1. Glossary
Common PostScript terminology and concepts.
1.1. A
- Array
-
An ordered collection of PostScript objects. Arrays can contain any type of object and are created using
[and]brackets or thearrayoperator. - ASCII
-
American Standard Code for Information Interchange. PostScript files are typically encoded in ASCII for portability.
1.2. B
- Bézier Curve
-
A smooth curve defined by control points, created with the
curvetooperator. - BoundingBox
-
The rectangular area that encloses all marks on a page, specified in the document’s header comments.
1.3. C
- Clipping Path
-
A path that restricts where subsequent painting operations can mark the page. Set with
cliporeoclip. - Current Point
-
The position in user space where the next path construction operator will begin. Set by
movetoand updated by path construction operators. - CTM (Current Transformation Matrix)
-
The matrix that transforms from user space to device space. Modified by
translate,rotate, andscale.
1.4. D
- Device Space
-
The coordinate system of the output device, measured in device pixels.
- Dictionary
-
A PostScript data structure that associates keys with values. Created with
dict. - DSC (Document Structuring Conventions)
-
Comments in PostScript files that provide document structure information, starting with
%%.
1.5. E
- Executable
-
An attribute of PostScript objects indicating they should be executed when encountered. Procedures are executable arrays.
- Execution Stack
-
The stack that controls the flow of program execution.
1.7. G
- Graphics State
-
The collection of parameters that control how graphics operations affect the page, including current path, color, line width, transformation matrix, etc.
- Glyph
-
A visual representation of a character in a font.
1.8. I
- Imaging Model
-
PostScript’s page description model, consisting of paths, painting, and text operations.
1.9. L
- Literal
-
An attribute of PostScript objects indicating they represent themselves rather than being executed.
1.10. M
- Mark
-
A special object used to delimit arrays and mark positions on the operand stack. Created with
markor[.
1.11. N
- Name
-
A PostScript object that serves as an identifier. Names begin with
/when used literally.
1.12. O
- Operand Stack
-
The stack where data values are stored and manipulated during PostScript execution.
- Operator
-
A built-in PostScript command that performs an operation.
1.13. P
- Packed Array
-
A more memory-efficient, read-only form of array introduced in PostScript Level 2. Created with
packedarray. - Path
-
A sequence of connected and disconnected subpaths that describe shapes. Constructed with operators like
movetoandlineto. - Point
-
A unit of measurement equal to 1/72 of an inch.
- Procedure
-
An executable array, typically delimited by
{and}.
1.14. R
- Raster
-
The rectangular array of pixels that forms an image.
- Resource
-
A named PostScript object such as a font, form, or pattern.
1.15. S
- Stack
-
A last-in, first-out (LIFO) data structure. PostScript uses multiple stacks including the operand stack, dictionary stack, and execution stack.
- Stroke
-
The operation of painting along a path with the current line width and color, using
stroke. - String
-
A sequence of bytes, typically representing text. Created with parentheses
()or thestringoperator.
1.16. T
- Token
-
The basic lexical element of PostScript syntax - a name, number, string, or special character sequence.
- Type
-
The classification of a PostScript object (integer, real, boolean, string, name, array, etc.).
1.17. U
- User Space
-
The coordinate system in which PostScript programs operate, independent of the output device. The default has origin at bottom-left with units in points.
1.18. V
- VM (Virtual Memory)
-
PostScript’s memory management system, supporting both local and global allocation.