gimp/app/base/tile-manager-preview.c

115 lines
4.1 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <glib-object.h>
#include "base-types.h"
#include "paint-funcs/subsample-region.h"
#include "pixel-region.h"
#include "temp-buf.h"
#include "tile-manager.h"
#include "tile-manager-preview.h"
static TempBuf * tile_manager_create_preview (TileManager *tiles,
gint src_x,
gint src_y,
gint src_width,
gint src_height,
gint dest_width,
gint dest_height);
TempBuf *
tile_manager_get_preview (TileManager *tiles,
gint width,
gint height)
{
g_return_val_if_fail (tiles != NULL, NULL);
g_return_val_if_fail (width > 0 && height > 0, NULL);
return tile_manager_create_preview (tiles,
0, 0,
tile_manager_width (tiles),
tile_manager_height (tiles),
width, height);
}
TempBuf *
tile_manager_get_sub_preview (TileManager *tiles,
gint src_x,
gint src_y,
gint src_width,
gint src_height,
gint dest_width,
gint dest_height)
{
g_return_val_if_fail (tiles != NULL, NULL);
g_return_val_if_fail (src_x >= 0 &&
src_x < tile_manager_width (tiles), NULL);
g_return_val_if_fail (src_y >= 0 &&
src_y < tile_manager_height (tiles), NULL);
g_return_val_if_fail (src_width > 0 &&
src_x + src_width <= tile_manager_width (tiles), NULL);
g_return_val_if_fail (src_height > 0 &&
src_y + src_height <= tile_manager_height (tiles),
NULL);
g_return_val_if_fail (dest_width > 0 && dest_height > 0, NULL);
return tile_manager_create_preview (tiles,
src_x, src_y, src_width, src_height,
dest_width, dest_height);
}
static TempBuf *
tile_manager_create_preview (TileManager *tiles,
gint src_x,
gint src_y,
gint src_width,
gint src_height,
gint dest_width,
gint dest_height)
{
TempBuf *preview;
PixelRegion srcPR;
PixelRegion destPR;
gint subsample = 1;
preview = temp_buf_new (dest_width, dest_height,
tile_manager_bpp (tiles), 0, 0, NULL);
pixel_region_init (&srcPR, tiles, src_x, src_y, src_width, src_height, FALSE);
pixel_region_init_temp_buf (&destPR, preview, 0, 0, dest_width, dest_height);
/* calculate 'acceptable' subsample */
while ((dest_width * (subsample + 1) * 2 < src_width) &&
(dest_height * (subsample + 1) * 2 < src_height))
subsample += 1;
subsample_region (&srcPR, &destPR, subsample);
return preview;
}