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gtk2/gdk/gdkdraw.c
Owen Taylor 93344f6dfe Add gdk_drawable_set_cairo_target(). 
2005-02-03  Owen Taylor  <otaylor@redhat.com>

        * gdk/gdkdrawable.[ch] gdkpixmap.c gdkwindow.c: Add
        gdk_drawable_set_cairo_target().

        * tests/testtreeflow.c (enum): Use grand not rand as a variable
        name because one of the cairo headers is pulling in stdlib.h.

        * tests/testcairo.c tests/Makefile.am: Add a simple cairo based
        example.

        * configure.in: Bump release to 2.7.0, gtk_binary_version to 2.7.0.

        * Require libpangocairo for all backends.
2005-02-03 23:29:02 +00:00

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/* GDK - The GIMP Drawing Kit
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include <config.h>
#include <math.h>
#include "gdkalias.h"
#include "gdkdrawable.h"
#include "gdkinternals.h"
#include "gdkwindow.h"
#include "gdkscreen.h"
#include "gdk-pixbuf-private.h"
#include "gdkpixbuf.h"
static GdkImage* gdk_drawable_real_get_image (GdkDrawable *drawable,
gint x,
gint y,
gint width,
gint height);
static GdkDrawable* gdk_drawable_real_get_composite_drawable (GdkDrawable *drawable,
gint x,
gint y,
gint width,
gint height,
gint *composite_x_offset,
gint *composite_y_offset);
static GdkRegion * gdk_drawable_real_get_visible_region (GdkDrawable *drawable);
static void gdk_drawable_real_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);
static void gdk_drawable_real_draw_trapezoids (GdkDrawable *drawable,
GdkGC *gc,
GdkTrapezoid *trapezoids,
gint n_trapezoids);
static void gdk_drawable_class_init (GdkDrawableClass *klass);
GType
gdk_drawable_get_type (void)
{
static GType object_type = 0;
if (!object_type)
{
static const GTypeInfo object_info =
{
sizeof (GdkDrawableClass),
(GBaseInitFunc) NULL,
(GBaseFinalizeFunc) NULL,
(GClassInitFunc) gdk_drawable_class_init,
NULL, /* class_finalize */
NULL, /* class_data */
sizeof (GdkDrawable),
0, /* n_preallocs */
(GInstanceInitFunc) NULL,
};
object_type = g_type_register_static (G_TYPE_OBJECT,
"GdkDrawable",
&object_info,
G_TYPE_FLAG_ABSTRACT);
}
return object_type;
}
static void
gdk_drawable_class_init (GdkDrawableClass *klass)
{
klass->get_image = gdk_drawable_real_get_image;
klass->get_composite_drawable = gdk_drawable_real_get_composite_drawable;
/* Default implementation for clip and visible region is the same */
klass->get_clip_region = gdk_drawable_real_get_visible_region;
klass->get_visible_region = gdk_drawable_real_get_visible_region;
klass->draw_pixbuf = gdk_drawable_real_draw_pixbuf;
klass->draw_trapezoids = gdk_drawable_real_draw_trapezoids;
}
/* Manipulation of drawables
*/
/**
* gdk_drawable_set_data:
* @drawable: a #GdkDrawable
* @key: name to store the data under
* @data: arbitrary data
* @destroy_func: function to free @data, or %NULL
*
* This function is equivalent to g_object_set_data(),
* the #GObject variant should be used instead.
*
**/
void
gdk_drawable_set_data (GdkDrawable *drawable,
const gchar *key,
gpointer data,
GDestroyNotify destroy_func)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_object_set_qdata_full (G_OBJECT (drawable),
g_quark_from_string (key),
data,
destroy_func);
}
/**
* gdk_drawable_get_data:
* @drawable: a #GdkDrawable
* @key: name the data was stored under
*
* Equivalent to g_object_get_data(); the #GObject variant should be
* used instead.
*
* Return value: the data stored at @key
**/
gpointer
gdk_drawable_get_data (GdkDrawable *drawable,
const gchar *key)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return g_object_get_qdata (G_OBJECT (drawable),
g_quark_try_string (key));
}
/**
* gdk_drawable_get_size:
* @drawable: a #GdkDrawable
* @width: location to store drawable's width, or %NULL
* @height: location to store drawable's height, or %NULL
*
* 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.
*
**/
void
gdk_drawable_get_size (GdkDrawable *drawable,
gint *width,
gint *height)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
GDK_DRAWABLE_GET_CLASS (drawable)->get_size (drawable, width, height);
}
/**
* gdk_drawable_get_visual:
* @drawable: a #GdkDrawable
*
* Gets the #GdkVisual describing the pixel format of @drawable.
*
* Return value: a #GdkVisual
**/
GdkVisual*
gdk_drawable_get_visual (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_visual (drawable);
}
/**
* gdk_drawable_get_depth:
* @drawable: a #GdkDrawable
*
* 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.
*
* Return value: number of bits per pixel
**/
gint
gdk_drawable_get_depth (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), 0);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_depth (drawable);
}
/**
* gdk_drawable_get_screen:
* @drawable: a #GdkDrawable
*
* Gets the #GdkScreen associated with a #GdkDrawable.
*
* Return value: the #GdkScreen associated with @drawable
*
* Since: 2.2
**/
GdkScreen*
gdk_drawable_get_screen(GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_screen (drawable);
}
/**
* gdk_drawable_get_display:
* @drawable: a #GdkDrawable
*
* Gets the #GdkDisplay associated with a #GdkDrawable.
*
* Return value: the #GdkDisplay associated with @drawable
*
* Since: 2.2
**/
GdkDisplay*
gdk_drawable_get_display (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return gdk_screen_get_display (gdk_drawable_get_screen (drawable));
}
/**
* gdk_drawable_set_colormap:
* @drawable: a #GdkDrawable
* @colormap: a #GdkColormap
*
* 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.
*
**/
void
gdk_drawable_set_colormap (GdkDrawable *drawable,
GdkColormap *cmap)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (cmap == NULL || gdk_drawable_get_depth (drawable)
== cmap->visual->depth);
GDK_DRAWABLE_GET_CLASS (drawable)->set_colormap (drawable, cmap);
}
/**
* gdk_drawable_get_colormap:
* @drawable: a #GdkDrawable
*
* Gets the colormap for @drawable, if one is set; returns
* %NULL otherwise.
*
* Return value: the colormap, or %NULL
**/
GdkColormap*
gdk_drawable_get_colormap (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_colormap (drawable);
}
/**
* gdk_drawable_ref:
* @drawable: a #GdkDrawable
*
* Deprecated equivalent of calling g_object_ref() on @drawable.
* (Drawables were not objects in previous versions of GDK.)
*
* Return value: the same @drawable passed in
**/
GdkDrawable*
gdk_drawable_ref (GdkDrawable *drawable)
{
return (GdkDrawable *) g_object_ref (drawable);
}
/**
* gdk_drawable_unref:
* @drawable: a #GdkDrawable
*
* Deprecated equivalent of calling g_object_unref() on @drawable.
*
**/
void
gdk_drawable_unref (GdkDrawable *drawable)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_object_unref (drawable);
}
/* Drawing
*/
/**
* gdk_draw_point:
* @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.
*
* Draws a point, using the foreground color and other attributes of
* the #GdkGC.
**/
void
gdk_draw_point (GdkDrawable *drawable,
GdkGC *gc,
gint x,
gint y)
{
GdkPoint point;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
point.x = x;
point.y = y;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_points (drawable, gc, &point, 1);
}
/**
* gdk_draw_line:
* @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.
*
* Draws a line, using the foreground color and other attributes of
* the #GdkGC.
**/
void
gdk_draw_line (GdkDrawable *drawable,
GdkGC *gc,
gint x1,
gint y1,
gint x2,
gint y2)
{
GdkSegment segment;
g_return_if_fail (drawable != NULL);
g_return_if_fail (gc != NULL);
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
segment.x1 = x1;
segment.y1 = y1;
segment.x2 = x2;
segment.y2 = y2;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_segments (drawable, gc, &segment, 1);
}
/**
* gdk_draw_rectangle:
* @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.
*
* 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
* <literal>gdk_draw_rectangle (window, gc, TRUE, 0, 0, 20, 20)</literal>
* results in a filled rectangle 20 pixels wide and 20 pixels high. Calling
* <literal>gdk_draw_rectangle (window, gc, FALSE, 0, 0, 20, 20)</literal>
* 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.
**/
void
gdk_draw_rectangle (GdkDrawable *drawable,
GdkGC *gc,
gboolean filled,
gint x,
gint y,
gint width,
gint height)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
if (width < 0 || height < 0)
{
gint real_width;
gint real_height;
gdk_drawable_get_size (drawable, &real_width, &real_height);
if (width < 0)
width = real_width;
if (height < 0)
height = real_height;
}
GDK_DRAWABLE_GET_CLASS (drawable)->draw_rectangle (drawable, gc, filled, x, y,
width, height);
}
/**
* gdk_draw_arc:
* @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.
*
* 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.
**/
void
gdk_draw_arc (GdkDrawable *drawable,
GdkGC *gc,
gboolean filled,
gint x,
gint y,
gint width,
gint height,
gint angle1,
gint angle2)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
if (width < 0 || height < 0)
{
gint real_width;
gint real_height;
gdk_drawable_get_size (drawable, &real_width, &real_height);
if (width < 0)
width = real_width;
if (height < 0)
height = real_height;
}
GDK_DRAWABLE_GET_CLASS (drawable)->draw_arc (drawable, gc, filled,
x, y, width, height, angle1, angle2);
}
/**
* gdk_draw_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.
*
* Draws an outlined or filled polygon.
**/
void
gdk_draw_polygon (GdkDrawable *drawable,
GdkGC *gc,
gboolean filled,
GdkPoint *points,
gint npoints)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
GDK_DRAWABLE_GET_CLASS (drawable)->draw_polygon (drawable, gc, filled,
points, npoints);
}
/* gdk_draw_string
*
* Modified by Li-Da Lho to draw 16 bits and Multibyte strings
*
* Interface changed: add "GdkFont *font" to specify font or fontset explicitely
*/
/**
* gdk_draw_string:
* @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.
*
* Draws a string of characters in the given font or fontset.
*
* Deprecated: Use gdk_draw_layout() instead.
**/
void
gdk_draw_string (GdkDrawable *drawable,
GdkFont *font,
GdkGC *gc,
gint x,
gint y,
const gchar *string)
{
gdk_draw_text (drawable, font, gc, x, y, string, _gdk_font_strlen (font, string));
}
/* gdk_draw_text
*
* Modified by Li-Da Lho to draw 16 bits and Multibyte strings
*
* Interface changed: add "GdkFont *font" to specify font or fontset explicitely
*/
/**
* gdk_draw_text:
* @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.
*
* Draws a number of characters in the given font or fontset.
*
* Deprecated: Use gdk_draw_layout() instead.
**/
void
gdk_draw_text (GdkDrawable *drawable,
GdkFont *font,
GdkGC *gc,
gint x,
gint y,
const gchar *text,
gint text_length)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (font != NULL);
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (text != NULL);
GDK_DRAWABLE_GET_CLASS (drawable)->draw_text (drawable, font, gc, x, y, text, text_length);
}
/**
* gdk_draw_text_wc:
* @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.
*
* 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.
*
* Deprecated: Use gdk_draw_layout() instead.
**/
void
gdk_draw_text_wc (GdkDrawable *drawable,
GdkFont *font,
GdkGC *gc,
gint x,
gint y,
const GdkWChar *text,
gint text_length)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (font != NULL);
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (text != NULL);
GDK_DRAWABLE_GET_CLASS (drawable)->draw_text_wc (drawable, font, gc, x, y, text, text_length);
}
/**
* gdk_draw_drawable:
* @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
*
* 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.
**/
void
gdk_draw_drawable (GdkDrawable *drawable,
GdkGC *gc,
GdkDrawable *src,
gint xsrc,
gint ysrc,
gint xdest,
gint ydest,
gint width,
gint height)
{
GdkDrawable *composite;
gint composite_x_offset = 0;
gint composite_y_offset = 0;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (src != NULL);
g_return_if_fail (GDK_IS_GC (gc));
if (width < 0 || height < 0)
{
gint real_width;
gint real_height;
gdk_drawable_get_size (src, &real_width, &real_height);
if (width < 0)
width = real_width;
if (height < 0)
height = real_height;
}
composite =
GDK_DRAWABLE_GET_CLASS (src)->get_composite_drawable (src,
xsrc, ysrc,
width, height,
&composite_x_offset,
&composite_y_offset);
GDK_DRAWABLE_GET_CLASS (drawable)->draw_drawable (drawable, gc, composite,
xsrc - composite_x_offset,
ysrc - composite_y_offset,
xdest, ydest,
width, height);
g_object_unref (composite);
}
/**
* gdk_draw_image:
* @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.
*
* Draws a #GdkImage onto a drawable.
* The depth of the #GdkImage must match the depth of the #GdkDrawable.
**/
void
gdk_draw_image (GdkDrawable *drawable,
GdkGC *gc,
GdkImage *image,
gint xsrc,
gint ysrc,
gint xdest,
gint ydest,
gint width,
gint height)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (image != NULL);
g_return_if_fail (GDK_IS_GC (gc));
if (width == -1)
width = image->width;
if (height == -1)
height = image->height;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_image (drawable, gc, image, xsrc, ysrc,
xdest, ydest, width, height);
}
/**
* gdk_draw_pixbuf:
* @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.
*
* 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.
*
* Since: 2.2
**/
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)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (gc == NULL || GDK_IS_GC (gc));
g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
if (width == -1)
width = gdk_pixbuf_get_width (pixbuf);
if (height == -1)
height = gdk_pixbuf_get_height (pixbuf);
GDK_DRAWABLE_GET_CLASS (drawable)->draw_pixbuf (drawable, gc, pixbuf,
src_x, src_y, dest_x, dest_y, width, height,
dither, x_dither, y_dither);
}
/**
* gdk_draw_points:
* @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.
*
* Draws a number of points, using the foreground color and other
* attributes of the #GdkGC.
**/
void
gdk_draw_points (GdkDrawable *drawable,
GdkGC *gc,
GdkPoint *points,
gint npoints)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail ((points != NULL) && (npoints > 0));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (npoints >= 0);
if (npoints == 0)
return;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_points (drawable, gc, points, npoints);
}
/**
* gdk_draw_segments:
* @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.
*
* Draws a number of unconnected lines.
**/
void
gdk_draw_segments (GdkDrawable *drawable,
GdkGC *gc,
GdkSegment *segs,
gint nsegs)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
if (nsegs == 0)
return;
g_return_if_fail (segs != NULL);
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (nsegs >= 0);
GDK_DRAWABLE_GET_CLASS (drawable)->draw_segments (drawable, gc, segs, nsegs);
}
/**
* gdk_draw_lines:
* @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.
*
* 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().
**/
void
gdk_draw_lines (GdkDrawable *drawable,
GdkGC *gc,
GdkPoint *points,
gint npoints)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (points != NULL);
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (npoints >= 0);
if (npoints == 0)
return;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_lines (drawable, gc, points, npoints);
}
/**
* gdk_draw_glyphs:
* @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
*
* 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.
*
**/
void
gdk_draw_glyphs (GdkDrawable *drawable,
GdkGC *gc,
PangoFont *font,
gint x,
gint y,
PangoGlyphString *glyphs)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
GDK_DRAWABLE_GET_CLASS (drawable)->draw_glyphs (drawable, gc, font, x, y, glyphs);
}
/**
* gdk_draw_glyphs_transformed:
* @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
*
* 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().
*
* Since: 2.6
**/
void
gdk_draw_glyphs_transformed (GdkDrawable *drawable,
GdkGC *gc,
PangoMatrix *matrix,
PangoFont *font,
gint x,
gint y,
PangoGlyphString *glyphs)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
if (GDK_DRAWABLE_GET_CLASS (drawable)->draw_glyphs_transformed)
GDK_DRAWABLE_GET_CLASS (drawable)->draw_glyphs_transformed (drawable, gc, matrix,
font, x, y, glyphs);
}
/**
* gdk_draw_trapezoids:
* @drawable: a #GdkDrawable
* @gc: a #GdkGC
* @trapezoids: an array of #GdkTrapezoid structures
* @n_trapezoids: the number of trapezoids to draw
*
* 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
**/
void
gdk_draw_trapezoids (GdkDrawable *drawable,
GdkGC *gc,
GdkTrapezoid *trapezoids,
gint n_trapezoids)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (n_trapezoids == 0 || trapezoids != NULL);
GDK_DRAWABLE_GET_CLASS (drawable)->draw_trapezoids (drawable, gc,
trapezoids, n_trapezoids);
}
/**
* gdk_drawable_copy_to_image:
* @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
*
* 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.
*
* Return value: @image, or a new a #GdkImage containing the contents
* of @drawable
*
* Since: 2.4
**/
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)
{
GdkDrawable *composite;
gint composite_x_offset = 0;
gint composite_y_offset = 0;
GdkImage *retval;
GdkColormap *cmap;
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
g_return_val_if_fail (src_x >= 0, NULL);
g_return_val_if_fail (src_y >= 0, NULL);
/* FIXME? Note race condition since we get the size then
* get the image, and the size may have changed.
*/
if (width < 0 || height < 0)
gdk_drawable_get_size (drawable,
width < 0 ? &width : NULL,
height < 0 ? &height : NULL);
composite =
GDK_DRAWABLE_GET_CLASS (drawable)->get_composite_drawable (drawable,
src_x, src_y,
width, height,
&composite_x_offset,
&composite_y_offset);
retval = GDK_DRAWABLE_GET_CLASS (composite)->_copy_to_image (composite,
image,
src_x - composite_x_offset,
src_y - composite_y_offset,
dest_x, dest_y,
width, height);
g_object_unref (composite);
if (!image && retval)
{
cmap = gdk_drawable_get_colormap (drawable);
if (cmap)
gdk_image_set_colormap (retval, cmap);
}
return retval;
}
/**
* gdk_drawable_get_image:
* @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
*
* 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.
*
* Return value: a #GdkImage containing the contents of @drawable
**/
GdkImage*
gdk_drawable_get_image (GdkDrawable *drawable,
gint x,
gint y,
gint width,
gint height)
{
GdkDrawable *composite;
gint composite_x_offset = 0;
gint composite_y_offset = 0;
GdkImage *retval;
GdkColormap *cmap;
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
g_return_val_if_fail (x >= 0, NULL);
g_return_val_if_fail (y >= 0, NULL);
/* FIXME? Note race condition since we get the size then
* get the image, and the size may have changed.
*/
if (width < 0 || height < 0)
gdk_drawable_get_size (drawable,
width < 0 ? &width : NULL,
height < 0 ? &height : NULL);
composite =
GDK_DRAWABLE_GET_CLASS (drawable)->get_composite_drawable (drawable,
x, y,
width, height,
&composite_x_offset,
&composite_y_offset);
retval = GDK_DRAWABLE_GET_CLASS (composite)->get_image (composite,
x - composite_x_offset,
y - composite_y_offset,
width, height);
g_object_unref (composite);
cmap = gdk_drawable_get_colormap (drawable);
if (retval && cmap)
gdk_image_set_colormap (retval, cmap);
return retval;
}
static GdkImage*
gdk_drawable_real_get_image (GdkDrawable *drawable,
gint x,
gint y,
gint width,
gint height)
{
return gdk_drawable_copy_to_image (drawable, NULL, x, y, 0, 0, width, height);
}
static GdkDrawable*
gdk_drawable_real_get_composite_drawable (GdkDrawable *drawable,
gint x,
gint y,
gint width,
gint height,
gint *composite_x_offset,
gint *composite_y_offset)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
*composite_x_offset = 0;
*composite_y_offset = 0;
return g_object_ref (drawable);
}
/**
* gdk_drawable_get_clip_region:
* @drawable: a #GdkDrawable
*
* 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.
*
* Return value: a #GdkRegion. This must be freed with gdk_region_destroy()
* when you are done.
**/
GdkRegion *
gdk_drawable_get_clip_region (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_clip_region (drawable);
}
/**
* gdk_drawable_get_visible_region:
* @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.
*
* Return value: a #GdkRegion. This must be freed with gdk_region_destroy()
* when you are done.
**/
GdkRegion *
gdk_drawable_get_visible_region (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_visible_region (drawable);
}
static GdkRegion *
gdk_drawable_real_get_visible_region (GdkDrawable *drawable)
{
GdkRectangle rect;
rect.x = 0;
rect.y = 0;
gdk_drawable_get_size (drawable, &rect.width, &rect.height);
return gdk_region_rectangle (&rect);
}
/**
* gdk_drawable_set_cairo_target:
* @drawable: a #GdkDrawable
* @cr: a cairo context
*
* Sets the given drawable as the target surface for a Cairo context.
* Note that when @drawable is a window and gdk_window_begin_paint()
* has been called, the target surface will be set to the temporary
* backing pixmap, so you can only use the Cairo context until
* the matching call to gdk_window_end_paint().
*
* Since: 2.10
**/
void
gdk_drawable_set_cairo_target (GdkDrawable *drawable,
cairo_t *cr)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (cr != NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->set_cairo_target (drawable, cr);
}
static void
composite (guchar *src_buf,
gint src_rowstride,
guchar *dest_buf,
gint dest_rowstride,
gint width,
gint height)
{
guchar *src = src_buf;
guchar *dest = dest_buf;
while (height--)
{
gint twidth = width;
guchar *p = src;
guchar *q = dest;
while (twidth--)
{
guchar a = p[3];
guint t;
t = a * p[0] + (255 - a) * q[0] + 0x80;
q[0] = (t + (t >> 8)) >> 8;
t = a * p[1] + (255 - a) * q[1] + 0x80;
q[1] = (t + (t >> 8)) >> 8;
t = a * p[2] + (255 - a) * q[2] + 0x80;
q[2] = (t + (t >> 8)) >> 8;
p += 4;
q += 3;
}
src += src_rowstride;
dest += dest_rowstride;
}
}
static void
composite_0888 (guchar *src_buf,
gint src_rowstride,
guchar *dest_buf,
gint dest_rowstride,
GdkByteOrder dest_byte_order,
gint width,
gint height)
{
guchar *src = src_buf;
guchar *dest = dest_buf;
while (height--)
{
gint twidth = width;
guchar *p = src;
guchar *q = dest;
if (dest_byte_order == GDK_LSB_FIRST)
{
while (twidth--)
{
guint t;
t = p[3] * p[2] + (255 - p[3]) * q[0] + 0x80;
q[0] = (t + (t >> 8)) >> 8;
t = p[3] * p[1] + (255 - p[3]) * q[1] + 0x80;
q[1] = (t + (t >> 8)) >> 8;
t = p[3] * p[0] + (255 - p[3]) * q[2] + 0x80;
q[2] = (t + (t >> 8)) >> 8;
p += 4;
q += 4;
}
}
else
{
while (twidth--)
{
guint t;
t = p[3] * p[0] + (255 - p[3]) * q[1] + 0x80;
q[1] = (t + (t >> 8)) >> 8;
t = p[3] * p[1] + (255 - p[3]) * q[2] + 0x80;
q[2] = (t + (t >> 8)) >> 8;
t = p[3] * p[2] + (255 - p[3]) * q[3] + 0x80;
q[3] = (t + (t >> 8)) >> 8;
p += 4;
q += 4;
}
}
src += src_rowstride;
dest += dest_rowstride;
}
}
static void
composite_565 (guchar *src_buf,
gint src_rowstride,
guchar *dest_buf,
gint dest_rowstride,
GdkByteOrder dest_byte_order,
gint width,
gint height)
{
guchar *src = src_buf;
guchar *dest = dest_buf;
while (height--)
{
gint twidth = width;
guchar *p = src;
gushort *q = (gushort *)dest;
while (twidth--)
{
guchar a = p[3];
guint tr, tg, tb;
guint tr1, tg1, tb1;
guint tmp = *q;
#if 1
/* This is fast, and corresponds to what composite() above does
* if we converted to 8-bit first.
*/
tr = (tmp & 0xf800);
tr1 = a * p[0] + (255 - a) * ((tr >> 8) + (tr >> 13)) + 0x80;
tg = (tmp & 0x07e0);
tg1 = a * p[1] + (255 - a) * ((tg >> 3) + (tg >> 9)) + 0x80;
tb = (tmp & 0x001f);
tb1 = a * p[2] + (255 - a) * ((tb << 3) + (tb >> 2)) + 0x80;
*q = (((tr1 + (tr1 >> 8)) & 0xf800) |
(((tg1 + (tg1 >> 8)) & 0xfc00) >> 5) |
((tb1 + (tb1 >> 8)) >> 11));
#else
/* This version correspond to the result we get with XRENDER -
* a bit of precision is lost since we convert to 8 bit after premultiplying
* instead of at the end
*/
guint tr2, tg2, tb2;
guint tr3, tg3, tb3;
tr = (tmp & 0xf800);
tr1 = (255 - a) * ((tr >> 8) + (tr >> 13)) + 0x80;
tr2 = a * p[0] + 0x80;
tr3 = ((tr1 + (tr1 >> 8)) >> 8) + ((tr2 + (tr2 >> 8)) >> 8);
tg = (tmp & 0x07e0);
tg1 = (255 - a) * ((tg >> 3) + (tg >> 9)) + 0x80;
tg2 = a * p[0] + 0x80;
tg3 = ((tg1 + (tg1 >> 8)) >> 8) + ((tg2 + (tg2 >> 8)) >> 8);
tb = (tmp & 0x001f);
tb1 = (255 - a) * ((tb << 3) + (tb >> 2)) + 0x80;
tb2 = a * p[0] + 0x80;
tb3 = ((tb1 + (tb1 >> 8)) >> 8) + ((tb2 + (tb2 >> 8)) >> 8);
*q = (((tr3 & 0xf8) << 8) |
((tg3 & 0xfc) << 3) |
((tb3 >> 3)));
#endif
p += 4;
q++;
}
src += src_rowstride;
dest += dest_rowstride;
}
}
static void
gdk_drawable_real_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)
{
GdkPixbuf *composited = NULL;
gint dwidth, dheight;
GdkRegion *clip;
GdkRegion *drect;
GdkRectangle tmp_rect;
g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
g_return_if_fail (pixbuf->colorspace == GDK_COLORSPACE_RGB);
g_return_if_fail (pixbuf->n_channels == 3 || pixbuf->n_channels == 4);
g_return_if_fail (pixbuf->bits_per_sample == 8);
g_return_if_fail (drawable != NULL);
if (width == -1)
width = pixbuf->width;
if (height == -1)
height = pixbuf->height;
g_return_if_fail (width >= 0 && height >= 0);
g_return_if_fail (src_x >= 0 && src_x + width <= pixbuf->width);
g_return_if_fail (src_y >= 0 && src_y + height <= pixbuf->height);
/* Clip to the drawable; this is required for get_from_drawable() so
* can't be done implicitly
*/
if (dest_x < 0)
{
src_x -= dest_x;
width += dest_x;
dest_x = 0;
}
if (dest_y < 0)
{
src_y -= dest_y;
height += dest_y;
dest_y = 0;
}
gdk_drawable_get_size (drawable, &dwidth, &dheight);
if ((dest_x + width) > dwidth)
width = dwidth - dest_x;
if ((dest_y + height) > dheight)
height = dheight - dest_y;
if (width <= 0 || height <= 0)
return;
/* Clip to the clip region; this avoids getting more
* image data from the server than we need to.
*/
tmp_rect.x = dest_x;
tmp_rect.y = dest_y;
tmp_rect.width = width;
tmp_rect.height = height;
drect = gdk_region_rectangle (&tmp_rect);
clip = gdk_drawable_get_clip_region (drawable);
gdk_region_intersect (drect, clip);
gdk_region_get_clipbox (drect, &tmp_rect);
gdk_region_destroy (drect);
gdk_region_destroy (clip);
if (tmp_rect.width == 0 ||
tmp_rect.height == 0)
return;
/* Actually draw */
if (!gc)
gc = _gdk_drawable_get_scratch_gc (drawable, FALSE);
if (pixbuf->has_alpha)
{
GdkVisual *visual = gdk_drawable_get_visual (drawable);
void (*composite_func) (guchar *src_buf,
gint src_rowstride,
guchar *dest_buf,
gint dest_rowstride,
GdkByteOrder dest_byte_order,
gint width,
gint height) = NULL;
/* First we see if we have a visual-specific composition function that can composite
* the pixbuf data directly onto the image
*/
if (visual)
{
gint bits_per_pixel = _gdk_windowing_get_bits_for_depth (gdk_drawable_get_display (drawable),
visual->depth);
if (visual->byte_order == (G_BYTE_ORDER == G_BIG_ENDIAN ? GDK_MSB_FIRST : GDK_LSB_FIRST) &&
visual->depth == 16 &&
visual->red_mask == 0xf800 &&
visual->green_mask == 0x07e0 &&
visual->blue_mask == 0x001f)
composite_func = composite_565;
else if (visual->depth == 24 && bits_per_pixel == 32 &&
visual->red_mask == 0xff0000 &&
visual->green_mask == 0x00ff00 &&
visual->blue_mask == 0x0000ff)
composite_func = composite_0888;
}
/* We can't use our composite func if we are required to dither
*/
if (composite_func && !(dither == GDK_RGB_DITHER_MAX && visual->depth != 24))
{
gint x0, y0;
for (y0 = 0; y0 < height; y0 += GDK_SCRATCH_IMAGE_HEIGHT)
{
gint height1 = MIN (height - y0, GDK_SCRATCH_IMAGE_HEIGHT);
for (x0 = 0; x0 < width; x0 += GDK_SCRATCH_IMAGE_WIDTH)
{
gint xs0, ys0;
gint width1 = MIN (width - x0, GDK_SCRATCH_IMAGE_WIDTH);
GdkImage *image = _gdk_image_get_scratch (gdk_drawable_get_screen (drawable),
width1, height1,
gdk_drawable_get_depth (drawable), &xs0, &ys0);
gdk_drawable_copy_to_image (drawable, image,
dest_x + x0, dest_y + y0,
xs0, ys0,
width1, height1);
(*composite_func) (pixbuf->pixels + (src_y + y0) * pixbuf->rowstride + (src_x + x0) * 4,
pixbuf->rowstride,
(guchar*)image->mem + ys0 * image->bpl + xs0 * image->bpp,
image->bpl,
visual->byte_order,
width1, height1);
gdk_draw_image (drawable, gc, image,
xs0, ys0,
dest_x + x0, dest_y + y0,
width1, height1);
}
}
goto out;
}
else
{
/* No special composition func, convert dest to 24 bit RGB data, composite against
* that, and convert back.
*/
composited = gdk_pixbuf_get_from_drawable (NULL,
drawable,
NULL,
dest_x, dest_y,
0, 0,
width, height);
if (composited)
composite (pixbuf->pixels + src_y * pixbuf->rowstride + src_x * 4,
pixbuf->rowstride,
composited->pixels,
composited->rowstride,
width, height);
}
}
if (composited)
{
src_x = 0;
src_y = 0;
pixbuf = composited;
}
if (pixbuf->n_channels == 4)
{
guchar *buf = pixbuf->pixels + src_y * pixbuf->rowstride + src_x * 4;
gdk_draw_rgb_32_image_dithalign (drawable, gc,
dest_x, dest_y,
width, height,
dither,
buf, pixbuf->rowstride,
x_dither, y_dither);
}
else /* n_channels == 3 */
{
guchar *buf = pixbuf->pixels + src_y * pixbuf->rowstride + src_x * 3;
gdk_draw_rgb_image_dithalign (drawable, gc,
dest_x, dest_y,
width, height,
dither,
buf, pixbuf->rowstride,
x_dither, y_dither);
}
out:
if (composited)
g_object_unref (composited);
}
/************************************************************************/
/* Fallback rendering code for anti-aliased trapezoids. Note that this code
* is cut-and-pasted (with the substitution of GdkPixbuf for FT_Bitmap) between
* here and pangoft2-render.c.
*/
typedef struct {
double y;
double x1;
double x2;
} Position;
static void
draw_simple_trap (GdkPixbuf *pixbuf,
int pixbuf_x,
int pixbuf_y,
Position *t,
Position *b)
{
guchar *pixels = gdk_pixbuf_get_pixels (pixbuf);
int rowstride = gdk_pixbuf_get_rowstride (pixbuf);
int pixbuf_width = gdk_pixbuf_get_width (pixbuf);
int pixbuf_height = gdk_pixbuf_get_height (pixbuf);
int iy = floor (t->y);
int x1, x2, x;
double dy = b->y - t->y;
guchar *dest;
if (iy < pixbuf_y || iy >= pixbuf_y + pixbuf_height)
return;
if (t->x1 < b->x1)
x1 = floor (t->x1);
else
x1 = floor (b->x1);
if (t->x2 > b->x2)
x2 = ceil (t->x2);
else
x2 = ceil (b->x2);
x1 = CLAMP (x1, pixbuf_x, pixbuf_x + pixbuf_width);
x2 = CLAMP (x2, pixbuf_x, pixbuf_x + pixbuf_width);
dest = pixels + (iy - pixbuf_y) * rowstride + (x1 - pixbuf_x) * 4;
for (x = x1; x < x2; x++, dest += 4)
{
double top_left = MAX (t->x1, x);
double top_right = MIN (t->x2, x + 1);
double bottom_left = MAX (b->x1, x);
double bottom_right = MIN (b->x2, x + 1);
double c = 0.5 * dy * ((top_right - top_left) + (bottom_right - bottom_left));
/* When converting to [0,255], we round up. This is intended
* to prevent the problem of pixels that get divided into
* multiple slices not being fully black.
*/
int ic = c * 256;
/* We already set the entire buffer to the destination color */
dest[3] = MIN (dest[3] + ic, 255);
}
}
static void
interpolate_position (Position *result,
Position *top,
Position *bottom,
double val,
double val1,
double val2)
{
result->y = (top->y * (val2 - val) + bottom->y * (val - val1)) / (val2 - val1);
result->x1 = (top->x1 * (val2 - val) + bottom->x1 * (val - val1)) / (val2 - val1);
result->x2 = (top->x2 * (val2 - val) + bottom->x2 * (val - val1)) / (val2 - val1);
}
/* This draws a trapezoid with the parallel sides aligned with
* the X axis. We do this by subdividing the trapezoid vertically
* into thin slices (themselves trapezoids) where two edge sides are each
* contained within a single pixel and then rasterizing each
* slice. There are frequently multiple slices within a single
* line so we have to accumulate to get the final result.
*/
static void
draw_trapezoid (GdkPixbuf *pixbuf,
int pixbuf_x,
int pixbuf_y,
GdkTrapezoid *trapezoid)
{
Position pos;
Position t;
Position b;
gboolean done = FALSE;
if (trapezoid->y1 == trapezoid->y2)
return;
pos.y = t.y = trapezoid->y1;
pos.x1 = t.x1 = trapezoid->x11;
pos.x2 = t.x2 = trapezoid->x21;
b.y = trapezoid->y2;
b.x1 = trapezoid->x12;
b.x2 = trapezoid->x22;
while (!done)
{
Position pos_next;
double y_next, x1_next, x2_next;
double ix1, ix2;
/* The algorithm here is written to emphasize simplicity and
* numerical stability as opposed to speed.
*
* While the end result is slicing up the polygon vertically,
* conceptually we aren't walking in the X direction, rather we
* are walking along the edges. When we compute crossing of
* horizontal pixel boundaries, we use the X coordinate as the
* interpolating variable, when we compute crossing for vertical
* pixel boundaries, we use the Y coordinate.
*
* This allows us to handle almost exactly horizontal edges without
* running into difficulties. (Almost exactly horizontal edges
* come up frequently due to inexactness in computing, say,
* a 90 degree rotation transformation)
*/
pos_next = b;
done = TRUE;
/* Check for crossing vertical pixel boundaries */
y_next = floor (pos.y) + 1;
if (y_next < pos_next.y)
{
interpolate_position (&pos_next, &t, &b,
y_next, t.y, b.y);
pos_next.y = y_next;
done = FALSE;
}
/* Check left side for crossing horizontal pixel boundaries */
ix1 = floor (pos.x1);
if (b.x1 < t.x1)
{
if (ix1 == pos.x1)
x1_next = ix1 - 1;
else
x1_next = ix1;
if (x1_next > pos_next.x1)
{
interpolate_position (&pos_next, &t, &b,
x1_next, t.x1, b.x1);
pos_next.x1 = x1_next;
done = FALSE;
}
}
else if (b.x1 > t.x1)
{
x1_next = ix1 + 1;
if (x1_next < pos_next.x1)
{
interpolate_position (&pos_next, &t, &b,
x1_next, t.x1, b.x1);
pos_next.x1 = x1_next;
done = FALSE;
}
}
/* Check right side for crossing horizontal pixel boundaries */
ix2 = floor (pos.x2);
if (b.x2 < t.x2)
{
if (ix2 == pos.x2)
x2_next = ix2 - 1;
else
x2_next = ix2;
if (x2_next > pos_next.x2)
{
interpolate_position (&pos_next, &t, &b,
x2_next, t.x2, b.x2);
pos_next.x2 = x2_next;
done = FALSE;
}
}
else if (trapezoid->x22 > trapezoid->x21)
{
x2_next = ix2 + 1;
if (x2_next < pos_next.x2)
{
interpolate_position (&pos_next, &t, &b,
x2_next, t.x2, b.x2);
pos_next.x2 = x2_next;
done = FALSE;
}
}
draw_simple_trap (pixbuf, pixbuf_x, pixbuf_y, &pos, &pos_next);
pos = pos_next;
}
}
static void
gdk_drawable_real_draw_trapezoids (GdkDrawable *drawable,
GdkGC *gc,
GdkTrapezoid *trapezoids,
gint n_trapezoids)
{
GdkPixbuf *pixbuf;
double min_x, max_x, min_y, max_y;
int x, y, width, height;
GdkColor color;
int i;
if (n_trapezoids == 0)
return;
/* compute bounding box */
min_x = max_x = trapezoids[0].x11;
min_y = max_y = trapezoids[0].y1;
for (i = 0; i < n_trapezoids; i++)
{
if (trapezoids[i].x11 < min_x) min_x = trapezoids[i].x11;
if (trapezoids[i].x21 > max_x) max_x = trapezoids[i].x21;
if (trapezoids[i].x12 < min_x) min_x = trapezoids[i].x12;
if (trapezoids[i].x22 > max_x) max_x = trapezoids[i].x22;
if (trapezoids[i].y1 < min_y) min_y = trapezoids[i].y1;
if (trapezoids[i].y2 > max_y) max_y = trapezoids[i].y2;
}
/* allocate temporary pixbuf */
x = floor (min_x);
width = ceil (max_x) - x;
y = floor (min_y);
height = ceil (max_y) - y;
if (width == 0 || height == 0)
return;
pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, width, height);
if (!pixbuf)
return;
/* Fill the pixbuf with the foreground color and alpha 0 */
_gdk_windowing_gc_get_foreground (gc, &color);
gdk_pixbuf_fill (pixbuf,
(((color.red & 0xff00) << 16) |
((color.green & 0xff00) << 8) |
((color.blue & 0xff00))));
/* draw the trapezoids into the alpha channel */
for (i = 0; i < n_trapezoids; i++)
draw_trapezoid (pixbuf, x, y, &trapezoids[i]);
/* composite that onto the drawable */
gdk_draw_pixbuf (drawable, gc, pixbuf,
0, 0, x, y, width, height,
GDK_RGB_DITHER_NORMAL, 0, 0);
g_object_unref (pixbuf);
}
/************************************************************************/
/**
* _gdk_drawable_get_scratch_gc:
* @drawable: A #GdkDrawable
* @graphics_exposures: Whether the returned #GdkGC should generate graphics exposures
*
* Returns a #GdkGC suitable for drawing on @drawable. The #GdkGC has
* the standard values for @drawable, except for the graphics_exposures
* field which is determined by the @graphics_exposures parameter.
*
* The foreground color of the returned #GdkGC is undefined. The #GdkGC
* must not be altered in any way, except to change its foreground color.
*
* Return value: A #GdkGC suitable for drawing on @drawable
*
* Since: 2.4
**/
GdkGC *
_gdk_drawable_get_scratch_gc (GdkDrawable *drawable,
gboolean graphics_exposures)
{
GdkScreen *screen;
gint depth;
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
screen = gdk_drawable_get_screen (drawable);
g_return_val_if_fail (!screen->closed, NULL);
depth = gdk_drawable_get_depth (drawable) - 1;
if (graphics_exposures)
{
if (!screen->exposure_gcs[depth])
{
GdkGCValues values;
GdkGCValuesMask mask;
values.graphics_exposures = TRUE;
mask = GDK_GC_EXPOSURES;
screen->exposure_gcs[depth] =
gdk_gc_new_with_values (drawable, &values, mask);
}
return screen->exposure_gcs[depth];
}
else
{
if (!screen->normal_gcs[depth])
{
screen->normal_gcs[depth] =
gdk_gc_new (drawable);
}
return screen->normal_gcs[depth];
}
}
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