# -*- coding: utf-8 -*-
#
# libcaca Colour ASCII-Art library
# Python language bindings
# Copyright (c) 2010 Alex Foulon <alxf@lavabit.com>
# All Rights Reserved
#
# This library is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the Do What the Fuck You Want
# to Public License, Version 2, as published by Sam Hocevar. See
# http://www.wtfpl.net/ for more details.
#
""" Libcaca Python bindings """
import ctypes
from caca import _lib
from caca.canvas import _Canvas
class _DitherStruct(ctypes.Structure):
pass
class _Dither(object):
""" Model for Dither object.
"""
def __init__(self):
self._dither = None
def from_param(self):
""" Required by ctypes module to call object as parameter of
a C function.
"""
return self._dither
def __del__(self):
if self._dither:
self._free()
def __str__(self):
return "<CacaDither>"
def _free(self):
""" Free a libcaca dither.
"""
_lib.caca_free_dither.argtypes = [_Dither]
_lib.caca_free_dither.restype = ctypes.c_int
return _lib.caca_free_dither(self)
class Dither(_Dither):
""" Dither object, methods are libcaca functions with caca_dither_t as first
argument.
"""
def __init__(self, bpp, width, height, pitch, rmask, gmask, bmask, amask):
""" Dither constructor
bpp -- bitmap depth in bits per pixels
width -- bitmap width in pixels
height -- bitmap height in pixels
pitch -- bitmap pitch in bytes
rmask -- bitmask for red values
gmask -- bitmask for green values
bmask -- bitmask for blue values
amask -- bitmask for alpha values
"""
_lib.caca_create_dither.argtypes = [
ctypes.c_int, ctypes.c_int, ctypes.c_int, ctypes.c_int,
ctypes.c_uint, ctypes.c_uint, ctypes.c_uint, ctypes.c_uint,
]
_lib.caca_create_dither.restype = ctypes.POINTER(_DitherStruct)
self._dither = _lib.caca_create_dither(bpp, width, height, pitch,
rmask, gmask, bmask, amask)
if self._dither == 0:
raise DitherError("Failed to create dither object")
def set_palette(self, red, green, blue, alpha):
""" Set the palette of an 8 bits per pixel bitmap. Values should be
between 0 and 4095 (0xfff).
red -- array of 256 red values
green -- array of 256 green values
blue -- array of 256 blue values
alpha -- array of 256 alpha values
"""
raise DitherError("Not implemented")
def set_brightness(self, brightness):
""" Set the brightness of the dither object.
brightness -- brightness value
"""
if isinstance(brightness, int):
brightness = float(brightness)
_lib.caca_set_dither_brightness.argtypes = [_Dither, ctypes.c_float]
_lib.caca_set_dither_brightness.restype = ctypes.c_int
return _lib.caca_set_dither_brightness(self, brightness)
def get_brightness(self):
""" Get the brightness of the dither object.
"""
_lib.caca_get_dither_brightness.argtypes = [_Dither]
_lib.caca_get_dither_brightness.restype = ctypes.c_float
return _lib.caca_get_dither_brightness(self)
def set_gamma(self, gamma):
""" Set the gamma of the dither object. A negative value causes colour
inversion.
gamma -- gamma value
"""
if isinstance(gamma, int):
gamma = float(gamma)
_lib.caca_set_dither_gamma.argtypes = [_Dither, ctypes.c_float]
_lib.caca_set_dither_gamma.restype = ctypes.c_int
return _lib.caca_set_dither_gamma(self, gamma)
def get_gamma(self):
""" Get the gamma of the dither object.
"""
_lib.caca_get_dither_gamma.argtypes = [_Dither]
_lib.caca_get_dither_gamma.restype = ctypes.c_float
return _lib.caca_get_dither_gamma(self)
def set_contrast(self, contrast):
""" Set the contrast of dither.
contrast -- contrast value
"""
if isinstance(contrast, int):
contrast = float(contrast)
_lib.caca_set_dither_contrast.argtypes = [_Dither, ctypes.c_float]
_lib.caca_set_dither_contrast.restype = ctypes.c_int
return _lib.caca_set_dither_contrast(self, contrast)
def get_contrast(self):
""" Get the contrast of the dither object.
"""
_lib.caca_get_dither_contrast.argtypes = [_Dither]
_lib.caca_get_dither_contrast.restype = ctypes.c_float
return _lib.caca_get_dither_contrast(self)
def set_antialias(self, value):
""" Set dither antialiasing.
value -- A string describing the antialiasing method that will
be used for the dithering.
+ "none": no antialiasing
+ "prefilter" or "default": simple prefilter antialiasing. (default)
"""
_lib.caca_set_dither_antialias.argtypes = [_Dither, ctypes.c_char_p]
_lib.caca_set_dither_antialias.restype = ctypes.c_int
return _lib.caca_set_dither_antialias(self, value)
def get_antialias(self):
""" Return the dither's current antialiasing method.
"""
_lib.caca_get_dither_antialias.argtypes = [_Dither]
_lib.caca_get_dither_antialias.restype = ctypes.c_char_p
return _lib.caca_get_dither_antialias(self)
def get_antialias_list(self):
""" Get available antialiasing methods.
"""
lst = []
_lib.caca_get_dither_antialias_list.argtypes = [_Dither]
_lib.caca_get_dither_antialias_list.restype = ctypes.POINTER(ctypes.c_char_p)
for item in _lib.caca_get_dither_antialias_list(self):
if item is not None and item != "":
lst.append(item)
else:
#memory occurs otherwise
break
return lst
def set_color(self, value):
""" Choose colours used for dithering.
value -- A string describing the colour set that will be
used for the dithering.
+ "mono": use light gray on a black background
+ "gray": use white and two shades of gray on a black background
+ "8": use the 8 ANSI colours on a black background
+ "16": use the 16 ANSI colours on a black background
+ "fullgray": use black, white and two shades of gray
for both the characters and the background
+ "full8": use the 8 ANSI colours for both the characters and
the background
+ "full16" or "default": use the 16 ANSI colours for both the
characters and the background (default)
"""
_lib.caca_set_dither_color.argtypes = [_Dither, ctypes.c_char_p]
_lib.caca_set_dither_color.restype = ctypes.c_int
return _lib.caca_set_dither_color(self, value)
def get_color(self):
""" Get current colour mode.
"""
_lib.caca_get_dither_color.argtypes = [_Dither]
_lib.caca_get_dither_color.restype = ctypes.c_char_p
return _lib.caca_get_dither_color(self)
def get_color_list(self):
""" Get available colour modes.
"""
lst = []
_lib.caca_get_dither_color_list.argtypes = [_Dither]
_lib.caca_get_dither_color_list.restype = ctypes.POINTER(ctypes.c_char_p)
for item in _lib.caca_get_dither_color_list(self):
if item is not None and item != "":
lst.append(item)
else:
#memory occurs otherwise
break
return lst
def set_charset(self, value):
""" Choose characters used for dithering.
value -- A string describing the characters that need to be
used for the dithering.
+ "ascii" or "default": use only ASCII characters (default).
+ "shades": use Unicode characters "U+2591 LIGHT SHADE",
"U+2592 MEDIUM SHADE" and "U+2593 DARK SHADE". These characters are
also present in the CP437 codepage available on DOS and VGA.
+ "blocks": use Unicode quarter-cell block combinations.
These characters are only found in the Unicode set.
"""
_lib.caca_set_dither_charset.argtypes = [_Dither, ctypes.c_char_p]
_lib.caca_set_dither_charset.restype = ctypes.c_int
return _lib.caca_set_dither_charset(self, value)
def get_charset(self):
""" Get current character set.
"""
_lib.caca_get_dither_charset.argtypes = [_Dither]
_lib.caca_get_dither_charset.restype = ctypes.c_char_p
return _lib.caca_get_dither_charset(self)
def get_charset_list(self):
""" Get available dither character sets.
"""
lst = []
_lib.caca_get_dither_color_list.argtypes = [_Dither]
_lib.caca_get_dither_color_list.restype = ctypes.POINTER(ctypes.c_char_p)
for item in _lib.caca_get_dither_color_list(self):
if item is not None and item != "":
lst.append(item)
else:
#memory occurs otherwise
break
return lst
def set_algorithm(self, value):
""" Set dithering algorithm.
value -- A string describing the algorithm that needs to be
used for the dithering.
+ "none": no dithering is used, the nearest matching colour is used.
+ "ordered2": use a 2x2 Bayer matrix for dithering.
+ "ordered4": use a 4x4 Bayer matrix for dithering.
+ "ordered8": use a 8x8 Bayer matrix for dithering.
+ "random": use random dithering.
+ "fstein": use Floyd-Steinberg dithering (default).
"""
_lib.caca_set_dither_algorithm.argtypes = [_Dither, ctypes.c_char_p]
_lib.caca_set_dither_algorithm.restype = ctypes.c_int
return _lib.caca_set_dither_algorithm(self, value)
def get_algorithm(self):
""" Get dithering algorithms.
"""
_lib.caca_get_dither_algorithm.argtypes = [_Dither]
_lib.caca_get_dither_algorithm.restype = ctypes.c_char_p
return _lib.caca_get_dither_algorithm(self)
def get_algorithm_list(self):
""" Get dithering algorithms.
"""
lst = []
_lib.caca_get_dither_color_list.argtypes = [_Dither]
_lib.caca_get_dither_color_list.restype = ctypes.POINTER(ctypes.c_char_p)
for item in _lib.caca_get_dither_color_list(self):
if item is not None and item != "":
lst.append(item)
else:
#memory occurs otherwise
break
return lst
def bitmap(self, canvas, x, y, width, height, pixels):
""" Dither a bitmap on the canvas.
canvas -- a handle to libcaca canvas
x -- X coordinate of the upper-left corner of the drawing area
y -- Y coordinate of the upper-left corner of the drawing area
width -- width of the drawing area
height -- height of the drawing area
pixels -- bitmap's pixels
"""
_lib.caca_dither_bitmap.argtypes = [
_Canvas, ctypes.c_int, ctypes.c_int,
ctypes.c_int, ctypes.c_int, _Dither,
ctypes.c_char_p
]
_lib.caca_dither_bitmap.restype = ctypes.c_int
return _lib.caca_dither_bitmap(canvas, x, y, width, height, self, pixels)
class DitherError(Exception):
pass