cairo.Surface



class Surface ;
cairo_surface_t is the abstract type representing all different drawing targets that cairo can render to. The actual drawings are performed using a cairo context.

A cairo surface is created by using backend-specific constructors, typically of the form cairo_backend_surface_create().

Most surface types allow accessing the surface without using Cairo functions. If you do this, keep in mind that it is mandatory that you call cairo_surface_flush() before reading from or writing to the surface and that you must use cairo_surface_mark_dirty() after modifying it.



Note that for other surface types it might be necessary to acquire the surface's device first. See cairo_device_acquire() for a discussion of devices.

protected cairo_surface_t* cairo_surface ;
the main Gtk struct

protected void* getStruct ();
the main Gtk struct as a void*

this(cairo_surface_t* cairo_surface);
Sets our main struct and passes it to the parent class

void getMimeData (string mimeType, out ubyte[] data);
Return mime data previously attached to surface using the specified mime type. If no data has been attached with the given mime type, data is set NULL. Since 1.10

Params:
string mimeType the mime type of the image data
ubyte[] data the image data to attached to the surface

Surface createSimilar (cairo_content_t content, int width, int height);
Create a new surface that is as compatible as possible with an existing surface. For example the new surface will have the same fallback resolution and font options as other. Generally, the new surface will also use the same backend as other, 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.) Use cairo_surface_create_similar_image() if you need an image surface which can be painted quickly to the target surface. Since 1.0

Params:
cairo_content_t content the content for the new surface
int width width of the new surface, (in device-space units)
int height height of the new surface (in device-space units)

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.

Surface createSimilarImage (cairo_format_t format, int width, int height);
Create a new image surface that is as compatible as possible for uploading to and the use in conjunction with an existing surface. However, this surface can still be used like any normal image surface. Initially the surface contents are all 0 (transparent if contents have transparency, black otherwise.) Use cairo_surface_create_similar() if you don't need an image surface. Since 1.12

Params:
cairo_format_t format the format for the new surface
int width width of the new surface, (in device-space units)
int height height of the new surface (in device-space units)

Returns:
a pointer to the newly allocated image 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.

Surface createForRectangle (double x, double y, double width, double height);
Create a new surface that is a rectangle within the target surface. All operations drawn to this surface are then clipped and translated onto the target surface. Nothing drawn via this sub-surface outside of its bounds is drawn onto the target surface, making this a useful method for passing constrained child surfaces to library routines that draw directly onto the parent surface, i.e. with no further backend allocations, double buffering or copies. Note The semantics of subsurfaces have not been finalized yet unless the rectangle is in full device units, is contained within the extents of the target surface, and the target or subsurface's device transforms are not changed. Since 1.10

Params:
double x the x-origin of the sub-surface from the top-left of the target surface (in device-space units)
double y the y-origin of the sub-surface from the top-left of the target surface (in device-space units)
double width width of the sub-surface (in device-space units)
double height height of the sub-surface (in device-space units)

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.

Surface reference ();
Increases the reference count on surface by one. This prevents surface from being destroyed until a matching call to cairo_surface_destroy() is made. The number of references to a cairo_surface_t can be get using cairo_surface_get_reference_count(). Since 1.0

Returns:
the referenced cairo_surface_t.

void destroy ();
Decreases the reference count on surface by one. If the result is zero, then surface and all associated resources are freed. See cairo_surface_reference(). Since 1.0

cairo_status_t status ();
Checks whether an error has previously occurred for this surface. Since 1.0

Returns:
CAIRO_STATUS_SUCCESS, CAIRO_STATUS_NULL_POINTER, CAIRO_STATUS_NO_MEMORY, CAIRO_STATUS_READ_ERROR, CAIRO_STATUS_INVALID_CONTENT, CAIRO_STATUS_INVALID_FORMAT, or CAIRO_STATUS_INVALID_VISUAL.

void finish ();
This function finishes the surface and drops all references to external resources. For example, for the Xlib backend it means that cairo will no longer access the drawable, which can be freed. After calling cairo_surface_finish() the only valid operations on a surface are getting and setting user, referencing and destroying, and flushing and finishing it. Further drawing to the surface will not affect the surface but will instead trigger a CAIRO_STATUS_SURFACE_FINISHED error. When the last call to cairo_surface_destroy() decreases the reference count to zero, cairo will call cairo_surface_finish() if it hasn't been called already, before freeing the resources associated with the surface. Since 1.0

void flush ();
Do any pending drawing for the surface and also restore any temporary modifications cairo has made to the surface's state. This function must be called before switching from drawing on the surface with cairo to drawing on it directly with native APIs. If the surface doesn't support direct access, then this function does nothing. Since 1.0

Device getDevice ();
This function returns the device for a surface. See cairo_device_t. Since 1.10

Returns:
The device for surface or NULL if the surface does not have an associated device.

void getFontOptions (FontOption options);
Retrieves the default font rendering options for the surface. This allows display surfaces to report the correct subpixel order for rendering on them, print surfaces to disable hinting of metrics and so forth. The result can then be used with cairo_scaled_font_create(). Since 1.0

Params:
FontOption options a cairo_font_options_t object into which to store the retrieved options. All existing values are overwritten

cairo_content_t getContent ();
This function returns the content type of surface which indicates whether the surface contains color and/or alpha information. See cairo_content_t. Since 1.2

Returns:
The content type of surface.

void markDirty ();
Tells cairo that drawing has been done to surface using means other than cairo, and that cairo should reread any cached areas. Note that you must call cairo_surface_flush() before doing such drawing. Since 1.0

void markDirtyRectangle (int x, int y, int width, int height);
Like cairo_surface_mark_dirty(), but drawing has been done only to the specified rectangle, so that cairo can retain cached contents for other parts of the surface. Any cached clip set on the surface will be reset by this function, to make sure that future cairo calls have the clip set that they expect. Since 1.0

Params:
int x X coordinate of dirty rectangle
int y Y coordinate of dirty rectangle
int width width of dirty rectangle
int height height of dirty rectangle

void setDeviceOffset (double xOffset, double yOffset);
Sets an offset that is added to the device coordinates determined by the CTM when drawing to surface. One use case for this function is when we want to create a cairo_surface_t that redirects drawing for a portion of an onscreen surface to an offscreen surface in a way that is completely invisible to the user of the cairo API. Setting a transformation via cairo_translate() isn't sufficient to do this, since functions like cairo_device_to_user() will expose the hidden offset. Note that the offset affects drawing to the surface as well as using the surface in a source pattern. Since 1.0

Params:
double xOffset the offset in the X direction, in device units
double yOffset the offset in the Y direction, in device units

void getDeviceOffset (out double xOffset, out double yOffset);
This function returns the previous device offset set by cairo_surface_set_device_offset(). Since 1.2

Params:
double xOffset the offset in the X direction, in device units
double yOffset the offset in the Y direction, in device units

void setFallbackResolution (double xPixelsPerInch, double yPixelsPerInch);
Set the horizontal and vertical resolution for image fallbacks. When certain operations aren't supported natively by a backend, cairo will fallback by rendering operations to an image and then overlaying that image onto the output. For backends that are natively vector-oriented, this function can be used to set the resolution used for these image fallbacks, (larger values will result in more detailed images, but also larger file sizes). Some examples of natively vector-oriented backends are the ps, pdf, and svg backends. For backends that are natively raster-oriented, image fallbacks are still possible, but they are always performed at the native device resolution. So this function has no effect on those backends.

Note:
The fallback resolution only takes effect at the time of completing a page (with cairo_show_page() or cairo_copy_page()) so there is currently no way to have more than one fallback resolution in effect on a single page. The default fallback resoultion is 300 pixels per inch in both dimensions. Since 1.2

Params:
double xPixelsPerInch horizontal setting for pixels per inch
double yPixelsPerInch vertical setting for pixels per inch

void getFallbackResolution (out double xPixelsPerInch, out double yPixelsPerInch);
This function returns the previous fallback resolution set by cairo_surface_set_fallback_resolution(), or default fallback resolution if never set. Since 1.8

Params:
double xPixelsPerInch horizontal pixels per inch
double yPixelsPerInch vertical pixels per inch

cairo_surface_type_t getType ();
This function returns the type of the backend used to create a surface. See cairo_surface_type_t for available types. Since 1.2

Params:
surface a cairo_surface_t

Returns:
The type of surface.

uint getReferenceCount ();
Returns the current reference count of surface. Since 1.4

Returns:
the current reference count of surface. If the object is a nil object, 0 will be returned.

cairo_status_t setUserData (cairo_user_data_key_t* key, void* userData, cairo_destroy_func_t destroy);
Attach user data to surface. To remove user data from a surface, call this function with the key that was used to set it and NULL for data. Since 1.0

Params:
cairo_user_data_key_t* key the address of a cairo_user_data_key_t to attach the user data to
void* userData the user data to attach to the surface
cairo_destroy_func_t destroy a cairo_destroy_func_t which will be called when the surface is destroyed or when new user data is attached using the same key.

Returns:
CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY if a slot could not be allocated for the user data.

void* getUserData (cairo_user_data_key_t* key);
Return user data previously attached to surface using the specified key. If no user data has been attached with the given key this function returns NULL. Since 1.0

Params:
cairo_user_data_key_t* key the address of the cairo_user_data_key_t the user data was attached to

Returns:
the user data previously attached or NULL.

void copyPage ();
Emits the current page for backends that support multiple pages, but doesn't clear it, so that the contents of the current page will be retained for the next page. Use cairo_surface_show_page() if you want to get an empty page after the emission. There is a convenience function for this that takes a cairo_t, namely cairo_copy_page(). Since 1.6

void showPage ();
Emits and clears the current page for backends that support multiple pages. Use cairo_surface_copy_page() if you don't want to clear the page. There is a convenience function for this that takes a cairo_t, namely cairo_show_page(). Since 1.6

cairo_bool_t hasShowTextGlyphs ();
Returns whether the surface supports sophisticated cairo_show_text_glyphs() operations. That is, whether it actually uses the provided text and cluster data to a cairo_show_text_glyphs() call.

Note:
Even if this function returns FALSE, a cairo_show_text_glyphs() operation targeted at surface will still succeed. It just will act like a cairo_show_glyphs() operation. Users can use this function to avoid computing UTF-8 text and cluster mapping if the target surface does not use it. Since 1.8

Returns:
TRUE if surface supports cairo_show_text_glyphs(), FALSE otherwise

cairo_status_t setMimeData (string mimeType, ubyte[] data, cairo_destroy_func_t destroy, void* closure);
Attach an image in the format mime_type to surface. To remove the data from a surface, call this function with same mime type and NULL for data. The attached image (or filename) data can later be used by backends which support it (currently: PDF, PS, SVG and Win32 Printing surfaces) to emit this data instead of making a snapshot of the surface. This approach tends to be faster and requires less memory and disk space. The recognized MIME types are the following: CAIRO_MIME_TYPE_JPEG, CAIRO_MIME_TYPE_PNG, CAIRO_MIME_TYPE_JP2, CAIRO_MIME_TYPE_URI. See corresponding backend surface docs for details about which MIME types it can handle. Caution: the associated MIME data will be discarded if you draw on the surface afterwards. Use this function with care. Since 1.10

Params:
string mimeType the MIME type of the image data
ubyte[] data the image data to attach to the surface
cairo_destroy_func_t destroy a cairo_destroy_func_t which will be called when the surface is destroyed or when new image data is attached using the same mime type.
void* closure the data to be passed to the destroy notifier

Returns:
CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY if a slot could not be allocated for the user data.

cairo_bool_t supportsMimeType (string mimeType);
Return whether surface supports mime_type. Since 1.12

Params:
string mimeType the mime type

Returns:
TRUE if surface supports mime_type, FALSE otherwise

Surface mapToImage (ref cairo_rectangle_int_t extents);
Returns an image surface that is the most efficient mechanism for modifying the backing store of the target surface. The region retrieved may be limited to the extents or NULL for the whole surface Note, the use of the original surface as a target or source whilst it is mapped is undefined. The result of mapping the surface multiple times is undefined. Calling cairo_surface_destroy() or cairo_surface_finish() on the resulting image surface results in undefined behavior. Since 1.12

Params:
cairo_rectangle_int_t extents limit the extraction to an rectangular region

Returns:
a pointer to the newly allocated image surface. The caller must use cairo_surface_unmap_image() to destroy this image surface. 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.

void unmapImage (Surface image);
Unmaps the image surface as returned from #cairo_surface_map_to_image(). The content of the image will be uploaded to the target surface. Afterwards, the image is destroyed. Using an image surface which wasn't returned by cairo_surface_map_to_image() results in undefined behavior. Since 1.12

Params:
Surface image the currently mapped image

Page was generated with on Fri May 17 23:50:22 2013