README
¶
folio
Document rendering in pure Go.
PDF, SVG, EPUB, MOBI, CHM, FB2, DOCX, PPTX, XLSX, HTML and plain text.
Rendering
doc, err := pdf.Open("file.pdf") // or svg.Open a drawing, html.Open a book or a document
defer doc.Close()
p, err := doc.Page(0)
img, err := p.ImageDPI(150)
txt, err := p.Text()
Supported
| paths, text, images, shadings, patterns, transparency, annotations, layers; damaged files repaired, encrypted files opened | |
| SVG | shapes, paths, text on a path and down the page, paint servers, clipping, masking, markers, filters |
| EPUB, MOBI, CHM, FB2, HTML, text | container, HTML, CSS cascade and layout: floats, tables, pagination, writing modes, embedded fonts |
| DOCX, PPTX, XLSX | styles, lists, tables, pictures, footnotes; a slide is a page, a sheet a part, cells formatted as the file asks |
A page also reads as structured text with the box every character occupies, as plain text, as its links, as SVG and as HTML, and a reflowable document as Markdown. A document carries its outline, metadata and page labels.
Not in scope: writing or editing documents, form field values, JavaScript, XFA, signature validation, PDF/A validation.
Packages
| doc | one Open over the three, for a file of unknown format |
| the content interpreter and the public API | |
| svg | a drawing as a document of its own |
| html | reflowable and office documents, and the layout over them |
| gfx | the device interface and the devices behind it |
| raster | the 2D engine: paths, rasterizer, pixmaps, blend modes |
| font | font programs in, outlines and metrics out |
| syntax | the file format: objects, filters, encryption, repair |
Every format renders through one gfx.Device, so a caller can drive something other than the rasterizer.
raster and font know nothing about PDF, gfx knows no file format, and syntax has no graphics in it.
Correctness
Objects, device calls, glyphs, text and rendered pixels are each compared against the established implementations: MuPDF, poppler, qpdf, AGG, OpenJPEG, cairo, Ghostscript, librsvg, resvg and a browser.
License
Apache-2.0. NOTICE lists what this derives from.
Directories
¶
| Path | Synopsis |
|---|---|
|
Package doc opens a document without the caller knowing what it is.
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Package doc opens a document without the caller knowing what it is. |
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Package font reads font programs and returns glyph outlines and metrics.
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Package font reads font programs and returns glyph outlines and metrics. |
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Package gfx is the graphics model a document is drawn through: the Device interface, the devices behind it, color spaces, and the text, image and shading a device is handed.
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Package gfx is the graphics model a document is drawn through: the Device interface, the devices behind it, color spaces, and the text, image and shading a device is handed. |
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Package html reads reflowable documents: EPUB, MOBI, CHM, FB2, DOCX, PPTX, XLSX and plain text.
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Package html reads reflowable documents: EPUB, MOBI, CHM, FB2, DOCX, PPTX, XLSX and plain text. |
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Package pdf renders PDF documents.
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Package pdf renders PDF documents. |
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Package raster is a two dimensional graphics engine: paths, curve flattening, an anti-aliased cell rasterizer with both fill rules, a stroker and a dasher, clip masks, pixmaps of one to four color components with an optional alpha channel, and the span pipeline over them.
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Package raster is a two dimensional graphics engine: paths, curve flattening, an anti-aliased cell rasterizer with both fill rules, a stroker and a dasher, clip masks, pixmaps of one to four color components with an optional alpha channel, and the span pipeline over them. |
|
Package svg renders an SVG drawing.
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Package svg renders an SVG drawing. |
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Package syntax reads the PDF file format: objects, cross references, object streams, damaged file recovery, the stream filters and encryption.
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Package syntax reads the PDF file format: objects, cross references, object streams, damaged file recovery, the stream filters and encryption. |