lib/vips.rb in vips-8.11.3 vs lib/vips.rb in vips-8.12.1

@@ -2,12 +2,12 @@
 # via ruby-ffi.
 #
 # Author::    John Cupitt  (mailto:[e-mail])
 # License::   MIT
 
-require 'ffi'
-require 'logger'
+require "ffi"
+require "logger"
 
 # This module uses FFI to make a simple layer over the glib and gobject
 # libraries.
 
 # Generate a library name for ffi.
@@ -35,39 +35,39 @@
 
 module GLib
   class << self
     attr_accessor :logger
   end
-  @logger = Logger.new(STDOUT)
+  @logger = Logger.new($stdout)
   @logger.level = Logger::WARN
 
   extend FFI::Library
 
-  ffi_lib library_name('glib-2.0', 0)
+  ffi_lib library_name("glib-2.0", 0)
 
   attach_function :g_malloc, [:size_t], :pointer
 
   # save the FFI::Function that attach will return ... we can use it directly
   # as a param for callbacks
   G_FREE = attach_function :g_free, [:pointer], :void
 
   callback :g_log_func, [:string, :int, :string, :pointer], :void
   attach_function :g_log_set_handler,
-      [:string, :int, :g_log_func, :pointer], :int
+    [:string, :int, :g_log_func, :pointer], :int
   attach_function :g_log_remove_handler, [:string, :int], :void
 
   # log flags
-  LOG_FLAG_RECURSION          = 1 << 0
-  LOG_FLAG_FATAL              = 1 << 1
+  LOG_FLAG_RECURSION = 1 << 0
+  LOG_FLAG_FATAL = 1 << 1
 
   # GLib log levels
-  LOG_LEVEL_ERROR             = 1 << 2 # always fatal
-  LOG_LEVEL_CRITICAL          = 1 << 3
-  LOG_LEVEL_WARNING           = 1 << 4
-  LOG_LEVEL_MESSAGE           = 1 << 5
-  LOG_LEVEL_INFO              = 1 << 6
-  LOG_LEVEL_DEBUG             = 1 << 7
+  LOG_LEVEL_ERROR = 1 << 2 # always fatal
+  LOG_LEVEL_CRITICAL = 1 << 3
+  LOG_LEVEL_WARNING = 1 << 4
+  LOG_LEVEL_MESSAGE = 1 << 5
+  LOG_LEVEL_INFO = 1 << 6
+  LOG_LEVEL_DEBUG = 1 << 7
 
   # map glib levels to Logger::Severity
   GLIB_TO_SEVERITY = {
     LOG_LEVEL_ERROR => Logger::ERROR,
     LOG_LEVEL_CRITICAL => Logger::FATAL,
@@ -81,23 +81,23 @@
   # nil being the default
   @glib_log_domain = nil
   @glib_log_handler_id = 0
 
   # module-level, so it's not GCd away
-  LOG_HANDLER = Proc.new do |domain, level, message, _user_data|
+  LOG_HANDLER = proc { |domain, level, message, _user_data|
     @logger.log(GLIB_TO_SEVERITY[level], message, domain)
-  end
+  }
 
   def self.remove_log_handler
     if @glib_log_handler_id != 0 && @glib_log_domain
       g_log_remove_handler @glib_log_domain, @glib_log_handler_id
       @glib_log_handler_id = nil
     end
   end
 
   def self.set_log_domain domain
-    GLib::remove_log_handler
+    GLib.remove_log_handler
 
     @glib_log_domain = domain
 
     # forward all glib logging output from this domain to a Ruby logger
     if @glib_log_domain
@@ -123,20 +123,20 @@
 
       # we must remove any handlers on exit, since libvips may log stuff
       # on shutdown and we don't want LOG_HANDLER to be invoked
       # after Ruby has gone
       at_exit {
-        GLib::remove_log_handler
+        GLib.remove_log_handler
       }
     end
   end
 end
 
 module GObject
   extend FFI::Library
 
-  ffi_lib library_name('gobject-2.0', 0)
+  ffi_lib library_name("gobject-2.0", 0)
 
   # we can't just use ulong, windows has different int sizing rules
   if FFI::Platform::ADDRESS_SIZE == 64
     typedef :uint64, :GType
   else
@@ -160,12 +160,12 @@
   GFLAGS_TYPE = g_type_from_name "GFlags"
   GSTR_TYPE = g_type_from_name "gchararray"
   GOBJECT_TYPE = g_type_from_name "GObject"
 end
 
-require 'vips/gobject'
-require 'vips/gvalue'
+require "vips/gobject"
+require "vips/gvalue"
 
 # This module provides a binding for the [libvips image processing
 # library](https://libvips.github.io/libvips/).
 #
 # # Example
@@ -206,17 +206,15 @@
 # default mode is `:random`: this allows for full random access to image pixels,
 # but is slower and needs more memory. See {Access}
 # for full details
 # on the various modes available.
 #
-# You can also load formatted images from
-# memory buffers, create images that wrap C-style memory arrays, or make images
-# from constants.
+# You can also load formatted images from memory buffers, create images that
+# wrap C-style memory arrays, or make images from constants. Use {Source}
+# and {Image.new_from_source} to load images from any data source, for
+# example URIs.
 #
-# Use {Source} and {Image.new_from_source} to load images from any data
-# source, for example URIs.
-#
 # The next line:
 #
 # ```ruby
 # im *= [1, 2, 1]
 # ```
@@ -254,11 +252,11 @@
 # {Image#write_to_file} writes an image back to the filesystem. It can
 # write any format supported by vips: the file type is set from the filename
 # suffix. You can also write formatted images to memory buffers, or dump
 # image data to a raw memory array.
 #
-# Use {Target} and {Image#write_to_target} to write formatted images to 
+# Use {Target} and {Image#write_to_target} to write formatted images to
 # any data sink, for example URIs.
 #
 # # How it works
 #
 # The binding uses [ruby-ffi](https://github.com/ffi/ffi) to open the libvips
@@ -407,75 +405,122 @@
 # The wrapper spots errors from vips operations and raises the {Vips::Error}
 # exception. You can catch it in the usual way.
 #
 # # Automatic YARD documentation
 #
-# The bulk of these API docs are generated automatically by
-# {Vips::Yard::generate}. It examines
-# libvips and writes a summary of each operation and the arguments and options
-# that that operation expects.
+# The bulk of these API docs are generated automatically by {Yard#generate}.
+# It examines libvips and writes a summary of each operation and the arguments
+# and options that that operation expects.
 #
-# Use the [C API
-# docs](https://libvips.github.io/libvips/API/current)
+# Use the [C API # docs](https://libvips.github.io/libvips/API/current)
 # for more detail.
 #
 # # Enums
 #
 # The libvips enums, such as `VipsBandFormat` appear in ruby-vips as Symbols
 # like `:uchar`. They are documented as a set of classes for convenience, see
-# the class list.
+# {Vips::BandFormat}, for example.
 #
 # # Draw operations
 #
-# Paint operations like {Image#draw_circle} and {Image#draw_line}
-# modify their input image. This
-# makes them hard to use with the rest of libvips: you need to be very careful
-# about the order in which operations execute or you can get nasty crashes.
+# There are two ways of calling the libvips draw operations, like
+# {Image#draw_circle} and {Image#draw_line}.
 #
-# The wrapper spots operations of this type and makes a private copy of the
-# image in memory before calling the operation. This stops crashes, but it does
-# make it inefficient. If you draw 100 lines on an image, for example, you'll
-# copy the image 100 times. The wrapper does make sure that memory is recycled
-# where possible, so you won't have 100 copies in memory.
+# First, you can use them like functions. For example:
 #
-# If you want to avoid the copies, you'll need to call drawing operations
-# yourself.
+# ```ruby
+# y = x.draw_line 255, 0, 0, x.width, x.height
+# ```
 #
+# This will make a new image, `y`, which is a copy of `x` but with a line
+# drawn across it. `x` is unchanged.
+#
+# This is simple, but will be slow if you want to draw many lines, since
+# ruby-vips will make a copy of the whole image each time.
+#
+# You can use {Image#mutate} to make a {MutableImage}. This is an image which
+# is unshared and is only available inside the {Image#mutate} block. Within
+# this block, you can use `!` versions of the draw operations to modify images
+# and avoid the copy. For example:
+#
+# ```ruby
+# image = image.mutate do |mutable|
+#   (0 ... 1).step(0.01) do |i|
+#     mutable.draw_line! 255, mutable.width * i, 0, 0, mutable.height * (1 - i)
+#   end
+# end
+# ```
+#
+# Now each {Image#draw_line} will directly modify the mutable image, saving
+# the copy. This is much faster and needs much less memory.
+#
+# # Metadata read
+#
+# Use {Image#get_fields} to get a list of the metadata fields that an image
+# supports. ICC profiles, for example, are in a field called
+# `icc-profile-data`. Use `vipsheader -a something.jpg` at the command-line
+# to see all the fields on an image.
+#
+# Use {Image#get_typeof} to get the type of a field. Types are integers, with
+# 0 meaning "no such field". Constants like {GObject::GINT_TYPE} are useful for
+# testing field types.
+#
+# You can read image metadata using {Image#get}. The field value is converted
+# to a Ruby value in the obvious way.
+#
+# # Metadata write
+#
+# You can also set and remove image metadata fields. Images are immutable, so
+# you must make any changes inside a {Image#mutate} block. For example:
+#
+# ```ruby
+# image = image.mutate do |mutable|
+#   image.get_fields.each do |field|
+#     mutable.remove! field unless field == "icc-profile-data"
+#   end
+# end
+# ```
+#
+# To remove all metadata except the icc profile.
+#
+# You can use {MutableImage#set!} to change the value of an existing field,
+# and {MutableImage#set_type!} to create a new field with a specified type.
+#
 # # Progress
 #
 # You can attach signal handlers to images to watch computation progress. For
 # example:
 #
 # ```ruby
 # image = Vips::Image.black 1, 100000
 # image.set_progress true
-# 
+#
 # def progress_to_s(name, progress)
 #   puts "#{name}:"
 #   puts "    run = #{progress[:run]}"
 #   puts "    eta = #{progress[:eta]}"
 #   puts "    tpels = #{progress[:tpels]}"
 #   puts "    npels = #{progress[:npels]}"
 #   puts "    percent = #{progress[:percent]}"
 # end
-# 
+#
 # image.signal_connect :preeval do |progress|
 #   progress_to_s("preeval", progress)
 # end
-# 
+#
 # image.signal_connect :eval do |progress|
 #   progress_to_s("eval", progress)
 #   image.set_kill(true) if progress[:percent] > 50
 # end
-# 
+#
 # image.signal_connect :posteval do |progress|
 #   progress_to_s("posteval", progress)
 # end
-# 
+#
 # image.avg
 # ```
-# 
+#
 # The `:eval` signal will fire for every tile that is processed. You can stop
 # progress with {Image#set_kill} and processing will end with an exception.
 #
 # User streams
 #
@@ -523,57 +568,58 @@
 # {Image#median}.
 
 module Vips
   extend FFI::Library
 
-  if FFI::Platform.windows?
-    vips_libname = 'libvips-42.dll'
-  else
-    vips_libname = File.expand_path(FFI.map_library_name('vips'), __dir__)
-  end
+  ffi_lib library_name("vips", 42)
 
-  ffi_lib vips_libname
-
   LOG_DOMAIN = "VIPS"
-  GLib::set_log_domain LOG_DOMAIN
+  GLib.set_log_domain LOG_DOMAIN
 
-  typedef :ulong, :GType
+  # we can't just use ulong, windows has different int sizing rules
+  if FFI::Platform::ADDRESS_SIZE == 64
+    typedef :uint64, :GType
+  else
+    typedef :uint32, :GType
+  end
 
   attach_function :vips_error_buffer, [], :string
   attach_function :vips_error_clear, [], :void
+  attach_function :vips_error_freeze, [], :void
+  attach_function :vips_error_thaw, [], :void
 
   # The ruby-vips error class.
   class Error < RuntimeError
     # @param msg [String] The error message. If this is not supplied, grab
     #   and clear the vips error buffer and use that.
     def initialize msg = nil
       if msg
         @details = msg
-      elsif Vips::vips_error_buffer != ""
-        @details = Vips::vips_error_buffer
-        Vips::vips_error_clear
+      elsif Vips.vips_error_buffer != ""
+        @details = Vips.vips_error_buffer
+        Vips.vips_error_clear
       else
         @details = nil
       end
     end
 
     # Pretty-print a {Vips::Error}.
     #
     # @return [String] The error message
     def to_s
-      if @details != nil
+      if !@details.nil?
         @details
       else
         super.to_s
       end
     end
   end
 
   attach_function :vips_init, [:string], :int
 
-  if Vips::vips_init($0) != 0
-    throw Vips::get_error
+  if Vips.vips_init($0) != 0
+    throw Vips.get_error
   end
 
   # don't use at_exit to call vips_shutdown, it causes problems with fork, and
   # in any case libvips does this for us
 
@@ -633,11 +679,11 @@
   # Deprecated compatibility function.
   #
   # Don't use this, instead change GLib::logger.level.
   def self.set_debug debug
     if debug
-      GLib::logger.level = Logger::DEBUG
+      GLib.logger.level = Logger::DEBUG
     end
   end
 
   attach_function :version, :vips_version, [:int], :int
   attach_function :version_string, :vips_version_string, [], :string
@@ -655,38 +701,39 @@
   # @return [[String]] array of supported suffixes
   def self.get_suffixes
     # vips_foreign_get_suffixes() was added in libvips 8.8
     return [] unless Vips.respond_to? :vips_foreign_get_suffixes
 
-    array = Vips::vips_foreign_get_suffixes
+    array = Vips.vips_foreign_get_suffixes
 
     names = []
     p = array
     until (q = p.read_pointer).null?
       suff = q.read_string
-      GLib::g_free q
+      GLib.g_free q
       names << suff unless names.include? suff
       p += FFI::Type::POINTER.size
     end
-    GLib::g_free array
+    GLib.g_free array
 
     names
   end
 
-  LIBRARY_VERSION = Vips::version_string
+  LIBRARY_VERSION = Vips.version_string
 
   # libvips has this arbitrary number as a sanity-check upper bound on image
   # size. It's sometimes useful to know when calculating scale factors.
   MAX_COORD = 10000000
 end
 
-require 'vips/object'
-require 'vips/operation'
-require 'vips/image'
-require 'vips/interpolate'
-require 'vips/region'
-require 'vips/version'
-require 'vips/connection'
-require 'vips/source'
-require 'vips/sourcecustom'
-require 'vips/target'
-require 'vips/targetcustom'
+require "vips/object"
+require "vips/operation"
+require "vips/image"
+require "vips/mutableimage"
+require "vips/interpolate"
+require "vips/region"
+require "vips/version"
+require "vips/connection"
+require "vips/source"
+require "vips/sourcecustom"
+require "vips/target"
+require "vips/targetcustom"