rsvg-bpath-util.c

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim: set sw=4 sts=4 ts=4 expandtab: */
/* 
   rsvg-bpath-util.c: Data structure and convenience functions for creating bezier paths.
 
   Copyright (C) 2000 Eazel, Inc.
  
   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.
  
   You should have received a copy of the GNU Library General Public
   License along with this program; if not, write to the
   Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.
  
   Author: Raph Levien <raph@artofcode.com>
*/

#include "config.h"
#include "rsvg-bpath-util.h"

#include <stdio.h>
#include <math.h>
#include <string.h>

#include <glib.h>

/* This is adapted from gnome-canvas-bpath-util in libgnomeprint
   (originally developed as part of Gill). */

RsvgBpathDef *
rsvg_bpath_def_new (void)
{
    RsvgBpathDef *bpd;

    bpd = g_new (RsvgBpathDef, 1);
    bpd->n_bpath = 0;
    bpd->n_bpath_max = 16;
    bpd->moveto_idx = -1;
    bpd->bpath = g_new (RsvgBpath, bpd->n_bpath_max);

    return bpd;
}

RsvgBpathDef *
rsvg_bpath_def_new_from (RsvgBpath * path)
{
    RsvgBpathDef *bpd;
    int i;

    g_return_val_if_fail (path != NULL, NULL);

    for (i = 0; path[i].code != RSVG_END; i++);
    if (i <= 0)
        return rsvg_bpath_def_new ();

    bpd = g_new (RsvgBpathDef, 1);

    bpd->n_bpath = i;
    bpd->n_bpath_max = i;
    bpd->moveto_idx = -1;
    bpd->bpath = g_new (RsvgBpath, i);

    memcpy (bpd->bpath, path, i * sizeof (RsvgBpath));
    return bpd;
}

void
rsvg_bpath_def_free (RsvgBpathDef * bpd)
{
    g_return_if_fail (bpd != NULL);

    g_free (bpd->bpath);
    g_free (bpd);
}

void
rsvg_bpath_def_moveto (RsvgBpathDef * bpd, double x, double y)
{
    RsvgBpath *bpath;
    int n_bpath;

    g_return_if_fail (bpd != NULL);

    /* if the last command was a moveto then change that last moveto instead of
       creating a new one */
    bpath = bpd->bpath;
    n_bpath = bpd->n_bpath;

    if (n_bpath > 0)
        if (bpath[n_bpath - 1].code == RSVG_MOVETO_OPEN) {
            bpath[n_bpath - 1].x3 = x;
            bpath[n_bpath - 1].y3 = y;
            bpd->moveto_idx = n_bpath - 1;
            return;
        }

    n_bpath = bpd->n_bpath++;

    if (n_bpath == bpd->n_bpath_max)
        bpd->bpath = g_realloc (bpd->bpath, (bpd->n_bpath_max <<= 1) * sizeof (RsvgBpath));
    bpath = bpd->bpath;
    bpath[n_bpath].code = RSVG_MOVETO_OPEN;
    bpath[n_bpath].x3 = x;
    bpath[n_bpath].y3 = y;
    bpd->moveto_idx = n_bpath;
}

void
rsvg_bpath_def_lineto (RsvgBpathDef * bpd, double x, double y)
{
    RsvgBpath *bpath;
    int n_bpath;

    g_return_if_fail (bpd != NULL);
    g_return_if_fail (bpd->moveto_idx >= 0);

    n_bpath = bpd->n_bpath++;

    if (n_bpath == bpd->n_bpath_max)
        bpd->bpath = g_realloc (bpd->bpath, (bpd->n_bpath_max <<= 1) * sizeof (RsvgBpath));
    bpath = bpd->bpath;
    bpath[n_bpath].code = RSVG_LINETO;
    bpath[n_bpath].x3 = x;
    bpath[n_bpath].y3 = y;
}

void
rsvg_bpath_def_curveto (RsvgBpathDef * bpd, double x1, double y1, double x2, double y2, double x3,
                        double y3)
{
    RsvgBpath *bpath;
    int n_bpath;

    g_return_if_fail (bpd != NULL);
    g_return_if_fail (bpd->moveto_idx >= 0);

    n_bpath = bpd->n_bpath++;

    if (n_bpath == bpd->n_bpath_max)
        bpd->bpath = g_realloc (bpd->bpath, (bpd->n_bpath_max <<= 1) * sizeof (RsvgBpath));
    bpath = bpd->bpath;
    bpath[n_bpath].code = RSVG_CURVETO;
    bpath[n_bpath].x1 = x1;
    bpath[n_bpath].y1 = y1;
    bpath[n_bpath].x2 = x2;
    bpath[n_bpath].y2 = y2;
    bpath[n_bpath].x3 = x3;
    bpath[n_bpath].y3 = y3;
}

static void
rsvg_bpath_def_replicate (RsvgBpathDef * bpd, int index)
{
    RsvgBpath *bpath;
    int n_bpath;

    n_bpath = bpd->n_bpath++;

    if (n_bpath == bpd->n_bpath_max)
        bpd->bpath = g_realloc (bpd->bpath, (bpd->n_bpath_max <<= 1) * sizeof (RsvgBpath));
    bpath = bpd->bpath;
    bpath[n_bpath] = bpath[index];
}

void
rsvg_bpath_def_closepath (RsvgBpathDef * bpd)
{
    RsvgBpath *bpath;

    g_return_if_fail (bpd != NULL);
    g_return_if_fail (bpd->moveto_idx >= 0);
    g_return_if_fail (bpd->n_bpath > 0);

    rsvg_bpath_def_replicate (bpd, bpd->moveto_idx);
    bpath = bpd->bpath;

    bpath[bpd->n_bpath - 1].code = RSVG_MOVETO;
    bpd->moveto_idx = bpd->n_bpath - 1;
}

void
rsvg_bpath_def_art_finish (RsvgBpathDef * bpd)
{
    int n_bpath;

    g_return_if_fail (bpd != NULL);

    n_bpath = bpd->n_bpath++;

    if (n_bpath == bpd->n_bpath_max)
        bpd->bpath = g_realloc (bpd->bpath, (bpd->n_bpath_max <<= 1) * sizeof (RsvgBpath));
    bpd->bpath[n_bpath].code = RSVG_END;
}