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Drawing Primitives

Drawing Primitives — Functions for drawing points, lines, arcs, and text

Types and Values

Object Hierarchy

    GObject
    ╰── GdkDrawable
        ├── GdkWindow
        ╰── GdkPixmap

Includes

#include <gdk/gdk.h>

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.

Some of the drawing operations take Pango data structures like PangoContext, PangoLayout or PangoLayoutLine as arguments. If you're using GTK+, the ususal way to obtain these structures is via gtk_widget_create_pango_context() or gtk_widget_create_pango_layout().

Functions

gdk_drawable_ref ()

GdkDrawable *
gdk_drawable_ref (GdkDrawable *drawable);

gdk_drawable_ref has been deprecated since version 2.0 and should not be used in newly-written code.

Use g_object_ref() instead.

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

Parameters

drawable

a GdkDrawable

 

Returns

the same drawable passed in


gdk_drawable_unref ()

void
gdk_drawable_unref (GdkDrawable *drawable);

gdk_drawable_unref has been deprecated since version 2.0 and should not be used in newly-written code.

Use g_object_unref() instead.

Deprecated equivalent of calling g_object_unref() on drawable .

Parameters

drawable

a GdkDrawable

 

gdk_drawable_set_data ()

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

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.

Parameters

drawable

a GdkDrawable

 

key

name to store the data under

 

data

arbitrary data

 

destroy_func

function to free data , or NULL.

[allow-none]

gdk_drawable_get_data ()

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

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.

Parameters

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);

gdk_drawable_get_display has been deprecated since version 2.24 and should not be used in newly-written code.

Use gdk_window_get_display() instead

Gets the GdkDisplay associated with a GdkDrawable.

Parameters

drawable

a GdkDrawable

 

Returns

the GdkDisplay associated with drawable

Since: 2.2


gdk_drawable_get_screen ()

GdkScreen *
gdk_drawable_get_screen (GdkDrawable *drawable);

gdk_drawable_get_screen has been deprecated since version 2.24 and should not be used in newly-written code.

Use gdk_window_get_screen() instead

Gets the GdkScreen associated with a GdkDrawable.

Parameters

drawable

a GdkDrawable

 

Returns

the GdkScreen associated with drawable

Since: 2.2


gdk_drawable_get_visual ()

GdkVisual *
gdk_drawable_get_visual (GdkDrawable *drawable);

gdk_drawable_get_visual has been deprecated since version 2.24 and should not be used in newly-written code.

Use gdk_window_get_visual()

Gets the GdkVisual describing the pixel format of drawable .

Parameters

drawable

a GdkDrawable

 

Returns

a GdkVisual


gdk_drawable_set_colormap ()

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

gdk_drawable_set_colormap is deprecated and should not be used in newly-written code.

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.

Parameters

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.

Parameters

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.

Parameters

drawable

a GdkDrawable

 

Returns

number of bits per pixel


gdk_drawable_get_size ()

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

gdk_drawable_get_size has been deprecated since version 2.24 and should not be used in newly-written code.

Use gdk_window_get_width() and gdk_window_get_height() for GdkWindows. Use gdk_pixmap_get_size() for GdkPixmaps.

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.

Parameters

drawable

a GdkDrawable

 

width

location to store drawable's width, or NULL.

[out][allow-none]

height

location to store drawable's height, or NULL.

[out][allow-none]

gdk_drawable_get_clip_region ()

GdkRegion *
gdk_drawable_get_clip_region (GdkDrawable *drawable);

gdk_drawable_get_clip_region is deprecated and should not be used in newly-written code.

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.

Parameters

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.

Parameters

drawable

a GdkDrawable

 

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);

gdk_draw_point has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_rectangle() and cairo_fill() or cairo_move_to() and cairo_stroke() instead.

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

Parameters

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,
                 const GdkPoint *points,
                 gint n_points);

gdk_draw_points has been deprecated since version 2.22 and should not be used in newly-written code.

Use n_points calls to cairo_rectangle() and cairo_fill() instead.

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

Parameters

drawable

a GdkDrawable (a GdkWindow or a GdkPixmap).

 

gc

a GdkGC.

 

points

an array of GdkPoint structures.

 

n_points

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_);

gdk_draw_line has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_line_to() and cairo_stroke() instead. Be aware that the default line width in Cairo is 2 pixels and that your coordinates need to describe the center of the line. To draw a single pixel wide pixel-aligned line, you would use:

1
2
3
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5
6
cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
cairo_move_to (cr, 0.5, 0.5);
cairo_line_to (cr, 9.5, 0.5);
cairo_stroke (cr);]|
See also <ulink url="http://cairographics.org/FAQ/#sharp_lines">the Cairo
FAQ</ulink> on this topic.

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

Parameters

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,
                const GdkPoint *points,
                gint n_points);

gdk_draw_lines has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_line_to() and cairo_stroke() instead. See the documentation of gdk_draw_line() for notes on line drawing with Cairo.

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().

Parameters

drawable

a GdkDrawable (a GdkWindow or a GdkPixmap).

 

gc

a GdkGC.

 

points

an array of GdkPoint structures specifying the endpoints of the

 

n_points

the size of the points array.

 

gdk_draw_pixbuf ()

void
gdk_draw_pixbuf (GdkDrawable *drawable,
                 GdkGC *gc,
                 const GdkPixbuf *pixbuf,
                 gint src_x,
                 gint src_y,
                 gint dest_x,
                 gint dest_y,
                 gint width,
                 gint height,
                 GdkRgbDither dither,
                 gint x_dither,
                 gint y_dither);

gdk_draw_pixbuf has been deprecated since version 2.22 and should not be used in newly-written code.

Use gdk_cairo_set_source_pixbuf() and cairo_paint() or cairo_rectangle() and cairo_fill() instead.

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-NULL 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.

If GDK is built with the Sun mediaLib library, the gdk_draw_pixbuf function is accelerated using mediaLib, which provides hardware acceleration on Intel, AMD, and Sparc chipsets. If desired, mediaLib support can be turned off by setting the GDK_DISABLE_MEDIALIB environment variable.

Parameters

drawable

Destination drawable.

 

gc

a GdkGC, used for clipping, or NULL.

[allow-none]

pixbuf

a GdkPixbuf

 

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.

 

dither

Dithering mode for GdkRGB.

 

x_dither

X offset for dither.

 

y_dither

Y offset for dither.

 

Since: 2.2


gdk_draw_segments ()

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

gdk_draw_segments has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_move_to(), cairo_line_to() and cairo_stroke() instead. See the documentation of gdk_draw_line() for notes on line drawing with Cairo.

Draws a number of unconnected lines.

Parameters

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.

 

n_segs

the number of line segments to draw, i.e. the size of the segs array.

 

gdk_draw_rectangle ()

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

gdk_draw_rectangle has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_rectangle() and cairo_fill() or cairo_stroke() instead. For stroking, the same caveats for converting code apply as for gdk_draw_line().

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

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.

Parameters

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,
              gboolean filled,
              gint x,
              gint y,
              gint width,
              gint height,
              gint angle1,
              gint angle2);

gdk_draw_arc has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_arc() and cairo_fill() or cairo_stroke() instead. Note that arcs just like any drawing operation in Cairo are antialiased unless you call cairo_set_antialias().

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.

Parameters

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,
                  gboolean filled,
                  const GdkPoint *points,
                  gint n_points);

gdk_draw_polygon has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_line_to() or cairo_append_path() and cairo_fill() or cairo_stroke() instead.

Draws an outlined or filled polygon.

Parameters

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.

 

n_points

the number of points.

 

gdk_draw_trapezoids ()

void
gdk_draw_trapezoids (GdkDrawable *drawable,
                     GdkGC *gc,
                     const GdkTrapezoid *trapezoids,
                     gint n_trapezoids);

gdk_draw_trapezoids has been deprecated since version 2.22 and should not be used in newly-written code.

Use Cairo path contruction functions and cairo_fill() instead.

Draws a set of anti-aliased trapezoids. The trapezoids are combined using saturation addition, then drawn over the background as a set. This is low level functionality used internally to implement rotated underlines and backgrouds when rendering a PangoLayout and is likely not useful for applications.

Parameters

drawable

a GdkDrawable

 

gc

a GdkGC

 

trapezoids

an array of GdkTrapezoid structures

 

n_trapezoids

the number of trapezoids to draw

 

Since: 2.6


gdk_draw_glyphs ()

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

gdk_draw_glyphs has been deprecated since version 2.22 and should not be used in newly-written code.

Use pango_cairo_show_glyphs() instead.

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

A glyph is a single image 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.

Parameters

drawable

a GdkDrawable

 

gc

a GdkGC

 

font

font to be used

 

x

X coordinate of baseline origin

 

y

Y coordinate of baseline origin

 

glyphs

the glyph string to draw

 

gdk_draw_glyphs_transformed ()

void
gdk_draw_glyphs_transformed (GdkDrawable *drawable,
                             GdkGC *gc,
                             const PangoMatrix *matrix,
                             PangoFont *font,
                             gint x,
                             gint y,
                             PangoGlyphString *glyphs);

gdk_draw_glyphs_transformed has been deprecated since version 2.22 and should not be used in newly-written code.

Use pango_cairo_show_glyphs() instead.

Renders a PangoGlyphString onto a drawable, possibly transforming the layed-out coordinates through a transformation matrix. Note that the transformation matrix for font is not changed, so to produce correct rendering results, the font must have been loaded using a PangoContext with an identical transformation matrix to that passed in to this function.

See also gdk_draw_glyphs(), gdk_draw_layout().

Parameters

drawable

a GdkDrawable

 

gc

a GdkGC

 

matrix

a PangoMatrix, or NULL to use an identity transformation.

[allow-none]

font

the font in which to draw the string

 

x

the x position of the start of the string (in Pango units in user space coordinates)

 

y

the y position of the baseline (in Pango units in user space coordinates)

 

glyphs

the glyph string to draw

 

Since: 2.6


gdk_draw_layout_line ()

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

gdk_draw_layout_line is deprecated and should not be used in newly-written code.

Render a PangoLayoutLine onto an GDK drawable

If the layout's PangoContext has a transformation matrix set, then x and y specify the position of the left edge of the baseline (left is in before-tranform user coordinates) in after-transform device coordinates.

Parameters

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,
                                  const GdkColor *foreground,
                                  const GdkColor *background);

gdk_draw_layout_line_with_colors is deprecated and should not be used in newly-written code.

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

If the layout's PangoContext has a transformation matrix set, then x and y specify the position of the left edge of the baseline (left is in before-tranform user coordinates) in after-transform device coordinates.

Parameters

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.

[allow-none]

background

background override color, or NULL for none.

[allow-none]

gdk_draw_layout ()

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

gdk_draw_layout is deprecated and should not be used in newly-written code.

Render a PangoLayout onto a GDK drawable

If the layout's PangoContext has a transformation matrix set, then x and y specify the position of the top left corner of the bounding box (in device space) of the transformed layout.

If you're using GTK+, the usual way to obtain a PangoLayout is gtk_widget_create_pango_layout().

Parameters

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,
                             const GdkColor *foreground,
                             const GdkColor *background);

gdk_draw_layout_with_colors is deprecated and should not be used in newly-written code.

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

If the layout's PangoContext has a transformation matrix set, then x and y specify the position of the top left corner of the bounding box (in device space) of the transformed layout.

If you're using GTK+, the ususal way to obtain a PangoLayout is gtk_widget_create_pango_layout().

Parameters

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.

[allow-none]

background

background override color, or NULL for none.

[allow-none]

gdk_draw_string ()

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

gdk_draw_string has been deprecated since version 2.4 and should not be used in newly-written code.

Use gdk_draw_layout() instead.

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

Parameters

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);

gdk_draw_text has been deprecated since version 2.4 and should not be used in newly-written code.

Use gdk_draw_layout() instead.

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

Parameters

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);

gdk_draw_text_wc has been deprecated since version 2.4 and should not be used in newly-written code.

Use gdk_draw_layout() instead.

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.

Parameters

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_drawable ()

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

gdk_draw_drawable has been deprecated since version 2.22 and should not be used in newly-written code.

Use gdk_cairo_set_source_pixmap(), cairo_rectangle() and cairo_fill() to draw pixmap on top of other drawables. Also keep in mind that the limitations on allowed sources do not apply to Cairo.

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 the stipple on the GdkGC, set the fill mode to GDK_STIPPLED, and then draw the rectangle.

Parameters

drawable

a GdkDrawable

 

gc

a GdkGC sharing the drawable's visual and colormap

 

src

the source GdkDrawable, which may be the same as drawable

 

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);

gdk_draw_image has been deprecated since version 2.22 and should not be used in newly-written code.

Do not use GdkImage anymore, instead use Cairo image surfaces.

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

Parameters

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);

gdk_drawable_get_image has been deprecated since version 2.22 and should not be used in newly-written code.

Use drawable as the source and draw to a Cairo image surface if you want to download contents to the client.

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.

Parameters

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


gdk_drawable_copy_to_image ()

GdkImage *
gdk_drawable_copy_to_image (GdkDrawable *drawable,
                            GdkImage *image,
                            gint src_x,
                            gint src_y,
                            gint dest_x,
                            gint dest_y,
                            gint width,
                            gint height);

gdk_drawable_copy_to_image has been deprecated since version 2.22 and should not be used in newly-written code.

Use drawable as the source and draw to a Cairo image surface if you want to download contents to the client.

Copies a portion of drawable into the client side image structure image . If image is NULL, creates a new image of size width x height and copies into that. See gdk_drawable_get_image() for further details.

Parameters

drawable

a GdkDrawable

 

image

a GdkDrawable, or NULL if a new image should be created.

[allow-none]

src_x

x coordinate on drawable

 

src_y

y coordinate on drawable

 

dest_x

x coordinate within image . Must be 0 if image is NULL

 

dest_y

y coordinate within image . Must be 0 if image is NULL

 

width

width of region to get

 

height

height or region to get

 

Returns

image , or a new a GdkImage containing the contents of drawable

Since: 2.4

Types and Values

GdkDrawable

typedef struct _GdkDrawable GdkDrawable;

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


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.

Members

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.

 

struct GdkTrapezoid

struct GdkTrapezoid {
  double y1, x11, x21, y2, x12, x22;
};

Specifies a trapezpoid for use by the gdk_draw_trapezoids(). The trapezoids used here have parallel, horizontal top and bottom edges.

Members

double y1;

the y coordinate of the start point.

 

double x11;

the x coordinate of the top left corner

 

double x21;

the x coordinate of the top right corner

 

double y2;

the y coordinate of the end point.

 

double x12;

the x coordinate of the bottom left corner

 

double x22;

the x coordinate of the bottom right corner

 

gdk_draw_pixmap

#define gdk_draw_pixmap                gdk_draw_drawable

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

Use gdk_draw_drawable() instead.

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

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