Cairo: A Vector Graphics Library | ||||
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Top | Description |
#define CAIRO_HAS_PS_SURFACE 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_restrict_to_level (cairo_surface_t *surface
,cairo_ps_level_t level
); enum cairo_ps_level_t; void cairo_ps_get_levels (cairo_ps_level_t const **levels
,int *num_levels
); const char * cairo_ps_level_to_string (cairo_ps_level_t level
); void cairo_ps_surface_set_eps (cairo_surface_t *surface
,cairo_bool_t eps
); cairo_bool_t cairo_ps_surface_get_eps (cairo_surface_t *surface
); 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
);
The PostScript surface is used to render cairo graphics to Adobe PostScript files and is a multi-page vector surface backend.
#define CAIRO_HAS_PS_SURFACE 1
Defined if the PostScript surface backend is available. This macro can be used to conditionally compile backend-specific code.
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()
.
|
a filename for the PS output (must be writable), NULL may be
used to specify no output. This will generate a PS surface that
may be queried and used as a source, without generating a
temporary file.
|
|
width of the surface, in points (1 point == 1/72.0 inch) |
|
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_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()
.
|
a cairo_write_func_t to accept the output data, may be NULL
to indicate a no-op write_func . With a no-op write_func ,
the surface may be queried or used as a source without
generating any temporary files.
|
|
the closure argument for write_func
|
|
width of the surface, in points (1 point == 1/72.0 inch) |
|
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
void cairo_ps_surface_restrict_to_level (cairo_surface_t *surface
,cairo_ps_level_t level
);
Restricts the generated PostSript file to level
. See
cairo_ps_get_levels()
for a list of available level values that
can be used here.
This function should only be called before any drawing operations have been performed on the given surface. The simplest way to do this is to call this function immediately after creating the surface.
|
a PostScript cairo_surface_t |
|
PostScript level |
Since 1.6
typedef enum _cairo_ps_level { CAIRO_PS_LEVEL_2, CAIRO_PS_LEVEL_3 } cairo_ps_level_t;
cairo_ps_level_t is used to describe the language level of the PostScript Language Reference that a generated PostScript file will conform to.
void cairo_ps_get_levels (cairo_ps_level_t const **levels
,int *num_levels
);
Used to retrieve the list of supported levels. See
cairo_ps_surface_restrict_to_level()
.
|
supported level list |
|
list length |
Since 1.6
const char * cairo_ps_level_to_string (cairo_ps_level_t level
);
Get the string representation of the given level
id. This function
will return NULL
if level
id isn't valid. See cairo_ps_get_levels()
for a way to get the list of valid level ids.
|
a level id |
Returns : |
the string associated to given level. |
Since 1.6
void cairo_ps_surface_set_eps (cairo_surface_t *surface
,cairo_bool_t eps
);
If eps
is TRUE
, the PostScript surface will output Encapsulated
PostScript.
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. An Encapsulated PostScript file should never contain more than one page.
|
a PostScript cairo_surface_t |
|
TRUE to output EPS format PostScript
|
Since 1.6
cairo_bool_t cairo_ps_surface_get_eps (cairo_surface_t *surface
);
Check whether the PostScript surface will output Encapsulated PostScript.
|
a PostScript cairo_surface_t |
Returns : |
TRUE if the surface will output Encapsulated PostScript.
|
Since 1.6
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()
.
|
a PostScript cairo_surface_t |
|
new surface width, in points (1 point == 1/72.0 inch) |
|
new surface height, in points (1 point == 1/72.0 inch) |
Since 1.2
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.
|
a PostScript cairo_surface_t |
Since 1.2
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.
|
a PostScript cairo_surface_t |
Since 1.2
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_dsc_begin_setup()
.
For comments to appear in the Setup section, this function should
be called after a call to cairo_ps_surface_dsc_begin_setup()
but
before a call to cairo_ps_surface_dsc_begin_page_setup()
.
For comments to appear in the PageSetup section, this function
should be called after a call to
cairo_ps_surface_dsc_begin_page_setup()
.
Note that it is only necessary to call
cairo_ps_surface_dsc_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"); ...
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a PostScript cairo_surface_t |
|
a comment string to be emitted into the PostScript output |
Since 1.2