libvips/cplusplus/gen-operators.py

260 lines
7.4 KiB
Python
Executable File

#!/usr/bin/python3
# This file generates the member definitions and declarations for all vips
# operators.
# this needs pyvips
#
# pip install --user pyvips
# Sample member declaration:
# VImage invert(VOption *options = 0) const;
# Sample member definition:
# VImage VImage::invert( VOption *options ) const
# {
# VImage out;
#
# call( "invert",
# (options ? options : VImage::option())->
# set( "in", *this )->
# set( "out", &out ) );
#
# return( out );
# }
import argparse
from pyvips import Introspect, Operation, GValue, Error, \
ffi, gobject_lib, type_map, type_from_name, nickname_find, type_name
# turn a GType into a C++ type
gtype_to_cpp = {
GValue.gbool_type: 'bool',
GValue.gint_type: 'int',
GValue.gdouble_type: 'double',
GValue.gstr_type: 'const char *',
GValue.refstr_type: 'char *',
GValue.gflags_type: 'int',
GValue.image_type: 'VImage',
GValue.source_type: 'VSource',
GValue.target_type: 'VTarget',
GValue.guint64_type: 'guint64',
type_from_name('VipsInterpolate'): 'VInterpolate',
GValue.array_int_type: 'std::vector<int>',
GValue.array_double_type: 'std::vector<double>',
GValue.array_image_type: 'std::vector<VImage>',
GValue.blob_type: 'VipsBlob *'
}
cplusplus_suffixes = ('*', '&')
cplusplus_keywords = ('case', 'switch')
# values for VipsArgumentFlags
_REQUIRED = 1
_INPUT = 16
_OUTPUT = 32
_DEPRECATED = 64
_MODIFY = 128
# for VipsOperationFlags
_OPERATION_DEPRECATED = 8
def get_cpp_type(gtype):
"""Map a gtype to the C++ type name we use to represent it.
"""
if gtype in gtype_to_cpp:
return gtype_to_cpp[gtype]
fundamental = gobject_lib.g_type_fundamental(gtype)
# enum params use the C name as their name
if fundamental == GValue.genum_type:
return type_name(gtype)
if fundamental in gtype_to_cpp:
return gtype_to_cpp[fundamental]
return '<unknown type>'
# swap any '-' for '_'
def cppize(name):
return name.replace('-', '_')
def generate_operation(operation_name, declaration_only=False):
intro = Introspect.get(operation_name)
required_output = [name
for name in intro.required_output if name != intro.member_x]
has_output = len(required_output) >= 1
# Add a C++ style comment block with some additional markings (@param,
# @return)
if declaration_only:
result = f'\n/**\n * {intro.description.capitalize()}.'
if len(intro.optional_input) > 0:
result += '\n *\n * **Optional parameters**'
for name in intro.optional_input:
details = intro.details[name]
result += f'\n * - **{cppize(name)}** -- '
result += f'{details["blurb"]}, '
result += f'{get_cpp_type(details["type"])}.'
result += '\n *'
for name in intro.method_args:
details = intro.details[name]
result += f'\n * @param {cppize(name)} {details["blurb"]}.'
if has_output:
# skip the first element
for name in required_output[1:]:
details = intro.details[name]
result += f'\n * @param {cppize(name)} {details["blurb"]}.'
result += '\n * @param options Set of options.'
if has_output:
details = intro.details[required_output[0]]
result += f'\n * @return {details["blurb"]}.'
result += '\n */\n'
else:
result = '\n'
if intro.member_x is None and declaration_only:
result += 'static '
if has_output:
# the first output arg will be used as the result
cpp_type = get_cpp_type(intro.details[required_output[0]]['type'])
spacing = '' if cpp_type.endswith(cplusplus_suffixes) else ' '
result += f'{cpp_type}{spacing}'
else:
result += 'void '
if not declaration_only:
result += 'VImage::'
cplusplus_operation = operation_name
if operation_name in cplusplus_keywords:
cplusplus_operation += '_image'
result += f'{cplusplus_operation}( '
for name in intro.method_args:
details = intro.details[name]
gtype = details['type']
cpp_type = get_cpp_type(gtype)
spacing = '' if cpp_type.endswith(cplusplus_suffixes) else ' '
result += f'{cpp_type}{spacing}{cppize(name)}, '
# output params are passed by reference
if has_output:
# skip the first element
for name in required_output[1:]:
details = intro.details[name]
gtype = details['type']
cpp_type = get_cpp_type(gtype)
spacing = '' if cpp_type.endswith(cplusplus_suffixes) else ' '
result += f'{cpp_type}{spacing}*{cppize(name)}, '
result += f'VOption *options {"= 0 " if declaration_only else ""})'
# if no 'this' available, it's a class method and they are all const
if intro.member_x is not None:
result += ' const'
if declaration_only:
result += ';'
return result
result += '\n{\n'
if has_output:
# the first output arg will be used as the result
name = required_output[0]
cpp_type = get_cpp_type(intro.details[name]['type'])
spacing = '' if cpp_type.endswith(cplusplus_suffixes) else ' '
result += f' {cpp_type}{spacing}{cppize(name)};\n\n'
result += f' call( "{operation_name}",\n'
result += f' (options ? options : VImage::option())'
if intro.member_x is not None:
result += f'->\n'
result += f' set( "{intro.member_x}", *this )'
all_required = intro.method_args
if has_output:
# first element needs to be passed by reference
arg = cppize(required_output[0])
result += f'->\n'
result += f' set( "{required_output[0]}", &{arg} )'
# append the remaining list
all_required += required_output[1:]
for name in all_required:
arg = cppize(name)
result += f'->\n'
result += f' set( "{name}", {arg} )'
result += ' );\n'
if has_output:
result += f'\n'
result += f' return( {required_output[0]} );\n'
result += '}'
return result
def generate_operators(declarations_only=False):
all_nicknames = []
def add_nickname(gtype, a, b):
nickname = nickname_find(gtype)
try:
# can fail for abstract types
intro = Introspect.get(nickname)
# we are only interested in non-deprecated operations
if (intro.flags & _OPERATION_DEPRECATED) == 0:
all_nicknames.append(nickname)
except Error:
pass
type_map(gtype, add_nickname)
return ffi.NULL
type_map(type_from_name('VipsOperation'), add_nickname)
# add 'missing' synonyms by hand
all_nicknames.append('crop')
# make list unique and sort
all_nicknames = list(set(all_nicknames))
all_nicknames.sort()
for nickname in all_nicknames:
print(generate_operation(nickname, declarations_only))
parser = argparse.ArgumentParser(description='C++ binding generator')
parser.add_argument('--gen', '-g',
default='cpp',
choices=['h', 'cpp'],
help='File to generate: h (headers) or cpp ' + \
'(implementations) (default: %(default)s)')
if __name__ == '__main__':
args = parser.parse_args()
generate_operators(args.gen == 'h')