Version 3 of tclcairo

Updated 2012-03-09 08:36:49 by DDG

tclcairo

Swig based binding for tcl for the cairo library. Can be used to produce, png, pdf, ps and svg files using the same API. Provided as a starkit for Tclkit 8.4, 8.5 and 8.6 with compiled binaries for Win32-x86 and Linux-x86

Example session:

 [email protected](7:1441):mytcl$ tclkit-8.4.19
 % source tclcairo1.10.2.kit
 % package require cairo
 0.1
 % glob tclcairo1.10.2.kit/lib/*
 tclcairo1.10.2.kit/lib/tclcairo1.10.2
 glob tclcairo1.10.2.kit/lib/*/*
 tclcairo1.10.2.kit/lib/tclcairo1.10.2/cairo-test.tcl tclcairo1.10.2.kit/lib/tclcairo1.10.2/cairo.i 
 tclcairo1.10.2.kit/lib/tclcairo1.10.2/libcairo.dll tclcairo1.10.2.kit/lib/tclcairo1.10.2/libcairo.so  
 tclcairo1.10.2.kit/lib/tclcairo1.10.2/pkgIndex.tcl 
 % lrange [lsort [info commands cairo::*]] 0 10
 ::cairo::_cairo_path_data_t ::cairo::_cairo_path_data_t_header ::cairo::_cairo_path_data_t_header_get 
 ::cairo::_cairo_path_data_t_header_length_get ::cairo::_cairo_path_data_t_header_length_set 
 ::cairo::_cairo_path_data_t_header_type_get ::cairo::_cairo_path_data_t_header_type_set 
 ::cairo::_cairo_path_data_t_point ::cairo::_cairo_path_data_t_point_get ::cairo::_cairo_path_data_t_point_x_get 
 ::cairo::_cairo_path_data_t_point_x_set

 % source tclcairo1.10.2.kit/lib/tclcairo1.10.2/cairo-test.tcl
 % exit
 [email protected](7:1442):mytcl$ ls -lt | head
 insgesamt 55828
 -rw-r--r-- 1 usern users      254  7. Mär 15:07 cairo-test2.png
 -rw-r--r-- 1 usern users      929  7. Mär 15:07 test.pdf
 -rw-r--r-- 1 usern users     2503  7. Mär 15:07 test.ps
 -rw-r--r-- 1 usern users      484  7. Mär 15:07 test.svg

If the library loading on windows fails try the larger windows starkit which contains as well cairo, zip and png shared libs.

Ok let's create a PDF-file having a red rectangle:

 package require cairo
 set surface [::cairo::cairo_pdf_surface_create test.pdf 300 300]
 set cr [::cairo::cairo_create $surface]
 ::cairo::cairo_rectangle $cr 10 10 40 40
 ::cairo::cairo_set_source_rgb $cr 1 1 1
 ::cairo::cairo_fill $cr
 ::cairo::cairo_rectangle $cr 20 20 20 20
 ::cairo::cairo_set_source_rgb $cr 1 0 0
 ::cairo::cairo_fill $cr
 ::cairo::cairo_show_page $cr
 ::cairo::cairo_surface_flush $surface
 ::cairo::cairo_surface_destroy $surface
 ::cairo::cairo_destroy $cr

If you would like to create the same as svg just a replacemment of the first line is needed:

 set surface [::cairo::cairo_svg_surface_create test.svg 300 300]
 set cr [::cairo::cairo_create $surface]
 ::cairo::cairo_rectangle $cr 10 10 40 40
 ::cairo::cairo_set_source_rgb $cr 1 1 1
 ::cairo::cairo_fill $cr
 ::cairo::cairo_rectangle $cr 20 20 20 20
 ::cairo::cairo_set_source_rgb $cr 1 0 0
 ::cairo::cairo_fill $cr
 ::cairo::cairo_show_page $cr
 ::cairo::cairo_surface_flush $surface
 ::cairo::cairo_surface_destroy $surface
 ::cairo::cairo_destroy $cr

You have to use the C-API documentation provided here: http://cairographics.org/manual/ A tcl wrapper using an OO-framework like Snit or Itcl would be greet in making it more Tcl-ish.

Swig wrapper

file: cairo.i

 %module cairo
 %{
 #include <cairo-features.h>    
 #include <cairo.h>
 #include <cairo-deprecated.h>    
 #include <cairo-version.h>
 #include <cairo-pdf.h>    
 #include <cairo-ps.h>        
 #include <cairo-svg.h>    
 %}
 %include "/usr/include/cairo/cairo-features.h"
 %include "/usr/include/cairo/cairo.h"
 %include "/usr/include/cairo/cairo-deprecated.h"
 %include "/usr/include/cairo/cairo-version.h"
 %include "/usr/include/cairo/cairo-pdf.h"
 %include "/usr/include/cairo/cairo-svg.h"
 %include "/usr/include/cairo/cairo-ps.h"

This file is translated into c-code using swig and compiled using gcc and compressed using upx:

 $ swig -tcl -namespace cairo.i
 $ gcc -shared -fPIC -DUSE_TCL_STUBS \
 -I/usr/include/cairo -I/opt/tcl/include cairo_wrap.c -o libcairo.so \
 -lcairo -L/opt/tcl/lib -ltclstub8.4
 $ upx libcairo.so

As I could not compile cairo on OSX-X the starkit does not contain libraries for OS-X.