libcaca-ruby-api(3) Libcaca Ruby API


The classes available for libcaca are :

  • Caca::Canvas : functions that have a caca_canvas_t* as first argument
  • Caca::Dither : functions that have a caca_dither_t* as first argument
  • Caca::Font : functions that have a caca_font_t* as first argument (The constructor can currently only accept the name of a builtin font)
  • Caca::Display
  • Caca::Event
  • Caca::Event::Key
  • Caca::Event::Key::Press
  • Caca::Event::Key::Release
  • Caca::Event::Mouse
  • Caca::Event::Mouse::Press
  • Caca::Event::Mouse::Release
  • Caca::Event::Mouse::Motion
  • Caca::Event::Resize
  • Caca::Event::Quit

The character set conversion functions are not available yet in the binding.

$ irb -rcaca
irb(main):001:0> class Object
irb(main):002:1> def Object.my_instance_methods
irb(main):003:2> instance_methods.sort - ancestors[1].instance_methods
irb(main):004:2> end
irb(main):005:1> def Object.my_methods
irb(main):006:2> methods.sort - ancestors[1].methods
irb(main):007:2> end
irb(main):008:1> end

irb(main):009:0> Caca.constants
"ITALICS", "CYAN", "YELLOW", "LIGHTGREEN", "Canvas", "Dither", "Font"]

irb(main):010:0> Caca.my_methods
=> ["version"]

irb(main):011:0> Caca::Canvas.my_methods
=> ["export_list", "import_list"]

irb(main):012:0> Caca::Canvas.my_instance_methods
=> ["attr=", "blit", "clear", "create_frame",
"dither_bitmap", "draw_box", "draw_circle", "draw_cp437_box", "draw_ellipse",
"draw_line", "draw_polyline", "draw_thin_box", "draw_thin_ellipse",
"draw_thin_line", "draw_thin_polyline", "draw_thin_triangle",
"draw_triangle", "export_to_memory", "fill_box", "fill_ellipse",
"fill_triangle", "flip", "flop", "frame=", "frame_count", "frame_name",
"frame_name=", "free_frame", "get_attr", "get_char", "gotoxy",
"handle_x", "handle_y", "height", "height=", "import_file",
"import_from_memory", "invert", "printf", "put_attr", "put_char", "put_str",
"rotate_180", "rotate_left", "rotate_right", "set_attr",
"set_boundaries", "set_color_ansi", "set_color_argb", "set_frame",
"set_frame_name", "set_handle", "set_height", "set_size", "set_width",
"stretch_left", "stretch_right", "wherex", "wherey", "width", "width="]

irb(main):013:0> Caca::Font.my_methods
=> ["list"]

irb(main):014:0> Caca::Font.my_instance_methods
=> ["blocks", "height", "width"]

irb(main):015:0> Caca::Dither.my_instance_methods
=> ["algorithm=", "algorithm_list", "antialias=", "antialias_list",
"brightness=", "charset=", "charset_list", "color=", "color_list",
"contrast=", "gamma=", "palette=", "set_algorithm", "set_antialias",
"set_brightness", "set_charset", "set_color", "set_contrast",
"set_gamma", "set_palette"]

irb(main):010:0> Caca::Display.my_instance_methods
=> ["canvas", "get_event", "height", "mouse=", "mouse_x", "mouse_y", "refresh",
"set_mouse", "set_time", "set_title", "time", "time=", "title=", "width"]

irb(main):011:0> Caca::Event.constants
=> ["Key", "Quit", "TYPE", "Mouse", "Resize"]

irb(main):012:0> Caca::Event.my_instance_methods
=> ["quit?"]

irb(main):013:0> Caca::Event::Key.my_instance_methods
=> ["ch", "utf32", "utf8"]

irb(main):014:0> Caca::Event::Mouse.my_instance_methods
=> ["button", "x", "y"]

irb(main):015:0> Caca::Event::Resize.my_instance_methods
=> ["w", "h"]


$ ruby -rcaca -e ', 3).fill_box(0,0,2,2,"#"[0]);,1).put_str(0,0,"x"); c.blit(1,1,c2); puts

$ ruby -e 'puts,3).draw_thin_polyline([[0,0], [0,2],
| `.

$ ruby -rcaca -e 'p Caca::Canvas.export_list'
[["caca", "native libcaca format"], ["ansi", "ANSI"], ["utf8", "UTF-8
withANSI escape codes"], ["utf8cr", "UTF-8 with ANSI escape codes and
MS-DOS\r"], ["html", "HTML"], ["html3", "backwards-compatible HTML"],
["irc", "IRC with mIRC colours"], ["ps", "PostScript document"], ["svg",
"SVGvector image"], ["tga", "TGA image"]]

$ ruby -rcaca -e 'p Caca::Font.list'
["Monospace9", "Monospace Bold 12"]

require 'caca'
c =,10)
c.put_str(2,3, "plop!")
c.draw_thin_polyline([[0,0],[0,2], [5,2], [0,0]])
d =
d.title= "Test !"
#Redefine Event::Key#quit? so that q, Q, and Esc become exit keys
module Caca
  class Event::Key
    def quit?
while((e= d.get_event(Caca::Event, -1)) && ! e.quit?)
  p e