PIKApp/libpikawidgets/pikacairo-utils.c

203 lines
4.7 KiB
C

/* LIBPIKA - The PIKA Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* pikacairo-utils.c
* Copyright (C) 2007 Sven Neumann <sven@gimp.org>
*
* 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 3 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, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <string.h>
#include <gegl.h>
#include <gtk/gtk.h>
#include "libpikabase/pikabase.h"
#include "libpikacolor/pikacolor.h"
#include "pikacairo-utils.h"
/**
* SECTION: pikacairo-utils
* @title: PikaCairo-utils
* @short_description: Utility functions for cairo
*
* Utility functions that make cairo easier to use with common
* PIKA data types.
**/
/**
* pika_cairo_set_focus_line_pattern:
* @cr: Cairo context
* @widget: widget to draw the focus indicator on
*
* Sets color and dash pattern for stroking a focus line on the given
* @cr. The line pattern is taken from @widget.
*
* Returns: %TRUE if the widget style has a focus line pattern,
* %FALSE otherwise
*
* Since: 2.6
**/
gboolean
pika_cairo_set_focus_line_pattern (cairo_t *cr,
GtkWidget *widget)
{
gint8 *dash_list;
gboolean retval = FALSE;
g_return_val_if_fail (cr != NULL, FALSE);
g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
gtk_widget_style_get (widget,
"focus-line-pattern", (gchar *) &dash_list,
NULL);
if (dash_list[0])
{
/* Taken straight from gtk_default_draw_focus()
*/
gint n_dashes = strlen ((const gchar *) dash_list);
gdouble *dashes = g_new (gdouble, n_dashes);
gdouble total_length = 0;
gint i;
for (i = 0; i < n_dashes; i++)
{
dashes[i] = dash_list[i];
total_length += dash_list[i];
}
cairo_set_dash (cr, dashes, n_dashes, 0.5);
g_free (dashes);
retval = TRUE;
}
g_free (dash_list);
return retval;
}
/**
* pika_cairo_surface_create_from_pixbuf:
* @pixbuf: a #GdkPixbuf
*
* Create a Cairo image surface from a GdkPixbuf.
*
* You should avoid calling this function as there are probably more
* efficient ways of achieving the result you are looking for.
*
* Returns: a #cairo_surface_t.
*
* Since: 2.6
**/
cairo_surface_t *
pika_cairo_surface_create_from_pixbuf (GdkPixbuf *pixbuf)
{
cairo_surface_t *surface;
cairo_format_t format;
guchar *dest;
const guchar *src;
gint width;
gint height;
gint src_stride;
gint dest_stride;
gint y;
g_return_val_if_fail (GDK_IS_PIXBUF (pixbuf), NULL);
width = gdk_pixbuf_get_width (pixbuf);
height = gdk_pixbuf_get_height (pixbuf);
switch (gdk_pixbuf_get_n_channels (pixbuf))
{
case 3:
format = CAIRO_FORMAT_RGB24;
break;
case 4:
format = CAIRO_FORMAT_ARGB32;
break;
default:
g_assert_not_reached ();
break;
}
surface = cairo_image_surface_create (format, width, height);
cairo_surface_flush (surface);
src = gdk_pixbuf_get_pixels (pixbuf);
src_stride = gdk_pixbuf_get_rowstride (pixbuf);
dest = cairo_image_surface_get_data (surface);
dest_stride = cairo_image_surface_get_stride (surface);
switch (format)
{
case CAIRO_FORMAT_RGB24:
for (y = 0; y < height; y++)
{
const guchar *s = src;
guchar *d = dest;
gint w = width;
while (w--)
{
PIKA_CAIRO_RGB24_SET_PIXEL (d, s[0], s[1], s[2]);
s += 3;
d += 4;
}
src += src_stride;
dest += dest_stride;
}
break;
case CAIRO_FORMAT_ARGB32:
for (y = 0; y < height; y++)
{
const guchar *s = src;
guchar *d = dest;
gint w = width;
while (w--)
{
PIKA_CAIRO_ARGB32_SET_PIXEL (d, s[0], s[1], s[2], s[3]);
s += 4;
d += 4;
}
src += src_stride;
dest += dest_stride;
}
break;
default:
break;
}
cairo_surface_mark_dirty (surface);
return surface;
}