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gimp/app/core/gimpdrawable-transform.c

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/* The GIMP -- an image manipulation program
* Copyright (C) 1995-2003 Spencer Kimball, Peter Mattis, and others
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include <stdlib.h>
#include <glib-object.h>
#include "libgimpmath/gimpmath.h"
#include "core-types.h"
#include "base/pixel-region.h"
#include "base/pixel-surround.h"
#include "base/tile-manager.h"
#include "base/tile.h"
#include "paint-funcs/paint-funcs.h"
#include "paint-funcs/scale-funcs.h"
#include "gimp.h"
#include "gimp-utils.h"
#include "gimpchannel.h"
#include "gimpcontext.h"
#include "gimpdrawable.h"
#include "gimpdrawable-transform.h"
#include "gimpimage.h"
#include "gimpimage-undo.h"
#include "gimpimage-undo-push.h"
#include "gimplayer.h"
#include "gimplayer-floating-sel.h"
#include "gimpprogress.h"
#include "gimpselection.h"
#include "gimp-intl.h"
#if defined (HAVE_FINITE)
#define FINITE(x) finite(x)
#elif defined (HAVE_ISFINITE)
#define FINITE(x) isfinite(x)
#elif defined (G_OS_WIN32)
#define FINITE(x) _finite(x)
#else
#error "no FINITE() implementation available?!"
#endif
#define MIN4(a,b,c,d) MIN(MIN(a,b),MIN(c,d))
#define MAX4(a,b,c,d) MAX(MAX(a,b),MAX(c,d))
/* forward function prototypes */
static gboolean supersample_dtest (gdouble u0, gdouble v0,
gdouble u1, gdouble v1,
gdouble u2, gdouble v2,
gdouble u3, gdouble v3);
static void sample_adapt (TileManager *tm,
gdouble uc, gdouble vc,
gdouble u0, gdouble v0,
gdouble u1, gdouble v1,
gdouble u2, gdouble v2,
gdouble u3, gdouble v3,
gint level,
guchar *color,
guchar *bg_color,
gint bpp,
gint alpha);
static void sample_cubic (PixelSurround *surround,
gdouble u,
gdouble v,
guchar *color,
gint bytes,
gint alpha);
static void sample_linear (PixelSurround *surround,
gdouble u,
gdouble v,
guchar *color,
gint bytes,
gint alpha);
static void sample_lanczos (PixelSurround *surround,
gdouble u,
gdouble v,
guchar *color,
gint bytes,
gint alpha,
const gdouble *kernel);
static gdouble * kernel_lanczos (void);
/* public functions */
TileManager *
gimp_drawable_transform_tiles_affine (GimpDrawable *drawable,
GimpContext *context,
TileManager *orig_tiles,
const GimpMatrix3 *matrix,
GimpTransformDirection direction,
GimpInterpolationType interpolation_type,
gboolean supersample,
gint recursion_level,
gboolean clip_result,
GimpProgress *progress)
{
GimpImage *gimage;
PixelRegion destPR;
TileManager *new_tiles;
GimpMatrix3 m;
GimpMatrix3 inv;
PixelSurround surround;
gint x1, y1, x2, y2; /* target bounding box */
gint x, y; /* target coordinates */
gint u1, v1, u2, v2; /* source bounding box */
gdouble uinc, vinc, winc; /* increments in source coordinates
pr horizontal target coordinate */
gdouble u[5],v[5]; /* source coordinates,
2
/ \ 0 is sample in the centre of pixel
1 0 3 1..4 is offset 1 pixel in each
\ / direction (in target space)
4
*/
gdouble tu[5],tv[5],tw[5]; /* undivided source coordinates and
divisor */
gdouble *kernel = NULL; /* Lanczos kernel */
gint coords;
gint width;
gint alpha;
gint bytes;
guchar *dest, *d;
guchar bg_color[MAX_CHANNELS];
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), NULL);
g_return_val_if_fail (GIMP_IS_CONTEXT (context), NULL);
g_return_val_if_fail (orig_tiles != NULL, NULL);
g_return_val_if_fail (matrix != NULL, NULL);
g_return_val_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress), NULL);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
m = *matrix;
inv = *matrix;
alpha = 0;
/* turn interpolation off for simple transformations (e.g. rot90) */
if (gimp_matrix3_is_simple (matrix))
interpolation_type = GIMP_INTERPOLATION_NONE;
/* Get the background color */
gimp_image_get_background (gimage, drawable, context, bg_color);
switch (GIMP_IMAGE_TYPE_BASE_TYPE (gimp_drawable_type (drawable)))
{
case GIMP_RGB:
bg_color[ALPHA_PIX] = TRANSPARENT_OPACITY;
alpha = ALPHA_PIX;
break;
case GIMP_GRAY:
bg_color[ALPHA_G_PIX] = TRANSPARENT_OPACITY;
alpha = ALPHA_G_PIX;
break;
case GIMP_INDEXED:
bg_color[ALPHA_I_PIX] = TRANSPARENT_OPACITY;
alpha = ALPHA_I_PIX;
/* If the gimage is indexed color, ignore interpolation value */
interpolation_type = GIMP_INTERPOLATION_NONE;
break;
default:
g_assert_not_reached ();
break;
}
/* "Outside" a channel is transparency, not the bg color */
if (GIMP_IS_CHANNEL (drawable))
bg_color[0] = TRANSPARENT_OPACITY;
/* setting alpha = 0 will cause the channel's value to be treated
* as alpha and the color channel loops never to be entered
*/
if (tile_manager_bpp (orig_tiles) == 1)
alpha = 0;
if (direction == GIMP_TRANSFORM_BACKWARD)
{
/* keep the original matrix here, so we dont need to recalculate
* the inverse later
*/
gimp_matrix3_invert (&inv);
}
else
{
/* Find the inverse of the transformation matrix */
gimp_matrix3_invert (&m);
}
tile_manager_get_offsets (orig_tiles, &u1, &v1);
u2 = u1 + tile_manager_width (orig_tiles);
v2 = v1 + tile_manager_height (orig_tiles);
/* Always clip unfloated tiles since they must keep their size */
if (G_TYPE_FROM_INSTANCE (drawable) == GIMP_TYPE_CHANNEL && alpha == 0)
clip_result = TRUE;
/* Find the bounding coordinates of target */
if (clip_result)
{
x1 = u1;
y1 = v1;
x2 = u2;
y2 = v2;
}
else
{
gdouble dx1, dy1;
gdouble dx2, dy2;
gdouble dx3, dy3;
gdouble dx4, dy4;
gimp_matrix3_transform_point (&inv, u1, v1, &dx1, &dy1);
gimp_matrix3_transform_point (&inv, u2, v1, &dx2, &dy2);
gimp_matrix3_transform_point (&inv, u1, v2, &dx3, &dy3);
gimp_matrix3_transform_point (&inv, u2, v2, &dx4, &dy4);
if (! FINITE (dx1) || ! FINITE (dy1) ||
! FINITE (dx2) || ! FINITE (dy2) ||
! FINITE (dx3) || ! FINITE (dy3) ||
! FINITE (dx4) || ! FINITE (dy4))
{
/* fallback to clip_result if the passed matrix is broken */
x1 = u1;
y1 = v1;
x2 = u2;
y2 = v2;
}
else
{
x1 = (gint) floor (MIN4 (dx1, dx2, dx3, dx4));
y1 = (gint) floor (MIN4 (dy1, dy2, dy3, dy4));
x2 = (gint) ceil (MAX4 (dx1, dx2, dx3, dx4));
y2 = (gint) ceil (MAX4 (dy1, dy2, dy3, dy4));
if (x1 == x2)
x2++;
if (y1 == y2)
y2++;
}
}
/* Get the new temporary buffer for the transformed result */
new_tiles = tile_manager_new (x2 - x1, y2 - y1,
tile_manager_bpp (orig_tiles));
pixel_region_init (&destPR, new_tiles,
0, 0, x2 - x1, y2 - y1, TRUE);
tile_manager_set_offsets (new_tiles, x1, y1);
width = tile_manager_width (new_tiles);
bytes = tile_manager_bpp (new_tiles);
/* If the image is too small for lanczos, switch to cubic interpolation */
if (interpolation_type == GIMP_INTERPOLATION_LANCZOS &&
(x2 - x1 < LANCZOS_WIDTH2 || y2 - y1 < LANCZOS_WIDTH2))
interpolation_type = GIMP_INTERPOLATION_CUBIC;
/* initialise the pixel_surround and pixel_cache accessors */
switch (interpolation_type)
{
case GIMP_INTERPOLATION_NONE:
break;
case GIMP_INTERPOLATION_CUBIC:
pixel_surround_init (&surround, orig_tiles, 4, 4, bg_color);
break;
case GIMP_INTERPOLATION_LINEAR:
pixel_surround_init (&surround, orig_tiles, 2, 2, bg_color);
break;
case GIMP_INTERPOLATION_LANCZOS:
kernel = kernel_lanczos ();
pixel_surround_init (&surround, orig_tiles,
LANCZOS_WIDTH2, LANCZOS_WIDTH2, bg_color);
break;
}
dest = g_new (guchar, tile_manager_width (new_tiles) * bytes);
uinc = m.coeff[0][0];
vinc = m.coeff[1][0];
winc = m.coeff[2][0];
coords = (interpolation_type != GIMP_INTERPOLATION_NONE) ? 5 : 1;
/* these loops could be rearranged, depending on which bit of code
* you'd most like to write more than once.
*/
for (y = y1; y < y2; y++)
{
if (progress && !(y & 0xf))
gimp_progress_set_value (progress,
(gdouble) (y - y1) / (gdouble) (y2 - y1));
/* set up inverse transform steps */
tu[0] = uinc * x1 + m.coeff[0][1] * y + m.coeff[0][2];
tv[0] = vinc * x1 + m.coeff[1][1] * y + m.coeff[1][2];
tw[0] = winc * x1 + m.coeff[2][1] * y + m.coeff[2][2];
if (interpolation_type != GIMP_INTERPOLATION_NONE)
{
gdouble xx = x1;
gdouble yy = y;
tu[1] = uinc * (xx - 1) + m.coeff[0][1] * (yy ) + m.coeff[0][2];
tv[1] = vinc * (xx - 1) + m.coeff[1][1] * (yy ) + m.coeff[1][2];
tw[1] = winc * (xx - 1) + m.coeff[2][1] * (yy ) + m.coeff[2][2];
tu[2] = uinc * (xx ) + m.coeff[0][1] * (yy - 1) + m.coeff[0][2];
tv[2] = vinc * (xx ) + m.coeff[1][1] * (yy - 1) + m.coeff[1][2];
tw[2] = winc * (xx ) + m.coeff[2][1] * (yy - 1) + m.coeff[2][2];
tu[3] = uinc * (xx + 1) + m.coeff[0][1] * (yy ) + m.coeff[0][2];
tv[3] = vinc * (xx + 1) + m.coeff[1][1] * (yy ) + m.coeff[1][2];
tw[3] = winc * (xx + 1) + m.coeff[2][1] * (yy ) + m.coeff[2][2];
tu[4] = uinc * (xx ) + m.coeff[0][1] * (yy + 1) + m.coeff[0][2];
tv[4] = vinc * (xx ) + m.coeff[1][1] * (yy + 1) + m.coeff[1][2];
tw[4] = winc * (xx ) + m.coeff[2][1] * (yy + 1) + m.coeff[2][2];
}
d = dest;
for (x = x1; x < x2; x++)
{
gint i; /* normalize homogeneous coords */
for (i = 0; i < coords; i++)
{
if (tw[i] == 1.0)
{
u[i] = tu[i];
v[i] = tv[i];
}
else if (tw[i] != 0.0)
{
u[i] = tu[i] / tw[i];
v[i] = tv[i] / tw[i];
}
else
{
g_warning ("homogeneous coordinate = 0...\n");
}
}
/* Set the destination pixels */
if (interpolation_type == GIMP_INTERPOLATION_NONE)
{
guchar color[MAX_CHANNELS];
gint iu = (gint) u[0];
gint iv = (gint) v[0];
gint b;
if (iu >= u1 && iu < u2 &&
iv >= v1 && iv < v2)
{
/* u, v coordinates into source tiles */
gint u = iu - u1;
gint v = iv - v1;
read_pixel_data_1 (orig_tiles, u, v, color);
for (b = 0; b < bytes; b++)
*d++ = color[b];
}
else /* not in source range */
{
/* increment the destination pointers */
for (b = 0; b < bytes; b++)
*d++ = bg_color[b];
}
}
else
{
gint b;
if (u [0] < u1 || v [0] < v1 ||
u [0] >= u2 || v [0] >= v2 )
{
/* not in source range */
/* increment the destination pointers */
for (b = 0; b < bytes; b++)
*d++ = bg_color[b];
}
else
{
guchar color[MAX_CHANNELS];
/* clamp texture coordinates */
for (b = 0; b < 5; b++)
{
u[b] = CLAMP (u[b], u1, u2 - 1);
v[b] = CLAMP (v[b], v1, v2 - 1);
}
if (supersample &&
supersample_dtest (u[1], v[1], u[2], v[2],
u[3], v[3], u[4], v[4]))
{
sample_adapt (orig_tiles,
u[0]-u1, v[0]-v1,
u[1]-u1, v[1]-v1,
u[2]-u1, v[2]-v1,
u[3]-u1, v[3]-v1,
u[4]-u1, v[4]-v1,
recursion_level,
color, bg_color, bytes, alpha);
}
else
{
switch (interpolation_type)
{
case GIMP_INTERPOLATION_NONE:
break;
case GIMP_INTERPOLATION_LINEAR:
sample_linear (&surround, u[0] - u1, v[0] - v1,
color, bytes, alpha);
break;
case GIMP_INTERPOLATION_CUBIC:
sample_cubic (&surround, u[0] - u1, v[0] - v1,
color, bytes, alpha);
break;
case GIMP_INTERPOLATION_LANCZOS:
sample_lanczos (&surround, u[0] - u1, v[0] - v1,
color, bytes, alpha, kernel);
break;
}
}
/* Set the destination pixel */
for (b = 0; b < bytes; b++)
*d++ = color[b];
}
}
for (i = 0; i < coords; i++)
{
tu[i] += uinc;
tv[i] += vinc;
tw[i] += winc;
}
}
/* set the pixel region row */
pixel_region_set_row (&destPR, 0, (y - y1), width, dest);
}
switch (interpolation_type)
{
case GIMP_INTERPOLATION_NONE:
break;
case GIMP_INTERPOLATION_CUBIC:
case GIMP_INTERPOLATION_LINEAR:
pixel_surround_clear (&surround);
break;
case GIMP_INTERPOLATION_LANCZOS:
pixel_surround_clear (&surround);
g_free (kernel);
break;
}
g_free (dest);
return new_tiles;
}
TileManager *
gimp_drawable_transform_tiles_flip (GimpDrawable *drawable,
GimpContext *context,
TileManager *orig_tiles,
GimpOrientationType flip_type,
gdouble axis,
gboolean clip_result)
{
GimpImage *gimage;
TileManager *new_tiles;
PixelRegion srcPR, destPR;
gint orig_x, orig_y;
gint orig_width, orig_height;
gint orig_bpp;
gint new_x, new_y;
gint new_width, new_height;
gint i;
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), NULL);
g_return_val_if_fail (GIMP_IS_CONTEXT (context), NULL);
g_return_val_if_fail (orig_tiles != NULL, NULL);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
orig_width = tile_manager_width (orig_tiles);
orig_height = tile_manager_height (orig_tiles);
orig_bpp = tile_manager_bpp (orig_tiles);
tile_manager_get_offsets (orig_tiles, &orig_x, &orig_y);
new_x = orig_x;
new_y = orig_y;
new_width = orig_width;
new_height = orig_height;
switch (flip_type)
{
case GIMP_ORIENTATION_HORIZONTAL:
new_x = RINT (-((gdouble) orig_x +
(gdouble) orig_width - axis) + axis);
break;
case GIMP_ORIENTATION_VERTICAL:
new_y = RINT (-((gdouble) orig_y +
(gdouble) orig_height - axis) + axis);
break;
default:
break;
}
new_tiles = tile_manager_new (new_width, new_height, orig_bpp);
if (clip_result && (new_x != orig_y || new_y != orig_y))
{
guchar bg_color[MAX_CHANNELS];
gint clip_x, clip_y;
gint clip_width, clip_height;
tile_manager_set_offsets (new_tiles, orig_x, orig_y);
gimp_image_get_background (gimage, drawable, context, bg_color);
/* "Outside" a channel is transparency, not the bg color */
if (GIMP_IS_CHANNEL (drawable))
bg_color[0] = TRANSPARENT_OPACITY;
pixel_region_init (&destPR, new_tiles,
0, 0, new_width, new_height, TRUE);
color_region (&destPR, bg_color);
if (gimp_rectangle_intersect (orig_x, orig_y, orig_width, orig_height,
new_x, new_y, new_width, new_height,
&clip_x, &clip_y,
&clip_width, &clip_height))
{
orig_x = new_x = clip_x - orig_x;
orig_y = new_y = clip_y - orig_y;
}
orig_width = new_width = clip_width;
orig_height = new_height = clip_height;
}
else
{
tile_manager_set_offsets (new_tiles, new_x, new_y);
orig_x = 0;
orig_y = 0;
new_x = 0;
new_y = 0;
}
if (new_width == 0 && new_height == 0)
return new_tiles;
if (flip_type == GIMP_ORIENTATION_HORIZONTAL)
{
for (i = 0; i < orig_width; i++)
{
pixel_region_init (&srcPR, orig_tiles,
i + orig_x, orig_y,
1, orig_height, FALSE);
pixel_region_init (&destPR, new_tiles,
new_x + new_width - i - 1, new_y,
1, new_height, TRUE);
copy_region (&srcPR, &destPR);
}
}
else
{
for (i = 0; i < orig_height; i++)
{
pixel_region_init (&srcPR, orig_tiles,
orig_x, i + orig_y,
orig_width, 1, FALSE);
pixel_region_init (&destPR, new_tiles,
new_x, new_y + new_height - i - 1,
new_width, 1, TRUE);
copy_region (&srcPR, &destPR);
}
}
return new_tiles;
}
static void
gimp_drawable_transform_rotate_point (gint x,
gint y,
GimpRotationType rotate_type,
gdouble center_x,
gdouble center_y,
gint *new_x,
gint *new_y)
{
g_return_if_fail (new_x != NULL);
g_return_if_fail (new_y != NULL);
switch (rotate_type)
{
case GIMP_ROTATE_90:
*new_x = RINT (center_x - (gdouble) y + center_y);
*new_y = RINT (center_y + (gdouble) x - center_x);
break;
case GIMP_ROTATE_180:
*new_x = RINT (center_x - ((gdouble) x - center_x));
*new_y = RINT (center_y - ((gdouble) y - center_y));
break;
case GIMP_ROTATE_270:
*new_x = RINT (center_x + (gdouble) y - center_y);
*new_y = RINT (center_y - (gdouble) x + center_x);
break;
default:
g_assert_not_reached ();
}
}
TileManager *
gimp_drawable_transform_tiles_rotate (GimpDrawable *drawable,
GimpContext *context,
TileManager *orig_tiles,
GimpRotationType rotate_type,
gdouble center_x,
gdouble center_y,
gboolean clip_result)
{
GimpImage *gimage;
TileManager *new_tiles;
PixelRegion srcPR, destPR;
guchar *buf = NULL;
gint orig_x, orig_y;
gint orig_width, orig_height;
gint orig_bpp;
gint new_x, new_y;
gint new_width, new_height;
gint i, j, k;
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), NULL);
g_return_val_if_fail (GIMP_IS_CONTEXT (context), NULL);
g_return_val_if_fail (orig_tiles != NULL, NULL);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
orig_width = tile_manager_width (orig_tiles);
orig_height = tile_manager_height (orig_tiles);
orig_bpp = tile_manager_bpp (orig_tiles);
tile_manager_get_offsets (orig_tiles, &orig_x, &orig_y);
switch (rotate_type)
{
case GIMP_ROTATE_90:
gimp_drawable_transform_rotate_point (orig_x,
orig_y + orig_height,
rotate_type, center_x, center_y,
&new_x, &new_y);
new_width = orig_height;
new_height = orig_width;
break;
case GIMP_ROTATE_180:
gimp_drawable_transform_rotate_point (orig_x + orig_width,
orig_y + orig_height,
rotate_type, center_x, center_y,
&new_x, &new_y);
new_width = orig_width;
new_height = orig_height;
break;
case GIMP_ROTATE_270:
gimp_drawable_transform_rotate_point (orig_x + orig_width,
orig_y,
rotate_type, center_x, center_y,
&new_x, &new_y);
new_width = orig_height;
new_height = orig_width;
break;
default:
g_assert_not_reached ();
return NULL;
}
if (clip_result && (new_x != orig_x || new_y != orig_y ||
new_width != orig_width || new_height != orig_height))
{
guchar bg_color[MAX_CHANNELS];
gint clip_x, clip_y;
gint clip_width, clip_height;
new_tiles = tile_manager_new (orig_width, orig_height, orig_bpp);
tile_manager_set_offsets (new_tiles, orig_x, orig_y);
gimp_image_get_background (gimage, drawable, context, bg_color);
/* "Outside" a channel is transparency, not the bg color */
if (GIMP_IS_CHANNEL (drawable))
bg_color[0] = TRANSPARENT_OPACITY;
pixel_region_init (&destPR, new_tiles,
0, 0, orig_width, orig_height, TRUE);
color_region (&destPR, bg_color);
if (gimp_rectangle_intersect (orig_x, orig_y, orig_width, orig_height,
new_x, new_y, new_width, new_height,
&clip_x, &clip_y,
&clip_width, &clip_height))
{
gint saved_orig_x = orig_x;
gint saved_orig_y = orig_y;
new_x = clip_x - orig_x;
new_y = clip_y - orig_y;
switch (rotate_type)
{
case GIMP_ROTATE_90:
gimp_drawable_transform_rotate_point (clip_x + clip_width,
clip_y,
GIMP_ROTATE_270,
center_x,
center_y,
&orig_x,
&orig_y);
orig_x -= saved_orig_x;
orig_y -= saved_orig_y;
orig_width = clip_height;
orig_height = clip_width;
break;
case GIMP_ROTATE_180:
orig_x = clip_x - orig_x;
orig_y = clip_y - orig_y;
orig_width = clip_width;
orig_height = clip_height;
break;
case GIMP_ROTATE_270:
gimp_drawable_transform_rotate_point (clip_x,
clip_y + clip_height,
GIMP_ROTATE_90,
center_x,
center_y,
&orig_x,
&orig_y);
orig_x -= saved_orig_x;
orig_y -= saved_orig_y;
orig_width = clip_height;
orig_height = clip_width;
break;
}
}
new_width = clip_width;
new_height = clip_height;
}
else
{
new_tiles = tile_manager_new (new_width, new_height, orig_bpp);
tile_manager_set_offsets (new_tiles, new_x, new_y);
orig_x = 0;
orig_y = 0;
new_x = 0;
new_y = 0;
}
if (new_width == 0 && new_height == 0)
return new_tiles;
pixel_region_init (&srcPR, orig_tiles,
orig_x, orig_y, orig_width, orig_height, FALSE);
pixel_region_init (&destPR, new_tiles,
new_x, new_y, new_width, new_height, TRUE);
switch (rotate_type)
{
case GIMP_ROTATE_90:
g_assert (new_height == orig_width);
buf = g_new (guchar, new_height * orig_bpp);
for (i = 0; i < orig_height; i++)
{
pixel_region_get_row (&srcPR, orig_x, orig_y + orig_height - 1 - i,
orig_width, buf, 1);
pixel_region_set_col (&destPR, new_x + i, new_y, new_height, buf);
}
break;
case GIMP_ROTATE_180:
g_assert (new_width == orig_width);
buf = g_new (guchar, new_width * orig_bpp);
for (i = 0; i < orig_height; i++)
{
pixel_region_get_row (&srcPR, orig_x, orig_y + orig_height - 1 - i,
orig_width, buf, 1);
for (j = 0; j < orig_width / 2; j++)
{
guchar *left = buf + j * orig_bpp;
guchar *right = buf + (orig_width - 1 - j) * orig_bpp;
for (k = 0; k < orig_bpp; k++)
{
guchar tmp = left[k];
left[k] = right[k];
right[k] = tmp;
}
}
pixel_region_set_row (&destPR, new_x, new_y + i, new_width, buf);
}
break;
case GIMP_ROTATE_270:
g_assert (new_width == orig_height);
buf = g_new (guchar, new_width * orig_bpp);
for (i = 0; i < orig_width; i++)
{
pixel_region_get_col (&srcPR, orig_x + orig_width - 1 - i, orig_y,
orig_height, buf, 1);
pixel_region_set_row (&destPR, new_x, new_y + i, new_width, buf);
}
break;
}
g_free (buf);
return new_tiles;
}
gboolean
gimp_drawable_transform_affine (GimpDrawable *drawable,
GimpContext *context,
const GimpMatrix3 *matrix,
GimpTransformDirection direction,
GimpInterpolationType interpolation_type,
gboolean supersample,
gint recursion_level,
gboolean clip_result,
GimpProgress *progress)
{
GimpImage *gimage;
TileManager *orig_tiles;
gboolean new_layer;
gboolean success = FALSE;
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), FALSE);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), FALSE);
g_return_val_if_fail (GIMP_IS_CONTEXT (context), FALSE);
g_return_val_if_fail (matrix != NULL, FALSE);
g_return_val_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress), FALSE);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
/* Start a transform undo group */
gimp_image_undo_group_start (gimage,
GIMP_UNDO_GROUP_TRANSFORM, _("Transform"));
/* Cut/Copy from the specified drawable */
orig_tiles = gimp_drawable_transform_cut (drawable, context, &new_layer);
if (orig_tiles)
{
TileManager *new_tiles;
/* always clip unfloated tiles so they keep their size */
if (GIMP_IS_CHANNEL (drawable) && tile_manager_bpp (orig_tiles) == 1)
clip_result = TRUE;
/* transform the buffer */
new_tiles = gimp_drawable_transform_tiles_affine (drawable, context,
orig_tiles,
matrix,
GIMP_TRANSFORM_FORWARD,
interpolation_type,
supersample,
recursion_level,
clip_result,
progress);
/* Free the cut/copied buffer */
tile_manager_unref (orig_tiles);
if (new_tiles)
{
success = gimp_drawable_transform_paste (drawable, new_tiles,
new_layer);
tile_manager_unref (new_tiles);
}
}
/* push the undo group end */
gimp_image_undo_group_end (gimage);
return success;
}
gboolean
gimp_drawable_transform_flip (GimpDrawable *drawable,
GimpContext *context,
GimpOrientationType flip_type,
gboolean auto_center,
gdouble axis,
gboolean clip_result)
{
GimpImage *gimage;
TileManager *orig_tiles;
gboolean new_layer;
gboolean success = FALSE;
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), FALSE);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), FALSE);
g_return_val_if_fail (GIMP_IS_CONTEXT (context), FALSE);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
/* Start a transform undo group */
gimp_image_undo_group_start (gimage, GIMP_UNDO_GROUP_TRANSFORM, _("Flip"));
/* Cut/Copy from the specified drawable */
orig_tiles = gimp_drawable_transform_cut (drawable, context, &new_layer);
if (orig_tiles)
{
TileManager *new_tiles = NULL;
if (auto_center)
{
gint off_x, off_y;
gint width, height;
tile_manager_get_offsets (orig_tiles, &off_x, &off_y);
width = tile_manager_width (orig_tiles);
height = tile_manager_height (orig_tiles);
switch (flip_type)
{
case GIMP_ORIENTATION_HORIZONTAL:
axis = ((gdouble) off_x + (gdouble) width / 2.0);
break;
case GIMP_ORIENTATION_VERTICAL:
axis = ((gdouble) off_y + (gdouble) height / 2.0);
break;
default:
break;
}
}
/* always clip unfloated tiles so they keep their size */
if (GIMP_IS_CHANNEL (drawable) && tile_manager_bpp (orig_tiles) == 1)
clip_result = TRUE;
/* transform the buffer */
if (orig_tiles)
{
new_tiles = gimp_drawable_transform_tiles_flip (drawable, context,
orig_tiles,
flip_type, axis,
clip_result);
/* Free the cut/copied buffer */
tile_manager_unref (orig_tiles);
}
if (new_tiles)
{
success = gimp_drawable_transform_paste (drawable, new_tiles,
new_layer);
tile_manager_unref (new_tiles);
}
}
/* push the undo group end */
gimp_image_undo_group_end (gimage);
return success;
}
gboolean
gimp_drawable_transform_rotate (GimpDrawable *drawable,
GimpContext *context,
GimpRotationType rotate_type,
gboolean auto_center,
gdouble center_x,
gdouble center_y,
gboolean clip_result)
{
GimpImage *gimage;
TileManager *orig_tiles;
gboolean new_layer;
gboolean success = FALSE;
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), FALSE);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), FALSE);
g_return_val_if_fail (GIMP_IS_CONTEXT (context), FALSE);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
/* Start a transform undo group */
gimp_image_undo_group_start (gimage, GIMP_UNDO_GROUP_TRANSFORM, _("Rotate"));
/* Cut/Copy from the specified drawable */
orig_tiles = gimp_drawable_transform_cut (drawable, context, &new_layer);
if (orig_tiles)
{
TileManager *new_tiles;
if (auto_center)
{
gint off_x, off_y;
gint width, height;
tile_manager_get_offsets (orig_tiles, &off_x, &off_y);
width = tile_manager_width (orig_tiles);
height = tile_manager_height (orig_tiles);
center_x = (gdouble) off_x + (gdouble) width / 2.0;
center_y = (gdouble) off_y + (gdouble) height / 2.0;
}
/* always clip unfloated tiles so they keep their size */
if (GIMP_IS_CHANNEL (drawable) && tile_manager_bpp (orig_tiles) == 1)
clip_result = TRUE;
/* transform the buffer */
new_tiles = gimp_drawable_transform_tiles_rotate (drawable, context,
orig_tiles,
rotate_type,
center_x, center_y,
clip_result);
/* Free the cut/copied buffer */
tile_manager_unref (orig_tiles);
if (new_tiles)
{
success = gimp_drawable_transform_paste (drawable, new_tiles,
new_layer);
tile_manager_unref (new_tiles);
}
}
/* push the undo group end */
gimp_image_undo_group_end (gimage);
return success;
}
TileManager *
gimp_drawable_transform_cut (GimpDrawable *drawable,
GimpContext *context,
gboolean *new_layer)
{
GimpImage *gimage;
TileManager *tiles;
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), NULL);
g_return_val_if_fail (GIMP_IS_CONTEXT (context), NULL);
g_return_val_if_fail (new_layer != NULL, NULL);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
/* extract the selected mask if there is a selection */
if (! gimp_channel_is_empty (gimp_image_get_mask (gimage)))
{
gint x, y, w, h;
/* set the keep_indexed flag to FALSE here, since we use
* gimp_layer_new_from_tiles() later which assumes that the tiles
* are either RGB or GRAY. Eeek!!! (Sven)
*/
if (gimp_drawable_mask_intersect (drawable, &x, &y, &w, &h))
{
tiles = gimp_selection_extract (gimp_image_get_mask (gimage),
drawable, context, TRUE, FALSE, TRUE);
*new_layer = TRUE;
}
else
{
tiles = NULL;
*new_layer = FALSE;
}
}
else /* otherwise, just copy the layer */
{
if (GIMP_IS_LAYER (drawable))
tiles = gimp_selection_extract (gimp_image_get_mask (gimage),
drawable, context, FALSE, TRUE, TRUE);
else
tiles = gimp_selection_extract (gimp_image_get_mask (gimage),
drawable, context, FALSE, TRUE, FALSE);
*new_layer = FALSE;
}
return tiles;
}
gboolean
gimp_drawable_transform_paste (GimpDrawable *drawable,
TileManager *tiles,
gboolean new_layer)
{
GimpImage *gimage;
GimpLayer *layer = NULL;
const gchar *undo_desc = NULL;
gint offset_x;
gint offset_y;
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), FALSE);
g_return_val_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)), FALSE);
g_return_val_if_fail (tiles != NULL, FALSE);
gimage = gimp_item_get_image (GIMP_ITEM (drawable));
if (GIMP_IS_LAYER (drawable))
undo_desc = _("Transform Layer");
else if (GIMP_IS_CHANNEL (drawable))
undo_desc = _("Transform Channel");
else
return FALSE;
tile_manager_get_offsets (tiles, &offset_x, &offset_y);
gimp_image_undo_group_start (gimage, GIMP_UNDO_GROUP_EDIT_PASTE, undo_desc);
if (new_layer)
{
layer =
gimp_layer_new_from_tiles (tiles, gimage,
gimp_drawable_type_with_alpha (drawable),
_("Transformation"),
GIMP_OPACITY_OPAQUE, GIMP_NORMAL_MODE);
GIMP_ITEM (layer)->offset_x = offset_x;
GIMP_ITEM (layer)->offset_y = offset_y;
floating_sel_attach (layer, drawable);
}
else
{
GimpImageType drawable_type;
if (GIMP_IS_LAYER (drawable) && (tile_manager_bpp (tiles) == 2 ||
tile_manager_bpp (tiles) == 4))
{
drawable_type = gimp_drawable_type_with_alpha (drawable);
}
else
{
drawable_type = gimp_drawable_type (drawable);
}
gimp_drawable_set_tiles_full (drawable, TRUE, NULL,
tiles, drawable_type,
offset_x, offset_y);
}
gimp_image_undo_group_end (gimage);
return TRUE;
}
#define BILINEAR(jk, j1k, jk1, j1k1, dx, dy) \
((1 - dy) * (jk + dx * (j1k - jk)) + \
dy * (jk1 + dx * (j1k1 - jk1)))
/* u & v are the subpixel coordinates of the point in
* the original selection's floating buffer.
* We need the two pixel coords around them:
* iu to iu + 1, iv to iv + 1
*/
static void
sample_linear (PixelSurround *surround,
gdouble u,
gdouble v,
guchar *color,
gint bytes,
gint alpha)
{
gdouble a_val, a_recip;
gint i;
gint iu = floor (u);
gint iv = floor (v);
gint row;
gdouble du,dv;
guchar *alphachan;
guchar *data;
/* lock the pixel surround */
data = pixel_surround_lock (surround, iu, iv);
row = pixel_surround_rowstride (surround);
/* the fractional error */
du = u - iu;
dv = v - iv;
/* calculate alpha value of result pixel */
alphachan = &data[alpha];
a_val = BILINEAR (alphachan[0], alphachan[bytes],
alphachan[row], alphachan[row + bytes], du, dv);
if (a_val <= 0.0)
{
a_recip = 0.0;
color[alpha] = 0.0;
}
else if (a_val >= 255.0)
{
a_recip = 1.0 / a_val;
color[alpha] = 255;
}
else
{
a_recip = 1.0 / a_val;
color[alpha] = RINT (a_val);
}
/* for colour channels c,
* result = bilinear (c * alpha) / bilinear (alpha)
*
* never entered for alpha == 0
*/
for (i = 0; i < alpha; i++)
{
gint newval = (a_recip *
BILINEAR (alphachan[0] * data[i],
alphachan[bytes] * data[bytes + i],
alphachan[row] * data[row + i],
alphachan[row + bytes] * data[row + bytes + i],
du, dv));
color[i] = CLAMP (newval, 0, 255);
}
pixel_surround_release (surround);
}
/* macros to handle conversion to/from fixed point, this fixed point code
* uses signed integers, by using 8 bits for the fractional part we have
*
* 1 bit sign
* 21 bits integer part
* 8 bit fractional part
*
* 1023 discrete subpixel sample positions should be enough for the needs
* of the supersampling algorithm, drawables where the dimensions have a need
* exceeding 2^21 ( 2097152px, will typically use terabytes of memory, when
* that is the common need, we can probably assume 64 bit integers and adjust
* FIXED_SHIFT accordingly.
*/
#define FIXED_SHIFT 10
#define FIXED_UNIT (1 << FIXED_SHIFT)
#define DOUBLE2FIXED(val) ((val) * FIXED_UNIT)
#define FIXED2DOUBLE(val) ((val) / FIXED_UNIT)
/*
bilinear interpolation of a fixed point pixel
*/
static void
sample_bi (TileManager *tm,
gint x,
gint y,
guchar *color,
guchar *bg_color,
gint bpp,
gint alpha)
{
guchar C[4][4];
gint i;
gint xscale = (x & (FIXED_UNIT-1));
gint yscale = (y & (FIXED_UNIT-1));
gint x0 = x >> FIXED_SHIFT;
gint y0 = y >> FIXED_SHIFT;
gint x1 = x0 + 1;
gint y1 = y0 + 1;
/* fill the color with default values, since read_pixel_data_1
* does nothing, when accesses are out of bounds.
*/
for (i = 0; i < 4; i++)
*(guint*) (&C[i]) = *(guint*) (bg_color);
read_pixel_data_1 (tm, x0, y0, C[0]);
read_pixel_data_1 (tm, x1, y0, C[2]);
read_pixel_data_1 (tm, x0, y1, C[1]);
read_pixel_data_1 (tm, x1, y1, C[3]);
#define lerp(v1,v2,r) \
(((guint)(v1) * (FIXED_UNIT - (guint)(r)) + \
(guint)(v2) * (guint)(r)) >> FIXED_SHIFT)
color[alpha]= lerp (lerp (C[0][alpha], C[1][alpha], yscale),
lerp (C[2][alpha], C[3][alpha], yscale), xscale);
if (color[alpha])
{ /* to avoid problems, calculate with premultiplied alpha */
for (i=0; i<alpha; i++)
{
C[0][i] = (C[0][i] * C[0][alpha] / 255);
C[1][i] = (C[1][i] * C[1][alpha] / 255);
C[2][i] = (C[2][i] * C[2][alpha] / 255);
C[3][i] = (C[3][i] * C[3][alpha] / 255);
}
for (i = 0; i < alpha; i++)
color[i] = lerp (lerp (C[0][i], C[1][i], yscale),
lerp (C[2][i], C[3][i], yscale), xscale);
}
else
{
for (i = 0; i < alpha; i++)
color[i] = 0;
}
#undef lerp
}
/*
* Returns TRUE if one of the deltas of the
* quad edge is > 1.0 (16.16 fixed values).
*/
static gboolean
supersample_test (gint x0, gint y0,
gint x1, gint y1,
gint x2, gint y2,
gint x3, gint y3)
{
if (abs (x0 - x1) > FIXED_UNIT ||
abs (x1 - x2) > FIXED_UNIT ||
abs (x2 - x3) > FIXED_UNIT ||
abs (x3 - x0) > FIXED_UNIT ||
abs (y0 - y1) > FIXED_UNIT ||
abs (y1 - y2) > FIXED_UNIT ||
abs (y2 - y3) > FIXED_UNIT ||
abs (y3 - y0) > FIXED_UNIT) return TRUE;
return FALSE;
}
/*
* Returns TRUE if one of the deltas of the
* quad edge is > 1.0 (double values).
*/
static gboolean
supersample_dtest (gdouble x0, gdouble y0,
gdouble x1, gdouble y1,
gdouble x2, gdouble y2,
gdouble x3, gdouble y3)
{
if (fabs (x0 - x1) > 1.0 ||
fabs (x1 - x2) > 1.0 ||
fabs (x2 - x3) > 1.0 ||
fabs (x3 - x0) > 1.0 ||
fabs (y0 - y1) > 1.0 ||
fabs (y1 - y2) > 1.0 ||
fabs (y2 - y3) > 1.0 ||
fabs (y3 - y0) > 1.0)
return TRUE;
return FALSE;
}
/*
sample a grid that is spaced according to the quadraliteral's edges,
it subdivides a maximum of level times before sampling.
0..3 is a cycle around the quad
*/
static void
get_sample (TileManager *tm,
gint xc, gint yc,
gint x0, gint y0,
gint x1, gint y1,
gint x2, gint y2,
gint x3, gint y3,
gint *cc,
gint level,
guint *color,
guchar *bg_color,
gint bpp,
gint alpha)
{
if (!level || !supersample_test (x0, y0, x1, y1, x2, y2, x3, y3))
{
gint i;
guchar C[4];
sample_bi (tm, xc, yc, C, bg_color, bpp, alpha);
for (i = 0; i < bpp; i++)
color[i]+= C[i];
(*cc)++; /* increase number of samples taken */
}
else
{
gint tx, lx, rx, bx, tlx, trx, blx, brx;
gint ty, ly, ry, by, tly, try, bly, bry;
/* calculate subdivided corner coordinates (including centercoords
thus using a bilinear interpolation,. almost as good as
doing the perspective transform for each subpixel coordinate*/
tx = (x0 + x1) / 2;
tlx = (x0 + xc) / 2;
trx = (x1 + xc) / 2;
lx = (x0 + x3) / 2;
rx = (x1 + x2) / 2;
blx = (x3 + xc) / 2;
brx = (x2 + xc) / 2;
bx = (x3 + x2) / 2;
ty = (y0 + y1) / 2;
tly = (y0 + yc) / 2;
try = (y1 + yc) / 2;
ly = (y0 + y3) / 2;
ry = (y1 + y2) / 2;
bly = (y3 + yc) / 2;
bry = (y2 + yc) / 2;
by = (y3 + y2) / 2;
get_sample (tm,
tlx,tly,
x0,y0, tx,ty, xc,yc, lx,ly,
cc, level-1, color, bg_color, bpp, alpha);
get_sample (tm,
trx,try,
tx,ty, x1,y1, rx,ry, xc,yc,
cc, level-1, color, bg_color, bpp, alpha);
get_sample (tm,
brx,bry,
xc,yc, rx,ry, x2,y2, bx,by,
cc, level-1, color, bg_color, bpp, alpha);
get_sample (tm,
blx,bly,
lx,ly, xc,yc, bx,by, x3,y3,
cc, level-1, color, bg_color, bpp, alpha);
}
}
static void
sample_adapt (TileManager *tm,
gdouble xc, gdouble yc,
gdouble x0, gdouble y0,
gdouble x1, gdouble y1,
gdouble x2, gdouble y2,
gdouble x3, gdouble y3,
gint level,
guchar *color,
guchar *bg_color,
gint bpp,
gint alpha)
{
gint cc = 0;
gint i;
guint C[MAX_CHANNELS];
C[0] = C[1] = C[2] = C[3] = 0;
get_sample (tm,
DOUBLE2FIXED (xc), DOUBLE2FIXED (yc),
DOUBLE2FIXED (x0), DOUBLE2FIXED (y0),
DOUBLE2FIXED (x1), DOUBLE2FIXED (y1),
DOUBLE2FIXED (x2), DOUBLE2FIXED (y2),
DOUBLE2FIXED (x3), DOUBLE2FIXED (y3),
&cc, level, C, bg_color, bpp, alpha);
if (!cc)
cc=1;
color[alpha] = C[alpha] / cc;
if (color[alpha])
{
/* go from premultiplied to postmultiplied alpha */
for (i = 0; i < alpha; i++)
color[i] = ((C[i] / cc) * 255) / color[alpha];
}
else
{
for (i = 0; i < alpha; i++)
color[i] = 0;
}
}
/* access interleaved pixels */
#define CUBIC_ROW(dx, row, step) \
gimp_drawable_transform_cubic(dx,\
(row)[0], (row)[step], (row)[step+step], (row)[step+step+step])
#define CUBIC_SCALED_ROW(dx, row, arow, step) \
gimp_drawable_transform_cubic(dx, \
(arow)[0] * (row)[0], \
(arow)[step] * (row)[step], \
(arow)[step+step] * (row)[step+step], \
(arow)[step+step+step] * (row)[step+step+step])
/* Note: cubic function no longer clips result. */
/* Inlining this function makes sample_cubic() run about 10% faster. (Sven) */
static inline gdouble
gimp_drawable_transform_cubic (gdouble dx,
gint jm1,
gint j,
gint jp1,
gint jp2)
{
gdouble result;
#if 0
/* Equivalent to Gimp 1.1.1 and earlier - some ringing */
result = ((( ( - jm1 + j - jp1 + jp2 ) * dx +
( jm1 + jm1 - j - j + jp1 - jp2 ) ) * dx +
( - jm1 + jp1 ) ) * dx + j );
/* Recommended by Mitchell and Netravali - too blurred? */
result = ((( ( - 7 * jm1 + 21 * j - 21 * jp1 + 7 * jp2 ) * dx +
( 15 * jm1 - 36 * j + 27 * jp1 - 6 * jp2 ) ) * dx +
( - 9 * jm1 + 9 * jp1 ) ) * dx + (jm1 + 16 * j + jp1) ) / 18.0;
#endif
/* Catmull-Rom - not bad */
result = ((( ( - jm1 + 3 * j - 3 * jp1 + jp2 ) * dx +
( 2 * jm1 - 5 * j + 4 * jp1 - jp2 ) ) * dx +
( - jm1 + jp1 ) ) * dx + (j + j) ) / 2.0;
return result;
}
/* u & v are the subpixel coordinates of the point in
* the original selection's floating buffer.
* We need the four integer pixel coords around them:
* iu to iu + 3, iv to iv + 3
*/
static void
sample_cubic (PixelSurround *surround,
gdouble u,
gdouble v,
guchar *color,
gint bytes,
gint alpha)
{
gdouble a_val, a_recip;
gint i;
gint iu = floor(u);
gint iv = floor(v);
gint row;
gdouble du,dv;
guchar *data;
/* lock the pixel surround */
data = pixel_surround_lock (surround, iu - 1 , iv - 1 );
row = pixel_surround_rowstride (surround);
/* the fractional error */
du = u - iu;
dv = v - iv;
/* calculate alpha of result */
a_val = gimp_drawable_transform_cubic
(dv,
CUBIC_ROW (du, data + alpha + row * 0, bytes),
CUBIC_ROW (du, data + alpha + row * 1, bytes),
CUBIC_ROW (du, data + alpha + row * 2, bytes),
CUBIC_ROW (du, data + alpha + row * 3, bytes));
if (a_val <= 0.0)
{
a_recip = 0.0;
color[alpha] = 0;
}
else if (a_val > 255.0)
{
a_recip = 1.0 / a_val;
color[alpha] = 255;
}
else
{
a_recip = 1.0 / a_val;
color[alpha] = RINT (a_val);
}
/* for colour channels c,
* result = bicubic (c * alpha) / bicubic (alpha)
*
* never entered for alpha == 0
*/
for (i = 0; i < alpha; i++)
{
gint newval = (a_recip *
gimp_drawable_transform_cubic
(dv,
CUBIC_SCALED_ROW (du,
i + data + row * 0,
data + alpha + row * 0,
bytes),
CUBIC_SCALED_ROW (du,
i + data + row * 1,
data + alpha + row * 1,
bytes),
CUBIC_SCALED_ROW (du,
i + data + row * 2,
data + alpha + row * 2,
bytes),
CUBIC_SCALED_ROW (du,
i + data + row * 3,
data + alpha + row * 3,
bytes)));
color[i] = CLAMP (newval, 0, 255);
}
pixel_surround_release (surround);
}
/* Lanczos */
static inline gdouble
sinc (gdouble x)
{
gdouble y = x * G_PI;
if (ABS (x) < EPSILON)
return 1.0;
return sin (y) / y;
}
static inline gdouble
lanczos_sum (const guchar *data,
gdouble *l,
gint row,
gint bytes,
gint byte)
{
gdouble sum = 0;
gint j, k;
for (k = 0, j = 0; j < LANCZOS_WIDTH2; j++, k += bytes)
sum += (l[j] * data[row + k + byte]);
return sum;
}
static inline gdouble
lanczos_sum_mul (const guchar *data,
const gdouble *l,
gint row,
gint bytes,
gint byte,
gint alpha)
{
gdouble sum = 0;
gint j, k;
for (k = 0, j = 0; j < LANCZOS_WIDTH2; j++, k += bytes)
sum += (l[j] *
data[row + k + byte] *
data[row + k + alpha]);
return sum;
}
static gdouble *
kernel_lanczos (void)
{
gdouble *kernel ;
gdouble x = 0.0;
gdouble dx = (gdouble) LANCZOS_WIDTH / (gdouble) (LANCZOS_SAMPLES - 1);
gint i;
kernel = g_new (gdouble, LANCZOS_SAMPLES);
for (i = 0 ;i < LANCZOS_SAMPLES; i++)
{
kernel[i] = ((ABS (x) < LANCZOS_WIDTH) ?
(sinc (x) * sinc (x / LANCZOS_WIDTH)) : 0.0);
x += dx;
}
return kernel;
}
static void
sample_lanczos (PixelSurround *surround,
gdouble u,
gdouble v,
guchar *color,
gint bytes,
gint alpha,
const gdouble *kernel)
{
gdouble lu[LANCZOS_WIDTH2]; /* Lanczos sample value */
gdouble lv[LANCZOS_WIDTH2]; /* Lanczos sample value */
gdouble lusum, lvsum, weight; /* Lanczos weighting vars */
gint i,j,row, byte; /* loop vars to fill source window */
gint du,dv;
guchar *data;
gdouble aval, arecip; /* Handle alpha values */
gdouble newval; /* New interpolated RGB value */
gint iu = floor(u);
gint iv = floor(v);
/* lock the pixel surround */
data = pixel_surround_lock (surround,
iu - LANCZOS_WIDTH, iv - LANCZOS_WIDTH);
row = pixel_surround_rowstride (surround);
/* the fractional error */
du = (gint)((u - iu) * LANCZOS_SPP);
dv = (gint)((v - iv) * LANCZOS_SPP);
for (lusum = lvsum = i = 0, j = LANCZOS_WIDTH - 1;
j >= - LANCZOS_WIDTH;
j--, i++)
{
lusum += lu[i] = kernel[ABS (j * LANCZOS_SPP + du)];
lvsum += lv[i] = kernel[ABS (j * LANCZOS_SPP + dv)];
}
weight = lusum * lvsum;
for ( aval = 0, i = 0 ; i < LANCZOS_WIDTH2 ; i ++ )
aval += lv[i] * lanczos_sum (data, lu, i * row, bytes, alpha);
/* calculate alpha of result */
aval /= weight;
if ( aval <= 0.0 )
{
arecip = 0.0;
color[alpha] = 0;
}
else if ( aval > 255.0 )
{
arecip = 1.0 / aval;
color[alpha] = 255;
}
else
{
arecip = 1.0 / aval;
color[alpha] = RINT (aval);
}
for (byte = 0; byte < alpha; byte++)
{
for (newval = 0, i = 0; i < LANCZOS_WIDTH2; i ++)
newval += lv[i] * lanczos_sum_mul (data, lu,
i * row, bytes, byte, alpha);
newval *= arecip;
color[byte] = CLAMP (newval, 0, 255);
}
pixel_surround_release (surround);
}
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