ref: c02b2618969584ea563f1df1608dc923de639af1
dir: /README.md/
# ORCΛ
<img src='https://raw.githubusercontent.com/hundredrabbits/Orca/master/resources/logo.png' width="600"/>
**Each letter of the alphabet is an operation**, lowercase letters typically operate on bang(`*`), uppercase letters operate on each frame. Bangs can be generated by various operations, such as `E` colliding with a `0`, see the [bang.orca](https://github.com/hundredrabbits/Orca/blob/master/examples/bang.orca) example. Watch a music video of [ORCΛ in action](https://twitter.com/neauoire/status/1069129232708657152).
**C Port** for the [ORCΛ](https://github.com/hundredrabbits/Orca) programming environment, with a commandline interpreter.
## Prerequisites
Core library: A C99 compiler (no VLAs required), plus enough libc for `malloc`, `realloc`, `free`, `memcpy`, `memset`, and `memmove`.
Command-line interpreter: The above, plus POSIX, and enough libc for the common string operations (`strlen`, `strcmp`, etc.)
Interactive terminal UI: The above, plus ncurses (or compatible curses library), and floating point support (for timing.)
Note: the core library for running an orca virtual machine *should* in theory build on anything, but the project is being worked on quickly right now, so it might accidentally include something from POSIX that isn't available on Windows, for example. The header files also need some restructuring. Please open an issue or send a message on twitter if you need help building the core virtual machine for your own use, and I'll try to clean it for you.
## Build
The build script is in `bash`. It should work with `gcc` (including the `musl-gcc` wrapper) and `clang`, and will automatically detect your compiler.
Currently known to build on macOS (`gcc`, `clang`) and Linux (`gcc`, `musl-gcc`, and `clang`, optionally with `LLD`).
Not yet tested on Windows, but it's likely that it already works under `cygwin`. Further testing will be performed soon.
There is a fire-and-forget `make` wrapper around the build script.
### Make
```sh
make debug # debugging build, binary placed at build/debug/orca
make release # optimized build, binary placed at build/release/orca
make clean # removes build/
```
### Build Script
Run `./tool --help` to see usage info. Examples:
```sh
./tool -c clang-7 build release orca
# build the terminal ui with a compiler named
# clang-7, with optimizations enabled.
# binary placed at build/release/orca
./tool build debug cli
# debug build of the headless CLI interpreter
# binary placed at build/debug/cli
./tool clean
# same as make clean, removes build/
```
## Run
### Interactive terminal UI
```sh
orca [options] [file]
```
Run the interactive terminal UI, useful for debugging or observing behavior. Pass `-h` or `--help` to see command-line argument usage.
#### Controls
- `ctrl+q`: quit
- Arrow keys or `ctrl+h/j/k/l`: move cursor
- `A`-`Z`, `a`-`z`, `0`-`9`, and other printable characters: write character to grid at cursor
- Spacebar: play or pause
- `ctrl+f`: step the simulation one tick forward
- `ctrl+z` or `ctrl+u`: undo
- return or enter: change into or out of overwrite/append mode
- `/`: change into or out of key-trigger mode (for the `!` operator)
- `[` and `]`: Adjust cosmetic grid rulers horizontally
- `{` and `}`: Adjust cosmetic grid rulers vertically
- `(` and `)`: resize grid horizontally
- `_` and `+`: resize grid vertically
### CLI interpreter
The CLI (`cli` binary) reads from a file and runs the orca simulation for 1 timestep (default) or a specified number (`-t` option) and writes the resulting state of the grid to stdout.
```sh
cli [-t timesteps] infile
```
You can also make `cli` read from stdin:
```sh
echo -e "...\na34\n..." | cli /dev/stdin
```
## Extras
- Support this project through [Patreon](https://patreon.com/100).
- See the [License](LICENSE.md) file for license rights and limitations (MIT).
- Pull Requests are welcome!