nimPDF

nimPDF is a free PDF writer library, written mostly in nim programming language

nimPDF was heavily inspired by PHP-FPDF but also influenced by jagPDF, libHaru(especially for the demo), PyFPDF, pdfkit

after lodePNG substituted with PNG decoder written in nim, nimPDF become one step closer to 100% pure nim

nimPDF implements the following features(see demo.pdf):

nimPDF version 0.4.0 introduces many breaking changes, see migration guide to help you change your code.

• images

  • PNG -- use LodePNG, still in C now written in nim
  • JPEG -- use uJPEG (MicroJPEG) -- KeyJ's Small Baseline JPEG Decoder, still in C
  • BMP -- use EasyBMP, already ported to nim, support 1bit, 4bit, 8bit, 16bit, 24bit, and 32bit images
  • beside transparency from original image(such as from PNG), you can adjust individual image transparency as easy as other elements in your document

• text and fonts

  • support TTF/TTC font subsetting -- use Google sfntly, ported(partially) to nim and modified
  • you can easily tell the library to look for fonts in certain folder(s)
  • you only need to ask for font family name and it's style, the library will try to find the right one for you(if avilable)
  • text encoded in UTF-8 if you use TTF/TTC
  • 14 base font in PDF use Standard,MacRoman,WinAnsi encoding
  • TTF/TTC fonts can be written vertically if they have vertical metrics

• Path construction

  • straight segments, Bezier curves, elliptical arcs, roundrect
  • join styles and miter limits
  • dash patterns
  • path clipping
  • arbitrary path bounding box calculation(i use it to implement gradient too)
  • construct path from mathematical function - taken from C# GraphDisplay

• Color spaces

  • Gray, RGB, CMYK
  • alpha channel for text, path, and images too!
  • linear gradient to fill any closed shape
  • radial gradient to fill any closed shape

• Interactive Features(see demo folder)

  • Page Labels
  • Document Outline
  • Hyperlinks
  • Text annotation
  • Encryption(protect document with password)
  • choose between ARC4-40, ARC4-128, AES-128, AES-256 encryption mode
  • Form Field:
  • TextField
  • Combo Box
  • Radio
  • Push Button
  • List Box
  • Check Box

• Coordinate Space

  • top-down mode
  • bottom-up mode
  • unit measured in point, inch, and mm

• others

  • output to file or memory using nim stream module
  • images, fonts, and other resources search path(s)
  • document compression using flate decode(use lodePNG compressor)
  • transformation and graphics state

• unimplemented features

  • CIE based color space
  • patterns(this can be achieved using PDF primitives and path clipping)
  • encryption
  • annotation
  • hyperlinks
  • other encoding beside UTF-8(nim has encoding module, i will use it someday)
  • basic text formating(will be implemented as separate layer)
  • radial gradient and multi color gradient
  • table generator(as in FPDF)(will be implemented as separate layer)
  • document outline
  • permission
  • digital signature

Documentation

The documentation is generated using docutils

The documentation provided may not be complete, please help to improve it

Installation and build instructions

nimble install nimPDF

• build general demo: nim c demo
• build specific demo: goto nimPDF/demo folder, type nim e build.nims

Dependencies