svg-affine.cpp revision 6c7f5d1327d2ca00d7df575258146637834da3f4
#define __SP_SVG_AFFINE_C__
/*
* SVG data parser
*
* Authors:
* Lauris Kaplinski <lauris@kaplinski.com>
* Raph Levien <raph@acm.org>
*
* Copyright (C) 1999-2002 Lauris Kaplinski
* Copyright (C) 1999 Raph Levien
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <glib/gstrfuncs.h>
#include <libnr/nr-matrix-fns.h>
#include <libnr/nr-matrix-ops.h>
#include <libnr/nr-matrix-translate-ops.h>
#include <libnr/nr-rotate-fns.h>
#include <libnr/nr-rotate-matrix-ops.h>
#include <libnr/nr-scale-matrix-ops.h>
#include <libnr/nr-translate-matrix-ops.h>
#include <libnr/nr-translate-rotate-ops.h>
#include "svg.h"
#include "prefs-utils.h"
#ifndef M_PI
# define M_PI 3.14159265358979323846
#endif
bool
sp_svg_transform_read(gchar const *str, NR::Matrix *transform)
{
int idx;
char keyword[32];
double args[6];
int n_args;
size_t key_len;
if (str == NULL) return false;
NR::Matrix a(NR::identity());
idx = 0;
while (str[idx]) {
/* skip initial whitespace */
while (g_ascii_isspace (str[idx])) idx++;
/* parse keyword */
for (key_len = 0; key_len < sizeof (keyword); key_len++) {
char c;
c = str[idx];
if (g_ascii_isalpha (c) || c == '-') {
keyword[key_len] = str[idx++];
} else {
break;
}
}
if (key_len >= sizeof (keyword)) return false;
keyword[key_len] = '\0';
/* skip whitespace */
while (g_ascii_isspace (str[idx])) idx++;
if (str[idx] != '(') return false;
idx++;
for (n_args = 0; ; n_args++) {
char c;
char *end_ptr;
/* skip whitespace */
while (g_ascii_isspace (str[idx])) idx++;
c = str[idx];
if (g_ascii_isdigit (c) || c == '+' || c == '-' || c == '.') {
if (n_args == sizeof (args) / sizeof (args[0])) return false; /* Too many args */
args[n_args] = g_ascii_strtod (str + idx, &end_ptr);
//printf("took %d chars from '%s' to make %f\n",
// end_ptr-(str+idx),
// str+idx,
// args[n_args]);
idx = end_ptr - (char *) str;
while (g_ascii_isspace (str[idx])) idx++;
/* skip optional comma */
if (str[idx] == ',') idx++;
} else if (c == ')') {
break;
} else {
return false;
}
}
idx++;
/* ok, have parsed keyword and args, now modify the transform */
if (!strcmp (keyword, "matrix")) {
if (n_args != 6) return false;
a = NR_MATRIX_D_FROM_DOUBLE(args) * a;
} else if (!strcmp (keyword, "translate")) {
if (n_args == 1) {
args[1] = 0;
} else if (n_args != 2) {
return false;
}
a = NR::translate(args[0], args[1]) * a;
} else if (!strcmp (keyword, "scale")) {
if (n_args == 1) {
args[1] = args[0];
} else if (n_args != 2) {
return false;
}
a = NR::scale(args[0], args[1]) * a;
} else if (!strcmp (keyword, "rotate")) {
if (n_args != 1 && n_args != 3) {
return false;
}
NR::rotate const rot(rotate_degrees(args[0]));
if (n_args == 3) {
a = ( NR::translate(-args[1], -args[2])
* rot
* NR::translate(args[1], args[2])
* a );
} else {
a = rot * a;
}
} else if (!strcmp (keyword, "skewX")) {
if (n_args != 1) return false;
a = ( NR::Matrix(1, 0,
tan(args[0] * M_PI / 180.0), 1,
0, 0)
* a );
} else if (!strcmp (keyword, "skewY")) {
if (n_args != 1) return false;
a = ( NR::Matrix(1, tan(args[0] * M_PI / 180.0),
0, 1,
0, 0)
* a );
} else {
return false; /* unknown keyword */
}
/* Skip trailing whitespace */
while (g_ascii_isspace (str[idx])) idx++;
}
*transform = a;
return true;
}
#define EQ(a,b) (fabs ((a) - (b)) < 1e-9)
unsigned
sp_svg_transform_write(gchar str[], unsigned const size, NR::Matrix const &transform)
{
NRMatrix const t(transform);
return sp_svg_transform_write(str, size, &t);
}
unsigned
sp_svg_transform_write(gchar str[], unsigned const size, NRMatrix const *transform)
{
double e;
if (!transform) {
*str = 0;
return 0;
}
e = 0.000001 * NR_MATRIX_DF_EXPANSION (transform);
int prec = prefs_get_int_attribute("options.svgoutput", "numericprecision", 8);
int min_exp = prefs_get_int_attribute("options.svgoutput", "minimumexponent", -8);
/* fixme: We could use t1 * t1 + t2 * t2 here instead */
if (NR_DF_TEST_CLOSE (transform->c[1], 0.0, e) && NR_DF_TEST_CLOSE (transform->c[2], 0.0, e)) {
if (NR_DF_TEST_CLOSE (transform->c[4], 0.0, e) && NR_DF_TEST_CLOSE (transform->c[5], 0.0, e)) {
if (NR_DF_TEST_CLOSE (transform->c[0], 1.0, e) && NR_DF_TEST_CLOSE (transform->c[3], 1.0, e)) {
/* We are more or less identity */
*str = 0;
return 0;
} else {
/* We are more or less scale */
gchar c[256];
unsigned p = 0;
strcpy (c + p, "scale(");
p += 6;
p += sp_svg_number_write_de (c + p, transform->c[0], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[3], prec, min_exp, FALSE);
c[p++] = ')';
g_assert( p <= sizeof(c) );
p = MIN (p, size - 1 );
memcpy (str, c, p);
str[p] = 0;
return p;
}
} else {
if (NR_DF_TEST_CLOSE (transform->c[0], 1.0, e) && NR_DF_TEST_CLOSE (transform->c[3], 1.0, e)) {
/* We are more or less translate */
gchar c[256];
unsigned p = 0;
strcpy (c + p, "translate(");
p += 10;
p += sp_svg_number_write_de (c + p, transform->c[4], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[5], prec, min_exp, FALSE);
c[p++] = ')';
g_assert( p <= sizeof(c) );
p = MIN(p, size - 1);
memcpy (str, c, p);
str[p] = 0;
return p;
} else {
gchar c[256];
unsigned p = 0;
strcpy (c + p, "matrix(");
p += 7;
p += sp_svg_number_write_de (c + p, transform->c[0], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[1], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[2], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[3], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[4], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[5], prec, min_exp, FALSE);
c[p++] = ')';
g_assert( p <= sizeof(c) );
p = MIN(p, size - 1);
memcpy (str, c, p);
str[p] = 0;
return p;
}
}
} else {
gchar c[256];
unsigned p = 0;
strcpy (c + p, "matrix(");
p += 7;
p += sp_svg_number_write_de (c + p, transform->c[0], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[1], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[2], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[3], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[4], prec, min_exp, FALSE);
c[p++] = ',';
p += sp_svg_number_write_de (c + p, transform->c[5], prec, min_exp, FALSE);
c[p++] = ')';
g_assert( p <= sizeof(c) );
p = MIN(p, size - 1);
memcpy (str, c, p);
str[p] = 0;
return p;
}
}