X-Git-Url: http://git.subgeniuskitty.com/screensavers/.git/blobdiff_plain/b020506b4c6c168df097533cd935d6222d0c924d..f6e3cf3e0c192fbaf2d5677a93b7d254d4134fed:/hacks/WolframAutomata/README.md diff --git a/hacks/WolframAutomata/README.md b/hacks/WolframAutomata/README.md index 88ecbe7..91fe6e8 100644 --- a/hacks/WolframAutomata/README.md +++ b/hacks/WolframAutomata/README.md @@ -10,8 +10,9 @@ together, thereby forming a circular universe for the cells to inhabit. This line is drawn horizontally on the screen. Over time, this line of cells evolves according to rules, with some cells -switching on or off. Each new iteration is drawn below its predecessor, leading -the screen to scroll vertically over time. +switching on or off. Each new application of the rule to the universe is drawn +on the screen as a new line directly below the previous generation's line, +leading the screen to scroll vertically. The rules which govern the time evolution of this system depend only on the current state of a given cell and the state of its two immediate neighbors. @@ -26,24 +27,21 @@ discussed at length in a ![Rule 110 Animated Screenshot](/screensavers/.git/blob_plain/HEAD:/hacks/WolframAutomata/screenshot_rule_110.gif) -Commandline flags are provided enabling the user to tweak attributes such as -length and speed of simulation, cell size, rule number, colors, starting seed, -and other attributes. For example, the screenshot below depicts Rule 73 with -different colors than the Rule 110 screenshot. Like the Rule 110 screenshot, it -uses `-cell-size 2` and seeds the simulation with only a single active cell. +Commandline flags are provided which enable the user to tweak attributes such +as length and speed of simulation, cell size, rule number, colors, starting +seed, and other attributes. For example, the screenshot below depicts Rule 73 +with different colors than the Rule 110 screenshot. Like the Rule 110 +screenshot, it uses `-cell-size 2` and seeds the simulation with only a single +active cell. ![Rule 73 Animated Screenshot](/screensavers/.git/blob_plain/HEAD:/hacks/WolframAutomata/screenshot_rule_73.gif) In situations where true randomness would lead to visually unappealing -displays, this program provides random selection from curated lists. For +displays, this program provides random selection from curated lists. As one example, to avoid randomly selecting visually indistinguishable colors like `dark red` and `brown` to depict on/off cells, the program includes a pre-selected list of color pairs that complement each other and chooses -randomly from this list when the `-random-color` flag is passed. Similarly, to -avoid the visually uninteresting rules like rule 0, a rule which simply turns -every cell off and keeps it off, the program includes a list of rulesets and -starting seeds which are visually appealing, selecting randomly from this list -when the `-random-rule` flag is passed. +randomly from this list. Status @@ -68,9 +66,9 @@ else, edit the `Makefile` to suit your environment per the comments included in that file. Note that the `Makefile` assumes a copy of the screenhack library source code is located at `../screenhack/` relative to this directory. -For assistance setting `$(DEFINES)` on non-FreeBSD platforms, consider -downloading the XScreensaver source tarball, running `./configure` in the -unpacked directory, and examining the resulting `config.h` file. +For assistance setting `$(DEFINES)` in the `Makefile` on non-FreeBSD platforms, +consider downloading the XScreensaver source tarball, running `./configure` in +the unpacked directory, and examining the resulting `config.h` file. Although WolframAutomata can integrate with XScreensaver, the presence of XScreensaver is not strictly required. WolframAutomata will both build and @@ -88,12 +86,30 @@ are re-randomized every time the simulation is reset, such as after a simulation completes or after resizing the window. +CLI: Rule Selection +------------------- + +If neither of the following two options are passed, rules are randomly selected +from `curated_ruleset_list[]` in `WolframAutomata.c`. + + - **`-true-random-rule`**: Select a rule completely at random, NOT randomly + from a curated list. Note that many rules are visually uninteresting. + + - **`-rule N`**: Select a specific rule where `N` is a Wolfram number. Values + from 0-255 inclusive are valid. + + CLI: Simulation Seed -------------------- -If none of the following options are specified, the starting seed will contain -randomly interspersed active/inactive cells at a 30/70, 50/50, or 70/30 ratio, -itself also randomly selected. +The following seed related CLI flags apply only when using the +`-true-random-rule` or `-rule N` flags. Without these flags, the program draws +rules from `curated_ruleset_list[]` which also includes curated seeds, all of +which override any seed related CLI flags. + +If the curated rule list is not in use and none of the following options are +specified, the starting seed will contain randomly interspersed active/inactive +cells at a 30/70, 50/50, or 70/30 ratio, itself also randomly selected. - **`-seed-left`**: Seeds a single active cell on the left side of the display. All other cells are inactive. @@ -105,22 +121,22 @@ itself also randomly selected. - **`-seed-density N`**: Generates random seed with `N` percent active cells. -CLI: Rule Selection -------------------- +CLI: Simulation Length +---------------------- -If neither of the following two options are passed, rules are randomly selected -from `curated_ruleset_list[]` in `WolframAutomata.c`. +If neither of the following two options are passed, the simulation runs as +though `-length 5000` was passed. - - **`-true-random-rule`**: Select a rule completely at random, NOT randomly - from a curated list. Note that many rules are visually uninteresting. + - **`-random-length`**: A random length smaller than 10,000 generations but + large enough to fill the screen is selected. - - **`-rule N`**: Select a specific rule where `N` is a Wolfram number. Values - from 1-255 inclusive are valid. + - **`-length N`**: Request `N` generations be simulated on each run. -Note that, although Rule 0 is a valid set of rules, it is reused as a null -value by the program and thus is ignored if passed as `-rule 0`. If you want to -see Rule 0, choose any starting conditions you desire, then turn off your -monitor and enjoy the resulting simulation. +Note that an upper limit of 10,000 generations is enforced in order to avoid +`BadAlloc` errors from some X servers. For more details, read +`WolframAutomata.c` starting around the comment, "The maximum number of +generations is cell_size dependent. This is a soft limit and may be increased +if ..." CLI: Simulation Speed @@ -140,24 +156,6 @@ though `-delay 25000` was passed. well respected. -CLI: Simulation Length ----------------------- - -If neither of the following two options are passed, the simulation runs as -thought `-length 5000` was passed. - - - **`-random-length`**: A random length smaller than 10,000 generations but - large enough to fill the screen is selected. - - - **`-length N`**: Request `N` generations be simulated on each run. - -Note that an upper limit of 10,000 generations is enforced in order to avoid -`BadAlloc` errors from some X servers. For more details, read -`WolframAutomata.c` starting around the comment, "The maximum number of -generations is cell_size dependent. This is a soft limit and may be increased -if ..." - - CLI: Cell Dimensions -------------------- @@ -165,11 +163,11 @@ Individual cells may be displayed as any square number of pixels (e.g. 1x1, 2x2, etc). Increasing the cell size may help with flickering on high DPI monitors displaying chaotic rulesets. -If neither of the following two options are passed, the simulation selects -whatever cell size it feels appropriate for the current simulation speed. +If neither of the following two options are passed, the simulation behaves as +though `-cell-size 2` was passed. - - **`-random-cell-size`**: Selects cell size of 2^N pixels for an `N` - randomly chosen in the inclusive range `0`-`5`. + - **`-random-cell-size`**: Randomly selects 1, 2, 4, 8, 16, or 32 as the cell + size on each reset of the simulation. - **`-cell-size N`**: Display each individual cell as an `N`x`N` square of pixels on the screen. @@ -196,10 +194,128 @@ Note that the names provided as comments in `color_list[]` are X11 color names. CLI: Admiration --------------- -When the simulation reaches its end as determined by flags like `-length N`, it +When the simulation reaches its end as determined by flags like `-length N` it will pause for a period of time, allowing the viewer to examine it without interference from scrolling. By default, this 'admiration window' is five seconds long. - **`-admiration-delay N`**: At the end of a simulation, pause for `N` seconds before resetting for the next simulation. + + +XScreensaver Integration +======================== + +In addition to running as a standalone program, WolframAutomata can be +integrated into the XScreensaver framework. + +To accomplish this integration, begin by installing and configuring +XScreensaver via whatever method is appropriate for your operating system. The +following instructions assume the filesystem paths used by FreeBSD packages and +ports; your paths may differ. After XScreensaver installation, ensure all +pertinent config files are created by running `xscreensaver-demo` and +configuring XScreensaver for your system. + +After XScreensaver is configured and working on your system, ensure that +WolframAutomata runs in standalone mode on your system. If you can `make clean run` +in the `screensavers/hacks/WolframAutomata/` folder and see the hack's visual +output, you're ready to move on. + +At this point, copy the hack into your XScreensaver hack directory. For +example, with prerequisite steps spelled out: + + git clone git://git.subgeniuskitty.com/screensavers + cd screensavers/hacks/WolframAutomata + make clean all + cp WolframAutomata /usr/local/bin/xscreensaver-hacks/wolframautomata + +Now create the file `wolframautomata.xml` wherever your system stores +XScreensaver config files and populate it with the contents shown below. For +example, on FreeBSD: + + vi /usr/local/share/xscreensaver/config/wolframautomata.xml + + + + + + + + + + + + + + + + + + + + + + + + + + + + + <_description> + Displays the time evolution of elementary cellular automata. + + These automata consist of a line of cells, each of which may be either on or + off. To ensure every cell has neighbors, the two endpoints of the line connect + together, thereby forming a circular universe for the cells to inhabit. This + line is drawn horizontally on the screen. + + Over time, this line of cells evolves according to rules, with some cells + switching on or off. Each new iteration is drawn below its predecessor, + leading the screen to scroll vertically over time. + + The rules which govern the time evolution of this system depend only on the + current state of a given cell and the state of its two immediate neighbors. + These rules are formalized as Wolfram codes, where the code number is directly + convertible into a rule set. + + + +The next step integrates WolframAutomata into an individual user's XScreensaver +config via the file `~/.xscreensaver`. If preferred, it could instead be done +in the global XScreensaver config. + +In the `~/.xscreensaver` file, create a WolframAutomata entry under the +`programs:` label in the same list as all the other hacks. Position in the +list is irrelevant, but ensure you don't paste WolframAutomata's entry into the +middle of pre-existing, multi-line entries. For context, the example below +includes a multi-line entry, a GL entry and a plain entry. All that is needed +is to insert the WolframAutomata line somewhere in the `programs:` list, as +demonstrated. + + vi ~/.xscreensaver + + + programs: \ + xplanet -vroot -wait 1 -timewarp 400 \ + -label -origin moon \n\ + GL: fireflies -root \n\ + wolframautomata -root \n\ + blitspin -root \n\ + + +That's all. Now you can run `xscreensaver-demo` and select WolframAutomata just +like any other hack. + + +Screen Tearing +============== + +Certain combinations of rules and display settings lead to full screen vertical +scrolling of alternating light and dark pixels, or other difficult to display +patterns. If your display doesn't include some type of vertical refresh +synchronization, such output will look terrible. + +If stuck in this situation, changing the output of WolframAutomata to scroll +horizontally may help, or simply increasing the cell size. +