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Flat — Generative infrastructure for Python

Flat is a library for creating and manipulating digital forms of fine arts. Its aim is to enable experimentation with and testing of unpredictable or automated processes, to inspect the beginning of the "new".

It grew out of the needs for generative design, architecture and art. The concept of "design" is more of a subject of study yet to be delved into, hence the fitter term for subtitle is "infrastructure".

It is written in pure Python and distributed under a liberal license.

Content

Features

Core concepts

Flat library consists of three (slightly overlapping) parts: image, document and scene. An image is basically a container of rows of pixels and a color kind. There are a few methods which operate over those pixels, such as "blur" or "put". It is possible to create completely new image, by opening a file or by "rasterizing" a page of document.

Document is then assembled from pages, and each page holds number of "placed" items, both of which can be exported, too. Here it also makes sense to introduce other entities: colors, shapes and strikes. There is support for following colors or color spaces, if you will: the usual ones (grayscale, RGB, CMYK, ...), "spot" and "DeviceN" colors that can be used for controlling the application of special colorants and "overprint", which allows for printing of a graphic figure without erasing anything below it. A shape includes both graphical properties such as stroke width or miter limit and means of creating items with said properties that are to be "placed" into a page, for example "line" or "circle". Strike is a similar combination of text attributes (font, size, color, ...) and a way of constructing text "spans". A span likewise connects text string to text attributes, one or more spans can form a "paragraph", which in turn may form "text" or "outlines". Outlines are similar to texts but they use paths of glyph outlines, instead of characters. One additional thing to note is that placed texts or outlines may be linked into a story or "chain" of blocks, making the text gradually "flow" from one "frame" of block to another. Any of the items may be placed into a "group" as well.

Finally, a scene is made of (possibly light emitting) materials, meshes built of triangular faces defined by "triplets" of 3D vertices and a camera.

Tutorial

from flat import rgb, font, shape, strike, document

red = rgb(255, 0, 0)
lato = font.open('Lato-Reg.otf')
figure = shape().stroke(red).width(2.5)
headline = strike(lato).color(red).size(20, 24)

d = document(100, 100, 'mm')
p = d.addpage()
p.place(figure.circle(50, 50, 20))
p.place(headline.text('Hello world!')).frame(10, 10, 80, 80)
p.image(kind='rgb').png('hello.png')
d.page(0).svg('hello.svg')
d.pdf('hello.pdf')

Short commentary:

We first prepared some invariants which we are going to make use of later, like the body typeface, some RGB color or that typeface we opened from a file on disk. One can think of shape and strike as of customizable factories which produce more concrete objects, for example lines or spans of text.

Next is the basic document hierarchy with just one page that can have items be placed into. The origin of coordinate system (0, 0) is at the top left corner and most of the time the default unit is "points" (1 inch = 72 points). A placed item may have some additional properties as position or frame. The latter is used to define the boundaries inside whose the text may run. As Flat currently lacks any kind of color management, we need to use the same color space for rasterizing the page into a PNG file. To access a page one can either keep a reference to it (p) or ask the parent document for it, with page numbers starting from 0. Lastly, PDF is one of the few graphic formats which can hold multiple pages.

API reference

Tree

image.py

document.py

mesh.py

scene.py

color.py

font.py

shape.py

command.py

text.py

group.py

structure.py

even.py

Installation

pip install flat

It currently requires Python 2.7.

Alternatively, there is Even application which integrates the library, a viewer and Python editor.

Source code

github.com/xxyxyz/flat

pypi.python.org/pypi/flat

Contributing

Any kind of help is more than welcomed! Especially with ICC, NURBS or booleans.

Contact

Juraj Sukop
contact@xxyxyz.org