path: root/docs/reference/gdk/tmpl/drawing.sgml

<!-- ##### SECTION Title ##### -->
Drawing Primitives

<!-- ##### SECTION Short_Description ##### -->
functions for drawing points, lines, arcs, and text.

<!-- ##### SECTION Long_Description ##### -->
<para>
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.
</para>
<para>
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
<link linkend="gdk-Graphics-Contexts">Graphics Contexts</link> section for
more information.
</para>

<!-- ##### SECTION See_Also ##### -->
<para>

</para>

<!-- ##### FUNCTION gdk_draw_point ##### -->
<para>
Draws a point, using the foreground color and other attributes of the #GdkGC.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_points ##### -->
<para>
Draws a number of points, using the foreground color and other attributes of
the #GdkGC.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_line ##### -->
<para>
Draws a line, using the foreground color and other attributes of the #GdkGC.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_lines ##### -->
<para>
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().
</para>

@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.


<!-- ##### FUNCTION gdk_draw_segments ##### -->
<para>
Draws a number of unconnected lines.
</para>

@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 ##### -->
<para>
Specifies the start and end point of a line for use by the gdk_draw_segments()
function.
</para>

@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.

<!-- ##### FUNCTION gdk_draw_rectangle ##### -->
<para>
Draws a rectangular outline or filled rectangle, using the foreground color
and other attributes of the #GdkGC.
</para>
<note>
<para>
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.
</para>
</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.


<!-- ##### FUNCTION gdk_draw_arc ##### -->
<para>
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.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_polygon ##### -->
<para>
Draws an outlined or filled polygon.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_string ##### -->
<para>
Draws a string of characters in the given font or fontset.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_text ##### -->
<para>
Draws a number of characters in the given font or fontset.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_text_wc ##### -->
<para>
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.
</para>

@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.


<!-- ##### FUNCTION gdk_draw_pixmap ##### -->
<para>
Draws a pixmap, or a part of a pixmap, onto another drawable.
</para>

@drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
@gc: a #GdkGC.
@src: the source #GdkPixmap to draw.
@xsrc: the left edge of the source rectangle within @src.
@ysrc: the top of the source rectangle within @src.
@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 the source pixmap.
@height: the height of the area to be copied, or -1 to make the area extend
to the bottom edge of the source pixmap.


<!-- ##### FUNCTION gdk_draw_image ##### -->
<para>
Draws a #GdkImage onto a drawable.
The depth of the #GdkImage must match the depth of the #GdkDrawable.
</para>

@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.