/**
* gimp_utils_point_to_line_distance:
* @point: The point to calculate the distance for.
* @point_on_line: A point on the line.
* @line_direction: Normalized line direction vector.
* @closest_line_point: Gets set to the point on the line that is
* closest to @point.
*
* Returns: The shortest distance from @point to the line defined by
* @point_on_line and @normalized_line_direction.
**/
static gdouble
gimp_utils_point_to_line_distance (const GimpVector2 *point,
const GimpVector2 *point_on_line,
const GimpVector2 *line_direction,
GimpVector2 *closest_line_point)
{
GimpVector2 distance_vector;
GimpVector2 tmp_a;
GimpVector2 tmp_b;
gdouble d;
gimp_vector2_sub (&tmp_a, point, point_on_line);
d = gimp_vector2_inner_product (&tmp_a, line_direction);
tmp_b = gimp_vector2_mul_val (*line_direction, d);
*closest_line_point = gimp_vector2_add_val (*point_on_line,
tmp_b);
gimp_vector2_sub (&distance_vector, closest_line_point, point);
return gimp_vector2_length (&distance_vector);
}
static gint32
do_curl_effect (gint32 drawable_id)
{
gint x = 0;
gint y = 0;
gboolean color_image;
gint x1, y1, k;
guint alpha_pos, progress, max_progress;
gdouble intensity, alpha;
GimpVector2 v, dl, dr;
gdouble dl_mag, dr_mag, angle, factor;
guchar *pp, *dest, fore_grayval, back_grayval;
guchar *gradsamp;
GimpPixelRgn dest_rgn;
gpointer pr;
gint32 curl_layer_id;
guchar *grad_samples = NULL;
color_image = gimp_drawable_is_rgb (drawable_id);
curl_layer =
gimp_drawable_get (gimp_layer_new (image_id,
_("Curl Layer"),
true_sel_width,
true_sel_height,
color_image ?
GIMP_RGBA_IMAGE : GIMP_GRAYA_IMAGE,
100, GIMP_NORMAL_MODE));
curl_layer_id = curl_layer->drawable_id;
gimp_image_insert_layer (image_id, curl_layer->drawable_id,
gimp_item_get_parent (drawable_id),
drawable_position);
gimp_drawable_fill (curl_layer->drawable_id, GIMP_FILL_TRANSPARENT);
gimp_drawable_offsets (drawable_id, &x1, &y1);
gimp_layer_set_offsets (curl_layer->drawable_id, sel_x + x1, sel_y + y1);
gimp_tile_cache_ntiles (2 * (curl_layer->width / gimp_tile_width () + 1));
gimp_pixel_rgn_init (&dest_rgn, curl_layer,
0, 0, true_sel_width, true_sel_height, TRUE, TRUE);
/* Init shade_under */
gimp_vector2_set (&dl, -sel_width, -sel_height);
dl_mag = gimp_vector2_length (&dl);
gimp_vector2_set (&dr,
-(sel_width - right_tangent.x),
-(sel_height - right_tangent.y));
dr_mag = gimp_vector2_length (&dr);
alpha = acos (gimp_vector2_inner_product (&dl, &dr) / (dl_mag * dr_mag));
/* Init shade_curl */
fore_grayval = GIMP_RGB_LUMINANCE (fore_color[0],
fore_color[1],
fore_color[2]) + 0.5;
back_grayval = GIMP_RGB_LUMINANCE (back_color[0],
back_color[1],
back_color[2]) + 0.5;
/* Gradient Samples */
switch (curl.colors)
{
case CURL_COLORS_FG_BG:
break;
case CURL_COLORS_GRADIENT:
grad_samples = get_gradient_samples (curl_layer->drawable_id, FALSE);
break;
case CURL_COLORS_GRADIENT_REVERSE:
grad_samples = get_gradient_samples (curl_layer->drawable_id, TRUE);
break;
}
max_progress = 2 * sel_width * sel_height;
progress = 0;
alpha_pos = dest_rgn.bpp - 1;
/* Main loop */
for (pr = gimp_pixel_rgns_register (1, &dest_rgn);
pr != NULL;
pr = gimp_pixel_rgns_process (pr))
{
dest = dest_rgn.data;
for (y1 = dest_rgn.y; y1 < dest_rgn.y + dest_rgn.h; y1++)
{
pp = dest;
for (x1 = dest_rgn.x; x1 < dest_rgn.x + dest_rgn.w; x1++)
{
/* Map coordinates to get the curl correct... */
switch (curl.orientation)
{
case CURL_ORIENTATION_VERTICAL:
x = CURL_EDGE_RIGHT (curl.edge) ? x1 : sel_width - 1 - x1;
y = CURL_EDGE_UPPER (curl.edge) ? y1 : sel_height - 1 - y1;
break;
case CURL_ORIENTATION_HORIZONTAL:
x = CURL_EDGE_LOWER (curl.edge) ? y1 : sel_width - 1 - y1;
y = CURL_EDGE_LEFT (curl.edge) ? x1 : sel_height - 1 - x1;
break;
}
if (left_of_diagl (x, y))
{ /* uncurled region */
for (k = 0; k <= alpha_pos; k++)
pp[k] = 0;
}
else if (right_of_diagr (x, y) ||
(right_of_diagm (x, y) &&
below_diagb (x, y) &&
!inside_circle (x, y)))
{
/* curled region */
for (k = 0; k <= alpha_pos; k++)
pp[k] = 0;
}
else
{
v.x = -(sel_width - x);
v.y = -(sel_height - y);
angle = acos (gimp_vector2_inner_product (&v, &dl) /
(gimp_vector2_length (&v) * dl_mag));
if (inside_circle (x, y) || below_diagb (x, y))
{
/* Below the curl. */
factor = angle / alpha;
for (k = 0; k < alpha_pos; k++)
pp[k] = 0;
pp[alpha_pos] = (curl.shade ?
(guchar) ((float) 255 * (float) factor) :
0);
}
else
{
/* On the curl */
switch (curl.colors)
{
case CURL_COLORS_FG_BG:
intensity = pow (sin (G_PI * angle / alpha), 1.5);
if (color_image)
{
pp[0] = (intensity * back_color[0] +
(1.0 - intensity) * fore_color[0]);
pp[1] = (intensity * back_color[1] +
(1.0 - intensity) * fore_color[1]);
pp[2] = (intensity * back_color[2] +
(1.0 - intensity) * fore_color[2]);
}
else
pp[0] = (intensity * back_grayval +
(1 - intensity) * fore_grayval);
pp[alpha_pos] = (guchar) ((double) 255.99 *
(1.0 - intensity *
(1.0 - curl.opacity)));
break;
case CURL_COLORS_GRADIENT:
case CURL_COLORS_GRADIENT_REVERSE:
/* Calculate position in Gradient */
intensity =
(angle/alpha) + sin (G_PI*2 * angle/alpha) * 0.075;
/* Check boundaries */
intensity = CLAMP (intensity, 0.0, 1.0);
gradsamp = (grad_samples +
((guint) (intensity * NGRADSAMPLES)) *
dest_rgn.bpp);
if (color_image)
{
pp[0] = gradsamp[0];
pp[1] = gradsamp[1];
pp[2] = gradsamp[2];
}
else
pp[0] = gradsamp[0];
pp[alpha_pos] =
(guchar) ((double) gradsamp[alpha_pos] *
(1.0 - intensity * (1.0 - curl.opacity)));
break;
}
}
}
pp += dest_rgn.bpp;
}
dest += dest_rgn.rowstride;
}
progress += dest_rgn.w * dest_rgn.h;
gimp_progress_update ((double) progress / (double) max_progress);
}
gimp_progress_update (1.0);
gimp_drawable_flush (curl_layer);
gimp_drawable_merge_shadow (curl_layer->drawable_id, FALSE);
gimp_drawable_update (curl_layer->drawable_id,
0, 0, curl_layer->width, curl_layer->height);
gimp_drawable_detach (curl_layer);
g_free (grad_samples);
return curl_layer_id;
}
static void
init_calculation (gint32 drawable_id)
{
gdouble k;
gdouble alpha, beta;
gdouble angle;
GimpVector2 v1, v2;
gint32 *image_layers;
gint32 nlayers;
GimpRGB color;
gimp_layer_add_alpha (drawable_id);
/* Image parameters */
/* Determine Position of original Layer in the Layer stack. */
image_layers = gimp_image_get_layers (image_id, &nlayers);
drawable_position = 0;
while (drawable_position < nlayers &&
image_layers[drawable_position] != drawable_id)
drawable_position++;
switch (curl.orientation)
{
case CURL_ORIENTATION_VERTICAL:
sel_width = true_sel_width;
sel_height = true_sel_height;
break;
case CURL_ORIENTATION_HORIZONTAL:
sel_width = true_sel_height;
sel_height = true_sel_width;
break;
}
/* Circle parameters */
alpha = atan ((double) sel_height / sel_width);
beta = alpha / 2.0;
k = sel_width / ((G_PI + alpha) * sin (beta) + cos (beta));
gimp_vector2_set (¢er, k * cos (beta), k * sin (beta));
radius = center.y;
/* left_tangent */
gimp_vector2_set (&left_tangent, radius * -sin (alpha), radius * cos (alpha));
gimp_vector2_add (&left_tangent, &left_tangent, ¢er);
/* right_tangent */
gimp_vector2_sub (&v1, &left_tangent, ¢er);
gimp_vector2_set (&v2, sel_width - center.x, sel_height - center.y);
angle = -2.0 * acos (gimp_vector2_inner_product (&v1, &v2) /
(gimp_vector2_length (&v1) *
gimp_vector2_length (&v2)));
gimp_vector2_set (&right_tangent,
v1.x * cos (angle) + v1.y * -sin (angle),
v1.x * sin (angle) + v1.y * cos (angle));
gimp_vector2_add (&right_tangent, &right_tangent, ¢er);
/* Slopes */
diagl_slope = (double) sel_width / sel_height;
diagr_slope = (sel_width - right_tangent.x) / (sel_height - right_tangent.y);
diagb_slope = ((right_tangent.y - left_tangent.y) /
(right_tangent.x - left_tangent.x));
diagm_slope = (sel_width - center.x) / sel_height;
/* Colors */
gimp_context_get_foreground (&color);
gimp_rgb_get_uchar (&color, &fore_color[0], &fore_color[1], &fore_color[2]);
gimp_context_get_background (&color);
gimp_rgb_get_uchar (&color, &back_color[0], &back_color[1], &back_color[2]);
}
