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, const GdkPoint *points, gint n_points); void gdk_draw_line (GdkDrawable *drawable, GdkGC *gc, gint x1_, gint y1_, gint x2_, gint y2_); void gdk_draw_lines (GdkDrawable *drawable, GdkGC *gc, const GdkPoint *points, gint n_points); 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); void gdk_draw_segments (GdkDrawable *drawable, GdkGC *gc, const GdkSegment *segs, gint n_segs); 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, const GdkPoint *points, gint n_points); void gdk_draw_trapezoids (GdkDrawable *drawable, GdkGC *gc, const 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, const 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); DescriptionThese 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 DetailsGdkDrawabletypedef 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
Deprecated equivalent of calling
gdk_drawable_unref ()void gdk_drawable_unref (GdkDrawable *drawable); Warning
Deprecated equivalent of calling
gdk_drawable_set_data ()void gdk_drawable_set_data (GdkDrawable *drawable, const gchar *key, gpointer data, GDestroyNotify destroy_func); Warning
This function is equivalent to
gdk_drawable_get_data ()gpointer gdk_drawable_get_data (GdkDrawable *drawable, const gchar *key); Warning
Equivalent to
gdk_drawable_get_display ()GdkDisplay* gdk_drawable_get_display (GdkDrawable *drawable); Gets the GdkDisplay associated with a GdkDrawable.
Since 2.2 gdk_drawable_get_screen ()GdkScreen* gdk_drawable_get_screen (GdkDrawable *drawable); Gets the GdkScreen associated with a GdkDrawable.
Since 2.2 gdk_drawable_get_visual ()GdkVisual* gdk_drawable_get_visual (GdkDrawable *drawable);
Gets the GdkVisual describing the pixel format of
gdk_drawable_set_colormap ()void gdk_drawable_set_colormap (GdkDrawable *drawable, GdkColormap *colormap);
Sets the colormap associated with
gdk_drawable_get_colormap ()GdkColormap* gdk_drawable_get_colormap (GdkDrawable *drawable);
Gets the colormap for
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.
gdk_drawable_get_size ()void gdk_drawable_get_size (GdkDrawable *drawable, gint *width, gint *height);
Fills *
On the X11 platform, if
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.
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.
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.
gdk_draw_points ()void gdk_draw_points (GdkDrawable *drawable, GdkGC *gc, const GdkPoint *points, gint n_points); Draws a number of points, using the foreground color and other attributes of the GdkGC.
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.
gdk_draw_lines ()void gdk_draw_lines (GdkDrawable *drawable, GdkGC *gc, const GdkPoint *points, gint n_points);
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_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);
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- 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 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.
Since 2.2 gdk_draw_segments ()void gdk_draw_segments (GdkDrawable *drawable, GdkGC *gc, const GdkSegment *segs, gint n_segs); Draws a number of unconnected lines.
GdkSegmenttypedef 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_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
Note
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.
gdk_draw_polygon ()void gdk_draw_polygon (GdkDrawable *drawable, GdkGC *gc, gboolean filled, const GdkPoint *points, gint n_points); Draws an outlined or filled polygon.
gdk_draw_trapezoids ()void gdk_draw_trapezoids (GdkDrawable *drawable, GdkGC *gc, const 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.
Since 2.6 GdkTrapezoidtypedef struct { double y1, x11, x21, y2, x12, x22; } GdkTrapezoid;
Specifies a trapezpoid for use by the
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
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_glyphs_transformed ()void gdk_draw_glyphs_transformed (GdkDrawable *drawable, GdkGC *gc, const 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
See also
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
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
If the layout's PangoContext has a transformation matrix set, then
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
If you're using GTK+, the usual way to obtain a PangoLayout
is
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
If the layout's PangoContext has a transformation matrix set, then
If you're using GTK+, the ususal way to obtain a PangoLayout
is
gdk_draw_string ()void gdk_draw_string (GdkDrawable *drawable, GdkFont *font, GdkGC *gc, gint x, gint y, const gchar *string); Warning
Draws a string of characters in the given font or fontset.
gdk_draw_text ()void gdk_draw_text (GdkDrawable *drawable, GdkFont *font, GdkGC *gc, gint x, gint y, const gchar *text, gint text_length); Warning
Draws a number of characters in the given font or fontset.
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
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.
gdk_draw_pixmap#define gdk_draw_pixmap gdk_draw_drawable Warning
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
Most fields in
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_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.
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.
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.
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
Since 2.4 |