gtkmm 2.4: Gdk::Pixbuf Class Reference

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Public Member Functions

Glib::RefPtr < Gdk::Pixbuf > add_alpha (bool substitute_color, guint8 r, guint8 g, guint8 b) const Takes an existing pixbuf and adds an alpha channel to it.
void composite (const Glib::RefPtr < Gdk::Pixbuf >& dest, int dest_x, int dest_y, int dest_width, int dest_height, double offset_x, double offset_y, double scale_x, double scale_y, InterpType interp_type, int overall_alpha) const Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y .
void composite_color (const Glib::RefPtr < Gdk::Pixbuf >& dest, int dest_x, int dest_y, int dest_width, int dest_height, double offset_x, double offset_y, double scale_x, double scale_y, InterpType interp_type, int overall_alpha, int check_x, int check_y, int check_size, guint32 color1, guint32 color2) const Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y , then composites the rectangle ( dest_x , dest_y , dest_width , dest_height ) of the resulting image with a checkboard of the colors color1 and color2 and renders it onto the destination image.
Glib::RefPtr < Gdk::Pixbuf > composite_color_simple (int dest_width, int dest_height, InterpType interp_type, int overall_alpha, int check_size, guint32 color1, guint32 color2) const Creates a new Gdk::Pixbuf by scaling src to dest_width x dest_height and compositing the result with a checkboard of colors color1 and color2 .
Glib::RefPtr < Pixbuf > copy () const Creates a new Gdk::Pixbuf with a copy of the information in the specified pixbuf .
void copy_area (int src_x, int src_y, int width, int height, const Glib::RefPtr < Gdk::Pixbuf >& dest_pixbuf, int dest_x, int dest_y) const Copies a rectangular area from src_pixbuf to dest_pixbuf .
void fill (guint32 pixel) Clears a pixbuf to the given RGBA value, converting the RGBA value into the pixbuf's pixel format.
Glib::RefPtr < Gdk::Pixbuf > flip (bool horizontal=true) const Flips a pixbuf horizontally or vertically and returns the result in a new pixbuf.
int get_bits_per_sample () const Queries the number of bits per color sample in a pixbuf.
Colorspace get_colorspace () const Queries the color space of a pixbuf.
bool get_has_alpha () const Queries whether a pixbuf has an alpha channel (opacity information).
int get_height () const Queries the height of a pixbuf.
int get_n_channels () const Queries the number of channels of a pixbuf.
Glib::ustring get_option (const Glib::ustring & key) const Looks up key in the list of options that may have been attached to the pixbuf when it was loaded.
guint8* get_pixels () const Queries a pointer to the pixel data of a pixbuf.
int get_rowstride () const Queries the rowstride of a pixbuf, which is the number of bytes between the start of a row and the start of the next row.
int get_width () const Queries the width of a pixbuf.
const GdkPixbuf* gobj () const Provides access to the underlying C GObject.
GdkPixbuf* gobj () Provides access to the underlying C GObject.
GdkPixbuf* gobj_copy () Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
void render_pixmap_and_mask ( Glib::RefPtr < Pixmap >& pixmap_return, Glib::RefPtr < Bitmap >& mask_return, int alpha_threshold) void render_pixmap_and_mask_for_colormap (const Glib::RefPtr < Colormap >& colormap, Glib::RefPtr < Pixmap >& pixmap_return, Glib::RefPtr < Bitmap >& mask_return, int alpha_threshold) void render_threshold_alpha (const Glib::RefPtr < Gdk::Bitmap >& bitmap, int src_x, int src_y, int dest_x, int dest_y, int width, int height, int alpha_threshold) Takes the opacity values in a rectangular portion of a pixbuf and thresholds them to produce a bi-level alpha mask that can be used as a clipping mask for a drawable.
void render_to_drawable (const Glib::RefPtr < Drawable >& drawable, const Glib::RefPtr < Gdk::GC >& gc, int src_x, int src_y, int dest_x, int dest_y, int width, int height, RgbDither dither, int x_dither, int y_dither) Renders a rectangular portion of a pixbuf to a drawable while using the specified GC .
void render_to_drawable_alpha (const Glib::RefPtr < Drawable >& drawable, int src_x, int src_y, int dest_x, int dest_y, int width, int height, PixbufAlphaMode alpha_mode, int alpha_threshold, RgbDither dither, int x_dither, int y_dither) Renders a rectangular portion of a pixbuf to a drawable.
Glib::RefPtr < Gdk::Pixbuf > rotate_simple ( PixbufRotation angle) const Rotates a pixbuf by a multiple of 90 degrees, and returns the result in a new pixbuf.
void saturate_and_pixelate (const Glib::RefPtr < Gdk::Pixbuf >& dest, float saturation, bool pixelate) const Modifies saturation and optionally pixelates src , placing the result in dest .
void save (const std::string& filename, const Glib::ustring & type, const Glib::StringArrayHandle & option_keys, const Glib::StringArrayHandle & option_values) Saves pixbuf to a file in format type .
void save (const std::string& filename, const Glib::ustring & type) Saves pixbuf to a file in format type .
void save_to_buffer (gchar*& buffer, gsize& buffer_size, const Glib::ustring & type, const Glib::StringArrayHandle & option_keys, const Glib::StringArrayHandle & option_values) void save_to_buffer (gchar*& buffer, gsize& buffer_size, const Glib::ustring & type="png") void scale (const Glib::RefPtr < Gdk::Pixbuf >& dest, int dest_x, int dest_y, int dest_width, int dest_height, double offset_x, double offset_y, double scale_x, double scale_y, InterpType interp_type) const Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y , then renders the rectangle ( dest_x , dest_y , dest_width , dest_height ) of the resulting image onto the destination image replacing the previous contents.
Glib::RefPtr < Gdk::Pixbuf > scale_simple (int dest_width, int dest_height, InterpType interp_type) const Create a new Gdk::Pixbuf containing a copy of src scaled to dest_width x dest_height .
virtual ~Pixbuf ()

Static Public Member Functions

static Glib::RefPtr < Pixbuf > create ( Colorspace colorspace, bool has_alpha, int bits_per_sample, int width, int height) Creates a new Gdk::Pixbuf structure and allocates a buffer for it.
static Glib::RefPtr < Pixbuf > create (const Glib::RefPtr < Image >& src, const Glib::RefPtr < Colormap >& cmap, int src_x, int src_y, int dest_x, int dest_y, int width, int height) static Glib::RefPtr < Pixbuf > create (const Glib::RefPtr < Drawable >& src, const Glib::RefPtr < Colormap >& cmap, int src_x, int src_y, int dest_x, int dest_y, int width, int height) static Glib::RefPtr < Pixbuf > create_from_data (const guint8* data, Colorspace colorspace, bool has_alpha, int bits_per_sample, int width, int height, int rowstride, const SlotDestroyData & destroy_slot) Creates a new Gdk::Pixbuf out of in-memory image data.
static Glib::RefPtr < Pixbuf > create_from_data (const guint8* data, Colorspace colorspace, bool has_alpha, int bits_per_sample, int width, int height, int rowstride) Creates a new Gdk::Pixbuf out of in-memory image data.
static Glib::RefPtr < Pixbuf > create_from_file (const std::string& filename, int width, int height, bool preserve_aspect_ratio=true) Creates a new pixbuf by loading an image from a file.
static Glib::RefPtr < Pixbuf > create_from_file (const std::string& filename) Creates a new pixbuf by loading an image from a file.
static Glib::RefPtr < Pixbuf > create_from_inline (int data_length, const guint8* data, bool copy_pixels=false) Create a Gdk::Pixbuf from a flat representation that is suitable for storing as inline data in a program.
static Glib::RefPtr < Pixbuf > create_from_xpm_data (const char* const* data) Creates a new pixbuf by parsing XPM data in memory.
static Glib::RefPtr < Pixbuf > create_subpixbuf (const Glib::RefPtr < Pixbuf >& src_pixbuf, int src_x, int src_y, int width, int height) Creates a new pixbuf which represents a sub-region of src_pixbuf .
static SListHandle_PixbufFormat get_formats ()

Protected Member Functions

Pixbuf (const Glib::RefPtr < Image >& src, const Glib::RefPtr < Colormap >& cmap, int src_x, int src_y, int dest_x, int dest_y, int width, int height) Pixbuf (const Glib::RefPtr < Drawable >& src, const Glib::RefPtr < Colormap >& cmap, int src_x, int src_y, int dest_x, int dest_y, int width, int height)

Related Functions

(Note that these are not member functions.)

Glib::RefPtr < Gdk::Pixbuf > wrap (GdkPixbuf* object, bool take_copy=false) A Glib::wrap() method for this object.

Member Typedef Documentation

Takes an existing pixbuf and adds an alpha channel to it. If the existing pixbuf already had an alpha channel, the channel values are copied from the original; otherwise, the alpha channel is initialized to 255 (full opacity).

If substitute_color is true , then the color specified by ( r , g , b ) will be assigned zero opacity. That is, if you pass (255, 255, 255) for the substitute color, all white pixels will become fully transparent.

Parameters:

substitute_color Whether to set a color to zero opacity. If this is


      false

, then the ( r , g , b ) arguments will be ignored. r Red value to substitute. g Green value to substitute. b Blue value to substitute.

Returns:: A newly-created pixbuf with a reference count of 1.

Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y . This gives an image in the coordinates of the destination pixbuf. The rectangle ( dest_x , dest_y , dest_width , dest_height ) is then composited onto the corresponding rectangle of the original destination image.

When the destination rectangle contains parts not in the source image, the data at the edges of the source image is replicated to infinity.

<figure id="pixbuf-composite-diagram"> <title>Compositing of pixbufs</title> <graphic fileref="composite.png" format="PNG"/> </figure>

Parameters:

dest The Gdk::Pixbuf into which to render the results. dest_x The left coordinate for region to render. dest_y The top coordinate for region to render. dest_width The width of the region to render. dest_height The height of the region to render. offset_x The offset in the X direction (currently rounded to an integer). offset_y The offset in the Y direction (currently rounded to an integer). scale_x The scale factor in the X direction. scale_y The scale factor in the Y direction. interp_type The interpolation type for the transformation. overall_alpha Overall alpha for source image (0..255). Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y , then composites the rectangle ( dest_x , dest_y , dest_width , dest_height ) of the resulting image with a checkboard of the colors color1 and color2 and renders it onto the destination image. See composite_color_simple() for a simpler variant of this function suitable for many tasks.

Parameters:

dest The Gdk::Pixbuf into which to render the results. dest_x The left coordinate for region to render. dest_y The top coordinate for region to render. dest_width The width of the region to render. dest_height The height of the region to render. offset_x The offset in the X direction (currently rounded to an integer). offset_y The offset in the Y direction (currently rounded to an integer). scale_x The scale factor in the X direction. scale_y The scale factor in the Y direction. interp_type The interpolation type for the transformation. overall_alpha Overall alpha for source image (0..255). check_x The X offset for the checkboard (origin of checkboard is at - check_x , - check_y ). check_y The Y offset for the checkboard. check_size The size of checks in the checkboard (must be a power of two). color1 The color of check at upper left. color2 The color of the other check. Creates a new Gdk::Pixbuf by scaling src to dest_width x dest_height and compositing the result with a checkboard of colors color1 and color2 .

Parameters:

dest_width The width of destination image. dest_height The height of destination image. interp_type The interpolation type for the transformation. overall_alpha Overall alpha for source image (0..255). check_size The size of checks in the checkboard (must be a power of two). color1 The color of check at upper left. color2 The color of the other check.

Returns:: The new Gdk::Pixbuf , or 0 if not enough memory could be allocated for it.

Copies a rectangular area from src_pixbuf to dest_pixbuf . Conversion of pixbuf formats is done automatically.

Parameters:

src_x Source X coordinate within src_pixbuf . src_y Source Y coordinate within src_pixbuf . width Width of the area to copy. height Height of the area to copy. dest_pixbuf Destination pixbuf. dest_x X coordinate within dest_pixbuf . dest_y Y coordinate within dest_pixbuf . Creates a new Gdk::Pixbuf structure and allocates a buffer for it. The buffer has an optimal rowstride. Note that the buffer is not cleared; you will have to fill it completely yourself.

Parameters:

colorspace Color space for image. has_alpha Whether the image should have transparency information. bits_per_sample Number of bits per color sample. width Width of image in pixels. height Height of image in pixels.

Returns:: A newly-created Gdk::Pixbuf with a reference count of 1, or 0 if not enough memory could be allocated for the image buffer.

Creates a new Gdk::Pixbuf out of in-memory image data. Currently only RGB images with 8 bits per sample are supported.

Parameters:

data Image data in 8-bit/sample packed format. colorspace Colorspace for the image data. has_alpha Whether the data has an opacity channel. bits_per_sample Number of bits per sample. width Width of the image in pixels. height Height of the image in pixels. rowstride Distance in bytes between rows. destroy_slot Slot used to free the data when the pixbuf's reference count drops to zero.

Returns:: A newly-created Gdk::Pixbuf object.

Creates a new Gdk::Pixbuf out of in-memory image data. Currently only RGB images with 8 bits per sample are supported.

Parameters:

Returns:: A newly-created Gdk::Pixbuf object.

Creates a new pixbuf by loading an image from a file. The file format is detected automatically. If

is returned, then error will be set. Possible errors are in the Gdk::PIXBUF_ERROR and G::FILE_ERROR domains. The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio.

When preserving the aspect ratio, a width of -1 will cause the image to be scaled to the exact given height, and a height of -1 will cause the image to be scaled to the exact given width. When not preserving aspect ratio, a width or height of -1 means to not scale the image at all in that dimension. Negative values for width and height are allowed since 2.8.

Parameters:

filename Name of file to load, in the GLib file name encoding. width The width the image should have or -1 to not constrain the width. height The height the image should have or -1 to not constrain the height. preserve_aspect_ratio


                     true

to preserve the image's aspect ratio. error Return location for an error.

Returns:: A newly-created pixbuf with a reference count of 1, or 0 if any of several error conditions occurred: the file could not be opened, there was no loader for the file's format, there was not enough memory to allocate the image buffer, or the image file contained invalid data.

Since gtkmm 2.6:

Creates a new pixbuf by loading an image from a file. The file format is detected automatically. If

is returned, then error will be set. Possible errors are in the Gdk::PIXBUF_ERROR and G::FILE_ERROR domains.

Parameters:

filename Name of file to load, in the GLib file name encoding. error Return location for an error.

Returns:: A newly-created pixbuf with a reference count of 1, or 0 if any of several error conditions occurred: the file could not be opened, there was no loader for the file's format, there was not enough memory to allocate the image buffer, or the image file contained invalid data.

Create a Gdk::Pixbuf from a flat representation that is suitable for storing as inline data in a program. This is useful if you want to ship a program with images, but don't want to depend on any external files.

GTK+ ships with a program called <command>gdk-pixbuf-csource</command> which allows for conversion of Gdk::Pixbufs into such a inline representation. In almost all cases, you should pass the <option>--raw</option> flag to <command>gdk-pixbuf-csource</command>. A sample invocation would be:

gdk-pixbuf-csource --raw --name=myimage_inline myimage.png For the typical case where the inline pixbuf is read-only static data, you don't need to copy the pixel data unless you intend to write to it, so you can pass false for copy_pixels . (If you pass <option>--rle</option> to <command>gdk-pixbuf-csource</command>, a copy will be made even if copy_pixels is false, so using this option is generally a bad idea.)

If you create a pixbuf from const inline data compiled into your program, it's probably safe to ignore errors and disable length checks, since things will always succeed:

pixbuf = gdk_pixbuf_new_from_inline (-1, myimage_inline, <tt>false</tt>, <tt>0</tt>); For non-const inline data, you could get out of memory. For untrusted inline data located at runtime, you could have corrupt inline data in addition.

Parameters:

data_length Length in bytes of the data argument or -1 to disable length checks. data Byte data containing a serialized Gdk::Pixdata structure. copy_pixels Whether to copy the pixel data, or use direct pointers data for the resulting pixbuf. error G::Error return location, may be 0 to ignore errors.

Returns:: A newly-created Gdk::Pixbuf structure with a reference, count of 1, or 0 if an error occurred.

Creates a new pixbuf by parsing XPM data in memory. This data is commonly the result of including an XPM file into a program's C source.

Parameters:

data Pointer to inline XPM data.

Returns:: A newly-created pixbuf with a reference count of 1.

Creates a new pixbuf which represents a sub-region of src_pixbuf . The new pixbuf shares its pixels with the original pixbuf, so writing to one affects both. The new pixbuf holds a reference to src_pixbuf , so src_pixbuf will not be finalized until the new pixbuf is finalized.

Parameters:

src_pixbuf A Gdk::Pixbuf. src_x X coord in src_pixbuf . src_y Y coord in src_pixbuf . width Width of region in src_pixbuf . height Height of region in src_pixbuf .

Returns:: A new pixbuf.

Clears a pixbuf to the given RGBA value, converting the RGBA value into the pixbuf's pixel format. The alpha will be ignored if the pixbuf doesn't have an alpha channel.

Parameters:

pixel RGBA pixel to clear to (0xffffffff is opaque white, 0x00000000 transparent black). Flips a pixbuf horizontally or vertically and returns the result in a new pixbuf.

Parameters:

horizontal true to flip horizontally, false to flip vertically.

Returns:: A new pixbuf.

Since gtkmm 2.6:

Looks up key in the list of options that may have been attached to the pixbuf when it was loaded.

Parameters:

key A nul-terminated string.

Returns:: The value associated with key . This is a nul-terminated string that should not be freed or 0 if key was not found.

Queries the rowstride of a pixbuf, which is the number of bytes between the start of a row and the start of the next row.

Returns:: Distance between row starts.

Takes the opacity values in a rectangular portion of a pixbuf and thresholds them to produce a bi-level alpha mask that can be used as a clipping mask for a drawable.

Parameters:

bitmap Bitmap where the bilevel mask will be painted to. src_x Source X coordinate. src_y Source Y coordinate. dest_x Destination X coordinate. dest_y Destination Y coordinate. width Width of region to threshold, or -1 to use pixbuf width. height Height of region to threshold, or -1 to use pixbuf height. alpha_threshold Opacity values below this will be painted as zero; all other values will be painted as one. Renders a rectangular portion of a pixbuf to a drawable while using the specified GC. This is done using GdkRGB, so the specified drawable must have the GdkRGB visual and colormap. Note that this function will ignore the opacity information for images with an alpha channel; the GC must already have the clipping mask set if you want transparent regions to show through.

For an explanation of dither offsets, see the GdkRGB documentation. In brief, the dither offset is important when re-rendering partial regions of an image to a rendered version of the full image, or for when the offsets to a base position change, as in scrolling. The dither matrix has to be shifted for consistent visual results. If you do not have any of these cases, the dither offsets can be both zero.

Deprecated: This function is obsolete. Use gdk_draw_pixbuf() instead.

Parameters:

drawable Destination drawable. gc GC used for rendering. src_x Source X coordinate within pixbuf. src_y Source Y coordinate within pixbuf. dest_x Destination X coordinate within drawable. dest_y Destination Y coordinate within drawable. width Width of region to render, in pixels, or -1 to use pixbuf width. height Height of region to render, in pixels, or -1 to use pixbuf height. dither Dithering mode for GdkRGB. x_dither X offset for dither. y_dither Y offset for dither. Renders a rectangular portion of a pixbuf to a drawable. The destination drawable must have a colormap. All windows have a colormap, however, pixmaps only have colormap by default if they were created with a non-0 window argument. Otherwise a colormap must be set on them with gdk_drawable_set_colormap.

On older X servers, rendering pixbufs with an alpha channel involves round trips to the X server, and may be somewhat slow.

Deprecated: This function is obsolete. Use gdk_draw_pixbuf() instead.

Parameters:

drawable Destination drawable. src_x Source X coordinate within pixbuf. src_y Source Y coordinates within pixbuf. dest_x Destination X coordinate within drawable. dest_y Destination Y coordinate within drawable. width Width of region to render, in pixels, or -1 to use pixbuf width. height Height of region to render, in pixels, or -1 to use pixbuf height. alpha_mode Ignored. Present for backwards compatibility. alpha_threshold Ignored. Present for backwards compatibility. dither Dithering mode for GdkRGB. x_dither X offset for dither. y_dither Y offset for dither. Rotates a pixbuf by a multiple of 90 degrees, and returns the result in a new pixbuf.

Parameters:

angle The angle to rotate by.

Returns:: A new pixbuf

Since gtkmm 2.6:

Modifies saturation and optionally pixelates src , placing the result in dest . src and dest may be the same pixbuf with no ill effects. If saturation is 1.0 then saturation is not changed. If it's less than 1.0, saturation is reduced (the image is darkened); if greater than 1.0, saturation is increased (the image is brightened). If pixelate is true, then pixels are faded in a checkerboard pattern to create a pixelated image. src and dest must have the same image format, size, and rowstride.

Parameters:

dest Place to write modified version of src . saturation Saturation factor. pixelate Whether to pixelate. Saves pixbuf to a file in format type. By default, "jpeg", "png", "ico" and "bmp" are possible file formats to save in, but more formats may be installed. TThe list of all writable formats can be determined by using Gdk::Pixbuf::get_formats() with Gdk::PixbufFormat::is_writable().

The option_keys and , if not empty, should contain pairs of strings that modify the save parameters. For example, "quality", "100".

Currently only a few parameters exist. JPEG images can be saved with a "quality" parameter; its value should be in the range [0,100]. Text chunks can be attached to PNG images by specifying parameters of the form "tEXt::key", where key is an ASCII string of length 1-79. The values are UTF-8 encoded strings. ICO images can be saved in depth 16, 24, or 32, by using the "depth" parameter. When the ICO saver is given "x_hot" and "y_hot" parameters, it produces a CUR instead of an ICO.

Parameters:

filename The path of the file to be created. type The file type. option_keys option_values

Exceptions:

Glib::FileError Gdk::PixbufError Saves pixbuf to a file in format type. By default, "jpeg", "png", "ico" and "bmp" are possible file formats to save in, but more formats may be installed. TThe list of all writable formats can be determined by using Gdk::Pixbuf::get_formats() with Gdk::PixbufFormat::is_writable().

Parameters:

filename The path of the file to be created. type The file type.

Exceptions:

Glib::FileError Gdk::PixbufError Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y , then renders the rectangle ( dest_x , dest_y , dest_width , dest_height ) of the resulting image onto the destination image replacing the previous contents. Try to use scale_simple() first, this function is the industrial-strength power tool you can fall back to if scale_simple() isn't powerful enough.

Parameters:

dest The Gdk::Pixbuf into which to render the results. dest_x The left coordinate for region to render. dest_y The top coordinate for region to render. dest_width The width of the region to render. dest_height The height of the region to render. offset_x The offset in the X direction (currently rounded to an integer). offset_y The offset in the Y direction (currently rounded to an integer). scale_x The scale factor in the X direction. scale_y The scale factor in the Y direction. interp_type The interpolation type for the transformation. Create a new Gdk::Pixbuf containing a copy of src scaled to dest_width x dest_height . Leaves src unaffected. interp_type should be Gdk::INTERP_NEAREST if you want maximum speed (but when scaling down Gdk::INTERP_NEAREST is usually unusably ugly). The default interp_type should be Gdk::INTERP_BILINEAR which offers reasonable quality and speed.

You can scale a sub-portion of src by creating a sub-pixbuf pointing into src ; see new_subpixbuf().

For more complicated scaling/compositing see scale() and composite().

Parameters:

dest_width The width of destination image. dest_height The height of destination image. interp_type The interpolation type for the transformation.

Returns:: The new Gdk::Pixbuf, or 0 if not enough memory could be allocated for it.

Friends And Related Function Documentation

object The C instance. take_copy False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns:: A C++ instance that wraps this C instance.

The documentation for this class was generated from the following file:

pixbuf.h