/* 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 .
*/
#include "config.h"
#include
#include
#include
#include "libgimpbase/gimpbase.h"
#include "libgimpmath/gimpmath.h"
#include "gimp-gegl-types.h"
#include "gimp-gegl-mask-combine.h"
gboolean
gimp_gegl_mask_combine_rect (GeglBuffer *mask,
GimpChannelOps op,
gint x,
gint y,
gint w,
gint h)
{
GeglColor *color;
g_return_val_if_fail (GEGL_IS_BUFFER (mask), FALSE);
if (! gimp_rectangle_intersect (x, y, w, h,
0, 0,
gegl_buffer_get_width (mask),
gegl_buffer_get_height (mask),
&x, &y, &w, &h))
return FALSE;
if (op == GIMP_CHANNEL_OP_ADD || op == GIMP_CHANNEL_OP_REPLACE)
color = gegl_color_new ("#fff");
else
color = gegl_color_new ("#000");
gegl_buffer_set_color (mask, GEGL_RECTANGLE (x, y, w, h), color);
g_object_unref (color);
return TRUE;
}
/**
* gimp_gegl_mask_combine_ellipse:
* @mask: the channel with which to combine the ellipse
* @op: whether to replace, add to, or subtract from the current
* contents
* @x: x coordinate of upper left corner of ellipse
* @y: y coordinate of upper left corner of ellipse
* @w: width of ellipse bounding box
* @h: height of ellipse bounding box
* @antialias: if %TRUE, antialias the ellipse
*
* Mainly used for elliptical selections. If @op is
* %GIMP_CHANNEL_OP_REPLACE or %GIMP_CHANNEL_OP_ADD, sets pixels
* within the ellipse to 255. If @op is %GIMP_CHANNEL_OP_SUBTRACT,
* sets pixels within to zero. If @antialias is %TRUE, pixels that
* impinge on the edge of the ellipse are set to intermediate values,
* depending on how much they overlap.
**/
gboolean
gimp_gegl_mask_combine_ellipse (GeglBuffer *mask,
GimpChannelOps op,
gint x,
gint y,
gint w,
gint h,
gboolean antialias)
{
return gimp_gegl_mask_combine_ellipse_rect (mask, op, x, y, w, h,
w / 2.0, h / 2.0, antialias);
}
static void
gimp_gegl_mask_combine_span (gfloat *data,
GimpChannelOps op,
gint x1,
gint x2,
gfloat value)
{
if (x2 <= x1)
return;
switch (op)
{
case GIMP_CHANNEL_OP_ADD:
case GIMP_CHANNEL_OP_REPLACE:
if (value == 1.0)
{
while (x1 < x2)
data[x1++] = 1.0;
}
else
{
while (x1 < x2)
{
const gfloat val = data[x1] + value;
data[x1++] = val > 1.0 ? 1.0 : val;
}
}
break;
case GIMP_CHANNEL_OP_SUBTRACT:
if (value == 1.0)
{
while (x1 < x2)
data[x1++] = 0.0;
}
else
{
while (x1 < x2)
{
const gfloat val = data[x1] - value;
data[x1++] = val > 0.0 ? val : 0.0;
}
}
break;
case GIMP_CHANNEL_OP_INTERSECT:
/* Should not happen */
break;
}
}
/**
* gimp_gegl_mask_combine_ellipse_rect:
* @mask: the channel with which to combine the elliptic rect
* @op: whether to replace, add to, or subtract from the current
* contents
* @x: x coordinate of upper left corner of bounding rect
* @y: y coordinate of upper left corner of bounding rect
* @w: width of bounding rect
* @h: height of bounding rect
* @a: elliptic a-constant applied to corners
* @b: elliptic b-constant applied to corners
* @antialias: if %TRUE, antialias the elliptic corners
*
* Used for rounded cornered rectangles and ellipses. If @op is
* %GIMP_CHANNEL_OP_REPLACE or %GIMP_CHANNEL_OP_ADD, sets pixels
* within the ellipse to 255. If @op is %GIMP_CHANNEL_OP_SUBTRACT,
* sets pixels within to zero. If @antialias is %TRUE, pixels that
* impinge on the edge of the ellipse are set to intermediate values,
* depending on how much they overlap.
**/
gboolean
gimp_gegl_mask_combine_ellipse_rect (GeglBuffer *mask,
GimpChannelOps op,
gint x,
gint y,
gint w,
gint h,
gdouble a,
gdouble b,
gboolean antialias)
{
GeglBufferIterator *iter;
GeglRectangle *roi;
gdouble a_sqr;
gdouble b_sqr;
gdouble ellipse_center_x;
gint x0, y0;
gint width, height;
g_return_val_if_fail (GEGL_IS_BUFFER (mask), FALSE);
g_return_val_if_fail (a >= 0.0 && b >= 0.0, FALSE);
g_return_val_if_fail (op != GIMP_CHANNEL_OP_INTERSECT, FALSE);
/* Make sure the elliptic corners fit into the rect */
a = MIN (a, w / 2.0);
b = MIN (b, h / 2.0);
a_sqr = SQR (a);
b_sqr = SQR (b);
if (! gimp_rectangle_intersect (x, y, w, h,
0, 0,
gegl_buffer_get_width (mask),
gegl_buffer_get_height (mask),
&x0, &y0, &width, &height))
return FALSE;
ellipse_center_x = x + a;
iter = gegl_buffer_iterator_new (mask,
GEGL_RECTANGLE (x0, y0, width, height), 0,
babl_format ("Y float"),
GEGL_ACCESS_READWRITE, GEGL_ABYSS_NONE);
roi = &iter->roi[0];
while (gegl_buffer_iterator_next (iter))
{
gfloat *data = iter->data[0];
gint py;
for (py = roi->y;
py < roi->y + roi->height;
py++, data += roi->width)
{
const gint px = roi->x;
gdouble ellipse_center_y;
if (py >= y + b && py < y + h - b)
{
/* we are on a row without rounded corners */
gimp_gegl_mask_combine_span (data, op, 0, roi->width, 1.0);
continue;
}
/* Match the ellipse center y with our current y */
if (py < y + b)
{
ellipse_center_y = y + b;
}
else
{
ellipse_center_y = y + h - b;
}
/* For a non-antialiased ellipse, use the normal equation
* for an ellipse with an arbitrary center
* (ellipse_center_x, ellipse_center_y).
*/
if (! antialias)
{
gdouble half_ellipse_width_at_y;
gint x_start;
gint x_end;
half_ellipse_width_at_y =
sqrt (a_sqr -
a_sqr * SQR (py + 0.5f - ellipse_center_y) / b_sqr);
x_start = ROUND (ellipse_center_x - half_ellipse_width_at_y);
x_end = ROUND (ellipse_center_x + w - 2 * a +
half_ellipse_width_at_y);
gimp_gegl_mask_combine_span (data, op,
MAX (x_start - px, 0),
MIN (x_end - px, roi->width), 1.0);
}
else /* use antialiasing */
{
/* algorithm changed 7-18-04, because the previous one
* did not work well for eccentric ellipses. The new
* algorithm measures the distance to the ellipse in the
* X and Y directions, and uses trigonometry to
* approximate the distance to the ellipse as the
* distance to the hypotenuse of a right triangle whose
* legs are the X and Y distances. (WES)
*/
const gfloat yi = ABS (py + 0.5 - ellipse_center_y);
gfloat last_val = -1;
gint x_start = px;
gint cur_x;
for (cur_x = px; cur_x < (px + roi->width); cur_x++)
{
gfloat xj;
gfloat xdist;
gfloat ydist;
gfloat r;
gfloat dist;
gfloat val;
if (cur_x < x + w / 2)
{
ellipse_center_x = x + a;
}
else
{
ellipse_center_x = x + w - a;
}
xj = ABS (cur_x + 0.5 - ellipse_center_x);
if (yi < b)
xdist = xj - a * sqrt (1 - SQR (yi) / b_sqr);
else
xdist = 1000.0; /* anything large will work */
if (xj < a)
ydist = yi - b * sqrt (1 - SQR (xj) / a_sqr);
else
ydist = 1000.0; /* anything large will work */
r = hypot (xdist, ydist);
if (r < 0.001)
dist = 0.0;
else
dist = xdist * ydist / r; /* trig formula for distance to
* hypotenuse
*/
if (xdist < 0.0)
dist *= -1;
if (dist < -0.5)
val = 1.0;
else if (dist < 0.5)
val = (1.0 - (dist + 0.5));
else
val = 0.0;
if (last_val != val)
{
if (last_val != -1)
gimp_gegl_mask_combine_span (data, op,
MAX (x_start - px, 0),
MIN (cur_x - px, roi->width),
last_val);
x_start = cur_x;
last_val = val;
}
/* skip ahead if we are on the straight segment
* between rounded corners
*/
if (cur_x >= x + a && cur_x < x + w - a)
{
gimp_gegl_mask_combine_span (data, op,
MAX (x_start - px, 0),
MIN (cur_x - px, roi->width),
last_val);
x_start = cur_x;
cur_x = x + w - a;
last_val = val = 1.0;
}
/* Time to change center? */
if (cur_x >= x + w / 2)
{
ellipse_center_x = x + w - a;
}
}
gimp_gegl_mask_combine_span (data, op,
MAX (x_start - px, 0),
MIN (cur_x - px, roi->width),
last_val);
}
}
}
return TRUE;
}
gboolean
gimp_gegl_mask_combine_buffer (GeglBuffer *mask,
GeglBuffer *add_on,
GimpChannelOps op,
gint off_x,
gint off_y)
{
GeglBufferIterator *iter;
GeglRectangle rect;
gint x, y, w, h;
g_return_val_if_fail (GEGL_IS_BUFFER (mask), FALSE);
g_return_val_if_fail (GEGL_IS_BUFFER (add_on), FALSE);
if (! gimp_rectangle_intersect (off_x, off_y,
gegl_buffer_get_width (add_on),
gegl_buffer_get_height (add_on),
0, 0,
gegl_buffer_get_width (mask),
gegl_buffer_get_height (mask),
&x, &y, &w, &h))
return FALSE;
rect.x = x;
rect.y = y;
rect.width = w;
rect.height = h;
iter = gegl_buffer_iterator_new (mask, &rect, 0,
babl_format ("Y float"),
GEGL_ACCESS_READWRITE, GEGL_ABYSS_NONE);
rect.x -= off_x;
rect.y -= off_y;
gegl_buffer_iterator_add (iter, add_on, &rect, 0,
babl_format ("Y float"),
GEGL_ACCESS_READ, GEGL_ABYSS_NONE);
switch (op)
{
case GIMP_CHANNEL_OP_ADD:
case GIMP_CHANNEL_OP_REPLACE:
while (gegl_buffer_iterator_next (iter))
{
gfloat *mask_data = iter->data[0];
const gfloat *add_on_data = iter->data[1];
gint count = iter->length;
while (count--)
{
const gfloat val = *mask_data + *add_on_data;
*mask_data = CLAMP (val, 0.0, 1.0);
add_on_data++;
mask_data++;
}
}
break;
case GIMP_CHANNEL_OP_SUBTRACT:
while (gegl_buffer_iterator_next (iter))
{
gfloat *mask_data = iter->data[0];
const gfloat *add_on_data = iter->data[1];
gint count = iter->length;
while (count--)
{
if (*add_on_data > *mask_data)
*mask_data = 0.0;
else
*mask_data -= *add_on_data;
add_on_data++;
mask_data++;
}
}
break;
case GIMP_CHANNEL_OP_INTERSECT:
while (gegl_buffer_iterator_next (iter))
{
gfloat *mask_data = iter->data[0];
const gfloat *add_on_data = iter->data[1];
gint count = iter->length;
while (count--)
{
*mask_data = MIN (*mask_data, *add_on_data);
add_on_data++;
mask_data++;
}
}
break;
default:
g_warning ("%s: unknown operation type", G_STRFUNC);
break;
}
return TRUE;
}