gimp/libgimp/gimppixbuf.c

303 lines
9.3 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 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
* <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gimp.h"
#include "gimppixbuf.h"
/**
* SECTION: gimppixbuf
* @title: gimppixbuf
* @short_description: Get a thumbnail pixbuf for a drawable or image.
*
* Get a thumbnail pixbuf for a drawable or image.
**/
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 (<= 1024 pixels)
* @height: the requested thumbnail height (<= 1024 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 = width;
gint thumb_height = height;
gint thumb_bpp;
guchar *data;
g_return_val_if_fail (width > 0 && width <= 1024, NULL);
g_return_val_if_fail (height > 0 && height <= 1024, NULL);
data = gimp_image_get_thumbnail_data (image_ID,
&thumb_width,
&thumb_height,
&thumb_bpp);
if (data)
return gimp_pixbuf_from_data (data,
thumb_width, thumb_height, thumb_bpp,
alpha);
else
return NULL;
}
/**
* gimp_drawable_get_thumbnail:
* @drawable_ID: the drawable ID
* @width: the requested thumbnail width (<= 1024 pixels)
* @height: the requested thumbnail height (<= 1024 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 = width;
gint thumb_height = height;
gint thumb_bpp;
guchar *data;
g_return_val_if_fail (width > 0 && width <= 1024, NULL);
g_return_val_if_fail (height > 0 && height <= 1024, NULL);
data = gimp_drawable_get_thumbnail_data (drawable_ID,
&thumb_width,
&thumb_height,
&thumb_bpp);
if (data)
return gimp_pixbuf_from_data (data,
thumb_width, thumb_height, thumb_bpp,
alpha);
return NULL;
}
/**
* gimp_drawable_get_sub_thumbnail:
* @drawable_ID: the drawable ID
* @src_x: the x coordinate of the area
* @src_y: the y coordinate of the area
* @src_width: the width of the area
* @src_height: the height of the area
* @dest_width: the requested thumbnail width (<= 1024 pixels)
* @dest_height: the requested thumbnail height (<= 1024 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_sub_thumbnail (gint32 drawable_ID,
gint src_x,
gint src_y,
gint src_width,
gint src_height,
gint dest_width,
gint dest_height,
GimpPixbufTransparency alpha)
{
gint thumb_width = dest_width;
gint thumb_height = dest_height;
gint thumb_bpp;
guchar *data;
g_return_val_if_fail (src_x >= 0, NULL);
g_return_val_if_fail (src_y >= 0, NULL);
g_return_val_if_fail (src_width > 0, NULL);
g_return_val_if_fail (src_height > 0, NULL);
g_return_val_if_fail (dest_width > 0 && dest_width <= 1024, NULL);
g_return_val_if_fail (dest_height > 0 && dest_height <= 1024, NULL);
data = gimp_drawable_get_sub_thumbnail_data (drawable_ID,
src_x, src_y,
src_width, src_height,
&thumb_width,
&thumb_height,
&thumb_bpp);
if (data)
return gimp_pixbuf_from_data (data,
thumb_width, thumb_height, thumb_bpp,
alpha);
return NULL;
}
/*
* The data that is passed to this function is either freed here or
* owned by the returned pixbuf.
*/
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 *src = data;
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++, src += 1, dest += 3)
{
dest[0] = dest[1] = dest[2] = src[0];
}
pixels += rowstride;
}
g_free (data);
}
bpp = 3;
break;
case 2:
pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, width, height);
{
guchar *src = data;
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++, src += 2, dest += 4)
{
dest[0] = dest[1] = dest[2] = src[0];
dest[3] = src[1];
}
pixels += rowstride;
}
g_free (data);
}
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;
}