Post by jmlait in War of 1812 jam comments

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Thank you! I did try to optimize the controls. Most importantly, pressing shift and directions lets you move 5 squares at a time, otherwise it gets very painful to move about. Ideally it would be a mouse-driven interface, but I didn't have time to build that on top. (Not to mention mice have always felt out-of-spirit for roguelikes to me :>)

What were the aspects of the controls that made it most tedious for you?

I've made lots of 7DRLs, none of which have been epic combat :> But they definitely laid the ground work to achieve this. Notably Smart Kobold had huge work for dealing with solving the problem of having densely packed groups of mobs move in a turn-by-turn fashion, but not get all broken up. Basically they are able to both delay their turn to see if others will move out of their requested spot, and have a priority scheme for shoving other mobs. And Jacob's Matrix is where I developed the whole non-cartesian coordinate system that lets me stitch 100x100 "rooms" each with 100x100 tiles together in a fashion seamless to the AI and map code.

Source is all there (and BSD) if you want to look at it for your own epic combat game!

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aganm4 years ago

Yeah, I meant to say the mouse would be better for this type of game. What would be tedious is giving move orders such as 1cShift>>>^^^>>^^Enter, and then repeat 9 times for the whole army. But I agree that mice doesn't belong in a roguelike.

What is Smart Kobold and Jacob's Matrix? I don't see them on your profile page.

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jmlait4 years ago

Ah, true, moving multiple units is a pain. My original plan was for you to setup formations so you could join multiple regiments together as one unit for the purpose of commanding. This is pretty much how the AI general works.

My other roguelikes can be found on the http://www.zincland.com on the list of 7DRLs there with every increasing adjectives. I foolishly didn't provide any links on my itch.io profile :> I keep meaning some day to recompile them all so they can all be also hosted here.

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aganm4 years ago

Having formations like you described is a pretty good idea.

Referring to what you said about non-cartesian coordinate system, why would you want to split your map in 100x100 rooms instead of having one single 1000x1000 and more gigantic room?

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jmlait4 years ago

Well, the gigantic room would be 10,000 x 10,000. Which means storing just a single byte tile value is 100MB! And storing a single byte flag value is another 100MB! To make things more interesting, the UI drawing is decoupled from the actual game engine. So I have to make a copy of the map every update so the UI drawing thread can read the map without fear of it changing while it is reading. (The alternative is to lock all reads of the map, which would defeat threading entirely and be atrociously slow) Copying 100MB is a substantial time. By breaking into 100x100 rooms, each of a more manageable 10KB size, I can use reference counting to only copy sections that changes. So stuff like FOV flags are only set on the live rooms - the rest of the rooms just have a flag stating that their FOV flag is constant. The same is for the smoke simulation - I have to store the amount of smoke per tile, but for the vast majority this is zero, so I can have that allocated only where necessary.

Separate rooms is also a very useful optimization for things like MOB look up. Until 1812 I stored monster and item lists per-room. Usually rooms were small, so to see if an item was on a square it would be faster to look through all monsters to see if a monster was there than track it per square. (This particularly relevant for stuff like Everything is Fodder which is technically an infinite map as it generates rooms on demand) For 1812, I had to build a separate VDB-style (https://github.com/AcademySoftwareFoundation/openvdb) acceleration structure to swiftly locate all creatures globally. I ended up with separate tables for both teams and for the officers, so I could do efficient searches for all enemy troops, or all friendly officers.

Separate rooms is a very useful roguelike construction technique as you can piece together "levels" that are usually connected by staircases smoothly. Vicious Orcs is a good example of this. The original motivation was Jacob's Matrix where it was just to confuse people through non-cartesian coordinates. And I assure you, it can be very confusing :>

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aganm4 years ago

Have you measured the time it takes to process those 10000+ soldiers? Like is it a big bottleneck or you could afford putting even more?

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jmlait4 years ago

I spent a significant amount of time in optimization for this 7DRL. I could afford more at this point. The biggest bottlenecks right now:

1) Copying the soldiers from frame to frame. This could be vastly accelerated if I switched to a SOA rather than the current pointer-chasing format for the MOB class.

2) Registering bullets on the display. I already restrict this to only the current FOV, but there is an ugly O(n^2) for my event class that wasn't a problem since normally only have a dozen events per frame at most :>

The big problem is I feel it already runs a bit slow even on high end machines... The simulation is currently completely uncapped (so if we ever get faster machines some day, it will be stupidly fast :>) I'd have much rather if I could have simulated way faster so given you a 1x, 10x, 60x realtime options rather than the current all or nothing.

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