Document Structure and Content Processing

Presentation of an SPDL document requires that the Presentation Process interpret the content of the SPDL document. The content of an SPDL document consists of the values of the TOKENSEQUENCE structure elements.

The processing of the content of a TOKENSEQUENCE consists of interpreting the content by the Content Processor in a Context of Interpretation established by the Structure Processor. Each BLOCK has an associated Block State which is used to generate the Context of Interpretation for the processing of the content of the BLOCK. A consequence of the properties of BLOCK boundaries is that each PAGE of an SPDL document is independent of every other PAGE.

Each PAGE also has an associated with Current Page Image. The Current Page Image is affected by the processing of TOKENSEQUENCE structure elements which are immediately subordinate to the PAGE BODY and to any subordinate PICTURE structure elements.

BLOCK

A BLOCK structure element shall be one of:

Every BLOCK is either a TOP LEVEL STRUCTURE structure element or subordinate to another BLOCK.

Block State

Each BLOCK has an associated Block State. The Block State is created at the beginning of the processing of the BLOCK and is destroyed at the completion of that processing.

The initial Block State of a BLOCK depends on whether the BLOCK is a TOP LEVEL STRUCTURE structure element or is subordinate to a superior BLOCK. The Block State of a BLOCK may be changed as a result of the processing of its subordinates.

If one BLOCK is subordinate to another BLOCK, the Block State of the subordinate BLOCK is distinct from the Block State of the superior BLOCK. Changes to the Block State of the subordinate BLOCK do not affect the Block State of the superior BLOCK.

The Block State consists of:

Current Virtual Machine State

The Current Virtual Machine State consists of:

Initial Block State of a TOP LEVEL STRUCTURE

A BLOCK which is a TOP LEVEL STRUCTURE is either a DOCUMENT or an ENVIRONMENT RESOURCE. The initial Block State of a BLOCK which is a TOP LEVEL STRUCTURE shall be as follows.

Set of Presentation Parameters

The set of presentation parameters of the Initial Block State of a DOCUMENT is determined by Document Production Instructions as specified by through . The set of presentation parameters of the Initial Block State of an ENVIRONMENT RESOURCE consists of the default values of the presentation parameters. The presentation parameter values are derived from the default values, any Supplementary DPI, and any DPI DECLARATION subordinate to the immediately subordinate PROLOGUE.

Set of Defined Resources

The set of defined resources of the Initial Block State of a TOP LEVEL STRUCTURE consists of the set of resources in the environment of the Presentation Process.

Set of Declared Resources

The set of declared resources of the Initial Block State of a TOP LEVEL STRUCTURE is empty. The default font and the single color space in the color space family color-space-family::DeviceGray are in the default Current Graphics State, and as such are available to content processing without being declared and without the execution of FindFont or FindResource.

Initial CurrentTransformation

The Initial CurrentTransformation of the Initial Block State of a TOP LEVEL STRUCTURE which is PAGESET or an ENVIRONMENT RESOURCE is specified in .

The Initial CurrentTransformation of the Initial Block State of a TOP LEVEL STRUCTURE which is a PAGE is specified in .

Inheritable Context Stack

The initial value of the Inheritable Context Stack of the Initial Block State of a TOP LEVEL STRUCTURE consists of:

  • <UserDictRef: DictionaryReference>
  • <SystemDictRef: DictionaryReference>

    The Dictionaries referenced by SystemDictRef and UserDictRef are defined in .

    Operand Stack

    The Operand Stack of the Initial Block State of a TOP LEVEL STRUCTURE is empty.

    Context Stack

    The Context Stack of the Initial Block State of a TOP LEVEL STRUCTURE consists of:

  • <UserDictRef: DictionaryReference>
  • <SystemDictRef: DictionaryReference>

    The Dictionaries referenced by SystemDictRef and UserDictRef are defined in .

    Graphics State Stack

    The Graphics State Stack of the Initial Block State of a TOP LEVEL STRUCTURE consists of a single graphics state, which is a copy of the initial Current Graphics State.

    Current Graphics State

    The Current Graphics State of the Initial Block State of a TOP LEVEL STRUCTURE consists of the default values of the Graphics State Variables as specified in .

    Ordered Set of SaveObjects

    The Ordered Set of SaveObjects of the Initial Block State of a TOP LEVEL STRUCTURE is empty.

    Set of Referenced Objects

    The set of referenced objects of the Initial Block State of a TOP LEVEL STRUCTURE consists of the Dictionaries referenced by SystemDict and UserDict and any objects referenced directly or indirectly by the contents of those Dictionaries (see ).

    State Variables

    The set of state variables of the Initial Block State of a TOP LEVEL STRUCTURE consists of the default values of the State Variables as specified in .

    Initial Block State of a Subordinate BLOCK

    The initial Block State of a BLOCK which is subordinate to a higher level BLOCK shall be as follows.

    Set of Presentation Parameters

    The set of presentation parameters of the Initial Block State of a subordinate BLOCK is determined by Document Production Instructions as specified by through . With the exception of the page-select and current-side presentation parameters, the initial values of the presentation parameters are inherited from the most immediately superior BLOCK. In contrast, the initial value for each PAGESET, and the initial value of the current-side presentation parameter is derived from the value of the current-side presentation parameter for the immediately superior PAGESET as specified in . The processing of page-select presentation parameter with the supplementary-page-select presentation parameter are specified in .

    Set of Defined Resources

    The set of defined resources of the Initial Block State of a subordinate BLOCK shall be the set of defined resources in the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    Set of Declared Resources

    The set of declared resources of the Initial Block State of a subordinate BLOCK shall be the set of declared resources in the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    Initial CurrentTransformation

    The Initial CurrentTransformation of the Initial Block State of a PAGESET which is subordinate to a superior BLOCK is a copy of the CurrentTransformation of the Current Graphics State of the Block State of the most immediately superior PAGESET at the beginning of the processing of the current PAGESET.

    The Initial CurrentTransformation of the Initial Block State of a PAGE which is subordinate to a superior PAGESET is

  • { ICTp CTb ConcatT }

    where ICTp is the initial CurrentTransformation determined as specified by and CTb is a copy of the Current CurrentTransformation of the Current Graphics State of the Block State of the most immediately superior PAGESET at the beginning of the processing of the current PAGE.

    The Initial CurrentTransformation of the Initial Block State of a PICTURE which is subordinate to a PAGE is a copy of the CurrentTransformation of the Current Graphics State of the Block State of the most immediately superior PICTURE at the beginning of the processing of the current PICTURE.

    Inheritable Context Stack

    The initial value of the Inheritable Context Stack of the Initial Block State of a subordinate BLOCK is a copy of the Inheritable Context Stack of the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    Operand Stack

    The Operand Stack of the Initial Block State of a subordinate BLOCK is empty.

    Context Stack

    The Context Stack of the Initial Block State of a subordinate BLOCK is a copy of the Context Stack of the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    Graphics State Stack

    The Current Graphics State of the Initial Block State of a subordinate BLOCK is a copy of the Current Graphics State of the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    Current Graphics State

    The Current Graphics State of the Initial Block State of a subordinate BLOCK is a copy of the Current Graphics State of the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    Ordered Set of SaveObjects

    The Ordered Set of SaveObjects of the Initial Block State of a subordinate BLOCK is empty.

    Set of Referenced Objects

    The Set of Referenced Objects of the Initial Block State of a subordinate BLOCK is a copy of the Set of Referenced Objects of the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    State Variables

    The values of the State Variables of the Initial Block State of a subordinate BLOCK is a copy of the values of the State Variables of the Block State of the most immediately superior BLOCK at the beginning of the processing of the current BLOCK.

    Current Page Image

    There is a Current Page Image created for each PAGE of the SPDL document during document processing. The Current Page Image for each PAGE is initialized to an empty page image at the beginning of PAGE processing, and is modified by the processing of TOKENSEQUENCE structure elements which are immediately subordinate to subordinate PAGE BODY structure elements or by NON-SPDL PICTURE structure elements. The processing of TOKENSEQUENCE structure elements which are not immediately subordinate to a PICTURE BODY may affect the Block State but not the state of the Current Page Image.

    The Current Page Image is fully addressable during PAGE processing. A Presentation Process which can only mark on one part of the medium at a time creates a virtual page image and transfers that page image to the medium one area at a time. The actual presentation of the Current Page Image of a PAGE on the presentation surface may be done incrementally, as the TOKENSEQUENCE structure elements are processed, or the changes to the page image may be accumulated until the processing of the PAGE is complete and then transferred to the medium.

    The final result of the processing of the PAGE is the rendering of the page image which is the result of the sequence of basic imaging operations on the medium. When the transfer of the page image to the presentation surface is complete, the rendered page image contains all of the effects produced by the processing of the PAGE. The effect of rendering an empty page image is the natural color of the medium on which the page image is being presented.

    Interface to the Content Processor

    The interface to the Content Processor is specified as an abstract procedure call. The arguments of the call to the Content Processor consist of:

    • one content value;
    • one Context of Interpretation;
    • zero or one Current Page Image.

    Content value

    The content value represents an instance of the Content Representation and Interchange Format. The content value may be either:

    • a binary content value, consisting of a sequence of octets which represents an instance of the Binary Content Representation and Interchange Format;
    • a clear text content value, consisting of sequence of octets which represents an instance of the Clear Text Content Representation and Interchange Format.

    The Binary Content Representation and Interchange Format is specified in . The Clear Text Content Representation and Interchange Format is specified in .

    Context of Interpretation

    A Context of Interpretation consists of:

    • a content notation identifier;
    • a set of declared resources;
    • an Initial CurrentTransformation;
    • the current abort-policy;
    • an initial Virtual Machine State.
    The environment of the Presentation Process and the set of defined resources are not part of the Context of Interpretation.

    The Context of Interpretation used for an instance of content processing is derived from the current Block State of the most immediately superior BLOCK as described below.

    Content Notation Identifier

    The content notation identifier specifies whether the content value consists of a binary content value or a clear text content value.

    The content notation identifier of a Context of Interpretation derived from the current Block State of a BLOCK which is an ENVIRONMENT RESOURCE identifies the content value as being

    • a binary content value if the Structure Representation and Interchange Format used for the content of the BLOCK is in the Binary Structure Representation and Interchange Format;
    • a clear text content value if the Structure Representation and Interchange Format used for the content of the BLOCK is the Clear Text Structure Representation and Interchange Format.

    The content notation identifier of the Context of Interpretation derived from the current Block State of a BLOCK which is a PICTURE identifies the content value as being

    • a binary content value if the CONTENT REPRESENTATION IDENTIFIER of the PICTURE is content::spdl-binary;
    • a clear text content value if the CONTENT REPRESENTATION IDENTIFIER of the PICTURE is content::spdl-clear-text.

    Set of Declared Resources

    The set of declared resources is the Set of Declared Resources of the Block State of the most immediately superior BLOCK.

    Initial CurrentTransformation

    The Initial CurrentTransformation is a copy of the Initial CurrentTransformation of the Block State of the most immediately superior BLOCK.

    Current Abort Policy

    The current abort policy is a copy of the abort-policy presentation parameter of the set of presentation parameters of the Block State of the most immediately superior BLOCK.

    Virtual Machine State

    The Virtual Machine State consists of a copy of the Current Virtual machine State of the Block State of the most immediately superior BLOCK.

    Current Page Image

    A Current Page Image is created for each PAGE of the SPDL document. The Current Page Image of the most immediately superior PAGE passed to the Content Processor for the processing of the content of each TOKENSEQUENCE which is immediately subordinate to a PICTURE BODY.

    Content Processing

    Content processing consists of the interpretation of a content value as a sequence of tokens in the content notation specified by the content notation identifier, and the processing of those tokens by the Content Processor. Content processing may affect the Virtual Machine State of the Context of Interpretation which is passed to the Content Processor, and may also affect the Current Page Image if one was passed to the Content Processor as one of the arguments of the procedure call. The effect of content processing on the Virtual Machine State and the Current Page Image is specified by through of this International Standard.

    Return

    Upon completion of an instance of content processing, the Content Processor returns

    • one Virtual Machine State;
    • zero or one Current Page Image;
    • status.

    The returned Virtual Machine State is the result of the effects of content processing on the Virtual Machine State of the Context of Interpretation passed by the Structure Processor. The way in which the returned Virtual Machine State affects the Block State of the most immediately superior BLOCK is specified as part of the processing of the immediately superior structure elements.

    If a Current Page Image was passed as one of the arguments of the call to the Content Processor, it is returned at the completion of the instance of content processing. The returned Current Page Image is the result of the effects of content processing on the Current Page Image passed by the Structure Processor.

    The status shall be one of:

    • OK;
    • content-warning;
    • content-error.

    The meaning of OK is that no unhandled error or warning was generated in content processing. The meaning of content-warning is that one or more unhandled warnings but no unhandled errors were generated in content processing. The meaning of content-error is that one or more errors were generated in content processing. Exception handling is specified in .

    TOKENSEQUENCE

    A TOKENSEQUENCE structure element shall be a base structure element. The value of a TOKENSEQUENCE shall be a value of type Octet String.

    Each TOKENSEQUENCE structure element is immediately subordinate to one of:

    • a PICTURE BODY structure element;
    • a RESOURCE SPECIFICATION structure element;
    • a SETUP PROCEDURE structure element.

    The processing of a TOKENSEQUENCE structure element consists of calling the Content Processor and making specified changes to the Block State of the most immediately superior BLOCK. If the TOKENSEQUENCE is immediately subordinate to a PICTURE BODY, content processing may also include making changes to the Current Page Image. The changes to the state of the most immediately superior BLOCK depend on the immediately superior structure element, and are specified as part of the processing of that structure element. A structure error or warning occurs if the status returned by the Content Processor is other than OK.

    Association of Page Images with Instances of the Media

    Medium selection and the association of page images with instances of the media is a complex process which involves several presentation parameters.

    Page Selection and Numbering

    Each PAGESET in a DOCUMENT may contain a Page Select Document Production Instruction which specifies which of the PAGE structure elements in the PAGESET are to be considered to be part of the DOCUMENT. A PAGE structure element which is excluded by a Page Select Document Production Instruction in any PAGESET is ignored for the purposes of DOCUMENT processing.

    The PAGEs of the DOCUMENT are the PAGE structure elements which are not excluded by Page Select Document Production Instructions. Each of these PAGEs is assigned an ordinal page number in sequence which identifies the PAGE for the purposes of document presentation. These PAGEs include any PAGEs which were excluded by Supplementary Page Select DPI.

    Each PAGE of the DOCUMENT which is not excluded by Supplementary Page Select DPI has associated with it a page image which is the Current Page Image for that PAGE at the completion of PAGE processing. Each page image is assigned an ordinal number which is the ordinal page number of the PAGE with which it was associated.

    A Supplementary Page Select Document Production Instruction in Supplementary DPI can select a subset of the PAGEs of the DOCUMENT which are not excluded by Document Page Select Document Production Instructions for a particular instance of presentation. If a Supplementary Page Select Document Production Instruction in selects a subset of the PAGEs of the DOCUMENT for a particular instance of presentation, those PAGEs presented retain the ordinal page numbers assigned to them by processing the entire DOCUMENT, including those PAGEs excluded by the Supplementary Page Select Document Production Instruction (but not those excluded by Page Select Document Production Instructions).

    Medium Declaration and Selection

    The specification of the media to be used for document presentation is a two step process:

    1. Each medium which may be used for the presentation of one or more pages is first declared by a MEDIUM DECLARATION.
    2. The medium which is to be used for the presentation of each page is selected by the Medium Select or Current Medium Document Production Instructions.

    Medium declaration and selection are specified in . The result of medium declaration and selection is the association of a particular medium with each of the ordinal page numbers.

    Current Side Presentation Parameter

    Each PAGE of the DOCUMENT has associated with it a current-side presentation parameter value. The value of the current-side presentation parameter is either 1 or 2. The assignment of a value to the current-side presentation parameter for each PAGE of the DOCUMENT depends on the values of the plex, and sides presentation parameters and on the Current Side Document Production Instruction as specified below. The PAGEs to which these values are assigned include any PAGEs which were excluded by Supplementary Page Select DPI, but do not include any PAGEs which were excluded by Document Page Select DPI.

    Current Side Document Production Instruction

    If there is a Current Side Document Production Instruction associated with the PAGE, the value of the current-side presentation parameter associated with that PAGE shall be the value specified by the Current Side Document Production Instruction.

    Simplex

    If the value of the plex presentation parameter is dpi::plex::simplex, the values of the current-side presentation parameter associated with the PAGEs of the document for which there is no associated Current Side Document Production Instruction are determined as follows:

    1. If the value of the sides presentation parameter is 1, the value the current-side presentation parameter associated each PAGE of the DOCUMENT shall be 1.
    2. If the value of the sides presentation parameter is 2, the value the current-side presentation parameter associated each PAGE of the DOCUMENT shall be
      1. 1 if the PAGE is the first PAGE of the DOCUMENT or if the value of the current-side presentation parameter associated with the previous PAGE is 2;
      2. 2 if the PAGE is not the first PAGE of the DOCUMENT and if the value of the current-side presentation parameter associated with the previous PAGE is 1;

    Duplex or Tumble-Duplex

    If the value of the plex presentation parameter is dpi::plex::duplex, or dpi::plex::tumble, the values of the current-side presentation parameter do not depend on the value of sides. In this case, the values of the current-side presentation parameter associated with the PAGEs of the document for which there is no associated Current Side Document Production Instruction shall be

    1. 1 if the PAGE is the first PAGE of the DOCUMENT or if the value of the current-side presentation parameter associated with the previous PAGE is 2;
    2. 2 if the PAGE is not the first PAGE of the DOCUMENT and if the value of the current-side presentation parameter associated with the previous PAGE is 1.

    Other values of Plex

    If the value of the plex presentation parameter is other than dpi::plex::simplex, dpi::plex::duplex, or dpi::plex::tumble, the values of the current-side presentation parameter associated with the PAGEs of the document shall be either:

    • determined as specified by the owner of the Public Object Identifier which is the value of the plex presentation parameter;
    • the values of current-side specified for dpi::plex::simplex.

    Association of Page Images with Instances of the Media

    Each of the page images which was associated with one of the PAGEs which was selected for the current instance of presentation as specified in is presented on an instance of the medium which was associated with its ordinal page number as specified in . The page images are presented on instances of the media in their sequential order as specified below.

    One sided printing

    If the value of sides is 1, or if the medium or Presentation Process only supports the presentation of a single page image on each instance of the medium, each of the page images which was associated with one of the PAGEs which was selected for the current instance of presentation is presented on a separate instance of the medium.

    If the value of plex is dpi::plex::duplex or dpi::plex::tumble and if the value of current-side associated with the two successive PAGEs is the same, a blank instance of the medium associated with the first of the two PAGEs shall be presented between the two PAGEs.

    Two sided printing

    If the value of sides is 2 and if the medium and Presentation Process support the placement of page images on two sides of each instance of the medium, the page images which were associated with each of the PAGEs which were selected for the current instance of presentation are presented alternately on the first (obverse) side and the second (reverse) side of instances of the media. Page images are associated with the presentation surfaces of the instances of the media sequentially in the order specified by the ordinal page numbers. The medium on which each page image is presented is the medium which was associated with the ordinal page number which was associated with the page image.

    The Current Page Image associated with a PAGE is presented on a new instance of the medium if any of the following is true:

    • the value of the current-side presentation parameter associated with the PAGE is 1;
    • the value of the current-side presentation parameter associated with the previous PAGE was 2;
    • the ordinal page number of the current PAGE is other than the ordinal page number of the previous PAGE plus one;
    • the medium associated with the ordinal page number of the current PAGE is different from the medium on which the page image for the previous PAGE was placed.

    The last condition is satisfied only when the actual media on which the two page images is placed are placed are different. If the same medium is assigned to two different MEDIUM SPECIFICATIONs, consecutive page images shall not be placed on different instances of the medium simply because the MEDIUM SPECIFICATIONs are different.

    If the value of the current-side presentation parameter associated with the PAGE is 1, the page image is presented on the first (obverse) side of the medium. If the value of the current-side presentation parameter associated with the PAGE is 2, the page image is presented on the second (reverse) side of the medium. Further:

    • if a page image is presented on a new instance of the medium and the previous page image was placed on the obverse side of another instance of the medium, the reverse side of that instance of the medium is left blank;
    • if a page image is presented on the reverse side of a new instance of the medium, the obverse side of that instance of the medium is left blank.

    Placement of the Page Image on the Medium

    The placement of the page image generated by a PAGE on an imageable surface of the medium is determined by

    • the association of the page image with an imageable surface of an instance of the medium as described in ;
    • the location and orientation of the Reference Coordinate System of the page image on the medium as specified in this clause.

    Location and Orientation of the Reference Coordinate System on the Medium

    Each imageable surface has associated with it

    • a reference orientation;
    • a medium Reference Coordinate System;
    • two values, MediumXSize and MediumYSize, which indicate the size of the medium.

    The reference orientation and the location and orientation of the medium Reference Coordinate System on the medium are functions of the medium and not of the page image. The location and orientation of the medium Reference Coordinate System on the medium is the same even if the page images are being placed on the medium in such a way that the completed document will commonly be viewed in an orientation other than the reference orientation (e.g. with the long edge horizontal in landscape orientation).

    Reference Orientation

    For media which have a distinguished natural viewing orientation, the reference orientation shall be the natural viewing orientation of the medium.

    For media such as paper which have no distinguished natural viewing orientation, the reference orientation shall be with the long edge vertical (portrait orientation).

    Medium Reference Coordinate System for Rectangular Media

    For rectangular media, the location and orientation of the medium Reference Coordinate System on the medium shall be such that with the medium oriented in its reference orientation:

    • the origin of the Reference Coordinate System is at the bottom left corner of the medium;
    • the x-axis of the Reference Coordinate System is placed along the bottom edge with positive values of x to the right;
    • the y-axis of the Reference Coordinate System is placed along the left edge of the medium with positive values of y in the upward direction.

    Medium Reference Coordinate System for Non-Rectangular Media

    For non-rectangular media, the location and orientation of the medium Reference Coordinate System on the medium is a property of the medium, but should approximate the placement of the Reference Coordinate System for rectangular media.

    Two Sided Media

    When page images are placed on both sides of a two sided medium, the reference orientation for the second (reverse) side shall be the orientation that results from rotating the medium around an axis which coincides with the y-axis of the medium Reference Coordinate System for the first (obverse) side.

    MediumXSize and MediumYSize

    The values of MediumXSize and MediumYSize associated with each medium represent the extent of the medium in the medium Reference Coordinate System. The values of MediumXSize and MediumYSize (in the units of the current User Coordinate System) are available to content processing as values of the CurrentXMedium and CurrentYMedium entries in the Device Description Dictionary (see ). The values of MediumXSize and MediumYSize associated with each medium shall be such that the imageable region of the medium is contained within the rectangle bounded by the medium Reference Coordinate System and the values of MediumXSize and MediumYSize.

    Virtual Presentation Surfaces

    Softcopy devices may place page images on virtual presentation surfaces which can then be viewed on the physical presentation surface. For such devices, each virtual presentation surface is treated as a separate instance of the medium. The mapping of the virtual presentation surfaces to the physical display surface and the ability of the system to preserve a virtual presentation surface for future viewing are system dependent.

    Placement of the Page Image on the Imageable Surface of the Medium

    The placement of the Current Page Image for the PAGE on the imageable surface of the medium depends on the value of the plex presentation parameter.

    Simplex or Duplex

    If the value of the plex presentation parameter is dpi::plex::simplex or dpi::plex::duplex, the Current Page Image is placed on the imageable surface of the medium so that the Reference Coordinate System of the Current Page Image coincides with the medium Reference Coordinate System.

    Tumble Duplex

    If the value of the plex presentation parameter is dpi::plex::tumble, the page image associated a PAGE for which current-side is 1 is placed on the imageable surface of the medium so that the Reference Coordinate System of the Current Page Image coincides with the medium Reference Coordinate System. The page image associated a PAGE for which current-side is 2 is placed on the imageable surface of the medium so that:

    • the origin of the Reference Coordinate System of the Current Page Image coincides with the point whose coordinates are (MediumXSize, MediumYSize) in the medium Reference Coordinate System;
    • the point whose coordinates are (0, MediumYSize) in the Reference Coordinate System of the Current Page Image coincides with the point whose coordinates are (MediumXSize, 0) in the medium Reference Coordinate System;
    • the point whose coordinates are (MediumXSize, 0) in the Reference Coordinate System of the Current Page Image coincides with the point whose coordinates are (0, MediumYSize) in the medium Reference Coordinate System.
  • The effect is that the page images placed on the reverse side of the medium are rotated 180 degrees.
  • The specified page image rotation is used in one sided printing as well as two sided printing. This enables the output from one sided printing with plex=dpi::plex::tumble to be copied in tumble duplex form on a 1-side-to-2-side copier with long-edge feed.
  • Other values of plex

    If the value of the plex presentation parameter is other than dpi::plex::simplex, dpi::plex::duplex, or dpi::plex::tumble, the placement of the Current Page Image on the imageable surface of the medium shall be either:

    • the placement specified by the owner of the Public Object Identifier which is the value of the plex presentation parameter (if known);
    • the placement specified for plex=dpi::plex::simplex.

    Initial CurrentTransformation

    The CurrentTransformation of the initial Current Graphics State and the Initial Graphics State of the PAGE shall be referred to below as the Initial CurrentTransformation. The Initial CurrentTransformation depends on the values of the plex, current-side, x-image-shift, and y-image-shift presentation parameters. If for a particular PAGE:

    • the value of the x-image-shift presentation parameter is x;
    • the value of the y-image-shift presentation parameter is y;
    • the value of the current-side presentation parameter is side;

    then Initial CurrentTransformation depends on the value of the plex presentation parameter and these values as follows.

    Simplex

    If the value of the plex presentation parameter is dpi::plex::simplex, the Initial CurrentTransformation for each PAGE shall be

  • {x y TranslateT}.

    Duplex

    If the value of the plex presentation parameter is dpi::plex::duplex, the Initial CurrentTransformation for each PAGE shall be

  • {x side 2 Equal {Negate} If y TranslateT}

    Tumble Duplex

    If the value of the plex presentation parameter is dpi::plex::tumble, the Initial CurrentTransformation for each PAGE shall be

  • {x y side 2 Equal {Negate} If TranslateT}

    Other values of Plex

    If the value of the plex presentation parameter is other than dpi::plex::simplex, dpi::plex::duplex, or dpi::plex::tumble, the Initial CurrentTransformation for each PAGE shall be either:

    • the initial CurrentTransformation specified by the owner of the Public Object Identifier which is the value of the plex presentation parameter (if known);
    • the initial CurrentTransformation specified for plex=dpi::plex::simplex.