Gimp/app/core/gimpgradient-load.c
Jehan b6856af9d8 app: GimpGradient now uses GeglColor.
I still see some limitations in GimpGradient, and in particular, they are still
always stored as RGB in GGR files. It would be nice if we could store the actual
color format. This way, if someone chooses a gradient stop as Lab or CMYK color,
that's what the gradient file would keep track of. But also even storing the
space of a color (instead of storing/loading always in sRGB, even though this
may still work fine as we store unbounded double values). This might warrant for
a v2 of GGR file format.

This commit also fixes loading of SVG gradient which was apparently broken
regarding hexadecimal color parsing.

Finally I improve gegl_color_set_alpha() by adding an alpha channel when the
initial format had none.
2024-02-11 23:28:03 +01:00

603 lines
17 KiB
C

/* GIMP - The GNU 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 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 <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <cairo.h>
#include <gegl.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include "libgimpbase/gimpbase.h"
#include "libgimpcolor/gimpcolor.h"
#include "core-types.h"
#include "config/gimpxmlparser.h"
#include "gimp-utils.h"
#include "gimpgradient.h"
#include "gimpgradient-load.h"
#include "gimp-intl.h"
GList *
gimp_gradient_load (GimpContext *context,
GFile *file,
GInputStream *input,
GError **error)
{
GimpGradient *gradient = NULL;
GimpGradientSegment *prev;
gint num_segments;
gint i;
GDataInputStream *data_input;
gchar *line;
gsize line_len;
gint linenum;
g_return_val_if_fail (G_IS_FILE (file), NULL);
g_return_val_if_fail (G_IS_INPUT_STREAM (input), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
data_input = g_data_input_stream_new (input);
linenum = 1;
line_len = 1024;
line = gimp_data_input_stream_read_line_always (data_input, &line_len,
NULL, error);
if (! line)
goto failed;
if (! g_str_has_prefix (line, "GIMP Gradient"))
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Not a GIMP gradient file."));
g_free (line);
goto failed;
}
g_free (line);
gradient = g_object_new (GIMP_TYPE_GRADIENT,
"mime-type", "application/x-gimp-gradient",
NULL);
linenum++;
line_len = 1024;
line = gimp_data_input_stream_read_line_always (data_input, &line_len,
NULL, error);
if (! line)
goto failed;
if (g_str_has_prefix (line, "Name: "))
{
gchar *utf8;
utf8 = gimp_any_to_utf8 (g_strstrip (line + strlen ("Name: ")), -1,
_("Invalid UTF-8 string in gradient file '%s'."),
gimp_file_get_utf8_name (file));
gimp_object_take_name (GIMP_OBJECT (gradient), utf8);
g_free (line);
linenum++;
line_len = 1024;
line = gimp_data_input_stream_read_line_always (data_input, &line_len,
NULL, error);
if (! line)
goto failed;
}
else /* old gradient format */
{
gimp_object_take_name (GIMP_OBJECT (gradient),
g_path_get_basename (gimp_file_get_utf8_name (file)));
}
num_segments = atoi (line);
g_free (line);
if (num_segments < 1)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("File is corrupt."));
goto failed;
}
prev = NULL;
for (i = 0; i < num_segments; i++)
{
GimpGradientSegment *seg;
gchar *end;
gint color;
gint type;
gint left_color_type;
gint right_color_type;
gdouble left_rgba[4];
gdouble right_rgba[4];
seg = gimp_gradient_segment_new ();
seg->prev = prev;
if (prev)
prev->next = seg;
else
gradient->segments = seg;
linenum++;
line_len = 1024;
line = gimp_data_input_stream_read_line_always (data_input, &line_len,
NULL, error);
if (! line)
goto failed;
if (! gimp_ascii_strtod (line, &end, &seg->left) ||
! gimp_ascii_strtod (end, &end, &seg->middle) ||
! gimp_ascii_strtod (end, &end, &seg->right) ||
! gimp_ascii_strtod (end, &end, &left_rgba[0]) ||
! gimp_ascii_strtod (end, &end, &left_rgba[1]) ||
! gimp_ascii_strtod (end, &end, &left_rgba[2]) ||
! gimp_ascii_strtod (end, &end, &left_rgba[3]) ||
! gimp_ascii_strtod (end, &end, &right_rgba[0]) ||
! gimp_ascii_strtod (end, &end, &right_rgba[1]) ||
! gimp_ascii_strtod (end, &end, &right_rgba[2]) ||
! gimp_ascii_strtod (end, &end, &right_rgba[3]))
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Corrupt segment %d."), i);
g_free (line);
goto failed;
}
gegl_color_set_pixel (seg->left_color, babl_format ("R'G'B'A double"), left_rgba);
gegl_color_set_pixel (seg->right_color, babl_format ("R'G'B'A double"), right_rgba);
switch (sscanf (end, "%d %d %d %d",
&type, &color,
&left_color_type, &right_color_type))
{
case 4:
seg->left_color_type = (GimpGradientColor) left_color_type;
if (seg->left_color_type < GIMP_GRADIENT_COLOR_FIXED ||
seg->left_color_type > GIMP_GRADIENT_COLOR_BACKGROUND_TRANSPARENT)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Corrupt segment %d."), i);
g_free (line);
goto failed;
}
seg->right_color_type = (GimpGradientColor) right_color_type;
if (seg->right_color_type < GIMP_GRADIENT_COLOR_FIXED ||
seg->right_color_type > GIMP_GRADIENT_COLOR_BACKGROUND_TRANSPARENT)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Corrupt segment %d."), i);
g_free (line);
goto failed;
}
/* fall thru */
case 2:
seg->type = (GimpGradientSegmentType) type;
if (seg->type < GIMP_GRADIENT_SEGMENT_LINEAR ||
seg->type > GIMP_GRADIENT_SEGMENT_STEP)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Corrupt segment %d."), i);
g_free (line);
goto failed;
}
seg->color = (GimpGradientSegmentColor) color;
if (seg->color < GIMP_GRADIENT_SEGMENT_RGB ||
seg->color > GIMP_GRADIENT_SEGMENT_HSV_CW)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Corrupt segment %d."), i);
g_free (line);
goto failed;
}
break;
default:
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Corrupt segment %d."), i);
g_free (line);
goto failed;
}
g_free (line);
if (seg->left > seg->middle ||
seg->middle > seg->right ||
( prev && (prev->right != seg->left)) ||
(! prev && (0.0 != seg->left)))
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Segments do not span the range 0-1."));
goto failed;
}
prev = seg;
}
if (prev->right != 1.0)
{
g_set_error (error, GIMP_DATA_ERROR, GIMP_DATA_ERROR_READ,
_("Segments do not span the range 0-1."));
goto failed;
}
g_object_unref (data_input);
return g_list_prepend (NULL, gradient);
failed:
g_object_unref (data_input);
if (gradient)
g_object_unref (gradient);
g_prefix_error (error, _("In line %d of gradient file: "), linenum);
return NULL;
}
/* SVG gradient parser */
typedef struct
{
GimpGradient *gradient; /* current gradient */
GList *gradients; /* finished gradients */
GList *stops;
} SvgParser;
typedef struct
{
gdouble offset;
GeglColor *color;
gdouble opacity;
} 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 (GimpContext *context,
GFile *file,
GInputStream *input,
GError **error)
{
GimpXmlParser *xml_parser;
SvgParser parser = { NULL, };
gboolean success;
g_return_val_if_fail (G_IS_FILE (file), NULL);
g_return_val_if_fail (G_IS_INPUT_STREAM (input), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
/* FIXME input */
g_input_stream_close (input, NULL, NULL);
xml_parser = gimp_xml_parser_new (&markup_parser, &parser);
success = gimp_xml_parser_parse_gfile (xml_parser, file, 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."));
}
if (parser.gradient)
g_object_unref (parser.gradient);
if (parser.stops)
{
GList *list;
for (list = parser.stops; list; list = list->next)
g_slice_free (SvgStop, list->data);
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)
{
GList *list;
parser->gradient->segments = svg_parser_gradient_segments (parser->stops);
for (list = parser->stops; list; list = list->next)
{
SvgStop *stop = list->data;
g_clear_object (&stop->color);
g_slice_free (SvgStop, stop);
}
g_list_free (parser->stops);
parser->stops = NULL;
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 ();
g_clear_object (&segment->left_color);
segment->left_color = gegl_color_duplicate (stop->color);
g_clear_object (&segment->right_color);
segment->right_color = gegl_color_duplicate (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;
g_clear_object (&segment->right_color);
segment->right_color = gegl_color_duplicate (stop->color);
stop = list->data;
g_clear_object (&segment->left_color);
segment->left_color = gegl_color_duplicate (stop->color);
}
segment->middle = (segment->left + segment->right) / 2.0;
if (stop->offset > 0.0)
{
g_clear_object (&segment->right_color);
segment->right_color = gegl_color_duplicate (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)
{
g_clear_object (&stop->color);
stop->color = gimp_color_parse_css (value, -1);
}
else if (strcmp (name, "stop-opacity") == 0)
{
gdouble opacity = g_ascii_strtod (value, NULL);
if (errno != ERANGE)
stop->opacity = 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;
gchar *value;
name = g_strndup (style, sep - style);
sep++;
value = g_strndup (sep, end - sep);
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_slice_new0 (SvgStop);
stop->color = NULL;
stop->opacity = 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++;
}
if (! stop->color)
/* Default stop color is black:
* https://svgwg.org/svg2-draft/pservers.html#GradientStops
*/
stop->color = gegl_color_new ("black");
gimp_color_set_alpha (stop->color, stop->opacity);
return stop;
}