module Paperclip # Defines the geometry of an image. class Geometry attr_accessor :height, :width, :modifier # Gives a Geometry representing the given height and width def initialize width = nil, height = nil, modifier = nil height = nil if height == "" width = nil if width == "" @height = (height || width).to_f @width = (width || height).to_f @modifier = modifier end # Uses ImageMagick to determing the dimensions of a file, passed in as either a # File or path. def self.from_file file file = file.path if file.respond_to? "path" parse(`#{Paperclip.path_for_command('identify')} "#{file}"`) || raise(NotIdentifiedByImageMagickError.new("#{file} is not recognized by the 'identify' command.")) end # Parses a "WxH" formatted string, where W is the width and H is the height. def self.parse string if match = (string && string.match(/\b(\d*)x(\d*)\b([\>\<\#\@\%^!])?/)) Geometry.new(*match[1,3]) end end # True if the dimensions represent a square def square? height == width end # True if the dimensions represent a horizontal rectangle def horizontal? height < width end # True if the dimensions represent a vertical rectangle def vertical? height > width end # The aspect ratio of the dimensions. def aspect width / height end # Returns the larger of the two dimensions def larger [height, width].max end # Returns the smaller of the two dimensions def smaller [height, width].min end # Returns the width and height in a format suitable to be passed to Geometry.parse def to_s "%dx%d%s" % [width, height, modifier] end # Same as to_s def inspect to_s end # Returns the scaling and cropping geometries (in string-based ImageMagick format) # neccessary to transform this Geometry into the Geometry given. If crop is true, # then it is assumed the destination Geometry will be the exact final resolution. # In this case, the source Geometry is scaled so that an image containing the # destination Geometry would be completely filled by the source image, and any # overhanging image would be cropped. Useful for square thumbnail images. The cropping # is weighted at the center of the Geometry. def transformation_to dst, crop = false ratio = Geometry.new( dst.width / self.width, dst.height / self.height ) if crop scale_geometry, scale = scaling(dst, ratio) crop_geometry = cropping(dst, ratio, scale) else scale_geometry = dst.to_s end [ scale_geometry, crop_geometry ] end private def scaling dst, ratio if ratio.horizontal? || ratio.square? [ "%dx" % dst.width, ratio.width ] else [ "x%d" % dst.height, ratio.height ] end end def cropping dst, ratio, scale if ratio.horizontal? || ratio.square? "%dx%d+%d+%d" % [ dst.width, dst.height, 0, (self.height * scale - dst.height) / 2 ] else "%dx%d+%d+%d" % [ dst.width, dst.height, (self.width * scale - dst.width) / 2, 0 ] end end end end