def magick_raise(exc, force=False):
"""If the given `ExceptionInfo` pointer contains an exception, convert it
to a Python one and throw it.
Set `force` to True to throw a generic error even if the pointer doesn't
seem to indicate an exception. This is useful in cases where a function
uses both exceptions and `NULL` returns, which are sadly all too common in
ImageMagick.
"""
if exc == ffi.NULL or exc.severity == lib.UndefinedException:
if force:
raise MysteryError
return
# TODO have more exception classes
# An exception's description tends to be blank; the actual message
# is in `reason`
if exc.reason == ffi.NULL:
message = b''
else:
message = ffi.string(exc.reason)
severity_name = ffi.string(ffi.cast("ExceptionType", exc.severity))
# severity_name is an enum name and thus a string, not bytes
message = message + b' ' + severity_name.encode('ascii')
if exc.severity < lib.ErrorException:
# This is a warning, so do a warning
cls = magick_exception_map.get(exc.severity, GenericMagickWarning)
warnings.warn(cls(message))
else:
# ERROR ERROR
cls = magick_exception_map.get(exc.severity, GenericMagickError)
raise cls(message)
def magick_raise(exc, force=False):
"""If the given `ExceptionInfo` pointer contains an exception, convert it
to a Python one and throw it.
Set `force` to True to throw a generic error even if the pointer doesn't
seem to indicate an exception. This is useful in cases where a function
uses both exceptions and `NULL` returns, which are sadly all too common in
ImageMagick.
"""
if exc == ffi.NULL or exc.severity == lib.UndefinedException:
if force:
raise MysteryError
return
# TODO have more exception classes
# An exception's description tends to be blank; the actual message
# is in `reason`
if exc.reason == ffi.NULL:
message = b''
else:
message = ffi.string(exc.reason)
severity_name = ffi.string(ffi.cast("ExceptionType", exc.severity))
# severity_name is an enum name and thus a string, not bytes
message = message + b' ' + severity_name.encode('ascii')
if exc.severity < lib.ErrorException:
# This is a warning, so do a warning
cls = magick_exception_map.get(exc.severity, GenericMagickWarning)
warnings.warn(cls(message))
else:
# ERROR ERROR
cls = magick_exception_map.get(exc.severity, GenericMagickError)
raise cls(message)
def read(cls, filename):
with open(filename, "rb") as fh:
image_info = blank_image_info()
image_info.file = ffi.cast("FILE *", fh)
with magick_try() as exc:
ptr = lib.ReadImage(image_info, exc.ptr)
exc.check(ptr == ffi.NULL)
return cls(ptr)
def read(cls, filename):
with open(filename, "rb") as fh:
image_info = blank_image_info()
image_info.file = ffi.cast("FILE *", fh)
with magick_try() as exc:
ptr = lib.ReadImage(image_info, exc.ptr)
exc.check(ptr == ffi.NULL)
return cls(ptr)
def __call__(self, *frames, **kwargs):
channel = kwargs.get('channel', lib.DefaultChannels)
c_channel = ffi.cast('ChannelType', channel)
steps = ffi.new("sanpera_evaluate_step[]", self.compiled_steps)
c_frames = ffi.new("Image *[]", [f._frame for f in frames] + [ffi.NULL])
with magick_try() as exc:
new_frame = ffi.gc(
lib.sanpera_evaluate_filter(c_frames, steps, c_channel, exc.ptr),
lib.DestroyImageList)
return Image(new_frame)
def __call__(self, *frames, **kwargs):
channel = kwargs.get('channel', lib.DefaultChannels)
c_channel = ffi.cast('ChannelType', channel)
steps = ffi.new("sanpera_evaluate_step[]", self.compiled_steps)
c_frames = ffi.new("Image *[]", [f._frame for f in frames] + [ffi.NULL])
with magick_try() as exc:
# TODO can this raise an exception /but also/ return a new value?
# is that a thing i should be handling better
new_frame = lib.sanpera_evaluate_filter(
c_frames, steps, c_channel, exc.ptr)
return Image(new_frame)
def write(self, filename, format=None):
if not self._frames:
raise EmptyImageError
with open(filename, "wb") as fh:
image_info = blank_image_info()
image_info.file = ffi.cast("FILE *", fh)
# Force writing to a single file
image_info.adjoin = lib.MagickTrue
if format:
# If the caller provided an explicit format, pass it along
# Make sure not to overflow the char[]
# TODO maybe just error out when this happens
image_info.magick = format.encode('ascii')[:lib.MaxTextExtent]
elif self._frames[0]._frame.magick[0] == b'\0':
# Uhoh; no format provided and nothing given by caller
raise MissingFormatError
# TODO detect format from filename if explicitly asked to do so
with self._link_frames(self._frames) as ptr:
lib.WriteImage(image_info, ptr)
magick_raise(ptr.exception)
def write(self, filename, format=None):
if not self._frames:
raise EmptyImageError
with open(filename, "wb") as fh:
image_info = blank_image_info()
image_info.file = ffi.cast("FILE *", fh)
# Force writing to a single file
image_info.adjoin = lib.MagickTrue
if format:
# If the caller provided an explicit format, pass it along
# Make sure not to overflow the char[]
# TODO maybe just error out when this happens
image_info.magick = format.encode('ascii')[:lib.MaxTextExtent]
elif self._frames[0]._frame.magick[0] == b'\0':
# Uhoh; no format provided and nothing given by caller
raise MissingFormatError
# TODO detect format from filename if explicitly asked to do so
with self._link_frames(self._frames) as ptr:
lib.WriteImage(image_info, ptr)
magick_raise(ptr.exception)
def op_number(value):
return dict(
op=lib.SANPERA_OP_LOAD_NUMBER,
color=ffi.NULL,
number=ffi.cast("double", value),
)
def __call__(self, *frames, **kwargs):
channel = kwargs.get('channel', lib.DefaultChannels)
# TODO force_python should go away and this should become a wrapper for
# evaluate_python
# We're gonna be using this a lot, so let's cast it to a C int just
# once (and get the error early if it's a bogus type)
c_channel = ffi.cast('ChannelType', channel)
# TODO any gc concerns in this?
for f in frames:
assert isinstance(f, ImageFrame)
# XXX how to handle frames of different sizes? gravity? scaling? first
# frame as the master? hm
frame = frames[0]
# TODO does this create a blank image or actually duplicate the pixels?? docs say it actually copies with (0, 0) but the code just refs the same pixel cache?
# TODO could use an inplace version for, e.g. the SVG-style compose operators
# TODO also might want a different sized clone!
with magick_try() as exc:
new_stack = lib.CloneImage(frame._frame, 0, 0, lib.MagickTrue, exc.ptr)
exc.check(new_stack == ffi.NULL)
# TODO: set image to full-color.
# TODO: work out how this works, how different colorspaces work, and waht the ImageType has to do with anything
# QUESTION: this doesn't actually do anything. how does it work? does it leave indexes populated? what happens if this isn't done?
# if (SetImageStorageClass(fx_image,DirectClass) == MagickFalse) {
# InheritException(exception,&fx_image->exception);
# fx_image=DestroyImage(fx_image);
# return((Image *) NULL);
# }
out_view = lib.AcquireCacheView(new_stack)
# TODO i need to be a list
in_view = lib.AcquireCacheView(frame._frame)
state = FilterState()
for y in range(frame._frame.rows):
with magick_try() as exc:
q = lib.GetCacheViewAuthenticPixels(out_view, 0, y, frame._frame.columns, 1, exc.ptr)
exc.check(q == ffi.NULL)
# TODO is this useful who knows
#fx_indexes=GetCacheViewAuthenticIndexQueue(fx_view);
for x in range(frame._frame.columns):
# TODO per-channel things
# TODO for usage: see line 1453
#GetMagickPixelPacket(image,&pixel);
#(void) InterpolateMagickPixelPacket(image,fx_info->view[i],image->interpolate, point.x,point.y,&pixel,exception);
# Set up state object
# TODO document that this is reused, or somethin
state._color = BaseColor._from_pixel(q)
ret = self.impl(state)
#q.red = c_api.RoundToQuantum(<c_api.MagickRealType> ret.c_struct.red * c_api.QuantumRange)
#q.green = c_api.RoundToQuantum(<c_api.MagickRealType> ret.c_struct.green * c_api.QuantumRange)
#q.blue = c_api.RoundToQuantum(<c_api.MagickRealType> ret.c_struct.blue * c_api.QuantumRange)
# TODO black, opacity?
# TODO seems like this should apply to any set of channels, but
# IM's -fx only understands RGB
# TODO this is a little invasive, but given that this inner
# loop runs for every f*****g pixel, i'd like to avoid method
# calls as much as possible. even that rgb() can add up
rgb = ret.rgb()
lib.sanpera_pixel_from_doubles_channel(q, rgb._array, c_channel)
# XXX this is actually black
# if (((channel & IndexChannel) != 0) && (fx_image->colorspace == CMYKColorspace)) {
# (void) FxEvaluateChannelExpression(fx_info[id],IndexChannel,x,y, &alpha,exception);
# SetPixelIndex(fx_indexes+x,RoundToQuantum((MagickRealType) QuantumRange*alpha));
# }
q += 1 # q++
with magick_try() as exc:
lib.SyncCacheViewAuthenticPixels(in_view, exc.ptr)
# TODO check exception, return value
# XXX destroy in_view
# XXX destroy out_view s
return Image(new_stack)
