static void
stamp (GeglChantO *o,
const GeglRectangle *result,
gdouble x,
gdouble y)
{
WarpPrivate *priv = (WarpPrivate*) o->chant_data;
GeglBufferIterator *it;
const Babl *format;
gdouble influence;
gdouble x_mean = 0.0;
gdouble y_mean = 0.0;
gint x_iter, y_iter;
GeglRectangle area = {x - o->size / 2.0,
y - o->size / 2.0,
o->size,
o->size};
/* first point of the stroke */
if (!priv->last_point_set)
{
priv->last_x = x;
priv->last_y = y;
priv->last_point_set = TRUE;
return;
}
/* don't stamp if outside the roi treated */
if (!gegl_rectangle_intersect (NULL, result, &area))
return;
format = babl_format_n (babl_type ("float"), 2);
/* If needed, compute the mean deformation */
if (o->behavior == GEGL_WARP_BEHAVIOR_SMOOTH)
{
gint pixel_count = 0;
it = gegl_buffer_iterator_new (priv->buffer, &area, 0, format, GEGL_BUFFER_READ, GEGL_ABYSS_NONE);
while (gegl_buffer_iterator_next (it))
{
gint n_pixels = it->length;
gfloat *coords = it->data[0];
while (n_pixels--)
{
x_mean += coords[0];
y_mean += coords[1];
coords += 2;
}
pixel_count += it->roi->width * it->roi->height;
}
x_mean /= pixel_count;
y_mean /= pixel_count;
}
it = gegl_buffer_iterator_new (priv->buffer, &area, 0, format, GEGL_BUFFER_READWRITE, GEGL_ABYSS_NONE);
while (gegl_buffer_iterator_next (it))
{
/* iterate inside the stamp roi */
gint n_pixels = it->length;
gfloat *coords = it->data[0];
x_iter = it->roi->x; /* initial x */
y_iter = it->roi->y; /* and y coordinates */
while (n_pixels--)
{
influence = 0.01 * o->strength * get_stamp_force (o,
x_iter - x,
y_iter - y);
switch (o->behavior)
{
case GEGL_WARP_BEHAVIOR_MOVE:
coords[0] += influence * (priv->last_x - x);
coords[1] += influence * (priv->last_y - y);
break;
case GEGL_WARP_BEHAVIOR_GROW:
coords[0] -= 2.0 * influence * (x_iter - x) / o->size;
coords[1] -= 2.0 * influence * (y_iter - y) / o->size;
break;
case GEGL_WARP_BEHAVIOR_SHRINK:
coords[0] += 2.0 * influence * (x_iter - x) / o->size;
coords[1] += 2.0 * influence * (y_iter - y) / o->size;
break;
case GEGL_WARP_BEHAVIOR_SWIRL_CW:
coords[0] += 3.0 * influence * (y_iter - y) / o->size;
coords[1] -= 5.0 * influence * (x_iter - x) / o->size;
break;
case GEGL_WARP_BEHAVIOR_SWIRL_CCW:
coords[0] -= 3.0 * influence * (y_iter - y) / o->size;
coords[1] += 5.0 * influence * (x_iter - x) / o->size;
break;
case GEGL_WARP_BEHAVIOR_ERASE:
coords[0] *= 1.0 - MIN (influence, 1.0);
coords[1] *= 1.0 - MIN (influence, 1.0);
break;
case GEGL_WARP_BEHAVIOR_SMOOTH:
coords[0] -= influence * (coords[0] - x_mean);
coords[1] -= influence * (coords[1] - y_mean);
break;
}
coords += 2;
/* update x and y coordinates */
x_iter++;
if (x_iter >= (it->roi->x + it->roi->width))
{
x_iter = it->roi->x;
y_iter++;
}
}
}
/* Memorize the stamp location for movement dependant behavior like move */
priv->last_x = x;
priv->last_y = y;
}
static void
stamp (GeglProperties *o,
gdouble x,
gdouble y)
{
WarpPrivate *priv = (WarpPrivate*) o->user_data;
GeglBufferIterator *it;
const Babl *format;
gdouble stamp_force, influence;
gdouble x_mean = 0.0;
gdouble y_mean = 0.0;
gint x_iter, y_iter;
GeglRectangle area;
const GeglRectangle *src_extent;
gfloat *srcbuf, *stampbuf;
gint buf_rowstride = 0;
gfloat s = 0, c = 0;
area.x = floor (x - o->size / 2.0);
area.y = floor (y - o->size / 2.0);
area.width = ceil (x + o->size / 2.0);
area.height = ceil (y + o->size / 2.0);
area.width -= area.x;
area.height -= area.y;
format = babl_format_n (babl_type ("float"), 2);
/* If needed, compute the mean deformation */
if (o->behavior == GEGL_WARP_BEHAVIOR_SMOOTH)
{
gint pixel_count = 0;
it = gegl_buffer_iterator_new (priv->buffer, &area, 0, format,
GEGL_ACCESS_READ, GEGL_ABYSS_NONE);
while (gegl_buffer_iterator_next (it))
{
gint n_pixels = it->length;
gfloat *coords = it->data[0];
while (n_pixels--)
{
x_mean += coords[0];
y_mean += coords[1];
coords += 2;
}
pixel_count += it->roi->width * it->roi->height;
}
x_mean /= pixel_count;
y_mean /= pixel_count;
}
else if (o->behavior == GEGL_WARP_BEHAVIOR_SWIRL_CW ||
o->behavior == GEGL_WARP_BEHAVIOR_SWIRL_CCW)
{
/* swirl by 5 degrees per stamp (for strength 100).
* not exactly sin/cos factors,
* since we calculate an off-center offset-vector */
/* note that this is fudged for stamp_force < 1.0 and
* results in a slight upscaling there. It is a compromise
* between exactness and calculation speed. */
s = sin (0.01 * o->strength * 5.0 / 180 * G_PI);
c = cos (0.01 * o->strength * 5.0 / 180 * G_PI) - 1.0;
}
srcbuf = gegl_buffer_linear_open (priv->buffer, NULL, &buf_rowstride, NULL);
buf_rowstride /= sizeof (gfloat);
src_extent = gegl_buffer_get_extent (priv->buffer);
stampbuf = g_new0 (gfloat, 2 * area.height * area.width);
for (y_iter = 0; y_iter < area.height; y_iter++)
{
for (x_iter = 0; x_iter < area.width; x_iter++)
{
gfloat nvx, nvy;
gfloat xi, yi;
gfloat *vals;
gint dx, dy;
gfloat weight_x, weight_y;
gfloat *srcptr;
xi = area.x + x_iter;
xi += -x + 0.5;
yi = area.y + y_iter;
yi += -y + 0.5;
stamp_force = get_stamp_force (o, xi, yi);
influence = 0.01 * o->strength * stamp_force;
switch (o->behavior)
{
case GEGL_WARP_BEHAVIOR_MOVE:
nvx = influence * (priv->last_x - x);
nvy = influence * (priv->last_y - y);
break;
case GEGL_WARP_BEHAVIOR_GROW:
nvx = influence * -0.1 * xi;
nvy = influence * -0.1 * yi;
break;
case GEGL_WARP_BEHAVIOR_SHRINK:
nvx = influence * 0.1 * xi;
nvy = influence * 0.1 * yi;
break;
case GEGL_WARP_BEHAVIOR_SWIRL_CW:
nvx = stamp_force * ( c * xi + s * yi);
nvy = stamp_force * (-s * xi + c * yi);
break;
case GEGL_WARP_BEHAVIOR_SWIRL_CCW:
nvx = stamp_force * ( c * xi - s * yi);
nvy = stamp_force * ( s * xi + c * yi);
break;
case GEGL_WARP_BEHAVIOR_ERASE:
case GEGL_WARP_BEHAVIOR_SMOOTH:
default:
nvx = 0.0;
nvy = 0.0;
break;
}
vals = stampbuf + (y_iter * area.width + x_iter) * 2;
dx = floorf (nvx);
dy = floorf (nvy);
if (area.x + x_iter + dx < src_extent->x ||
area.x + x_iter + dx + 1 >= src_extent->x + src_extent->width ||
area.y + y_iter + dy < src_extent->y ||
area.y + y_iter + dy + 1 >= src_extent->y + src_extent->height)
{
continue;
}
srcptr = srcbuf + (area.y - src_extent->y + y_iter + dy) * buf_rowstride +
(area.x - src_extent->x + x_iter + dx) * 2;
if (o->behavior == GEGL_WARP_BEHAVIOR_ERASE)
{
vals[0] = srcptr[0] * (1.0 - MIN (influence, 1.0));
vals[1] = srcptr[1] * (1.0 - MIN (influence, 1.0));
}
else if (o->behavior == GEGL_WARP_BEHAVIOR_SMOOTH)
{
vals[0] = (1.0 - influence) * srcptr[0] + influence * x_mean;
vals[1] = (1.0 - influence) * srcptr[1] + influence * y_mean;
}
else
{
weight_x = nvx - dx;
weight_y = nvy - dy;
/* bilinear interpolation of the vectors */
vals[0] = srcptr[0] * (1.0 - weight_x) * (1.0 - weight_y);
vals[1] = srcptr[1] * (1.0 - weight_x) * (1.0 - weight_y);
vals[0] += srcptr[2] * weight_x * (1.0 - weight_y);
vals[1] += srcptr[3] * weight_x * (1.0 - weight_y);
vals[0] += srcptr[buf_rowstride + 0] * (1.0 - weight_x) * weight_y;
vals[1] += srcptr[buf_rowstride + 1] * (1.0 - weight_x) * weight_y;
vals[0] += srcptr[buf_rowstride + 2] * weight_x * weight_y;
vals[1] += srcptr[buf_rowstride + 3] * weight_x * weight_y;
vals[0] += nvx;
vals[1] += nvy;
}
}
}
gegl_buffer_linear_close (priv->buffer, srcbuf);
gegl_buffer_set (priv->buffer, &area, 0, format,
stampbuf, GEGL_AUTO_ROWSTRIDE);
g_free (stampbuf);
/* Memorize the stamp location for movement dependant behavior like move */
priv->last_x = x;
priv->last_y = y;
}
