gtk/gdk-pixbuf/gdk-pixbuf.c
Havoc Pennington 1a0a5d0399 New function to create a blank pixbuf.
1999-10-27  Havoc Pennington  <hp@pobox.com>

* src/gdk-pixbuf.c (gdk_pixbuf_new): New function to create a
blank pixbuf.

* src/gdk-pixbuf-loader.c (gdk_pixbuf_loader_write): Check all
three progressive load funcs are non-NULL, rather than checking
begin_load three times. Also, check whether begin_load returns
NULL on failure.
1999-10-27 17:28:44 +00:00

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/* GdkPixbuf library - Basic memory management
*
* Copyright (C) 1999 The Free Software Foundation
*
* Authors: Mark Crichton <crichton@gimp.org>
* Miguel de Icaza <miguel@gnu.org>
* 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 <math.h>
#include <libart_lgpl/art_misc.h>
#include <libart_lgpl/art_affine.h>
#include <libart_lgpl/art_pixbuf.h>
#include <libart_lgpl/art_rgb_pixbuf_affine.h>
#include <libart_lgpl/art_alphagamma.h>
#include "gdk-pixbuf.h"
/* Reference counting */
/**
* gdk_pixbuf_ref:
* @pixbuf: A pixbuf.
*
* Adds a reference to a pixbuf. It must be released afterwards using
* gdk_pixbuf_unref().
**/
void
gdk_pixbuf_ref (GdkPixbuf *pixbuf)
{
g_return_if_fail (pixbuf != NULL);
g_return_if_fail (pixbuf->ref_count > 0);
pixbuf->ref_count++;
}
/**
* gdk_pixbuf_unref:
* @pixbuf: A pixbuf.
*
* Removes a reference from a pixbuf. It will be destroyed when the reference
* count drops to zero.
**/
void
gdk_pixbuf_unref (GdkPixbuf *pixbuf)
{
g_return_if_fail (pixbuf != NULL);
g_return_if_fail (pixbuf->ref_count > 0);
pixbuf->ref_count--;
if (pixbuf->ref_count == 0) {
art_pixbuf_free (pixbuf->art_pixbuf);
pixbuf->art_pixbuf = NULL;
g_free (pixbuf);
}
}
/* Wrap a libart pixbuf */
/**
* gdk_pixbuf_new_from_art_pixbuf:
* @art_pixbuf: A libart pixbuf.
*
* Creates a &GdkPixbuf by wrapping a libart pixbuf.
*
* Return value: A newly-created &GdkPixbuf structure with a reference count of
* 1.
**/
GdkPixbuf *
gdk_pixbuf_new_from_art_pixbuf (ArtPixBuf *art_pixbuf)
{
GdkPixbuf *pixbuf;
g_return_val_if_fail (art_pixbuf != NULL, NULL);
pixbuf = g_new (GdkPixbuf, 1);
pixbuf->ref_count = 1;
pixbuf->art_pixbuf = art_pixbuf;
return pixbuf;
}
/**
* gdk_pixbuf_new:
* @art_pixbuf: A libart pixbuf.
*
* Creates a &GdkPixbuf; magically sets the ArtPixFormat, rowstride, and creates
* the buffer. Use gdk_pixbuf_new_from_data() to do things manually.
*
* Return value: A newly-created &GdkPixbuf structure with a reference count of
* 1. Somewhat oddly, returns NULL if it can't allocate the buffer; this unusual
* behavior is needed because images can be very large.
**/
GdkPixbuf *
gdk_pixbuf_new (gboolean has_alpha, int width, int height)
{
GdkPixbuf *pixbuf;
g_return_val_if_fail (width > 0, NULL);
g_return_val_if_fail (height > 0, NULL);
pixbuf = g_new (GdkPixbuf, 1);
pixbuf->ref_count = 1;
if (has_alpha) {
art_u8* pixels;
int rowstride;
/* FIXME, pick an optimal stride */
rowstride = 4*width;
pixels = art_alloc(rowstride*height);
if (pixels == NULL) {
g_free(pixbuf);
return NULL;
}
pixbuf->art_pixbuf = art_pixbuf_new_rgba(pixels, width, height, rowstride);
} else {
art_u8* pixels;
int rowstride;
/* FIXME, pick an optimal stride */
rowstride = 3*width;
pixels = art_alloc(rowstride*height);
if (pixels == NULL) {
g_free(pixbuf);
return NULL;
}
pixbuf->art_pixbuf = art_pixbuf_new_rgb(pixels, width, height, rowstride);
}
return pixbuf;
}