OCaml interface to Cairo
This is an OCaml binding for the Cairo library, a 2D graphics library with support for multiple output devices.
You can read the API of Cairo, Cairo_gtk, and Cairo_pango online.
Prerequisites
You need the development files of Cairo (see the
conf-cairo
package)
and the OCaml package
lablgtk2 (in the OPAM package
lablgtk).
Compilation & Installation
The easier way to install this library — once the prerequisites are set up — is to use opam:
opam install cairo2
If you would like to compile from the sources, install Dune
opam install dune
and do:
dune build @install
or just make. You can then install it with:
dune install
Examples
You can read a version of the
Cairo tutorial using
this module. The code of this tutorial is available in the
examples/ directory. To compile it, just do
dune build @examples
All the examples below are available (with some comments) by clicking on images in the tutorial.
Basic examples
-
stroke.ml shows how to draw (stroke) a simple rectangle on a PNG surface.
-
stroke.ml shows how to fill a simple rectangle on a PNG surface.
-
showtext.ml illustrates how to select a font and draw some text on a PNG surface.
-
paint.ml shows how to paint the current source everywhere within the current clip region.
-
mask.ml shows how to apply a radial transparency mask on top of a linear gradient.
-
setsourcergba.ml produces
-
setsourcegradient.ml shows how to use radial and linear patterns. It generates:
-
path_close.ml shows how to draw a closed path. It produces the PNG:
-
textextents.ml displays graphically the various dimensions one can request about text. It generates the PNG:
-
text_extents.ml exemplifies drawing consecutive UTF-8 strings in a PDF file. Some helping lines are also added to show the text extents.
-
tips_ellipse.ml shows the action of dilation on the line width and how to properly draw ellipses. It generates the PNG:
-
tips_letter.ml illustrates the wrong way of centering characters based on their individual extents:
Instead, one should combine them with the font extents as shown in tips_font.ml to have:
Examples generating the images of the tutorial
-
diagram.ml draw the images of the section Cairo's Drawing Model:
-
draw.ml generates the various images in Drawing with Cairo, namely:
