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NAME

Cairo driver - driver for bitmap or vector output using the Cairo graphics library.
(drivers)

DESCRIPTION

The Cairo driver generates PNG, BMP, PPM, PS, PDF or SVG images from GRASS display commands, using the Cairo graphics library. The image format is selected from the extension of the output file.

It is started as 'pseudo' monitor (output to an image file) and when stopped, all output from previously used display commands are written to the output file.

USAGE

Environment variables

Several environment variables affect the operation of the Cairo driver:

Examples

Example using the driver to generate a PNG file (bash-syntax):
export GRASS_PNGFILE=spearfish.png
export GRASS_WIDTH=800
export GRASS_HEIGHT=800
export GRASS_RENDER_IMMEDIATE=CAIRO

d.rast map=elevation.10m
d.vect map=streams width=1 color=blue fcolor=aqua type=area,line
d.vect map=roads width=2
Example using the driver to generate a PDF file (bash-syntax):
export GRASS_PNGFILE=spearfish.pdf
export GRASS_WIDTH=800
export GRASS_HEIGHT=800
export GRASS_RENDER_IMMEDIATE=CAIRO

d.rast map=elevation.10m
d.vect map=streams width=1 color=blue fcolor=aqua type=area,line
d.vect map=roads width=2

NOTES

The driver is still in development. Enable it by specifying --with-cairo when configuring GRASS. This requires a reasonably recent version of the Cairo libraries and a working pkg-config.

Antialiasing is enabled by default for bitmap formats. There is currently no way of disabling this.

Cairo supports true vector format output whenever possible. However, if the selected format doesn't support a necessary feature, Cairo may fall back on rendering a bitmap representation of the image wrapped in the selected vector format.

SEE ALSO

Display drivers
PNG driver, PostScript driver,
d.rast, d.vect

AUTHOR

Lars Ahlzen <lars (at) ahlzen.com>
and the GRASS Development Team.

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