gimp/app/core/gimpgradient-load.c

512 lines
14 KiB
C

/* The GIMP -- an image manipulation program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 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 General Public License for more details.
*
* You should have received a copy of the GNU 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.
*/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <glib-object.h>
#include <glib/gstdio.h>
#include "libgimpbase/gimpbase.h"
#include "libgimpcolor/gimpcolor.h"
#include "core-types.h"
#include "config/gimpxmlparser.h"
#include "gimpgradient.h"
#include "gimpgradient-load.h"
#include "gimp-intl.h"
GList *
gimp_gradient_load (const gchar *filename,
GError **error)
{
GimpGradient *gradient;
GimpGradientSegment *seg;
GimpGradientSegment *prev;
gint num_segments;
gint i;
gint type, color;
FILE *file;
gchar line[1024];
g_return_val_if_fail (filename != NULL, NULL);
g_return_val_if_fail (g_path_is_absolute (filename), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
file = g_fopen (filename, "rb");
if (!file)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_OPEN,
_("Could not open '%s' for reading: %s"),
gimp_filename_to_utf8 (filename), g_strerror (errno));
return NULL;
}
fgets (line, 1024, file);
if (strcmp (line, "GIMP Gradient\n") != 0)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Fatal parse error in gradient file '%s': "
"Not a GIMP gradient file."),
gimp_filename_to_utf8 (filename));
fclose (file);
return NULL;
}
gradient = g_object_new (GIMP_TYPE_GRADIENT,
"mime-type", "application/x-gimp-gradient",
NULL);
fgets (line, 1024, file);
if (! strncmp (line, "Name: ", strlen ("Name: ")))
{
gchar *utf8;
utf8 = gimp_any_to_utf8 (&line[strlen ("Name: ")], -1,
_("Invalid UTF-8 string in gradient file '%s'."),
gimp_filename_to_utf8 (filename));
g_strstrip (utf8);
gimp_object_set_name (GIMP_OBJECT (gradient), utf8);
g_free (utf8);
fgets (line, 1024, file);
}
else /* old gradient format */
{
gchar *name = g_filename_display_basename (filename);
gimp_object_set_name (GIMP_OBJECT (gradient), name);
g_free (name);
}
num_segments = atoi (line);
if (num_segments < 1)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Fatal parse error in gradient file '%s': "
"File is corrupt."),
gimp_filename_to_utf8 (filename));
g_object_unref (gradient);
fclose (file);
return NULL;
}
prev = NULL;
for (i = 0; i < num_segments; i++)
{
gchar *end;
seg = gimp_gradient_segment_new ();
seg->prev = prev;
if (prev)
prev->next = seg;
else
gradient->segments = seg;
fgets (line, 1024, file);
seg->left = g_ascii_strtod (line, &end);
if (end && errno != ERANGE)
seg->middle = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->right = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->left_color.r = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->left_color.g = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->left_color.b = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->left_color.a = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->right_color.r = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->right_color.g = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->right_color.b = g_ascii_strtod (end, &end);
if (end && errno != ERANGE)
seg->right_color.a = g_ascii_strtod (end, &end);
if (errno != ERANGE &&
sscanf (end, "%d %d", &type, &color) == 2)
{
seg->type = (GimpGradientSegmentType) type;
seg->color = (GimpGradientSegmentColor) color;
}
else
{
g_message (_("Corrupt segment %d in gradient file '%s'."),
i, gimp_filename_to_utf8 (filename));
g_object_unref (gradient);
fclose (file);
return NULL;
}
if ( (prev && (prev->right < seg->left))
|| (!prev && (0. < seg->left) ))
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Gradient file '%s' is corrupt: "
"Segments do not span the range 0-1."),
gimp_filename_to_utf8 (filename));
g_object_unref (gradient);
fclose (file);
return NULL;
}
prev = seg;
}
if (prev->right < 1.0)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Gradient file '%s' is corrupt: "
"Segments do not span the range 0-1."),
gimp_filename_to_utf8 (filename));
g_object_unref (gradient);
fclose (file);
return NULL;
}
fclose (file);
return g_list_prepend (NULL, gradient);
}
/* SVG gradient parser */
typedef struct
{
GimpGradient *gradient; /* current gradient */
GList *gradients; /* finished gradients */
GList *stops;
} SvgParser;
typedef struct
{
gdouble offset;
GimpRGB color;
} SvgStop;
static void svg_parser_start_element (GMarkupParseContext *context,
const gchar *element_name,
const gchar **attribute_names,
const gchar **attribute_values,
gpointer user_data,
GError **error);
static void svg_parser_end_element (GMarkupParseContext *context,
const gchar *element_name,
gpointer user_data,
GError **error);
static GimpGradientSegment *
svg_parser_gradient_segments (GList *stops);
static SvgStop * svg_parse_gradient_stop (const gchar **names,
const gchar **values);
static const GMarkupParser markup_parser =
{
svg_parser_start_element,
svg_parser_end_element,
NULL, /* characters */
NULL, /* passthrough */
NULL /* error */
};
GList *
gimp_gradient_load_svg (const gchar *filename,
GError **error)
{
GimpXmlParser *xml_parser;
SvgParser parser;
gboolean success;
g_return_val_if_fail (filename != NULL, NULL);
g_return_val_if_fail (g_path_is_absolute (filename), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
parser.gradient = NULL;
parser.gradients = NULL;
parser.stops = NULL;
xml_parser = gimp_xml_parser_new (&markup_parser, &parser);
success = gimp_xml_parser_parse_file (xml_parser, filename, error);
gimp_xml_parser_free (xml_parser);
if (success && ! parser.gradients)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("No linear gradients found in '%s'"),
gimp_filename_to_utf8 (filename));
}
else
{
if (error && *error) /* parser reported an error */
{
gchar *msg = (*error)->message;
(*error)->message =
g_strdup_printf (_("Failed to import gradients from '%s': %s"),
gimp_filename_to_utf8 (filename), msg);
g_free (msg);
}
}
if (parser.gradient)
g_object_unref (parser.gradient);
if (parser.stops)
{
g_list_foreach (parser.stops, (GFunc) g_free, NULL);
g_list_free (parser.stops);
}
return g_list_reverse (parser.gradients);
}
static void
svg_parser_start_element (GMarkupParseContext *context,
const gchar *element_name,
const gchar **attribute_names,
const gchar **attribute_values,
gpointer user_data,
GError **error)
{
SvgParser *parser = user_data;
if (! parser->gradient && strcmp (element_name, "linearGradient") == 0)
{
const gchar *name = NULL;
while (*attribute_names && *attribute_values)
{
if (strcmp (*attribute_names, "id") == 0 && *attribute_values)
name = *attribute_values;
attribute_names++;
attribute_values++;
}
parser->gradient = g_object_new (GIMP_TYPE_GRADIENT,
"name", name,
"mime-type", "image/svg+xml",
NULL);
}
else if (parser->gradient && strcmp (element_name, "stop") == 0)
{
SvgStop *stop = svg_parse_gradient_stop (attribute_names,
attribute_values);
/* The spec clearly states that each gradient stop's offset
* value is required to be equal to or greater than the
* previous gradient stop's offset value.
*/
if (parser->stops)
stop->offset = MAX (stop->offset,
((SvgStop *) parser->stops->data)->offset);
parser->stops = g_list_prepend (parser->stops, stop);
}
}
static void
svg_parser_end_element (GMarkupParseContext *context,
const gchar *element_name,
gpointer user_data,
GError **error)
{
SvgParser *parser = user_data;
if (parser->gradient &&
strcmp (element_name, "linearGradient") == 0)
{
parser->gradient->segments = svg_parser_gradient_segments (parser->stops);
if (parser->gradient->segments)
parser->gradients = g_list_prepend (parser->gradients,
parser->gradient);
else
g_object_unref (parser->gradient);
parser->gradient = NULL;
}
}
static GimpGradientSegment *
svg_parser_gradient_segments (GList *stops)
{
GimpGradientSegment *segment;
SvgStop *stop;
GList *list;
if (! stops)
return NULL;
stop = stops->data;
segment = gimp_gradient_segment_new ();
segment->left_color = stop->color;
segment->right_color = stop->color;
/* the list of offsets is sorted from largest to smallest */
for (list = g_list_next (stops); list; list = g_list_next (list))
{
GimpGradientSegment *next = segment;
segment->left = stop->offset;
segment->middle = (segment->left + segment->right) / 2.0;
segment = gimp_gradient_segment_new ();
segment->next = next;
next->prev = segment;
segment->right = stop->offset;
segment->right_color = stop->color;
stop = list->data;
segment->left_color = stop->color;
}
segment->middle = (segment->left + segment->right) / 2.0;
if (stop->offset > 0.0)
segment->right_color = stop->color;
/* FIXME: remove empty segments here or add a GimpGradient API to do that
*/
return segment;
}
static void
svg_parse_gradient_stop_style_prop (SvgStop *stop,
const gchar *name,
const gchar *value)
{
if (strcmp (name, "stop-color") == 0)
{
gimp_rgb_parse_css (&stop->color, value, -1);
}
else if (strcmp (name, "stop-opacity") == 0)
{
gdouble opacity = g_ascii_strtod (value, NULL);
if (errno != ERANGE)
gimp_rgb_set_alpha (&stop->color, CLAMP (opacity, 0.0, 1.0));
}
}
/* very simplistic CSS style parser */
static void
svg_parse_gradient_stop_style (SvgStop *stop,
const gchar *style)
{
const gchar *end;
const gchar *sep;
while (*style)
{
while (g_ascii_isspace (*style))
style++;
for (end = style; *end && *end != ';'; end++)
/* do nothing */;
for (sep = style; sep < end && *sep != ':'; sep++)
/* do nothing */;
if (end > sep && sep > style)
{
gchar *name = g_strndup (style, sep - style);
gchar *value = g_strndup (++sep, end - sep - (*end == ';' ? 1 : 0));
svg_parse_gradient_stop_style_prop (stop, name, value);
g_free (value);
g_free (name);
}
style = end;
if (*style == ';')
style++;
}
}
static SvgStop *
svg_parse_gradient_stop (const gchar **names,
const gchar **values)
{
SvgStop *stop = g_new0 (SvgStop, 1);
gimp_rgb_set_alpha (&stop->color, 1.0);
while (*names && *values)
{
if (strcmp (*names, "offset") == 0)
{
gchar *end;
stop->offset = g_ascii_strtod (*values, &end);
if (end && *end == '%')
stop->offset /= 100.0;
stop->offset = CLAMP (stop->offset, 0.0, 1.0);
}
else if (strcmp (*names, "style") == 0)
{
svg_parse_gradient_stop_style (stop, *values);
}
else
{
svg_parse_gradient_stop_style_prop (stop, *names, *values);
}
names++;
values++;
}
return stop;
}