A simple converter for Type2 charstrings in human readable and byte form.
npm install type2-charstringA simple converter for Type2 charstrings in human readable and byte form
Install with npm install type2-charstring, then use it in your code as:
``
var convert = require('type2-charstring');
var charstring = convert.toBytes([
]);
Use the convert.js from the repo:
`
The following functions are exposed:
- bindSubroutine: function(functor, bytes), binds a global subroutine (to do this from human readable form, run the code through .toBytes and then bind that to a name). The functor can be used in subsequent charstrings to autoresolve to the right subr, so:
`
bindSubroutine("sin()", [.....]);
// we can now use sin() as charstring code:
var ncs = "3.1415 sin() endchar";
var ncsBytes = Type2Convert.toBytes(ncs);
- getSubroutines: function(), returns the list of global subroutines known until now, with bias correction applied. Generally useful if you need to actually build a font based on the charstrings you've been creating.
- toBytes: function(string, subroutines), converts a human readable charstring to byte form. White space and commas are treated as non-semantic, and line comments are stripped, so you can write properly readable code:
`
...
// When we start the stack contains: [angle, ox, oy, x, y],
// so we put them onto the transient stack in argument order:
4 put, 3 put, 2 put, 1 put, 0 put
// compute the sin(x) and cos(x) of the provided angle
0 get, sin(x), 5 put
0 get, cos(x), 6 put
...
`
- toString: function(bytes, subroutines), converts a sequence of bytes into human readable charstring code, but not currently implemented
Clone the repo, then install with npm install.
Tests can be run with npm test`, and currently cover validation of three functions:
- sin(x)
- cos(x), with a dependency on sin(x)
- rotate(angle, ox, oy, x, y), with a dependency on sin(x) and cos(x)
I needed a way to write Type2 functions and automatically build them into subroutines.