cairo2

Binding to Cairo, a 2D Vector Graphics Library
README

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

Install
Published
03 Oct 2022
Sources
cairo2-0.6.4.tbz
sha256=40357352d7205d3a5735855643830cb345f2db838ff9d19a532018760d468a05
sha512=2fd755b32253a4c441146fb41d13bf7ad4ce3828bc479ece296fb58350e20c7349c22457ad99fa080407b5150ce337a753221043f18b7b641f4c5bc98e37e799
Dependencies
Reverse Dependencies
acgtk
>= "1.3.2"
cairo2-gtk
< "0.6.1" | >= "0.6.4"
cairo2-pango
< "0.6.1" | >= "0.6.4"
DrawGrammar
!= "0.2.1"
JsOfOCairo
= "1.0.1" | >= "2.0.0"
lablgtk3
>= "3.0.beta4"
mlpost
>= "0.9"