gimp/plug-ins/common/cubism.c

876 lines
25 KiB
C

/* Cubism --- image filter plug-in for GIMP
* Copyright (C) 1996 Spencer Kimball, Tracy Scott
*
* 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 <http://www.gnu.org/licenses/>.
*
* You can contact me at quartic@polloux.fciencias.unam.mx
* You can contact the original GIMP authors at gimp@xcf.berkeley.edu
* Speedups by Elliot Lee
*/
#include "config.h"
#include <string.h>
#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>
#include "libgimp/stdplugins-intl.h"
#define PLUG_IN_PROC "plug-in-cubism"
#define PLUG_IN_BINARY "cubism"
#define SCALE_WIDTH 125
#define BLACK 0
#define BG 1
#define SUPERSAMPLE 4
#define MAX_POINTS 4
#define RANDOMNESS 5
typedef struct
{
gint npts;
GimpVector2 pts[MAX_POINTS];
} Polygon;
typedef struct
{
gdouble tile_size;
gdouble tile_saturation;
gint bg_color;
gboolean preview;
} CubismVals;
/* Declare local functions.
*/
static void query (void);
static void run (const gchar *name,
gint nparams,
const GimpParam *param,
gint *nreturn_vals,
GimpParam **return_vals);
static void cubism (GimpDrawable *drawable,
GimpPreview *preview);
static gboolean cubism_dialog (GimpDrawable *drawable);
static void fill_poly_color (Polygon *poly,
GimpDrawable *drawable,
GimpPreview *preview,
guchar *col,
guchar *dest);
static void convert_segment (gint x1,
gint y1,
gint x2,
gint y2,
gint offset,
gint *min,
gint *max);
static void randomize_indices (gint count,
gint *indices);
static gdouble calc_alpha_blend (gdouble *vec,
gdouble one_over_dist,
gdouble x,
gdouble y);
static void polygon_add_point (Polygon *poly,
gdouble x,
gdouble y);
static void polygon_translate (Polygon *poly,
gdouble tx,
gdouble ty);
static void polygon_rotate (Polygon *poly,
gdouble theta);
static gint polygon_extents (Polygon *poly,
gdouble *min_x,
gdouble *min_y,
gdouble *max_x,
gdouble *max_y);
static void polygon_reset (Polygon *poly);
/*
* Local variables
*/
static CubismVals cvals =
{
10.0, /* tile_size */
2.5, /* tile_saturation */
BLACK, /* bg_color */
TRUE /* preview */
};
const GimpPlugInInfo PLUG_IN_INFO =
{
NULL, /* init_proc */
NULL, /* quit_proc */
query, /* query_proc */
run, /* run_proc */
};
/*
* Functions
*/
MAIN ()
static void
query (void)
{
static const GimpParamDef args[] =
{
{ GIMP_PDB_INT32, "run-mode", "The run mode { RUN-INTERACTIVE (0), RUN-NONINTERACTIVE (1) }" },
{ GIMP_PDB_IMAGE, "image", "Input image" },
{ GIMP_PDB_DRAWABLE, "drawable", "Input drawable" },
{ GIMP_PDB_FLOAT, "tile-size", "Average diameter of each tile (in pixels)" },
{ GIMP_PDB_FLOAT, "tile-saturation", "Expand tiles by this amount" },
{ GIMP_PDB_INT32, "bg-color", "Background color { BLACK (0), BG (1) }" }
};
gimp_install_procedure (PLUG_IN_PROC,
N_("Convert the image into randomly rotated square blobs"),
"Help not yet written for this plug-in",
"Spencer Kimball & Tracy Scott",
"Spencer Kimball & Tracy Scott",
"1996",
N_("_Cubism..."),
"RGB*, GRAY*",
GIMP_PLUGIN,
G_N_ELEMENTS (args), 0,
args, NULL);
gimp_plugin_menu_register (PLUG_IN_PROC, "<Image>/Filters/Artistic");
}
static void
run (const gchar *name,
gint nparams,
const GimpParam *param,
gint *nreturn_vals,
GimpParam **return_vals)
{
static GimpParam values[1];
GimpDrawable *drawable;
GimpRunMode run_mode;
GimpPDBStatusType status = GIMP_PDB_SUCCESS;
INIT_I18N ();
run_mode = param[0].data.d_int32;
*nreturn_vals = 1;
*return_vals = values;
values[0].type = GIMP_PDB_STATUS;
values[0].data.d_status = status;
/* get the active drawable */
drawable = gimp_drawable_get (param[2].data.d_drawable);
/* set cache size */
/* asking for a lot here but seems to give a speedup -- WES 12-23-04 */
gimp_tile_cache_ntiles (2 * drawable->ntile_rows * drawable->ntile_cols);
switch (run_mode)
{
case GIMP_RUN_INTERACTIVE:
/* Possibly retrieve data */
gimp_get_data (PLUG_IN_PROC, &cvals);
/* First acquire information with a dialog */
if (! cubism_dialog (drawable))
return;
break;
case GIMP_RUN_NONINTERACTIVE:
/* Make sure all the arguments are there! */
if (nparams != 6)
status = GIMP_PDB_CALLING_ERROR;
if (status == GIMP_PDB_SUCCESS)
{
cvals.tile_size = param[3].data.d_float;
cvals.tile_saturation = param[4].data.d_float;
cvals.bg_color = param[5].data.d_int32;
}
if (status == GIMP_PDB_SUCCESS &&
(cvals.bg_color < BLACK || cvals.bg_color > BG))
status = GIMP_PDB_CALLING_ERROR;
break;
case GIMP_RUN_WITH_LAST_VALS:
/* Possibly retrieve data */
gimp_get_data (PLUG_IN_PROC, &cvals);
break;
default:
break;
}
/* Render the cubism effect */
if ((status == GIMP_PDB_SUCCESS) &&
(gimp_drawable_is_rgb (drawable->drawable_id) ||
gimp_drawable_is_gray (drawable->drawable_id)))
{
cubism (drawable, NULL);
/* If the run mode is interactive, flush the displays */
if (run_mode != GIMP_RUN_NONINTERACTIVE)
gimp_displays_flush ();
/* Store mvals data */
if (run_mode == GIMP_RUN_INTERACTIVE)
gimp_set_data (PLUG_IN_PROC, &cvals, sizeof (CubismVals));
}
else if (status == GIMP_PDB_SUCCESS)
{
/* gimp_message ("cubism: cannot operate on indexed color images"); */
status = GIMP_PDB_EXECUTION_ERROR;
}
values[0].data.d_status = status;
gimp_drawable_detach (drawable);
}
static gboolean
cubism_dialog (GimpDrawable *drawable)
{
GtkWidget *dialog;
GtkWidget *main_vbox;
GtkWidget *preview;
GtkWidget *toggle;
GtkWidget *table;
GtkObject *scale_data;
gboolean run;
gimp_ui_init (PLUG_IN_BINARY, FALSE);
dialog = gimp_dialog_new (_("Cubism"), PLUG_IN_BINARY,
NULL, 0,
gimp_standard_help_func, PLUG_IN_PROC,
GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
GTK_STOCK_OK, GTK_RESPONSE_OK,
NULL);
gtk_dialog_set_alternative_button_order (GTK_DIALOG (dialog),
GTK_RESPONSE_OK,
GTK_RESPONSE_CANCEL,
-1);
gimp_window_set_transient (GTK_WINDOW (dialog));
main_vbox = gtk_vbox_new (FALSE, 12);
gtk_container_set_border_width (GTK_CONTAINER (main_vbox), 12);
gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))),
main_vbox);
gtk_widget_show (main_vbox);
preview = gimp_drawable_preview_new (drawable, &cvals.preview);
gtk_box_pack_start (GTK_BOX (main_vbox), preview, TRUE, TRUE, 0);
gtk_widget_show (preview);
g_signal_connect_swapped (preview, "invalidated",
G_CALLBACK (cubism),
drawable);
table = gtk_table_new (2, 3, FALSE);
gtk_table_set_col_spacings (GTK_TABLE (table), 6);
gtk_table_set_row_spacings (GTK_TABLE (table), 6);
gtk_table_set_row_spacing (GTK_TABLE (table), 0, 4);
gtk_box_pack_start (GTK_BOX (main_vbox), table, FALSE, FALSE, 0);
gtk_widget_show (table);
scale_data = gimp_scale_entry_new (GTK_TABLE (table), 0, 0,
_("_Tile size:"), SCALE_WIDTH, 5,
cvals.tile_size, 0.0, 100.0, 1.0, 10.0, 1,
TRUE, 0, 0,
NULL, NULL);
g_signal_connect (scale_data, "value-changed",
G_CALLBACK (gimp_double_adjustment_update),
&cvals.tile_size);
g_signal_connect_swapped (scale_data, "value-changed",
G_CALLBACK (gimp_preview_invalidate),
preview);
scale_data =
gimp_scale_entry_new (GTK_TABLE (table), 0, 1,
_("T_ile saturation:"), SCALE_WIDTH, 5,
cvals.tile_saturation, 0.0, 10.0, 0.1, 1, 1,
TRUE, 0, 0,
NULL, NULL);
g_signal_connect (scale_data, "value-changed",
G_CALLBACK (gimp_double_adjustment_update),
&cvals.tile_saturation);
g_signal_connect_swapped (scale_data, "value-changed",
G_CALLBACK (gimp_preview_invalidate),
preview);
toggle = gtk_check_button_new_with_mnemonic (_("_Use background color"));
gtk_box_pack_start (GTK_BOX (main_vbox), toggle, FALSE, FALSE, 0);
gtk_widget_show (toggle);
g_signal_connect (toggle, "toggled",
G_CALLBACK (gimp_toggle_button_update),
&cvals.bg_color);
g_signal_connect_swapped (toggle, "toggled",
G_CALLBACK (gimp_preview_invalidate),
preview);
gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle),
(cvals.bg_color == BG));
gtk_widget_show (dialog);
run = (gimp_dialog_run (GIMP_DIALOG (dialog)) == GTK_RESPONSE_OK);
gtk_widget_destroy (dialog);
return run;
}
static void
cubism (GimpDrawable *drawable,
GimpPreview *preview)
{
GimpPixelRgn src_rgn;
guchar bg_col[4];
gdouble x, y;
gdouble width, height;
gdouble theta;
gint ix, iy;
gint rows, cols;
gint i, j, count;
gint num_tiles;
gint x1, y1, x2, y2;
gint sel_width, sel_height;
Polygon poly;
guchar col[4];
guchar *dest = NULL;
gint bytes;
gboolean has_alpha;
gint *random_indices;
gpointer pr;
GRand *gr;
gr = g_rand_new ();
has_alpha = gimp_drawable_has_alpha (drawable->drawable_id);
bytes = drawable->bpp;
if (preview)
{
gimp_preview_get_position (preview, &x1, &y1);
gimp_preview_get_size (preview, &sel_width, &sel_height);
x2 = x1 + sel_width;
y2 = y1 + sel_height;
dest = g_new (guchar, sel_height * sel_width * bytes);
}
else
{
gimp_drawable_mask_bounds (drawable->drawable_id, &x1, &y1, &x2, &y2);
}
/* determine the background color */
if (cvals.bg_color == BLACK)
{
bg_col[0] = bg_col[1] = bg_col[2] = bg_col[3] = 0;
}
else
{
GimpRGB color;
gimp_context_get_background (&color);
gimp_rgb_set_alpha (&color, 0.0);
gimp_drawable_get_color_uchar (drawable->drawable_id, &color, bg_col);
}
cols = ((x2 - x1) + cvals.tile_size - 1) / cvals.tile_size;
rows = ((y2 - y1) + cvals.tile_size - 1) / cvals.tile_size;
/* Fill the image with the background color */
if (preview)
{
for (i = 0; i < sel_width * sel_height ; i++)
for (count = 0; count < bytes; count++)
dest[i * bytes + count] = bg_col[count];
}
else
{
gimp_progress_init (_("Cubistic transformation"));
gimp_pixel_rgn_init (&src_rgn, drawable,
x1, y1, (x2 - x1), (y2 - y1), TRUE, TRUE);
for (pr = gimp_pixel_rgns_register (1, &src_rgn);
pr != NULL;
pr = gimp_pixel_rgns_process (pr))
{
count = src_rgn.w * src_rgn.h;
dest = src_rgn.data;
while (count--)
for (i = 0; i < bytes; i++)
*dest++ = bg_col[i];
}
dest = NULL;
}
num_tiles = (rows + 1) * (cols + 1);
random_indices = g_new (gint, num_tiles);
for (i = 0; i < num_tiles; i++)
random_indices[i] = i;
randomize_indices (num_tiles, random_indices);
gimp_pixel_rgn_init (&src_rgn, drawable,
x1, y1, x2 - x1, y2 - y1, FALSE, FALSE);
for (count = 0; count < num_tiles; count++)
{
i = random_indices[count] / (cols + 1);
j = random_indices[count] % (cols + 1);
x = j * cvals.tile_size + (cvals.tile_size / 4.0)
- g_rand_double_range (gr, 0, cvals.tile_size/2.0) + x1;
y = i * cvals.tile_size + (cvals.tile_size / 4.0)
- g_rand_double_range (gr, 0, cvals.tile_size/2.0) + y1;
width = (cvals.tile_size +
g_rand_double_range (gr, 0, cvals.tile_size / 4.0) -
cvals.tile_size / 8.0) * cvals.tile_saturation;
height = (cvals.tile_size +
g_rand_double_range (gr, 0, cvals.tile_size / 4.0) -
cvals.tile_size / 8.0) * cvals.tile_saturation;
theta = g_rand_double_range (gr, 0, 2 * G_PI);
polygon_reset (&poly);
polygon_add_point (&poly, -width / 2.0, -height / 2.0);
polygon_add_point (&poly, width / 2.0, -height / 2.0);
polygon_add_point (&poly, width / 2.0, height / 2.0);
polygon_add_point (&poly, -width / 2.0, height / 2.0);
polygon_rotate (&poly, theta);
polygon_translate (&poly, x, y);
/* bounds check on x, y */
ix = CLAMP (x, x1, x2 - 1);
iy = CLAMP (y, y1, y2 - 1);
gimp_pixel_rgn_get_pixel (&src_rgn, col, ix, iy);
if (! has_alpha || col[bytes - 1])
fill_poly_color (&poly, drawable, preview, col, dest);
if (! preview)
{
if (count % 8 == 0)
gimp_progress_update ((gdouble) count / (gdouble) num_tiles);
}
}
g_free (random_indices);
g_rand_free (gr);
if (preview)
{
gimp_preview_draw_buffer (preview, dest, sel_width * bytes);
g_free (dest);
}
else
{
gimp_progress_update (1.0);
/* merge the shadow, update the drawable */
gimp_drawable_flush (drawable);
gimp_drawable_merge_shadow (drawable->drawable_id, TRUE);
gimp_drawable_update (drawable->drawable_id, x1, y1, x2 - x1, y2 - y1);
}
}
static inline gdouble
calc_alpha_blend (gdouble *vec,
gdouble one_over_dist,
gdouble x,
gdouble y)
{
gdouble r;
if (! one_over_dist)
return 1.0;
r = (vec[0] * x + vec[1] * y) * one_over_dist;
return CLAMP (r, 0.2, 1.0);
}
static void
fill_poly_color (Polygon *poly,
GimpDrawable *drawable,
GimpPreview *preview,
guchar *col,
guchar *dest)
{
GimpPixelRgn src_rgn;
gdouble dmin_x = 0.0;
gdouble dmin_y = 0.0;
gdouble dmax_x = 0.0;
gdouble dmax_y = 0.0;
gint xs, ys;
gint xe, ye;
gint min_x, min_y;
gint max_x, max_y;
gint size_x, size_y;
gint *max_scanlines, *max_scanlines_iter;
gint *min_scanlines, *min_scanlines_iter;
gint val;
gint alpha;
gint bytes;
guchar buf[4];
gint i, j, x, y;
gdouble sx, sy;
gdouble ex, ey;
gdouble xx, yy;
gdouble vec[2];
gdouble dist, one_over_dist;
gint x1, y1, x2, y2;
gint sel_width, sel_height;
gint *vals, *vals_iter, *vals_end;
gint b;
sx = poly->pts[0].x;
sy = poly->pts[0].y;
ex = poly->pts[1].x;
ey = poly->pts[1].y;
dist = sqrt (SQR (ex - sx) + SQR (ey - sy));
if (dist > 0.0)
{
one_over_dist = 1.0 / dist;
vec[0] = (ex - sx) * one_over_dist;
vec[1] = (ey - sy) * one_over_dist;
}
else
{
one_over_dist = 0.0;
vec[0] = 0.0;
vec[1] = 0.0;
}
if (preview)
{
gimp_preview_get_position (preview, &x1, &y1);
gimp_preview_get_size (preview, &sel_width, &sel_height);
x2 = x1 + sel_width;
y2 = y1 + sel_height;
}
else
{
gimp_drawable_mask_bounds (drawable->drawable_id, &x1, &y1, &x2, &y2);
gimp_pixel_rgn_init (&src_rgn, drawable,
x1, y1, x2 - x1, y2 - y1,
TRUE, TRUE);
}
bytes = drawable->bpp;
polygon_extents (poly, &dmin_x, &dmin_y, &dmax_x, &dmax_y);
min_x = (gint) dmin_x;
min_y = (gint) dmin_y;
max_x = (gint) dmax_x;
max_y = (gint) dmax_y;
size_y = (max_y - min_y) * SUPERSAMPLE;
size_x = (max_x - min_x) * SUPERSAMPLE;
min_scanlines = min_scanlines_iter = g_new (gint, size_y);
max_scanlines = max_scanlines_iter = g_new (gint, size_y);
for (i = 0; i < size_y; i++)
{
min_scanlines[i] = max_x * SUPERSAMPLE;
max_scanlines[i] = min_x * SUPERSAMPLE;
}
if (poly->npts)
{
GimpVector2 *curptr;
gint poly_npts = poly->npts;
xs = (gint) (poly->pts[poly_npts-1].x);
ys = (gint) (poly->pts[poly_npts-1].y);
xe = (gint) poly->pts[0].x;
ye = (gint) poly->pts[0].y;
xs *= SUPERSAMPLE;
ys *= SUPERSAMPLE;
xe *= SUPERSAMPLE;
ye *= SUPERSAMPLE;
convert_segment (xs, ys, xe, ye, min_y * SUPERSAMPLE,
min_scanlines, max_scanlines);
for (i = 1, curptr = &poly->pts[0]; i < poly_npts; i++)
{
xs = (gint) curptr->x;
ys = (gint) curptr->y;
curptr++;
xe = (gint) curptr->x;
ye = (gint) curptr->y;
xs *= SUPERSAMPLE;
ys *= SUPERSAMPLE;
xe *= SUPERSAMPLE;
ye *= SUPERSAMPLE;
convert_segment (xs, ys, xe, ye, min_y * SUPERSAMPLE,
min_scanlines, max_scanlines);
}
}
vals = g_new (gint, size_x);
for (i = 0; i < size_y; i++, min_scanlines_iter++, max_scanlines_iter++)
{
if (! (i % SUPERSAMPLE))
{
memset (vals, 0, sizeof (gint) * size_x);
}
yy = (gdouble)i / (gdouble)SUPERSAMPLE + min_y;
for (j = *min_scanlines_iter; j < *max_scanlines_iter; j++)
{
x = j - min_x * SUPERSAMPLE;
vals[x] += 255;
}
if (! ((i + 1) % SUPERSAMPLE))
{
y = (i / SUPERSAMPLE) + min_y;
if (y >= y1 && y < y2)
{
for (j = 0; j < size_x; j += SUPERSAMPLE)
{
x = (j / SUPERSAMPLE) + min_x;
if (x >= x1 && x < x2)
{
for (val = 0, vals_iter = &vals[j],
vals_end = &vals_iter[SUPERSAMPLE];
vals_iter < vals_end;
vals_iter++)
val += *vals_iter;
val /= SQR(SUPERSAMPLE);
if (val > 0)
{
xx = (gdouble) j / (gdouble) SUPERSAMPLE + min_x;
alpha = (gint) (val * calc_alpha_blend (vec,
one_over_dist,
xx - sx,
yy - sy));
if (preview)
{
for (b = 0; b < bytes; b++)
buf[b] = dest[ ( (y-y1) * sel_width + (x-x1) ) * bytes + b];
}
else
{
gimp_pixel_rgn_get_pixel (&src_rgn, buf, x, y);
}
#ifndef USE_READABLE_BUT_SLOW_CODE
{
guchar *buf_iter = buf;
guchar *col_iter = col;
guchar *buf_end = buf + bytes;
for(; buf_iter < buf_end; buf_iter++, col_iter++)
*buf_iter = ((guint) (*col_iter * alpha)
+ (((guint) *buf_iter)
* (256 - alpha))) >> 8;
}
#else /* original, pre-ECL code */
for (b = 0; b < bytes; b++)
buf[b] = ((col[b] * alpha) + (buf[b] * (255 - alpha))) / 255;
#endif
if (preview)
{
for (b = 0; b < bytes; b++)
dest[ ( (y-y1) * sel_width + (x-x1) ) * bytes + b] = buf[b];
}
else
{
gimp_pixel_rgn_set_pixel (&src_rgn, buf, x, y);
}
}
}
}
}
}
}
g_free (vals);
g_free (min_scanlines);
g_free (max_scanlines);
}
static void
convert_segment (gint x1,
gint y1,
gint x2,
gint y2,
gint offset,
gint *min,
gint *max)
{
gint ydiff, y, tmp;
gdouble xinc, xstart;
if (y1 > y2)
{
tmp = y2; y2 = y1; y1 = tmp;
tmp = x2; x2 = x1; x1 = tmp;
}
ydiff = (y2 - y1);
if (ydiff)
{
xinc = (gdouble) (x2 - x1) / (gdouble) ydiff;
xstart = x1 + 0.5 * xinc;
for (y = y1 ; y < y2; y++)
{
if (xstart < min[y - offset])
min[y-offset] = xstart;
if (xstart > max[y - offset])
max[y-offset] = xstart;
xstart += xinc;
}
}
}
static void
randomize_indices (gint count,
gint *indices)
{
gint i;
gint index1, index2;
gint tmp;
GRand *gr;
gr = g_rand_new();
for (i = 0; i < count * RANDOMNESS; i++)
{
index1 = g_rand_int_range (gr, 0, count);
index2 = g_rand_int_range (gr, 0, count);
tmp = indices[index1];
indices[index1] = indices[index2];
indices[index2] = tmp;
}
g_rand_free (gr);
}
static void
polygon_add_point (Polygon *poly,
gdouble x,
gdouble y)
{
if (poly->npts < MAX_POINTS)
{
poly->pts[poly->npts].x = x;
poly->pts[poly->npts].y = y;
poly->npts++;
}
else
g_print ("Unable to add additional point.\n");
}
static void
polygon_rotate (Polygon *poly,
gdouble theta)
{
gint i;
gdouble ct, st;
gdouble ox, oy;
ct = cos (theta);
st = sin (theta);
for (i = 0; i < poly->npts; i++)
{
ox = poly->pts[i].x;
oy = poly->pts[i].y;
poly->pts[i].x = ct * ox - st * oy;
poly->pts[i].y = st * ox + ct * oy;
}
}
static void
polygon_translate (Polygon *poly,
gdouble tx,
gdouble ty)
{
gint i;
for (i = 0; i < poly->npts; i++)
{
poly->pts[i].x += tx;
poly->pts[i].y += ty;
}
}
static gint
polygon_extents (Polygon *poly,
gdouble *x1,
gdouble *y1,
gdouble *x2,
gdouble *y2)
{
gint i;
if (!poly->npts)
return 0;
*x1 = *x2 = poly->pts[0].x;
*y1 = *y2 = poly->pts[0].y;
for (i = 1; i < poly->npts; i++)
{
if (poly->pts[i].x < *x1)
*x1 = poly->pts[i].x;
if (poly->pts[i].x > *x2)
*x2 = poly->pts[i].x;
if (poly->pts[i].y < *y1)
*y1 = poly->pts[i].y;
if (poly->pts[i].y > *y2)
*y2 = poly->pts[i].y;
}
return 1;
}
static void
polygon_reset (Polygon *poly)
{
poly->npts = 0;
}