static gint
gimp_cage_tool_is_on_edge (GimpCageTool *ct,
gdouble x,
gdouble y,
gint handle_size)
{
GimpCageOptions *options = GIMP_CAGE_TOOL_GET_OPTIONS (ct);
GimpCageConfig *config = ct->config;
gint i;
guint n_cage_vertices;
GimpVector2 A, B, C, AB, BC, AC;
gdouble lAB, lBC, lAC, lEB, lEC;
g_return_val_if_fail (GIMP_IS_CAGE_TOOL (ct), -1);
n_cage_vertices = gimp_cage_config_get_n_points (config);
if (n_cage_vertices < 2)
return -1;
A = gimp_cage_config_get_point_coordinate (config,
options->cage_mode,
n_cage_vertices-1);
B = gimp_cage_config_get_point_coordinate (config,
options->cage_mode,
0);
C.x = x;
C.y = y;
for (i = 0; i < n_cage_vertices; i++)
{
gimp_vector2_sub (&AB, &A, &B);
gimp_vector2_sub (&BC, &B, &C);
gimp_vector2_sub (&AC, &A, &C);
lAB = gimp_vector2_length (&AB);
lBC = gimp_vector2_length (&BC);
lAC = gimp_vector2_length (&AC);
lEB = lAB / 2 + (SQR (lBC) - SQR (lAC)) / (2 * lAB);
lEC = sqrt (SQR (lBC) - SQR (lEB));
if ((lEC < handle_size / 2) && (abs (SQR (lBC) - SQR (lAC)) <= SQR (lAB)))
return i;
A = B;
B = gimp_cage_config_get_point_coordinate (config,
options->cage_mode,
(i+1) % n_cage_vertices);
}
return -1;
}
/**
* 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 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]);
}
