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

• 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
• Encryption(protect document with password)
  • choose between ARC4-40, ARC4-128, AES-128, AES-256 encryption mode

• Table generator

• 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