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Functions
cairo_surface_t * | gdk_window_create_similar_surface () |
cairo_t * | gdk_cairo_create () |
void | gdk_cairo_set_source_color () |
void | gdk_cairo_set_source_pixbuf () |
void | gdk_cairo_set_source_pixmap () |
void | gdk_cairo_set_source_window () |
void | gdk_cairo_rectangle () |
void | gdk_cairo_region () |
void | gdk_cairo_reset_clip () |
Description
Cairo is a graphics library that supports vector graphics and image compositing that can be used with GDK. Since 2.8, GTK+ does most of its drawing using Cairo.
GDK does not wrap the Cairo API, instead it allows to create Cairo contexts which can be used to draw on GDK drawables. Additional functions allow to convert GDK's rectangles and regions into Cairo paths and to use pixbufs as sources for drawing operations.
Functions
gdk_window_create_similar_surface ()
cairo_surface_t * gdk_window_create_similar_surface (GdkWindow *window
,cairo_content_t content
,int width
,int height
);
Create a new surface that is as compatible as possible with the
given window
. For example the new surface will have the same
fallback resolution and font options as window
. Generally, the new
surface will also use the same backend as window
, unless that is
not possible for some reason. The type of the returned surface may
be examined with cairo_surface_get_type()
.
Initially the surface contents are all 0 (transparent if contents have transparency, black otherwise.)
Parameters
window |
window to make new surface similar to |
|
content |
the content for the new surface |
|
width |
width of the new surface |
|
height |
height of the new surface |
Returns
a pointer to the newly allocated 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 other
is already in an error state
or any other error occurs.
Since: 2.22
gdk_cairo_create ()
cairo_t *
gdk_cairo_create (GdkDrawable *drawable
);
Creates a Cairo context for drawing to drawable
.
Note that due to double-buffering, Cairo contexts created in a GTK+ expose event handler cannot be cached and reused between different expose events.
Since: 2.8
gdk_cairo_set_source_color ()
void gdk_cairo_set_source_color (cairo_t *cr
,const GdkColor *color
);
Sets the specified GdkColor as the source color of cr
.
Since: 2.8
gdk_cairo_set_source_pixbuf ()
void gdk_cairo_set_source_pixbuf (cairo_t *cr
,const GdkPixbuf *pixbuf
,double pixbuf_x
,double pixbuf_y
);
Sets the given pixbuf as the source pattern for the Cairo context.
The pattern has an extend mode of CAIRO_EXTEND_NONE
and is aligned
so that the origin of pixbuf
is pixbuf_x
, pixbuf_y
Parameters
cr |
a Cairo context |
|
pixbuf |
||
pixbuf_x |
X coordinate of location to place upper left corner of |
|
pixbuf_y |
Y coordinate of location to place upper left corner of |
Since: 2.8
gdk_cairo_set_source_pixmap ()
void gdk_cairo_set_source_pixmap (cairo_t *cr
,GdkPixmap *pixmap
,double pixmap_x
,double pixmap_y
);
gdk_cairo_set_source_pixmap
has been deprecated since version 2.24 and should not be used in newly-written code.
This function is being removed in GTK+ 3 (together
with GdkPixmap). Instead, use gdk_cairo_set_source_window()
where
appropriate.
Sets the given pixmap as the source pattern for the Cairo context.
The pattern has an extend mode of CAIRO_EXTEND_NONE
and is aligned
so that the origin of pixmap
is pixmap_x
, pixmap_y
Parameters
cr |
a Cairo context |
|
pixmap |
||
pixmap_x |
X coordinate of location to place upper left corner of |
|
pixmap_y |
Y coordinate of location to place upper left corner of |
Since: 2.10
gdk_cairo_set_source_window ()
void gdk_cairo_set_source_window (cairo_t *cr
,GdkWindow *window
,double x
,double y
);
Sets the given window as the source pattern for the Cairo context.
The pattern has an extend mode of CAIRO_EXTEND_NONE
and is aligned
so that the origin of window
is x
, y
. The window contains all its
subwindows when rendering.
Note that the contents of window
are undefined outside of the
visible part of window
, so use this function with care.
Parameters
cr |
a Cairo context |
|
window |
||
x |
X coordinate of location to place upper left corner of |
|
y |
Y coordinate of location to place upper left corner of |
Since: 2.24
gdk_cairo_rectangle ()
void gdk_cairo_rectangle (cairo_t *cr
,const GdkRectangle *rectangle
);
Adds the given rectangle to the current path of cr
.
Since: 2.8
gdk_cairo_region ()
void gdk_cairo_region (cairo_t *cr
,const GdkRegion *region
);
Adds the given region to the current path of cr
.
Since: 2.8
gdk_cairo_reset_clip ()
void gdk_cairo_reset_clip (cairo_t *cr
,GdkDrawable *drawable
);
Resets the clip region for a Cairo context created by gdk_cairo_create()
.
This resets the clip region to the "empty" state for the given drawable.
This is required for non-native windows since a direct call to
cairo_reset_clip()
would unset the clip region inherited from the
drawable (i.e. the window clip region), and thus let you e.g.
draw outside your window.
This is rarely needed though, since most code just create a new cairo_t
using gdk_cairo_create()
each time they want to draw something.
Since: 2.18