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223 lines
6.7 KiB
C
223 lines
6.7 KiB
C
/* GDK - The GIMP Drawing Kit
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* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
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* file for a list of people on the GTK+ Team. See the ChangeLog
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* files for a list of changes. These files are distributed with
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* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
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*/
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#include "config.h"
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#include "gdkrectangle.h"
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#include <cairo-gobject.h>
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/**
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* SECTION:regions
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* @Short_description: Simple graphical data types
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* @Title: Points and Rectangles
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*
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* GDK provides the #GdkPoint and #GdkRectangle data types for representing pixels
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* and sets of pixels on the screen. Together with Cairo’s #cairo_region_t data
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* type, they make up the central types for representing graphical data.
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*
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* A #GdkPoint represents an x and y coordinate of a point.
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*
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* A #GdkRectangle represents the position and size of a rectangle.
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* The intersection of two rectangles can be computed with
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* gdk_rectangle_intersect(). To find the union of two rectangles use
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* gdk_rectangle_union().
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*
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* #cairo_region_t is usually used for managing clipping of graphical operations.
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*/
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/**
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* gdk_rectangle_union:
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* @src1: a #GdkRectangle
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* @src2: a #GdkRectangle
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* @dest: (out): return location for the union of @src1 and @src2
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*
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* Calculates the union of two rectangles.
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* The union of rectangles @src1 and @src2 is the smallest rectangle which
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* includes both @src1 and @src2 within it.
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* It is allowed for @dest to be the same as either @src1 or @src2.
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*
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* Note that this function does not ignore 'empty' rectangles (ie. with
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* zero width or height).
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*/
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void
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gdk_rectangle_union (const GdkRectangle *src1,
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const GdkRectangle *src2,
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GdkRectangle *dest)
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{
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int dest_x, dest_y;
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g_return_if_fail (src1 != NULL);
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g_return_if_fail (src2 != NULL);
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g_return_if_fail (dest != NULL);
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dest_x = MIN (src1->x, src2->x);
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dest_y = MIN (src1->y, src2->y);
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dest->width = MAX (src1->x + src1->width, src2->x + src2->width) - dest_x;
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dest->height = MAX (src1->y + src1->height, src2->y + src2->height) - dest_y;
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dest->x = dest_x;
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dest->y = dest_y;
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}
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/**
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* gdk_rectangle_intersect:
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* @src1: a #GdkRectangle
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* @src2: a #GdkRectangle
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* @dest: (out caller-allocates) (allow-none): return location for the
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* intersection of @src1 and @src2, or %NULL
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*
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* Calculates the intersection of two rectangles. It is allowed for
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* @dest to be the same as either @src1 or @src2. If the rectangles
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* do not intersect, @dest’s width and height is set to 0 and its x
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* and y values are undefined. If you are only interested in whether
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* the rectangles intersect, but not in the intersecting area itself,
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* pass %NULL for @dest.
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*
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* Returns: %TRUE if the rectangles intersect.
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*/
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gboolean
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gdk_rectangle_intersect (const GdkRectangle *src1,
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const GdkRectangle *src2,
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GdkRectangle *dest)
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{
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int dest_x, dest_y;
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int dest_x2, dest_y2;
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int return_val;
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g_return_val_if_fail (src1 != NULL, FALSE);
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g_return_val_if_fail (src2 != NULL, FALSE);
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return_val = FALSE;
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dest_x = MAX (src1->x, src2->x);
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dest_y = MAX (src1->y, src2->y);
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dest_x2 = MIN (src1->x + src1->width, src2->x + src2->width);
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dest_y2 = MIN (src1->y + src1->height, src2->y + src2->height);
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if (dest_x2 > dest_x && dest_y2 > dest_y)
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{
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if (dest)
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{
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dest->x = dest_x;
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dest->y = dest_y;
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dest->width = dest_x2 - dest_x;
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dest->height = dest_y2 - dest_y;
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}
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return_val = TRUE;
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}
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else if (dest)
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{
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dest->width = 0;
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dest->height = 0;
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}
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return return_val;
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}
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/**
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* gdk_rectangle_contains_point:
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* @rect: a #GdkRectangle
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* @x: X coordinate
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* @y: Y coordinate
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*
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* Returns #TRUE if @rect contains the point described by @x and @y.
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*
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* Returns: #TRUE if @rect contains the point
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**/
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gboolean
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gdk_rectangle_contains_point (const GdkRectangle *rect,
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int x,
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int y)
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{
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g_return_val_if_fail (rect != NULL, FALSE);
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return x >= rect->x &&
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x < rect->x + rect->width &&
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y >= rect->y &&
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y < rect->y + rect->height;
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}
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/**
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* gdk_rectangle_equal:
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* @rect1: a #GdkRectangle
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* @rect2: a #GdkRectangle
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*
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* Checks if the two given rectangles are equal.
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*
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* Returns: %TRUE if the rectangles are equal.
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*/
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gboolean
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gdk_rectangle_equal (const GdkRectangle *rect1,
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const GdkRectangle *rect2)
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{
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return rect1->x == rect2->x
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&& rect1->y == rect2->y
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&& rect1->width == rect2->width
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&& rect1->height == rect2->height;
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}
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static GdkRectangle *
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gdk_rectangle_copy (const GdkRectangle *rectangle)
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{
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GdkRectangle *result = g_new (GdkRectangle, 1);
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*result = *rectangle;
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return result;
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}
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/* Transforms between identical boxed types.
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*/
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static void
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gdk_rectangle_value_transform_rect (const GValue *src_value, GValue *dest_value)
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{
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g_value_set_boxed (dest_value, g_value_get_boxed (src_value));
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}
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/* Allow GValue transformation between the identical structs
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* cairo_rectangle_int_t and GdkRectangle.
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*/
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static void
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gdk_rectangle_register_value_transform_funcs (GType gtype_gdk_rectangle)
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{
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/* This function is called from the first call to gdk_rectangle_get_type(),
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* before g_once_init_leave() has been called.
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* If gdk_rectangle_get_type() is called from here (e.g. via
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* GDK_TYPE_RECTANGLE), the program will wait indefinitely at
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* g_once_init_enter() in gdk_rectangle_get_type().
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*/
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g_value_register_transform_func (CAIRO_GOBJECT_TYPE_RECTANGLE_INT,
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gtype_gdk_rectangle,
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gdk_rectangle_value_transform_rect);
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g_value_register_transform_func (gtype_gdk_rectangle,
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CAIRO_GOBJECT_TYPE_RECTANGLE_INT,
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gdk_rectangle_value_transform_rect);
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}
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G_DEFINE_BOXED_TYPE_WITH_CODE (GdkRectangle, gdk_rectangle,
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gdk_rectangle_copy,
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g_free,
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gdk_rectangle_register_value_transform_funcs (g_define_type_id))
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