GDK Reference Manual
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# Drawing Primitives

## Name

Drawing Primitives -- functions for drawing points, lines, arcs, and text.

## Synopsis

    #include <gdk/gdk.h>

    struct      GdkDrawable;
    GdkDrawable* gdk_drawable_ref               (GdkDrawable *drawable);
    void        gdk_drawable_unref              (GdkDrawable *drawable);
    void        gdk_drawable_set_data           (GdkDrawable *drawable,
                                                 const gchar *key,
                                                 gpointer data,
                                                 GDestroyNotify destroy_func);
    gpointer    gdk_drawable_get_data           (GdkDrawable *drawable,
                                                 const gchar *key);
    GdkDisplay* gdk_drawable_get_display        (GdkDrawable *drawable);
    GdkScreen*  gdk_drawable_get_screen         (GdkDrawable *drawable);
    GdkVisual*  gdk_drawable_get_visual         (GdkDrawable *drawable);
    void        gdk_drawable_set_colormap       (GdkDrawable *drawable,
                                                 GdkColormap *colormap);
    GdkColormap* gdk_drawable_get_colormap      (GdkDrawable *drawable);
    gint        gdk_drawable_get_depth          (GdkDrawable *drawable);
    void        gdk_drawable_get_size           (GdkDrawable *drawable,
                                                 gint *width,
                                                 gint *height);
    GdkRegion*  gdk_drawable_get_clip_region    (GdkDrawable *drawable);
    GdkRegion*  gdk_drawable_get_visible_region (GdkDrawable *drawable);

    void        gdk_draw_point                  (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y);
    void        gdk_draw_points                 (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkPoint *points,
                                                 gint npoints);
    void        gdk_draw_line                   (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x1,
                                                 gint y1,
                                                 gint x2,
                                                 gint y2);
    void        gdk_draw_lines                  (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkPoint *points,
                                                 gint npoints);
    void        gdk_draw_segments               (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkSegment *segs,
                                                 gint nsegs);
    struct      GdkSegment;
    void        gdk_draw_rectangle              (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint filled,
                                                 gint x,
                                                 gint y,
                                                 gint width,
                                                 gint height);
    void        gdk_draw_arc                    (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint filled,
                                                 gint x,
                                                 gint y,
                                                 gint width,
                                                 gint height,
                                                 gint angle1,
                                                 gint angle2);
    void        gdk_draw_polygon                (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint filled,
                                                 GdkPoint *points,
                                                 gint npoints);
    void        gdk_draw_glyphs                 (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 PangoFont *font,
                                                 gint x,
                                                 gint y,
                                                 PangoGlyphString *glyphs);
    void        gdk_draw_layout_line            (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayoutLine *line);
    void        gdk_draw_layout_line_with_colors
                                                (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayoutLine *line,
                                                 GdkColor *foreground,
                                                 GdkColor *background);
    void        gdk_draw_layout                 (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayout *layout);
    void        gdk_draw_layout_with_colors     (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayout *layout,
                                                 GdkColor *foreground,
                                                 GdkColor *background);

    void        gdk_draw_string                 (GdkDrawable *drawable,
                                                 GdkFont *font,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 const gchar *string);
    void        gdk_draw_text                   (GdkDrawable *drawable,
                                                 GdkFont *font,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 const gchar *text,
                                                 gint text_length);
    void        gdk_draw_text_wc                (GdkDrawable *drawable,
                                                 GdkFont *font,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 const GdkWChar *text,
                                                 gint text_length);

    #define     gdk_draw_pixmap
    void        gdk_draw_drawable               (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkDrawable *src,
                                                 gint xsrc,
                                                 gint ysrc,
                                                 gint xdest,
                                                 gint ydest,
                                                 gint width,
                                                 gint height);
    void        gdk_draw_image                  (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkImage *image,
                                                 gint xsrc,
                                                 gint ysrc,
                                                 gint xdest,
                                                 gint ydest,
                                                 gint width,
                                                 gint height);
    GdkImage*   gdk_drawable_get_image          (GdkDrawable *drawable,
                                                 gint x,
                                                 gint y,
                                                 gint width,
                                                 gint height);

## Object Hierarchy

      GObject
       +----GdkDrawable

## Description

These functions provide support for drawing points, lines, arcs and text onto what are called 'drawables'. Drawables, as the name suggests, are things which support drawing onto them, and are either GdkWindow or GdkPixmap objects.

Many of the drawing operations take a GdkGC argument, which represents a graphics context. This GdkGC contains a number of drawing attributes such as foreground color, background color and line width, and is used to reduce the number of arguments needed for each drawing operation. See the Graphics Contexts section for more information.

## Details

### struct GdkDrawable

    struct GdkDrawable;

An opaque structure representing an object that can be drawn onto. This can be a GdkPixmap, a GdkBitmap, or a GdkWindow.

### gdk_drawable_ref ()

    GdkDrawable* gdk_drawable_ref               (GdkDrawable *drawable);

Warning
`gdk_drawable_ref` is deprecated and should not be used in newly-written code.

Deprecated equivalent of calling g_object_ref() on `drawable`. (Drawables were not objects in previous versions of GDK.)

`drawable` : | a GdkDrawable
Returns : | the same `drawable` passed in

### gdk_drawable_unref ()

    void        gdk_drawable_unref              (GdkDrawable *drawable);

Warning
`gdk_drawable_unref` is deprecated and should not be used in newly-written code.

Deprecated equivalent of calling g_object_unref() on `drawable`.

`drawable` : | a GdkDrawable

### gdk_drawable_set_data ()

    void        gdk_drawable_set_data           (GdkDrawable *drawable,
                                                 const gchar *key,
                                                 gpointer data,
                                                 GDestroyNotify destroy_func);

Warning
`gdk_drawable_set_data` is deprecated and should not be used in newly-written code.

This function is equivalent to g_object_set_data(), the GObject variant should be used instead.

`drawable` : | a GdkDrawable
`key` : | name to store the data under
`data` : | arbitrary data
`destroy_func` : | function to free `data`, or `NULL`

### gdk_drawable_get_data ()

    gpointer    gdk_drawable_get_data           (GdkDrawable *drawable,
                                                 const gchar *key);

Warning
`gdk_drawable_get_data` is deprecated and should not be used in newly-written code.

Equivalent to g_object_get_data(); the GObject variant should be used instead.

`drawable` : | a GdkDrawable
`key` : | name the data was stored under
Returns : | the data stored at `key`

### gdk_drawable_get_display ()

    GdkDisplay* gdk_drawable_get_display        (GdkDrawable *drawable);

Gets the GdkDisplay associated with a GdkDrawable.

`drawable` : | a GdkDrawable
Returns : | the GdkDisplay associated with `drawable`

### gdk_drawable_get_screen ()

    GdkScreen*  gdk_drawable_get_screen         (GdkDrawable *drawable);

Gets the GdkScreen associated with a GdkDrawable.

`drawable` : | a GdkDrawable
Returns : | the GdkScreen associated with `drawable`

### gdk_drawable_get_visual ()

    GdkVisual*  gdk_drawable_get_visual         (GdkDrawable *drawable);

Gets the GdkVisual describing the pixel format of `drawable`.

`drawable` : | a GdkDrawable
Returns : | a GdkVisual

### gdk_drawable_set_colormap ()

    void        gdk_drawable_set_colormap       (GdkDrawable *drawable,
                                                 GdkColormap *colormap);

Sets the colormap associated with `drawable`. Normally this will happen automatically when the drawable is created; you only need to use this function if the drawable-creating function did not have a way to determine the colormap, and you then use drawable operations that require a colormap. The colormap for all drawables and graphics contexts you intend to use together should match. i.e. when using a GdkGC to draw to a drawable, or copying one drawable to another, the colormaps should match.

`drawable` : | a GdkDrawable
`colormap` : | a GdkColormap

### gdk_drawable_get_colormap ()

    GdkColormap* gdk_drawable_get_colormap      (GdkDrawable *drawable);

Gets the colormap for `drawable`, if one is set; returns `NULL` otherwise.

`drawable` : | a GdkDrawable
Returns : | the colormap, or `NULL`

### gdk_drawable_get_depth ()

    gint        gdk_drawable_get_depth          (GdkDrawable *drawable);

Obtains the bit depth of the drawable, that is, the number of bits that make up a pixel in the drawable's visual. Examples are 8 bits per pixel, 24 bits per pixel, etc.

`drawable` : | a GdkDrawable
Returns : | number of bits per pixel

### gdk_drawable_get_size ()

    void        gdk_drawable_get_size           (GdkDrawable *drawable,
                                                 gint *width,
                                                 gint *height);

Fills *`width` and *`height` with the size of `drawable`. `width` or `height` can be `NULL` if you only want the other one.

On the X11 platform, if `drawable` is a GdkWindow, the returned size is the size reported in the most-recently-processed configure event, rather than the current size on the X server.

`drawable` : | a GdkDrawable
`width` : | location to store drawable's width, or `NULL`
`height` : | location to store drawable's height, or `NULL`

### gdk_drawable_get_clip_region ()

    GdkRegion*  gdk_drawable_get_clip_region    (GdkDrawable *drawable);

Computes the region of a drawable that potentially can be written to by drawing primitives. This region will not take into account the clip region for the GC, and may also not take into account other factors such as if the window is obscured by other windows, but no area outside of this region will be affected by drawing primitives.

`drawable` : | a GdkDrawable
Returns : | a GdkRegion. This must be freed with gdk_region_destroy() when you are done.

### gdk_drawable_get_visible_region ()

    GdkRegion*  gdk_drawable_get_visible_region (GdkDrawable *drawable);

Computes the region of a drawable that is potentially visible. This does not necessarily take into account if the window is obscured by other windows, but no area outside of this region is visible.

`drawable` : |
Returns : | a GdkRegion. This must be freed with gdk_region_destroy() when you are done.

### gdk_draw_point ()

    void        gdk_draw_point                  (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y);

Draws a point, using the foreground color and other attributes of the GdkGC.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`x` : | the x coordinate of the point.
`y` : | the y coordinate of the point.

### gdk_draw_points ()

    void        gdk_draw_points                 (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkPoint *points,
                                                 gint npoints);

Draws a number of points, using the foreground color and other attributes of the GdkGC.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`points` : | an array of GdkPoint structures.
`npoints` : | the number of points to be drawn.

### gdk_draw_line ()

    void        gdk_draw_line                   (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x1,
                                                 gint y1,
                                                 gint x2,
                                                 gint y2);

Draws a line, using the foreground color and other attributes of the GdkGC.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`x1` : | the x coordinate of the start point.
`y1` : | the y coordinate of the start point.
`x2` : | the x coordinate of the end point.
`y2` : | the y coordinate of the end point.

### gdk_draw_lines ()

    void        gdk_draw_lines                  (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkPoint *points,
                                                 gint npoints);

Draws a series of lines connecting the given points. The way in which joins between lines are draw is determined by the GdkCapStyle value in the GdkGC. This can be set with gdk_gc_set_line_attributes().

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`points` : | an array of GdkPoint structures specifying the endpoints of the lines.
`npoints` : | the size of the `points` array.

### gdk_draw_segments ()

    void        gdk_draw_segments               (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkSegment *segs,
                                                 gint nsegs);

Draws a number of unconnected lines.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`segs` : | an array of GdkSegment structures specifying the start and end points of the lines to be drawn,
`nsegs` : | the number of line segments to draw, i.e. the size of the `segs` array.

### struct GdkSegment

    struct GdkSegment
    {
      gint x1;
      gint y1;
      gint x2;
      gint y2;
    };

Specifies the start and end point of a line for use by the gdk_draw_segments() function.

gint `x1` | the x coordinate of the start point.
gint `y1` | the y coordinate of the start point.
gint `x2` | the x coordinate of the end point.
gint `y2` | the y coordinate of the end point.

### gdk_draw_rectangle ()

    void        gdk_draw_rectangle              (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint filled,
                                                 gint x,
                                                 gint y,
                                                 gint width,
                                                 gint height);

Draws a rectangular outline or filled rectangle, using the foreground color and other attributes of the GdkGC.

> Note: A rectangle drawn filled is 1 pixel smaller in both dimensions than a rectangle outlined. Calling `gdk_draw_rectangle (window, gc, TRUE, 0, 0, 20, 20)` results in a filled rectangle 20 pixels wide and 20 pixels high. Calling `gdk_draw_rectangle (window, gc, FALSE, 0, 0, 20, 20)` results in an outlined rectangle with corners at (0, 0), (0, 20), (20, 20), and (20, 0), which makes it 21 pixels wide and 21 pixels high.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`filled` : | `TRUE` if the rectangle should be filled.
`x` : | the x coordinate of the left edge of the rectangle.
`y` : | the y coordinate of the top edge of the rectangle.
`width` : | the width of the rectangle.
`height` : | the height of the rectangle.

### gdk_draw_arc ()

    void        gdk_draw_arc                    (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint filled,
                                                 gint x,
                                                 gint y,
                                                 gint width,
                                                 gint height,
                                                 gint angle1,
                                                 gint angle2);

Draws an arc or a filled 'pie slice'. The arc is defined by the bounding rectangle of the entire ellipse, and the start and end angles of the part of the ellipse to be drawn.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`filled` : | `TRUE` if the arc should be filled, producing a 'pie slice'.
`x` : | the x coordinate of the left edge of the bounding rectangle.
`y` : | the y coordinate of the top edge of the bounding rectangle.
`width` : | the width of the bounding rectangle.
`height` : | the height of the bounding rectangle.
`angle1` : | the start angle of the arc, relative to the 3 o'clock position, counter-clockwise, in 1/64ths of a degree.
`angle2` : | the end angle of the arc, relative to `angle1`, in 1/64ths of a degree.

### gdk_draw_polygon ()

    void        gdk_draw_polygon                (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint filled,
                                                 GdkPoint *points,
                                                 gint npoints);

Draws an outlined or filled polygon.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`filled` : | `TRUE` if the polygon should be filled. The polygon is closed automatically, connecting the last point to the first point if necessary.
`points` : | an array of GdkPoint structures specifying the points making up the polygon.
`npoints` : | the number of points.

### gdk_draw_glyphs ()

    void        gdk_draw_glyphs                 (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 PangoFont *font,
                                                 gint x,
                                                 gint y,
                                                 PangoGlyphString *glyphs);

This is a low-level function; 99% of text rendering should be done using gdk_draw_layout() instead.

A glyph is a character in a font. This function draws a sequence of glyphs. To obtain a sequence of glyphs you have to understand a lot about internationalized text handling, which you don't want to understand; thus, use gdk_draw_layout() instead of this function, gdk_draw_layout() handles the details.

`drawable` : | a GdkDrawable
`gc` : | a GdkGC
`font` : | font to be used
`x` : | X coordinate of baseline origin
`y` : | Y coordinate of baseline origin
`glyphs` : | glyphs to render

### gdk_draw_layout_line ()

    void        gdk_draw_layout_line            (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayoutLine *line);

Render a PangoLayoutLine onto an GDK drawable

`drawable` : | the drawable on which to draw the line
`gc` : | base graphics to use
`x` : | the x position of start of string (in pixels)
`y` : | the y position of baseline (in pixels)
`line` : | a PangoLayoutLine

### gdk_draw_layout_line_with_colors ()

    void        gdk_draw_layout_line_with_colors
                                                (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayoutLine *line,
                                                 GdkColor *foreground,
                                                 GdkColor *background);

Render a PangoLayoutLine onto a GdkDrawable, overriding the layout's normal colors with `foreground` and/or `background`. `foreground` and `background` need not be allocated.

`drawable` : | the drawable on which to draw the line
`gc` : | base graphics to use
`x` : | the x position of start of string (in pixels)
`y` : | the y position of baseline (in pixels)
`line` : | a PangoLayoutLine
`foreground` : | foreground override color, or `NULL` for none
`background` : | background override color, or `NULL` for none

### gdk_draw_layout ()

    void        gdk_draw_layout                 (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayout *layout);

Render a PangoLayout onto a GDK drawable

`drawable` : | the drawable on which to draw string
`gc` : | base graphics context to use
`x` : | the X position of the left of the layout (in pixels)
`y` : | the Y position of the top of the layout (in pixels)
`layout` : | a PangoLayout

### gdk_draw_layout_with_colors ()

    void        gdk_draw_layout_with_colors     (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 PangoLayout *layout,
                                                 GdkColor *foreground,
                                                 GdkColor *background);

Render a PangoLayout onto a GdkDrawable, overriding the layout's normal colors with `foreground` and/or `background`. `foreground` and `background` need not be allocated.

`drawable` : | the drawable on which to draw string
`gc` : | base graphics context to use
`x` : | the X position of the left of the layout (in pixels)
`y` : | the Y position of the top of the layout (in pixels)
`layout` : | a PangoLayout
`foreground` : | foreground override color, or `NULL` for none
`background` : | background override color, or `NULL` for none

### gdk_draw_string ()

    void        gdk_draw_string                 (GdkDrawable *drawable,
                                                 GdkFont *font,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 const gchar *string);

Warning
`gdk_draw_string` is deprecated and should not be used in newly-written code.

Draws a string of characters in the given font or fontset.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`font` : | a GdkFont.
`gc` : | a GdkGC.
`x` : | the x coordinate of the left edge of the text.
`y` : | the y coordinate of the baseline of the text.
`string` : | the string of characters to draw.

### gdk_draw_text ()

    void        gdk_draw_text                   (GdkDrawable *drawable,
                                                 GdkFont *font,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 const gchar *text,
                                                 gint text_length);

Warning
`gdk_draw_text` is deprecated and should not be used in newly-written code.

Draws a number of characters in the given font or fontset.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`font` : | a GdkFont.
`gc` : | a GdkGC.
`x` : | the x coordinate of the left edge of the text.
`y` : | the y coordinate of the baseline of the text.
`text` : | the characters to draw.
`text_length` : | the number of characters of `text` to draw.

### gdk_draw_text_wc ()

    void        gdk_draw_text_wc                (GdkDrawable *drawable,
                                                 GdkFont *font,
                                                 GdkGC *gc,
                                                 gint x,
                                                 gint y,
                                                 const GdkWChar *text,
                                                 gint text_length);

Warning
`gdk_draw_text_wc` is deprecated and should not be used in newly-written code.

Draws a number of wide characters using the given font of fontset. If the font is a 1-byte font, the string is converted into 1-byte characters (discarding the high bytes) before output.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`font` : | a GdkFont.
`gc` : | a GdkGC.
`x` : | the x coordinate of the left edge of the text.
`y` : | the y coordinate of the baseline of the text.
`text` : | the wide characters to draw.
`text_length` : | the number of characters to draw.

### gdk_draw_pixmap

    #define gdk_draw_pixmap                gdk_draw_drawable

Warning
`gdk_draw_pixmap` is deprecated and should not be used in newly-written code.

Draws a pixmap, or a part of a pixmap, onto another drawable.

### gdk_draw_drawable ()

    void        gdk_draw_drawable               (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkDrawable *src,
                                                 gint xsrc,
                                                 gint ysrc,
                                                 gint xdest,
                                                 gint ydest,
                                                 gint width,
                                                 gint height);

Copies the `width` x `height` region of `src` at coordinates (`xsrc`, `ysrc`) to coordinates (`xdest`, `ydest`) in `drawable`. `width` and/or `height` may be given as -1, in which case the entire `src` drawable will be copied.

Most fields in `gc` are not used for this operation, but notably the clip mask or clip region will be honored.

The source and destination drawables must have the same visual and colormap, or errors will result. (On X11, failure to match visual/colormap results in a BadMatch error from the X server.) A common cause of this problem is an attempt to draw a bitmap to a color drawable. The way to draw a bitmap is to set the bitmap as a clip mask on your GdkGC, then use gdk_draw_rectangle() to draw a rectangle clipped to the bitmap.

`drawable` : | a GdkDrawable
`gc` : | a GdkGC sharing the drawable's visual and colormap
`src` : | another GdkDrawable
`xsrc` : | X position in `src` of rectangle to draw
`ysrc` : | Y position in `src` of rectangle to draw
`xdest` : | X position in `drawable` where the rectangle should be drawn
`ydest` : | Y position in `drawable` where the rectangle should be drawn
`width` : | width of rectangle to draw, or -1 for entire `src` width
`height` : | height of rectangle to draw, or -1 for entire `src` height

### gdk_draw_image ()

    void        gdk_draw_image                  (GdkDrawable *drawable,
                                                 GdkGC *gc,
                                                 GdkImage *image,
                                                 gint xsrc,
                                                 gint ysrc,
                                                 gint xdest,
                                                 gint ydest,
                                                 gint width,
                                                 gint height);

Draws a GdkImage onto a drawable. The depth of the GdkImage must match the depth of the GdkDrawable.

`drawable` : | a GdkDrawable (a GdkWindow or a GdkPixmap).
`gc` : | a GdkGC.
`image` : | the GdkImage to draw.
`xsrc` : | the left edge of the source rectangle within `image`.
`ysrc` : | the top of the source rectangle within `image`.
`xdest` : | the x coordinate of the destination within `drawable`.
`ydest` : | the y coordinate of the destination within `drawable`.
`width` : | the width of the area to be copied, or -1 to make the area extend to the right edge of `image`.
`height` : | the height of the area to be copied, or -1 to make the area extend to the bottom edge of `image`.

### gdk_drawable_get_image ()

    GdkImage*   gdk_drawable_get_image          (GdkDrawable *drawable,
                                                 gint x,
                                                 gint y,
                                                 gint width,
                                                 gint height);

A GdkImage stores client-side image data (pixels). In contrast, GdkPixmap and GdkWindow are server-side objects. gdk_drawable_get_image() obtains the pixels from a server-side drawable as a client-side GdkImage. The format of a GdkImage depends on the GdkVisual of the current display, which makes manipulating GdkImage extremely difficult; therefore, in most cases you should use gdk_pixbuf_get_from_drawable() instead of this lower-level function. A GdkPixbuf contains image data in a canonicalized RGB format, rather than a display-dependent format. Of course, there's a convenience vs. speed tradeoff here, so you'll want to think about what makes sense for your application.

`x`, `y`, `width`, and `height` define the region of `drawable` to obtain as an image.

You would usually copy image data to the client side if you intend to examine the values of individual pixels, for example to darken an image or add a red tint. It would be prohibitively slow to make a round-trip request to the windowing system for each pixel, so instead you get all of them at once, modify them, then copy them all back at once.

If the X server or other windowing system backend is on the local machine, this function may use shared memory to avoid copying the image data.

If the source drawable is a GdkWindow and partially offscreen or obscured, then the obscured portions of the returned image will contain undefined data.

`drawable` : | a GdkDrawable
`x` : | x coordinate on `drawable`
`y` : | y coordinate on `drawable`
`width` : | width of region to get
`height` : | height or region to get
Returns : | a GdkImage containing the contents of `drawable`

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Graphics Contexts | Bitmaps and Pixmaps