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Drawing Primitives

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

Synopsis


#include <gdk/gdk.h>


            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_pixbuf                 (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             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);
void        gdk_draw_segments               (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             GdkSegment *segs,
                                             gint nsegs);
            GdkSegment;
void        gdk_draw_rectangle              (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             gboolean filled,
                                             gint x,
                                             gint y,
                                             gint width,
                                             gint height);
void        gdk_draw_arc                    (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             gboolean filled,
                                             gint x,
                                             gint y,
                                             gint width,
                                             gint height,
                                             gint angle1,
                                             gint angle2);
void        gdk_draw_polygon                (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             gboolean filled,
                                             GdkPoint *points,
                                             gint npoints);
void        gdk_draw_trapezoids             (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             GdkTrapezoid *trapezoids,
                                             gint n_trapezoids);
            GdkTrapezoid;
void        gdk_draw_glyphs                 (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             PangoFont *font,
                                             gint x,
                                             gint y,
                                             PangoGlyphString *glyphs);
void        gdk_draw_glyphs_transformed     (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             PangoMatrix *matrix,
                                             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,
                                             const GdkColor *foreground,
                                             const 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,
                                             const GdkColor *foreground,
                                             const 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);
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);


Object Hierarchy


  GObject
   +----GdkDrawable
         +----GdkWindow
         +----GdkPixmap

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().

Details

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.


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

Since 2.2


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

Since 2.2


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
npoints : the size of the points array.

gdk_draw_pixbuf ()

void        gdk_draw_pixbuf                 (GdkDrawable *drawable,
                                             GdkGC *gc,
                                             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);

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.

The clip mask of gc is ignored, but clip rectangles and clip regions work fine.

drawable : Destination drawable.
gc : a GdkGC, used for clipping, or NULL
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,
                                             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.

GdkSegment

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

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,
                                             gboolean 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.

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.

Note

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);

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,
                                             gboolean 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_trapezoids ()

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

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.

drawable : a GdkDrawable
gc : a GdkGC
trapezoids : an array of GdkTrapezoid structures
n_trapezoids : the number of trapezoids to draw

Since 2.6


GdkTrapezoid

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

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

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_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 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.

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,
                                             PangoMatrix *matrix,
                                             PangoFont *font,
                                             gint x,
                                             gint y,
                                             PangoGlyphString *glyphs);

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().

drawable : a GdkDrawable
gc : a GdkGC
matrix : a PangoMatrix, or NULL to use an identity transformation
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);

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.

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);

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.

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

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().

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);

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().

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. Use gdk_draw_layout() instead.

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. Use gdk_draw_layout() instead.

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. 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.

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. Use gdk_draw_drawable() instead.

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 : 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);

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

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);

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.

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