Welcome to eInkDraw’s documentation!¶
Overview¶
The characteristics of Electronic Ink (eInk) displays make them ideal for applications where information is only updated relatively infrequent and where one has to deal with a limited power budget.
This also implies that these displays will often be combined with low power embedded processors, such as the ESP8266 that have limited processing power.
Limited processing power implies that complex inages cannot be rendered on these controllers. – In order to avoid the restrictions imposed by these low power embedded processors, it is possible to render the image on the server side, and then transfer it to the embedded processor for display.
eInkDraw is a rendering library that can provide these server side rendering capabilities. It is based on PyCairo, the Python bindings for the Cairo Graphics library of the Gtk project.
eInkDraw facilitates the drawing of complex shapes using Cairo, while taking into account the characteristics of eInk displays, such as the requirement to render monochrome and often low-resolution images:
The main purpose of eInkDraw is to create status displays for eInk displays, but other use cases are possible as well.
eInkDraw provides building blocks, such as Labels (Text), Icons, various charting primitives and “Window Frames”. It also allows for grouping building blocks into Columns, Rows and Stacks (drawn from background to foreground), and these groups can also be nested.
This way fairly complex layouts can be achieved without the need of too much pixel counting.