Doom is a legendary video [game](game.md) released in 1993, perhaps the most famous video game of all time, the game that popularized the [first person shooter](first_person_shooter.md) genre and shocked by its at the time extremely advanced [3D](pseudo_3D.md) graphics (yes, it was actually 3D). It was made by [Id Software](id_software.md), most notably by [John Carmack](john_carmack.md) (graphics + engine programmer) and [John Romero](john_romero.md) (tool programmer + level designer). Doom is sadly [proprietary](proprietary.md), it was originally distributed as [shareware](shareware.md) (a free "demo" was available for playing and sharing with the option to buy a full version). However the game engine was later (1999) released as [free (as in freedom) software](free_software.md) under [GPL](gpl.md) which gave rise to many source [ports](port.md). The assets remain non-free but a completely free alternative is offered by the [Freedoom](freedoom.md) project that has created [free as in freedom](free_culture.md) asset replacements for the game. [Anarch](anarch.md) is an official [LRS](lrs.md) game inspired by Doom, completely in the [public domain](public_domain.md).
Doom is a legendary video [game](game.md) released in [1993](1990s.md), perhaps the most famous video game of all time, the game that popularized the [first person shooter](first_person_shooter.md) genre and shocked by its at the time extremely advanced [3D](pseudo_3D.md) graphics (yes, it was actually 3D). It was made by [Id Software](id_software.md), most notably by [John Carmack](john_carmack.md) (graphics + engine programmer) and [John Romero](john_romero.md) (tool programmer + level designer). Doom is sadly [proprietary](proprietary.md), it was originally distributed as [shareware](shareware.md) (a free "demo" was available for playing and sharing with the option to buy a full version). However the game engine was later (1999) released as [free (as in freedom) software](free_software.md) under [GPL](gpl.md) which gave rise to many source [ports](port.md). The assets remain non-free but a completely free alternative is offered by the [Freedoom](freedoom.md) project that has created [free as in freedom](free_culture.md) asset replacements for the game. [Anarch](anarch.md) is an official [LRS](lrs.md) game inspired by Doom, completely in the [public domain](public_domain.md).
{ Great books about Doom I can recommend: *Masters of Doom* (about the development) and *Game Engine Black Book: Doom* (details about the engine internals). ~drummyfish }
@ -26,4 +26,10 @@ Indexed ([palette](palette.md)) mode with "only" 256 colors was used for renderi
Doom also has a [deterministic](determinism.md) [FPS](fps.md)-independent physics which allows for efficient recording of [demos](demo.md) of its gameplay and creating [tool assisted speedruns](tas.md), i.e. the time step of game simulation is fixed (35 tics per second). Such demos can be played back in high quality while being minuscule in size and help us in many other ways, for example for verifying validity of [speedruns](speedrun.md). This is very nice and serves as an example of a well written engine (unlike later engines from the same creators, e.g. those of [Quake](quake.md) games which lacked this feature -- here we can see how things get progressively shittier in computer technology as we go forward in time).
There is no [antialiasing](antialiasing.md) in the engine, i.e. aliasing can be noticed on far-away textures, but it is suppressed by the use of low-res textures and dimming far-away areas. There is also no edge smoothing (kind of misledingly known as "antialiasing") in the geometry rendering, the engine is [subpixel](subpixel.md) accurate in rendering of the top and bottoms of the walls, i.e. the line these boundaries form may result in rasterizing slightly different pixels even if the start and end pixel is the same, depending on the subpixel position of the start and endpoint -- this feature doesn't much help in static screenshots but makes animation nicer.
There is no [antialiasing](antialiasing.md) in the engine, i.e. aliasing can be noticed on far-away textures, but it is suppressed by the use of low-res textures and dimming far-away areas. There is also no edge smoothing (kind of misledingly known as "antialiasing") in the geometry rendering, the engine is [subpixel](subpixel.md) accurate in rendering of the top and bottoms of the walls, i.e. the line these boundaries form may result in rasterizing slightly different pixels even if the start and end pixel is the same, depending on the subpixel position of the start and endpoint -- this feature doesn't much help in static screenshots but makes animation nicer.
If an "intellectual work" (song, book, computer program, ...) is in the public domain (PD), it has no "owner", meaning no one has any exclusive rights (such as [copyright](copyright.md) or [patent](patent.md)) over the work, no one can dictate how and by whom such work can be used and so anyone can basically do anything with such work (anything that's not otherwise illegal of course).
[LRS](lrs.md) highly supports public domain and recommends programmers and artists put their works in the public domain using [waivers](waiver.md) such as [CC0](cc0.md).
[LRS](lrs.md) highly supports public domain and recommends programmers and artists put their works in the public domain using [waivers](waiver.md) such as [CC0](cc0.md) (this very wiki is of course released as such).
Public domain is the ultimate form of freedom in the creative world. In public domain the creativity of people is not restricted. Anyone can study, remix, share and improve public domain works in any way, without a fear of being legally bullied by someone else.
