508 pointsby sklopec7 hours ago38 comments
  • corysama3 hours ago
    If you want to play with software rendering, here's probably the shortest code that will get an ARGB8888 2D array from main memory to the screen efficiently for all platforms using SDL2 in C https://gist.github.com/CoryBloyd/6725bb78323bb1157ff8d4175d... you'll need to do the translation from a 320x200x8-bit palletized framebuffer to ARGB yourself ;)

    If you want to get inspired by what can be done with palletized framebuffers check out http://www.effectgames.com/demos/canvascycle/ (click Show Options) and the GDC presentation by the artist https://youtu.be/aMcJ1Jvtef0

    With that you can fire up https://github.com/mriale/PyDPainter for that classic Deluxe Paint IIe vibe. Or, https://www.aseprite.org/ for something more modern.

  • ferguess_k24 minutes ago
    I find the most interesting things are the internal tools -- like the Python script to generate the gib animation, or the other Python script to generate 2D spritesheet from Blender. OP is definitely a 10x engineer who can also do good arts. This is very rare IMO. I'm very surprised to find that OP has consistent art direction.
  • rob746 hours ago
    This is taking a lot of inspiration from Doom, but the actual raycasting engine is more like Doom's predecessors, the most well-known of which is probably Wolfenstein 3D: perpendicular walls, constant floor and ceiling height. Wolf3D didn't have textured floors and ceilings because of performance reasons, but several other similar games had them. Doom and IIRC Duke Nukem as well used a BSP engine which was much more flexible (walls could intersect at any angle, variable floor and ceiling heights), although the levels were still "flat" (you couldn't have several "stories" inside a level, e.g. you couldn't design a bridge that you could walk over and under).
    • torginus15 minutes ago
      With regard to floors, afaik even DOOM didn't do them correctly. With vertical walls, the perspective divide needs to be done only once per column of pixels for a given wall segment.

      For floors, unfortunately there's no such luxury, and if I remember correctly DOOM subdivided floors into patches, and only did proper perspective at the corners, and interpolated inbetween.

    • bluedino5 hours ago
      > Wolf3D didn't have textured floors and ceilings because of performance reasons, but several other similar games had them

      Blake Stone Rise of the Triad used later versions of the Wolf3D engine and had textured floors/ceilings

      > Doom and IIRC Duke Nukem as well used a BSP engine which was much more flexible

      Duke Nukem (Build engine) did not use BSP

      https://www.jonof.id.au/forum/topic-137.html#msg1548

    • badsectoracula5 hours ago
      > Duke Nukem as well used a BSP engine

      The Build engine didn't use BSP, it treated connections between sectors as portals and rasterized the walls as (90 degree rotated) trapezoids while performing clipping against those portals. This allowed it to have dynamic wall geometry (e.g. moving trains, rotating light fixtures, etc) as well as "room-over-room" setups as long as you couldn't see both rooms at the same time (in both Blood and Shadow Warrior they found a workaround for it allowing to create more "3D" spaces by making identically shaped sectors with the floor of one sector acting as a portal to the ceiling of the other sector - supposedly this wasn't "natively" supported by the engine, but it was flexible enough for the game studios who used it -without even having access to the source- to do it themselves).

      The first level of Duke Nukem 3D does use a few Build tricks - e.g. another one is that sprites can be "axis aligned" instead of following the camera and they can also have collision - this can be used to create rudimentary 3D geometry by treating each sprite as an axis aligned quad and in the first level it is used to make a bridge between two buildings (right before the level exit button).

      • kridsdale116 minutes ago
        I always loved that the bridge you mentioned could take damage and fall down, screwing you over in the very first level, unless you knew where the Jetpack was stashed.
    • Grumbledour5 hours ago
      Later on, in Shadow Warrior, you could even do that, i think they used portals to implement it and i remeber it was a pain to set up in the editor.
      • kridsdale115 minutes ago
        That did give us our first software rendered transparent water rooms though (Quake had the water opaque unless you had 3DFX card IIRC)
    • scrumper5 hours ago
      I thought at first it was just a skinned Wolfenstein 3D. Which is grossly unfair. A lot of work here.
  • mroban hour ago
    In the final video, it looks like the destructible vases take several shots to destroy. IMO, they should only take one. Real life vases only take one, so requiring more makes the gun feel weak. It seems to be cosmetic anyway, so there's no game balance reason to require more.
  • mkl4 hours ago
    Graphics programming in the early to mid 1990s was pretty fun: write pixel data into the memory-mapped video RAM and it appears on the screen! A pointer to 0xA0000 was all you needed - no API or anything. The reason for the non-square-pixel 320×200 VGA mode they mention was that the video buffer took 64000 bytes, which fit into a 16-bit segment, making addressing it easy in 16-bit code/CPUs.
    • badsectoracula4 hours ago
      > A pointer to 0xA0000 was all you needed

      Though your extender could make things a little more annoying on that front :-P

      (DJGPP and Free Pascal -which use the same "go32" extender by DJ Delorie- do not do a full linear mapping so you need to do a bit more juggling to get stuff on screen there)

    • russdill2 hours ago
      Until VGA came along....the story was much more complex.
  • ogurechnyan hour ago
    Step 0 is missing: having a great taste. One look at the video example is enough to figure out that the author keeps things in balance and in style. Explanations of why pixel grid mismatch looks wrong, or why mismatch between texture density and geometric complexity (in both ways) looks horrible, or why smoothing does not blend with pixel art are then made in retrospect.

    Some details are a bit too cool for 1993, though, and assume high frame rate (won't work that well at low fps). Smooth weapon animations with a lot of frames, tiny per-pixel effects on bullet holes and flash sprites, smooth movement and object position calculations that use precise math instead of fast rough estimates resemble Chasm: The Rift or Quake (the concept of idle animations, e. g. objects moving in the starting view of difficulty selection room, assumes that there is some performance to waste on details that make the world less empty).

  • rob745 hours ago
    I just noticed that this might be one of the rare shooters with a female protagonist: the cat has a calico pattern, and those are almost always female (https://en.wikipedia.org/wiki/Calico_cat).
  • robterrell2 hours ago
    This is so great. Another fun trick we used in the 90s was palette animation -- by swapping the palette you can create incredibly cool effects at a low runtime cost.
  • gotski4 hours ago
    This is terrific. I love reading about the creative process involved in a project like this, finding cool solutions to self-imposed boundaries.

    I think the mix of highly rational reasoning and "it just feels right" is a killer combo too, it gives a rigorous basis for a lot of the decisions made, while also allowing for a strongly personal aesthetic to emerge. Very cool indeed.

  • boricj3 hours ago
    I'm tinkering with a voxel space rendering tech demo as a PlayStation homebrew. After one weekend of work I'm getting decent results (like, 10-15 FPS) and I've yet to use the DMA, the GTE or even polylines primitives.

    It's refreshing to dust up trigonometry and good old low-level optimization tricks. When the scratchbuffer has 1 KiB and the stack can only use a fraction of that, it makes me realize how spoiled I'm at work with the microcontrollers we have, with threads being allocated 8 KiB of stack and backtraces with over 50 functions of C++ templates on it.

  • mysterydip5 hours ago
    As a fellow 3d-engine-with-foolishly-unreasonable-constraints developer, I love the detail in the explanations here and seeing the process you went through.
  • phkahler3 hours ago
    >> What this actually means is, the constraints I have foolishly imposed upon myself are as follows....

    Those kind of constraints can lead to increased creativity, and can also influence the overall style of a game. It's part of the reason early 80's arcade games had so much diversity.

  • rezmason3 hours ago
    A great writeup of excellent work!

    The flight simulator / magic carpet easter egg in Microsoft Excel 97 used that same shaded-colormap palette trick, plus some dithering:

    https://rezmason.github.io/excel_97_egg https://rezmason.github.io/excel_97_egg/about.html

    I'm impressed by your sprite pipeline and gibs animations. Your attention to detail and navigation of constraints have really paid off, I can't wait to play this sometime

  • trumpdong5 hours ago
    For some reason I irrationally like the posterization effect that's created when something is darkened to almost zero.
  • fabiensanglardan hour ago
    Consider a premium, boxed version. I would buy it. And I think a lot other would. Maybe try a kickstarter to see how many are interested?
  • nticompass5 hours ago
    I respect the amount of work that goes into projects like this; I can't wait to be able to play it.
  • jonoxtoby2 hours ago
    This is a great write-up of your process and behind-the-scenes peek at the making of what looks to be a really fun game! Can't wait to play and delve into the code once you release it.
  • reifcodean hour ago
    one of my very first solo projects during high school was writing a wolfenstein-like raycaster from scratch. I still hold some very fond memories of programming it, arguably one of the moments I fell in love with the craft
  • kylemaxwell3 hours ago
    Every time I think about graphics programming, I think about how we did it in the mid 90s when I was in high school messing around with exactly these things. XOR operations to drive animations, writing directly to memory, etc. (Clearly I do backend stuff now...)
  • blackhaz5 hours ago
    Everything is perfect here. The hero, the graphics, the title... <3
  • renyicircle4 hours ago
    I really loved that article. Creating games always seemed so daunting to me since I don't know a lot about how it's done, there are so many different processes involved. The solutions described here are so satisfyingly compact and so easy to understand given the simple constraints, and yet they produce an actual game that looks nice.
  • progforlyfe4 hours ago
    Much respect -- at first glance when I saw the animated gif I thought this was just a project making assets from scratch for an existing game engine (e.g. Doom or Wolf 3D) but then I realize it's creating all the game code from scratch too! (But using similar techniques from the old days). Amazing work.
  • trashb4 hours ago
    This game looks great I really like the style it is inspiring.

    The author seems to consider open-sourcing the engine, I would also be interested in the mentioned scripts for asset creation. Those scripts would make a great toolset for asset creation in this style.

  • badsectoracula5 hours ago
    As a side note, the visual style in the game reminds me a lot of Exhumed / Powerslave :-).
  • sgt5 hours ago
    Really cool. It's also something LLM's are ridiculously bad at, so you kinda have to do it properly.
  • Levitating4 hours ago
    I love this! I have been working on a similar project, recreating the originale BBC Elite but with multiplayer networking. Though I have not limited myself as much (I use SDL).
  • cosiiine4 hours ago
    This is a wonderful deep dive into your project. I'm early days on creating pixel art style procedural art systems, and this gives me plenty to think about.
  • binaryturtle4 hours ago
    With the title I was expecting some notes about DeluxePaint, but it was still a nice read nonetheless. Wish you much success with the game! :-)
  • relativeadv20 minutes ago
    Bravo! Wonderful read.

    The comments here are a cesspool unfortunately. People bickering about pronouns used for cats, how many shots it takes for a vase to explode, or whether or not some circa-1993 software was used or mentioned.

  • harel4 hours ago
    This is beautiful. I wish one day I'll have to time for a project like that. Looking forward to buying it on Steam.
  • mempko2 hours ago
    Wow, this takes me back of making my own software renderer and game engine as a teen in the 90s. Then OpenGL came out and fixed pipelines and some of the cool magic of doing anything with pixels disappeared (until pixel shaders came back). One cool rendering technique you don't see much today is voxel graphics.
  • badsectoracula5 hours ago
    Nice, i've used similar approach for the lighting in Post Apocalyptic Petra[0] though i did use per-pixel LUT offset calculation[1] because it uses a generic 3D triangle rasterizer (the levels are based on grids like in Tomb Raider but they're rendered as triangles). Later i added sprite support for another gamejam but i never ended up finishing it and the sprite support is very rudimentary (and unoptimized - i just noticed i'm doing the LUT lookup for every pixel when drawing shaded sprites which isn't necessary).

    I did write a tool for generating the sprites from 3D models though[2]. It uses plain old OpenGL 1.1 to draw the sprite and grabs the framebuffer directly. It is drawn fullbright so i can paint the lighting directly on the sprite's texture (using a Krita plugin i wrote[3][4] - the model is something i threw together with Blender's default generated UV since i didn't care for the details).

    I wonder if doing some sort of postprocessing (after rendering with with shading) like you do with your game would help with the finer details since i also found that rendering from 3D models to sprites creates very "mushy" results most of the time because of all the details getting lost. I notice the colors also become more saturated after postprocessing in your examples, is this after it finds the closest color in the palette or the result of the postprocess? I'd like to keep the overall hue+saturation of the model so maybe doing post-processing on a grayscale render to shade the shadows/dark areas but keep highlights as-is and then multiplying that with the fullbright image would produce results that wont shift the saturation.

    [0] https://bad-sector.itch.io/post-apocalyptic-petra

    [1] https://codeberg.org/badsector/PetraEngine/src/commit/14ca16...

    [2] http://runtimeterror.com/pages/iv/images/95ddebc51e4dfa8a5af...

    [3] http://runtimeterror.com/tools/kritaview3d/

    [4] http://runtimeterror.com/pages/iv/images/535f0e09e590d8a1731...

    • sklopec5 hours ago
      >I notice the colors also become more saturated after postprocessing in your examples, is this after it finds the closest color in the palette or the result of the postprocess?

      It's the result of the Blender compositor postprocessing, just keep in mind it falls apart once you go low enough in resolution (it's an image space thing after all), so I'm not sure if that helps your case.

      EDIT: Also, your project is very cool!

  • wazooxan hour ago
    That's beautiful. I hope it will run on a 486DX2 :D
  • functionmouse3 hours ago
    cool cat game

    what's unreasonable about this though?

  • zerr4 hours ago
    I hope they leveraged Mode X :)
  • tobadzistsinian hour ago
    Unpopular opinion but the author remarks that the cat is female but uses "it" as pronouns. Human garbage.
  • xyzsparetimexyz5 hours ago
    It'd be more interesting if you made a similar looking game using modern APIs imo
    • sklopec5 hours ago
      How so? Doing this with modern OpenGL would be much simpler than the software rasterizer solution.

      I think I'm gonna have to do it anyway, because some players claim they get nausea when playing at such low resolution (320x240), and the only way to give them higher resolutions that perform reasonably is to have it hardware accelerated.

      Renderer is abstracted away already, but the real difference would probably be occlusion culling... With raycasting, I get it for free, but if I'd go down the hardware accelerated path I'd have to pick something more clever.

      Raycasting and software rendering in general tends to scale poorly with resolution, even with vectorization and all the bells and whistles of modern CPUs.

      • badsectoracula4 hours ago
        Unless you plan on rendering the level on some very retro hardware (think S3 Virge, maybe Voodoo 1) you can render the entire level in OpenGL with just zbuffer and alpha tested sprites and it'll run perfectly fine - if anything with such low polycount, chances are you're going to make the renderer slower by trying to do occlusion culling on any GPU released in the 21st century :-P. If you pack the geometry in a few vertex buffers (for each unique texture) even per-frame, you'll get four digit FPS in any relatively modern GPU.

        As an example this[0] video shows the benchmark from Post Apocalyptic Petra running on my previous GPU (RX 5700 XT) which all it does is build a per-frame (client-side) vertex-buffer in OpenGL 1.1 (the engine was made for actual retro PCs running DOS and Win9x so it does some rudimentary occlusion culling but that mainly affects 90s hardware, not anything released since 2000 or so). If anything, the rendering has so little overhead that half of the framerate is "eaten" by the FPS counter overlay :-P.

        [0] https://www.youtube.com/watch?v=64ysz5rXkzw

        • sklopec4 hours ago
          That's really cool.

          Thinking about modern games, a single character model probably has more vertices than my entire level (and yours probably), so it's definitely reasonable to expect occlusion culling for such simple geometry might actually reduce performance rather than increase it.

          • badsectoracula4 hours ago
            Yeah, even this model[0] i made a few years ago for a game i wanted to make for the OG xbox (which has a GeForce3-like GPU) has ~2230 triangles and the entire first level of Post Apocalyptic Petra is ~5800 triangles, so you could say that even a turn of the century 3D character has more or less the same polycount as an entire 90s level (the game i wanted to make would have many characters on screen so i kept the polycount low but i've heard games having 5-6K character or more - e.g. Kingdom Under Fire had ~10K triangles for the main character and a game like Dead or Alive where there are few characters on screen had 15-20K triangles).

            Meanwhile more current games have much higher polycounts, easily going above 100K triangles - e.g. Dante from DMC5, a ~7 year old game, apparently has ~190K triangles and that had to run on the more anemic PS4/XBone hardware :-P (though i'm not sure if it used the full 190K model there or some cut down version).

            [0] http://runtimeterror.com/pages/iv/images/1073c7062db40837240...

          • trumpdong4 hours ago
            I rendered some Source engine levels on a shitty laptop in 2012ish and they still rendered at perfectly acceptable FPS (30+) just by rendering all the geometry in the level in one shot.
        • pjc503 hours ago
          The synthesis technique would be to build the DOOM-style BSP tree and then construct a bunch of meshes for use depending on which portal space you're currently in, but .. as you say, you don't need to do that because it's at most a few hundred polygons.
      • xyzsparetimexyz3 hours ago
        Sure, but it becomes a question of how far you can push things. Maybe you raytrace the whole thing. Maybe there's some fractal geometry going on. Maybe you use a fisheye lens projection. Maybe your levels are dynamically tesselated. Maybe you have to do a few fancy tricks to achieve equivalent texturing etc.

        But ignoring the GPU you have on your system is boring

        • jonoxtoby2 hours ago
          Writing a retro-inspired game using retro approaches despite all the modern options is precisely what makes this interesting.
  • mg794613an hour ago
    There is nothing wrong with using AI.

    What I don't like is to see claims like "no AI slop"

    And yet it's riddled with emdashes and language "by hand"

    Seeing the skills of the writer, he definitely should be able to, but then I don't understand the claim.

    • ch_sman hour ago
      I don’t know. Em-dashes are normal punctuation. The prose on the site doesn‘t strike me as particularly AI-y, but of course I might be wrong. Generally speaking, if the person wants to not use AI and tell people that, thats fine by me too.