PostScript Surfaces

PostScript Surfaces — Rendering PostScript documents

Synopsis

cairo_surface_t*    cairo_ps_surface_create             (const char *filename,
                                                         double width_in_points,
                                                         double height_in_points);
cairo_surface_t*    cairo_ps_surface_create_for_stream  (cairo_write_func_t write_func,
                                                         void *closure,
                                                         double width_in_points,
                                                         double height_in_points);
void                cairo_ps_surface_set_size           (cairo_surface_t *surface,
                                                         double width_in_points,
                                                         double height_in_points);
void                cairo_ps_surface_dsc_begin_setup    (cairo_surface_t *surface);
void                cairo_ps_surface_dsc_begin_page_setup
                                                        (cairo_surface_t *surface);
void                cairo_ps_surface_dsc_comment        (cairo_surface_t *surface,
                                                         const char *comment);

Description

Details

cairo_ps_surface_create ()

cairo_surface_t*    cairo_ps_surface_create             (const char *filename,
                                                         double width_in_points,
                                                         double height_in_points);

Creates a PostScript surface of the specified size in points to be written to filename. See cairo_ps_surface_create_for_stream() for a more flexible mechanism for handling the PostScript output than simply writing it to a named file.

Note that the size of individual pages of the PostScript output can vary. See cairo_ps_surface_set_size().

filename :

a filename for the PS output (must be writable)

width_in_points :

width of the surface, in points (1 point == 1/72.0 inch)

height_in_points :

height of the surface, in points (1 point == 1/72.0 inch)

Returns :

a pointer to the newly created surface. The caller owns the surface and should call cairo_surface_destroy when done with it. This function always returns a valid pointer, but it will return a pointer to a "nil" surface if an error such as out of memory occurs. You can use cairo_surface_status() to check for this.

Since 1.2


cairo_ps_surface_create_for_stream ()

cairo_surface_t*    cairo_ps_surface_create_for_stream  (cairo_write_func_t write_func,
                                                         void *closure,
                                                         double width_in_points,
                                                         double height_in_points);

Creates a PostScript surface of the specified size in points to be written incrementally to the stream represented by write_func and closure. See cairo_ps_surface_create() for a more convenient way to simply direct the PostScript output to a named file.

Note that the size of individual pages of the PostScript output can vary. See cairo_ps_surface_set_size().

write_func :

a cairo_write_func_t to accept the output data

closure :

the closure argument for write_func

width_in_points :

width of the surface, in points (1 point == 1/72.0 inch)

height_in_points :

height of the surface, in points (1 point == 1/72.0 inch)

Returns :

a pointer to the newly created surface. The caller owns the surface and should call cairo_surface_destroy when done with it. This function always returns a valid pointer, but it will return a pointer to a "nil" surface if an error such as out of memory occurs. You can use cairo_surface_status() to check for this.

Since 1.2


cairo_ps_surface_set_size ()

void                cairo_ps_surface_set_size           (cairo_surface_t *surface,
                                                         double width_in_points,
                                                         double height_in_points);

Changes the size of a PostScript surface for the current (and subsequent) pages.

This function should only be called before any drawing operations have been performed on the current page. The simplest way to do this is to call this function immediately after creating the surface or immediately after completing a page with either cairo_show_page() or cairo_copy_page().

surface :

a PostScript cairo_surface_t

width_in_points :

new surface width, in points (1 point == 1/72.0 inch)

height_in_points :

new surface height, in points (1 point == 1/72.0 inch)

Since 1.2


cairo_ps_surface_dsc_begin_setup ()

void                cairo_ps_surface_dsc_begin_setup    (cairo_surface_t *surface);

This function indicates that subsequent calls to cairo_ps_surface_dsc_comment() should direct comments to the Setup section of the PostScript output.

This function should be called at most once per surface, and must be called before any call to cairo_ps_surface_dsc_begin_page_setup() and before any drawing is performed to the surface.

See cairo_ps_surface_dsc_comment() for more details.

surface :

a PostScript cairo_surface_t

Since 1.2


cairo_ps_surface_dsc_begin_page_setup ()

void                cairo_ps_surface_dsc_begin_page_setup
                                                        (cairo_surface_t *surface);

This function indicates that subsequent calls to cairo_ps_surface_dsc_comment() should direct comments to the PageSetup section of the PostScript output.

This function call is only needed for the first page of a surface. It should be called after any call to cairo_ps_surface_dsc_begin_setup() and before any drawing is performed to the surface.

See cairo_ps_surface_dsc_comment() for more details.

surface :

a PostScript cairo_surface_t

Since 1.2


cairo_ps_surface_dsc_comment ()

void                cairo_ps_surface_dsc_comment        (cairo_surface_t *surface,
                                                         const char *comment);

Emit a comment into the PostScript output for the given surface.

The comment is expected to conform to the PostScript Language Document Structuring Conventions (DSC). Please see that manual for details on the available comments and their meanings. In particular, the %IncludeFeature comment allows a device-independent means of controlling printer device features. So the PostScript Printer Description Files Specification will also be a useful reference.

The comment string must begin with a percent character (%) and the total length of the string (including any initial percent characters) must not exceed 255 characters. Violating either of these conditions will place surface into an error state. But beyond these two conditions, this function will not enforce conformance of the comment with any particular specification.

The comment string should not have a trailing newline.

The DSC specifies different sections in which particular comments can appear. This function provides for comments to be emitted within three sections: the header, the Setup section, and the PageSetup section. Comments appearing in the first two sections apply to the entire document while comments in the BeginPageSetup section apply only to a single page.

For comments to appear in the header section, this function should be called after the surface is created, but before a call to cairo_ps_surface_begin_setup().

For comments to appear in the Setup section, this function should be called after a call to cairo_ps_surface_begin_setup() but before a call to cairo_ps_surface_begin_page_setup().

For comments to appear in the PageSetup section, this function should be called after a call to cairo_ps_surface_begin_page_setup().

Note that it is only necessary to call cairo_ps_surface_begin_page_setup() for the first page of any surface. After a call to cairo_show_page() or cairo_copy_page() comments are unambiguously directed to the PageSetup section of the current page. But it doesn't hurt to call this function at the beginning of every page as that consistency may make the calling code simpler.

As a final note, cairo automatically generates several comments on its own. As such, applications must not manually generate any of the following comments:

Header section: %!PS-Adobe-3.0, %Creator, %CreationDate, %Pages, %BoundingBox, %DocumentData, %LanguageLevel, %EndComments.

Setup section: %BeginSetup, %EndSetup

PageSetup section: %BeginPageSetup, %PageBoundingBox, %EndPageSetup.

Other sections: %BeginProlog, %EndProlog, %Page, %Trailer, %EOF

Here is an example sequence showing how this function might be used:

cairo_surface_t *surface = cairo_ps_surface_create (filename, width, height);
...
cairo_ps_surface_dsc_comment (surface, "%%Title: My excellent document");
cairo_ps_surface_dsc_comment (surface, "%%Copyright: Copyright (C) 2006 Cairo Lover")
...
cairo_ps_surface_dsc_begin_setup (surface);
cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *MediaColor White");
...
cairo_ps_surface_dsc_begin_page_setup (surface);
cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *PageSize A3");
cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *InputSlot LargeCapacity");
cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *MediaType Glossy");
cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *MediaColor Blue");
... draw to first page here ..
cairo_show_page (cr);
...
cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *PageSize A5");
...

surface :

a PostScript cairo_surface_t

comment :

a comment string to be emitted into the PostScript output

Since 1.2