gimp/libgimp/gimppixbuf.c

234 lines
7.0 KiB
C

/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* gimppixbuf.c
* Copyright (C) 2004 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 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.
*/
#include "config.h"
#include <gdk-pixbuf/gdk-pixbuf.h>
#include "gimp.h"
#include "gimppixbuf.h"
static GdkPixbuf * gimp_pixbuf_from_data (guchar *data,
gint width,
gint height,
gint bpp,
GimpPixbufTransparency alpha);
/**
* gimp_image_get_thumbnail:
* @image_ID: the image ID
* @width: the requested thumbnail width (<= 512 pixels)
* @height: the requested thumbnail height (<= 512 pixels)
* @alpha: how to handle an alpha channel
*
* Retrieves a thumbnail pixbuf for the image identified by @image_ID.
* The thumbnail will be not larger than the requested size.
*
* Return value: a new #GdkPixbuf
*
* Since: GIMP 2.2
**/
GdkPixbuf *
gimp_image_get_thumbnail (gint32 image_ID,
gint width,
gint height,
GimpPixbufTransparency alpha)
{
gint thumb_width;
gint thumb_height;
gint thumb_bpp;
gint data_size;
guchar *data;
g_return_val_if_fail (width > 0 && width <= 512, NULL);
g_return_val_if_fail (height > 0 && height <= 512, NULL);
if (! _gimp_image_thumbnail (image_ID,
width, height,
&thumb_width, &thumb_height, &thumb_bpp,
&data_size, &data))
return NULL;
g_return_val_if_fail (data_size == (thumb_width * thumb_height * thumb_bpp),
NULL);
return gimp_pixbuf_from_data (data,
thumb_width, thumb_height, thumb_bpp,
alpha);
}
/**
* gimp_drawable_get_thumbnail:
* @drawable_ID: the drawable ID
* @width: the requested thumbnail width (<= 512 pixels)
* @height: the requested thumbnail height (<= 512 pixels)
* @alpha: how to handle an alpha channel
*
* Retrieves a thumbnail pixbuf for the drawable identified by
* @drawable_ID. The thumbnail will be not larger than the requested
* size.
*
* Return value: a new #GdkPixbuf
*
* Since: GIMP 2.2
**/
GdkPixbuf *
gimp_drawable_get_thumbnail (gint32 drawable_ID,
gint width,
gint height,
GimpPixbufTransparency alpha)
{
gint thumb_width;
gint thumb_height;
gint thumb_bpp;
gint data_size;
guchar *data;
g_return_val_if_fail (width > 0 && width <= 512, NULL);
g_return_val_if_fail (height > 0 && height <= 512, NULL);
if (! _gimp_drawable_thumbnail (drawable_ID,
width, height,
&thumb_width, &thumb_height, &thumb_bpp,
&data_size, &data))
return NULL;
g_return_val_if_fail (data_size == (thumb_width * thumb_height * thumb_bpp),
NULL);
return gimp_pixbuf_from_data (data,
thumb_width, thumb_height, thumb_bpp, alpha);
}
static GdkPixbuf *
gimp_pixbuf_from_data (guchar *data,
gint width,
gint height,
gint bpp,
GimpPixbufTransparency alpha)
{
GdkPixbuf *pixbuf;
switch (bpp)
{
case 1:
pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, width, height);
{
guchar *pixels = gdk_pixbuf_get_pixels (pixbuf);
gint rowstride = gdk_pixbuf_get_rowstride (pixbuf);
gint y;
for (y = 0; y < height; y++)
{
guchar *dest = pixels;
gint x;
for (x = 0; x < width; x++, data += 1, dest += 3)
{
dest[0] = dest[1] = dest[2] = data[0];
}
pixels += rowstride;
}
}
bpp = 3;
break;
case 2:
pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, width, height);
{
guchar *pixels = gdk_pixbuf_get_pixels (pixbuf);
gint rowstride = gdk_pixbuf_get_rowstride (pixbuf);
gint y;
for (y = 0; y < height; y++)
{
guchar *dest = pixels;
gint x;
for (x = 0; x < width; x++, data += 2, dest += 4)
{
dest[0] = dest[1] = dest[2] = data[0];
dest[3] = data[1];
}
pixels += rowstride;
}
}
bpp = 4;
break;
case 3:
pixbuf = gdk_pixbuf_new_from_data (data,
GDK_COLORSPACE_RGB, FALSE, 8,
width, height, width * bpp,
(GdkPixbufDestroyNotify) g_free, NULL);
break;
case 4:
pixbuf = gdk_pixbuf_new_from_data (data,
GDK_COLORSPACE_RGB, TRUE, 8,
width, height, width * bpp,
(GdkPixbufDestroyNotify) g_free, NULL);
break;
default:
g_return_val_if_reached (NULL);
return NULL;
}
if (bpp == 4)
{
GdkPixbuf *tmp;
gint check_size = 0;
switch (alpha)
{
case GIMP_PIXBUF_KEEP_ALPHA:
return pixbuf;
case GIMP_PIXBUF_SMALL_CHECKS:
check_size = GIMP_CHECK_SIZE_SM;
break;
case GIMP_PIXBUF_LARGE_CHECKS:
check_size = GIMP_CHECK_SIZE;
break;
}
tmp = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, width, height);
gdk_pixbuf_composite_color (pixbuf, tmp,
0, 0, width, height, 0, 0, 1.0, 1.0,
GDK_INTERP_NEAREST, 255,
0, 0, check_size, 0x66666666, 0x99999999);
g_object_unref (pixbuf);
pixbuf = tmp;
}
return pixbuf;
}