#2d-graphics #graphics #print #2d #command-line-tool #tool #programming-language

app stdg

A command-line tool for cross-language, cross-platform 2D graphics

2 unstable releases

0.2.0 Nov 12, 2019
0.1.0 Nov 12, 2019

#301 in Graphics APIs

MIT license

60KB
935 lines

Standard Graphics is a command-line tool for printing 2D graphics from any language to any screen. It uses stdin and stdout to make 2D graphics as simple as printing commands with Python's print() or Java's System.out.println() for example. You can even write plain text and handle user interaction.

You only need to learn stdg once. Then it will no longer matter what language or frameworks you happen to be using. You will always be able to easily print 2D graphics using the same easy-to-remember commands.

features

  • Learn once - stdg provides a minimal set of commands for 2D graphics. These commands are designed to be intuitive, easy-to-learn, and easy-to-remember. They are mostly inspired by Khan Academy's computer programming environment and the Processing.
  • Use anywhere - stdg is both cross-language and cross-platform. This means that you can freely switch between programming languages and operating systems without having to learn a totally new 2D graphics library for the language/OS.
  • Get fast, performant graphics - stdg is an abstraction over MiniFB and Raqote which are both implemented entirely in Rust (except for MacOS which uses some Objective-C). Therefore, your graphics will be rendered at effectively native speed. There is no use of an Electron-like framework or "dynamic" languages in the rendering, event-handling.

example

print("start 400 400 Untitled")


# position of the car
x = 10

while True:
  print("background 151 244 247")

  # draw the car body
  print("fill 255 0 115")
  print("nostroke")
  print("rect " + str(x) + " 200 100 20")
  print("rect " + str(x + 15) + " 178 70 40")

  # draw the wheels
  print("fill 77 66 66")
  print("circle " + str(x + 25) + " 221 12")
  print("circle " + str(x + 75) + " 221 12")

  print("present") # this is what actually says to draw, must be in an infinite loop

  x = x + 1
python moving_car.py | stdg

An example output through standard graphics

usage

There are 2 ways of using Standard Graphics.

The first, and simplest, is by simply piping your program's output to stdg. All of your program's output (stuff that would normally be printed) will be sent to stdg. You can open a terminal and type in something like the following, provided stdg is installed.

my_data.csv | ruby my_program.rb | stdg

For each line of input that stdg recieves, it will check if the first word (first token in line split by whitespace) matches a command. If the word matches, it will look at the rest of the line and execute the command by printing a rectangle, or setting color, etc.. If the word doesn't match, it will just print the line out.

The second way is by giving stdg a process to run.

stdg node my_thing.js | settings.csv

In this case, stdg doesn't accept any input. You can't pipe anything to it. You can't interactively type stuff in the terminal. You can, however, give it a process to run.

You give it a process by providing arguments to stdg. These arguments get parsed into a single command that can be executed as a process. Basically you can write stdg python options.py or stdg ./menu but you can't do stdg python options.py && ./menu.

Then, stdg will run your process and read its output in exactly the same way the first usage has stdg reading. Commands get interpreted. Everything else gets printed as output. But now in addition to that, stdg will also sometimes print input to the process itself. This input will be information regarding things like mouse position, mouse click, etc.. The process can read this input one line at a time to get the mouse/key/etc. information.

This second way of using stdg allows for interactivity. You can do things like this-

print("start 400 400 A Rectangle")

while True:
  print("background 255 255 255")
  print("fill 255 0 0")
  
  print("get mousex")
  print("get mousey")
  print("rect " + str(float(input()) - 25.0) + " " + str(float(input()) - 25.0) + " 50.0 50.0")
  print("present")

cheat sheet

The following is a cheat sheet/reference for using stdg.

The following are commands for the most basic usage of stdg. Note that all whitespace in text like in start and text commands are converted to single spaces.

Command Example Note
Start everything start 400 400 A rectangle Must be first line printed
Present stuff to be drawn present Must be in an infinite loop
Present forever present forever Useful in .txt files
Get position of mouse get mousex, get mousey Sends back line containing position
Get "is mouse pressed?" get mouseispressed left Must be left, center, or right
Get "is key pressed?" get keyispressed space Valid keys listed below
Get all keys pressed get keys Sends space-seperated keys

The following are useful for styling.

Command Example Note
Set background color background 220 220 220
Set fill color fill 255 0 0 240 All values of red-green-blue-alpha are 0-255
Set stroke color stroke 20 20 20 Stroke is also called outline
Don't fill or don't stroke nostroke, nofill Default color is nofill, stroke 0 0 0
Get position of mouse get mousex, get mousey Sends back line containing position
Set stroke weight strokeweight 5 Default is 1
Set stroke cap strokecap round Must be square, project, or round (default)
Set stroke join strokejoin bevel Must be miter (default), bevel, or round

We can do transformations.

Command Example Note
Push a transformation push This lets us begin a new transformation
Pop top pop This will revert to the old transformation
Translate top translate 50 0
Scale top scale 0.5 1.0
Rotate top rotate 180 Degrees are in degrees

There are the common 2D primitives.

Command Example Note
Draw rectangle rect 50 50 300 300
Draw ellipse ellipse 200 200 50 40 Centered at given coordinates
Draw circle circle 200 200 50
Draw line line 300 100 100 300
Draw arc arc 200 200 50 40 0 90 Degrees are in degrees

Last but not least, we have text and images.

Command Example Note
Set text font textfont C:\Windows\Fonts\Arial.ttf \ might have to be \\
Set text size textsize 20
Draw text text 30 30 Must be followed by line with text
Load image open character.png as char Should be called only once, if possible
Draw image image char 30 70, image char 5 5 50 1 Should be a loaded image

And here are the keys supported by stdg-

  • All numeric characters
  • All lower-case alphabetic characters (use leftshift or rightshift to check for upper-case)
  • up, down, left, right
  • space, tab, enter
  • leftshift, rightshift
  • escape, backspace, delete

about

Standard Graphics is designed to be useful for many sorts of things-

  • User interfaces for Bash scripts
  • Visualization of Python-scripted simulations
  • Visualization of data
  • Desktop games written in JavaScript
  • Simple vector graphics with plain text
  • Simple animations with C
  • and much more...

The software itself is written entirely in pure Rust with the only exception being the MacOS back-end. It uses Raquote and MiniFB behind the scenes for drawing stuff.

getting started

There are two ways to install Standard Graphics.

The first way is to download the binaries from here. Once downloaded, make sure that the folder location where the binaries are stored is added to PATH (look that up on the Internet if you aren't sure "how to add folder location to PATH".

The second way is to install Standard Graphics with cargo. Make sure you have installed Rust. Then, simply install as follows.

cargo install stdg

During installation, you may have to install a bunch of packages. On Windows, I was personally able to simply install and run. However, on Linux, I had to install at least libfontconfig1-dev, xcursor.

Once installed, you can take a look at the cheat sheet for more information on the various commands you can print.

Dependencies

~3.5–6MB
~116K SLoC