Commit 56694adb authored by Federico Mena Quintero's avatar Federico Mena Quintero Committed by Arturo Espinosa

New file with utility and convenience functions for pixbufs.

1999-12-02  Federico Mena Quintero  <federico@redhat.com>

	* src/gdk-pixbuf-util.c: New file with utility and convenience
	functions for pixbufs.

	* src/Makefile.am (libgdk_pixbuf_la_SOURCES): Added gdk-pixbuf-util.c.

	* doc/gdk-pixbuf-sections.txt: Added section for utility functions.

	* doc/Makefile.am (tmpl_sources): Added tmpl/util.sgml.

	* doc/gdk-pixbuf.sgml: Added the utilities section.

	* doc/tmpl/util.sgml: Documentation for the utility functions.
parent 6303c4db
......@@ -40,6 +40,11 @@ gdk_pixbuf_render_to_drawable
gdk_pixbuf_render_threshold_alpha
</SECTION>
<SECTION>
<FILE>util</FILE>
gdk_pixbuf_add_alpha
</SECTION>
<SECTION>
<FILE>gnome-canvas-pixbuf</FILE>
GNOME_CANVAS_PIXBUF
......
......@@ -4,6 +4,7 @@
<!entity gdk-pixbuf-file-loading SYSTEM "sgml/file-loading.sgml">
<!entity gdk-pixbuf-creating SYSTEM "sgml/creating.sgml">
<!entity gdk-pixbuf-rendering SYSTEM "sgml/rendering.sgml">
<!entity gdk-pixbuf-util SYSTEM "sgml/util.sgml">
<!entity GnomeCanvasPixbuf SYSTEM "sgml/gnome-canvas-pixbuf.sgml">
<!entity GdkPixbufLoader SYSTEM "sgml/gdk-pixbuf-loader.sgml">
]>
......@@ -46,6 +47,7 @@
&gdk-pixbuf-file-loading;
&gdk-pixbuf-creating;
&gdk-pixbuf-rendering;
&gdk-pixbuf-util;
&GnomeCanvasPixbuf;
&GdkPixbufLoader;
</reference>
......
......@@ -74,6 +74,7 @@ libgdk_pixbuf_la_SOURCES = \
gdk-pixbuf-loader.c \
gdk-pixbuf-render.c \
gdk-pixbuf-drawable.c \
gdk-pixbuf-util.c \
$(CANVAS_SOURCEFILES)
libgdk_pixbuf_la_LDFLAGS = -version-info 1:0:0
......
/* GdkPixbuf library - Utilities and miscellaneous convenience functions
*
* Copyright (C) 1999 The Free Software Foundation
*
* Author: Federico Mena-Quintero <federico@gimp.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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.
*/
#include <config.h>
#include "gdk-pixbuf/gdk-pixbuf.h"
/**
* gdk_pixbuf_add_alpha:
* @pixbuf: A pixbuf.
* @substitute_color: Whether to substitute a color for zero opacity. If this
* is #FALSE, then the (@r, @g, @b) arguments will be ignored.
* @r: Red value to substitute.
* @g: Green value to substitute.
* @b: Blue value to substitute.
*
* Takes an existing pixbuf and adds an alpha channel to it. If the original
* pixbuf already had alpha information, then the contents of the new pixbuf are
* exactly the same as the original's. Otherwise, the new pixbuf will have all
* pixels with full opacity if @substitute_color is #FALSE. If
* @substitute_color is #TRUE, then the color specified by (@r, @g, @b) will be
* substituted for zero opacity.
*
* Return value: A newly-created pixbuf with a reference count of 1.
**/
GdkPixbuf *
gdk_pixbuf_add_alpha (GdkPixbuf *pixbuf, gboolean substitute_color, guchar r, guchar g, guchar b)
{
ArtPixBuf *apb;
ArtPixBuf *new_apb;
GdkPixbuf *new_pixbuf;
int x, y;
g_return_val_if_fail (pixbuf != NULL, NULL);
apb = pixbuf->art_pixbuf;
g_return_val_if_fail (apb->format == ART_PIX_RGB, NULL);
g_return_val_if_fail (apb->n_channels == 3 || apb->n_channels == 4, NULL);
g_return_val_if_fail (apb->bits_per_sample == 8, NULL);
if (apb->has_alpha) {
new_apb = art_pixbuf_duplicate (apb);
if (!new_apb)
return NULL;
return gdk_pixbuf_new_from_art_pixbuf (new_apb);
}
new_pixbuf = gdk_pixbuf_new (ART_PIX_RGB, TRUE, 8, apb->width, apb->height);
if (!new_pixbuf)
return NULL;
new_apb = new_pixbuf->art_pixbuf;
for (y = 0; y < apb->height; y++) {
guchar *src, *dest;
guchar tr, tg, tb;
src = apb->pixels + y * apb->rowstride;
dest = new_apb->pixels + y * new_apb->rowstride;
for (x = 0; x < apb->width; x++) {
tr = *dest++ = *src++;
tg = *dest++ = *src++;
tb = *dest++ = *src++;
if (substitute_color && tr == r && tg == g && tb == b)
*dest++ = 0;
else
*dest++ = 255;
}
}
return new_pixbuf;
}
......@@ -83,6 +83,11 @@ GdkPixbuf *gdk_pixbuf_new_from_data (guchar *data, ArtPixFormat format, gboolean
ArtDestroyNotify dfunc, gpointer dfunc_data);
GdkPixbuf *gdk_pixbuf_new_from_xpm_data (const gchar **data);
/* Adding or removing alpha */
GdkPixbuf *gdk_pixbuf_add_alpha (GdkPixbuf *pixbuf, gboolean substitute_color,
guchar r, guchar g, guchar b);
/* Rendering to a drawable */
typedef enum {
......
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