximum connectivity graph, minimum connectivity graph and interpolation between minimum and maximum. Don't get discouraged by the word graph, I won't dive too deep in graph theory mathematics, I'll just as a convenient word for "a way how points are connected with lines".

The general idea is to start with maximum connectivity and remove connections until desired starlane density is reached. Maximum connectivity algorithm has been the hardest part to nail down. I've tried and scrapped about a dozen methods. First couple of ideas looked promising until I've run into edge cases which were impossible to handle without introducing some undesired properties like bias toward topmost or leftmost star positions. Then I've tried to get so called Delunay triangulation working. Failing to find easy to copy-paste code and after contemplating whether it's worthy or not to spend time integrating nontrivial code I have found, a simple solution dawned on my mind. I figured my ideal solution would always contain shortest possible connection and from there I assumed the ideal would favor short connections over long ones. I expanded it to an algorithm which checks potential connections one by one, from shortest to longest, and adds a connection to a solution if it doesn't cross over previously added connections. Prototype was promising, there was only an issue where some points had a lot of lines coming out in a narrow cone. After adding a condition where a connections has to have certain minimal angle between them I solved that issue and got satisfactory results.

Minimum connectivity algorithm starts from maximum connectivity solution and finds the smallest set of connections necessary to connect all points. First it picks a point closest to the center and adds connections which form a shortest path from player homeworlds to that point. That central point is momentary substitution for what will later be a stareater's "brain" system so this steps ensure that players will have access to it and to eachother (and shortest path ensures there will be no cycles meaning no superfluous connections). Then the rest of points unconnected by those paths are added to solution by taking the shortest connection which would connect a new point with the set.

Finally, depending on chosen starlane desnity some extra connections are added to minimal graph. Again, the shortest candidate connections are added but this time the ones linking points with least connection endpoints have a priority.

All this was accompanied with some general map generator code refactoring. Parameters (map size, position randomness, starlane density) are handled in a much nicer way and last map settings are finally getting remembered. Now that I think about it last number of players is still not remembered, oh well. Anyway, the map still has to be filled with stars and planets in some meaningful way, I have some ideas and I'm look forward for a day when third piece of the puzzle will fall in place.

ponedjeljak, 6. ožujka 2017.

Warning: Graphic content

Few post ago I've thought about making planet orbits and combat grid textured, consider it done now. I've repurposed the shader to apply texture instead of flat color and instead of regular rectangular texturing it bends rectangular image to fit on curved surface. So orbits in system view are no more jagged and combat grid looks a bit nicer too.

Which drove me insane at one point. Adding texture to old polygons produced black spots around line intersections because they were overlapping and had same depth level, making depth test sometimes passed through a darker color. On top of that each hexagon produced all of it's boarder lines so lines between two hexagons were drawn twice. At first I've tried utilizing that by making each hexagon draw only it's half (half width, from border middle to line edge closest to the center of a hexagon). It worked well for all but for outermost lines which ended missing outer half. I've tried hundred ideas to get them finished properly but there was always some edge case which required twice as much code to handle as regular case. In the end I flipped the table, stopped thinking in hexagons, started thinking in lines and devised a two phase process. First phase was repurposed old code for processing grid per hexagon basis but this time it only made a list of where each border line starts and ends. Second phase inspects each line from the list, checks with which lines it is connected and generates draw polygons in a way that each line covers it's part of intersection. If you know me then it wouldn't surprise you that first phase is quadtree territory (for removing duplicate lines and points, plus cardinal sin of using non-integer numbers as a table key) and second phase is linear algebra town. Now I won't make any promises but I was pondering different shape for combat grid, something that still plays like current hex grid but looks more spacey :).

Shaders are not the limit of my limited artistic prowess. Oh, no I can make distinct low resolution images too. I've reworked two more smallest ship images and made up four new images for second ship size. Some long time ago I've came up with five distinct spacecraft shapes, some inspired by SF shows, some by permutating underlying shape. For instance, one of the inspirations is "fighter1" which resembles colonal Viper from Battlestar Galactica and it's rough shape it upside down kite. Simple way to get another shape of a spacecraft would be upside up kite. Make a broad part broader and thin part thinner and you get "T" shaped "fighter2".

Make rough outline with darker color, fill it with brighter and move pixels around until it looks right. That is how I arrived at images of the smallest spacecrafts. Larger ones I've made by inflating small ones, following the initial shape but adding a little twist here and there and adding a bit of detail.

I also thought more about hull size assortment and decided for fewer sizes then in CroVar iteration. Instead of having 10 or so sizes which grow by factor of 2.5 I decided to have 5 sizes which grow by factor of 5. I think having fewer but better defined sizes would suite the game better then having a lot of small increments and it gave me easier time coming up their names. I don't want to default to usual military frigate-destroyer-cruiser route if I have other options. One reason is that in real world navy these words describe ship role, not necesserly it's size class and second reason is that I don't want to depict spacecrafts as exclusively military vessels. For instance it would be awkward to describe a colony ship as a battleship class. I also don't want to use vague size gradations like small-medium-large because what is large for early game is medium or small in the late game and I want names to have some absolute meaning like X is this big. For now names are meteor, shuttle, cruiser, liner and asteroid but they are not set in stone and I'm open to suggestions.