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Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.

Display drivers

Table of contents

The current command line rendering mechanism is direct rendering into a file. The driver is selected by setting the GRASS_RENDER_IMMEDIATE variable or by running d.mon module.

List of available display drivers:

NOTES

GRASS_RENDER_COMMAND

If environmental variable GRASS_RENDER_COMMAND is defined, rendering is redirected by display library to the given external command defined by this variable. Currently only Python scrips are supported.

Lets start with simple example of Python script called render.py: 

#!/usr/bin/env python3

import os
import sys

import grass.script as grass
from grass.script import task as gtask

os.environ['GRASS_RENDER_IMMEDIATE'] = 'default'
os.environ['GRASS_RENDER_FILE'] = 'output.png'

cmd, dcmd = gtask.cmdstring_to_tuple(sys.argv[1])

grass.run_command('d.text', text="Test of GRASS_RENDER_COMMAND redirection")

os.environ['GRASS_RENDER_FILE_READ'] = 'TRUE'
grass.run_command(cmd, **dcmd)
After defining GRASS_RENDER_COMMAND variable (example for Bash): 
export GRASS_RENDER_COMMAND=render.py
Display GRASS modules like d.rast or d.vect will be executed by render.py program. For example the command 
d.vect roadsmajor
produces output PNG file output.png which will contain rendered features from vector map roadsmajor and sample text "Test of GRASS_RENDER_COMMAND redirection".

SEE ALSO

d.mon, variables

SOURCE CODE

Available at: Display drivers source code (history)

Latest change: Sun Oct 3 04:25:57 2021 in commit: 18b732a3cf8c8186bec13ed4728c5e30de95049a

Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.

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