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gimp/libgimpcolor/gimpcolor-parse.c

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/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* gimpcolor-parse.c
* Copyright (C) 2023 Jehan
*
* Some of the code in here was inspired and partly copied from pango
* and librsvg.
*
* This library is free software: you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library 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 Lesser General Public
* License along with this library. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <babl/babl.h>
#include <cairo.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gegl.h>
#include "libgimpbase/gimpbase.h"
#include "gimpcolor.h"
static GeglColor * gimp_color_parse_name_internal (const gchar *name);
static GeglColor * gimp_color_parse_hex_internal (const gchar *hex);
static GeglColor * gimp_color_parse_css_numeric (const gchar *css);
static GeglColor * gimp_color_parse_css_internal (const gchar *css);
static gchar * gimp_color_parse_strip (const gchar *str,
gint len);
static gint gimp_color_entry_compare (gconstpointer a,
gconstpointer b);
static gboolean gimp_color_parse_hex_component (const gchar *hex,
gint len,
gdouble *value);
typedef struct
{
const gchar *name;
const guchar red;
const guchar green;
const guchar blue;
} ColorEntry;
static const ColorEntry named_colors[] =
{
{ "aliceblue", 240, 248, 255 },
{ "antiquewhite", 250, 235, 215 },
{ "aqua", 0, 255, 255 },
{ "aquamarine", 127, 255, 212 },
{ "azure", 240, 255, 255 },
{ "beige", 245, 245, 220 },
{ "bisque", 255, 228, 196 },
{ "black", 0, 0, 0 },
{ "blanchedalmond", 255, 235, 205 },
{ "blue", 0, 0, 255 },
{ "blueviolet", 138, 43, 226 },
{ "brown", 165, 42, 42 },
{ "burlywood", 222, 184, 135 },
{ "cadetblue", 95, 158, 160 },
{ "chartreuse", 127, 255, 0 },
{ "chocolate", 210, 105, 30 },
{ "coral", 255, 127, 80 },
{ "cornflowerblue", 100, 149, 237 },
{ "cornsilk", 255, 248, 220 },
{ "crimson", 220, 20, 60 },
{ "cyan", 0, 255, 255 },
{ "darkblue", 0, 0, 139 },
{ "darkcyan", 0, 139, 139 },
{ "darkgoldenrod", 184, 134, 11 },
{ "darkgray", 169, 169, 169 },
{ "darkgreen", 0, 100, 0 },
{ "darkgrey", 169, 169, 169 },
{ "darkkhaki", 189, 183, 107 },
{ "darkmagenta", 139, 0, 139 },
{ "darkolivegreen", 85, 107, 47 },
{ "darkorange", 255, 140, 0 },
{ "darkorchid", 153, 50, 204 },
{ "darkred", 139, 0, 0 },
{ "darksalmon", 233, 150, 122 },
{ "darkseagreen", 143, 188, 143 },
{ "darkslateblue", 72, 61, 139 },
{ "darkslategray", 47, 79, 79 },
{ "darkslategrey", 47, 79, 79 },
{ "darkturquoise", 0, 206, 209 },
{ "darkviolet", 148, 0, 211 },
{ "deeppink", 255, 20, 147 },
{ "deepskyblue", 0, 191, 255 },
{ "dimgray", 105, 105, 105 },
{ "dimgrey", 105, 105, 105 },
{ "dodgerblue", 30, 144, 255 },
{ "firebrick", 178, 34, 34 },
{ "floralwhite" , 255, 250, 240 },
{ "forestgreen", 34, 139, 34 },
{ "fuchsia", 255, 0, 255 },
{ "gainsboro", 220, 220, 220 },
{ "ghostwhite", 248, 248, 255 },
{ "gold", 255, 215, 0 },
{ "goldenrod", 218, 165, 32 },
{ "gray", 128, 128, 128 },
{ "green", 0, 128, 0 },
{ "greenyellow", 173, 255, 47 },
{ "grey", 128, 128, 128 },
{ "honeydew", 240, 255, 240 },
{ "hotpink", 255, 105, 180 },
{ "indianred", 205, 92, 92 },
{ "indigo", 75, 0, 130 },
{ "ivory", 255, 255, 240 },
{ "khaki", 240, 230, 140 },
{ "lavender", 230, 230, 250 },
{ "lavenderblush", 255, 240, 245 },
{ "lawngreen", 124, 252, 0 },
{ "lemonchiffon", 255, 250, 205 },
{ "lightblue", 173, 216, 230 },
{ "lightcoral", 240, 128, 128 },
{ "lightcyan", 224, 255, 255 },
{ "lightgoldenrodyellow", 250, 250, 210 },
{ "lightgray", 211, 211, 211 },
{ "lightgreen", 144, 238, 144 },
{ "lightgrey", 211, 211, 211 },
{ "lightpink", 255, 182, 193 },
{ "lightsalmon", 255, 160, 122 },
{ "lightseagreen", 32, 178, 170 },
{ "lightskyblue", 135, 206, 250 },
{ "lightslategray", 119, 136, 153 },
{ "lightslategrey", 119, 136, 153 },
{ "lightsteelblue", 176, 196, 222 },
{ "lightyellow", 255, 255, 224 },
{ "lime", 0, 255, 0 },
{ "limegreen", 50, 205, 50 },
{ "linen", 250, 240, 230 },
{ "magenta", 255, 0, 255 },
{ "maroon", 128, 0, 0 },
{ "mediumaquamarine", 102, 205, 170 },
{ "mediumblue", 0, 0, 205 },
{ "mediumorchid", 186, 85, 211 },
{ "mediumpurple", 147, 112, 219 },
{ "mediumseagreen", 60, 179, 113 },
{ "mediumslateblue", 123, 104, 238 },
{ "mediumspringgreen", 0, 250, 154 },
{ "mediumturquoise", 72, 209, 204 },
{ "mediumvioletred", 199, 21, 133 },
{ "midnightblue", 25, 25, 112 },
{ "mintcream", 245, 255, 250 },
{ "mistyrose", 255, 228, 225 },
{ "moccasin", 255, 228, 181 },
{ "navajowhite", 255, 222, 173 },
{ "navy", 0, 0, 128 },
{ "oldlace", 253, 245, 230 },
{ "olive", 128, 128, 0 },
{ "olivedrab", 107, 142, 35 },
{ "orange", 255, 165, 0 },
{ "orangered", 255, 69, 0 },
{ "orchid", 218, 112, 214 },
{ "palegoldenrod", 238, 232, 170 },
{ "palegreen", 152, 251, 152 },
{ "paleturquoise", 175, 238, 238 },
{ "palevioletred", 219, 112, 147 },
{ "papayawhip", 255, 239, 213 },
{ "peachpuff", 255, 218, 185 },
{ "peru", 205, 133, 63 },
{ "pink", 255, 192, 203 },
{ "plum", 221, 160, 221 },
{ "powderblue", 176, 224, 230 },
{ "purple", 128, 0, 128 },
{ "red", 255, 0, 0 },
{ "rosybrown", 188, 143, 143 },
{ "royalblue", 65, 105, 225 },
{ "saddlebrown", 139, 69, 19 },
{ "salmon", 250, 128, 114 },
{ "sandybrown", 244, 164, 96 },
{ "seagreen", 46, 139, 87 },
{ "seashell", 255, 245, 238 },
{ "sienna", 160, 82, 45 },
{ "silver", 192, 192, 192 },
{ "skyblue", 135, 206, 235 },
{ "slateblue", 106, 90, 205 },
{ "slategray", 112, 128, 144 },
{ "slategrey", 112, 128, 144 },
{ "snow", 255, 250, 250 },
{ "springgreen", 0, 255, 127 },
{ "steelblue", 70, 130, 180 },
{ "tan", 210, 180, 140 },
{ "teal", 0, 128, 128 },
{ "thistle", 216, 191, 216 },
{ "tomato", 255, 99, 71 },
{ "turquoise", 64, 224, 208 },
{ "violet", 238, 130, 238 },
{ "wheat", 245, 222, 179 },
{ "white", 255, 255, 255 },
{ "whitesmoke", 245, 245, 245 },
{ "yellow", 255, 255, 0 },
{ "yellowgreen", 154, 205, 50 }
};
/**
* gimp_color_parse_css:
* @css: (type utf8): a string describing a color in CSS notation
*
* Attempts to parse a string describing an sRGB color in CSS notation. This can
* be either a numerical representation (`rgb(255,0,0)` or `rgb(100%,0%,0%)`)
* or a hexadecimal notation as parsed by [func@color_parse_hex] (`##ff0000`) or
* a color name as parsed by [func@color_parse_css] (`red`).
*
* Additionally the `rgba()`, `hsl()` and `hsla()` functions are supported too.
*
* Returns: (transfer full): a newly allocated [class@Gegl.Color] if @css was
* parsed successfully, %NULL otherwise
**/
GeglColor *
gimp_color_parse_css (const gchar *css)
{
return gimp_color_parse_css_substring (css, -1);
}
/**
* gimp_color_parse_hex:
* @hex: (type utf8): a string describing a color in hexadecimal notation
*
* Attempts to parse a string describing a sRGB color in hexadecimal
* notation (optionally prefixed with a '#').
*
* Returns: (transfer full): a newly allocated color representing @hex.
**/
GeglColor *
gimp_color_parse_hex (const gchar *hex)
{
return gimp_color_parse_hex_substring (hex, -1);
}
/**
* gimp_color_parse_name:
* @name: (type utf8): a color name (in UTF-8 encoding)
*
* Attempts to parse a color name. This function accepts [SVG 1.1 color
* keywords](https://www.w3.org/TR/SVG11/types.html#ColorKeywords).
*
* Returns: (transfer full): a sRGB color as defined in "4.4. Recognized color
* keyword names" list of SVG 1.1 specification, if @name was parsed
* successfully, %NULL otherwise
**/
GeglColor *
gimp_color_parse_name (const gchar *name)
{
return gimp_color_parse_name_substring (name, -1);
}
/**
* gimp_color_list_names:
* @colors: (out) (optional) (array zero-terminated=1) (element-type GeglColor) (transfer full): return location for an array of [class@Gegl.Color]
*
* Returns the list of [SVG 1.0 color
* keywords](https://www.w3.org/TR/SVG/types.html) that is recognized by
* [func@color_parse_name].
*
* The returned strings are const and must not be freed. Only the array
* must be freed with `g_free()`.
*
* The optional @colors arrays must be freed with [func@color_array_free] when
* they are no longer needed.
*
* Returns: (array zero-terminated=1) (transfer container): an array of color names.
*
* Since: 2.2
**/
const gchar **
gimp_color_list_names (GimpColorArray *colors)
{
const gchar **names;
gint i;
names = g_new0 (const gchar *, G_N_ELEMENTS (named_colors) + 1);
if (colors)
*colors = g_new0 (GeglColor *, G_N_ELEMENTS (named_colors) + 1);
for (i = 0; i < G_N_ELEMENTS (named_colors); i++)
{
names[i] = named_colors[i].name;
if (colors)
{
GeglColor *color = gegl_color_new (NULL);
gegl_color_set_rgba_with_space (color,
(gdouble) named_colors[i].red / 255.0,
(gdouble) named_colors[i].green / 255.0,
(gdouble) named_colors[i].blue / 255.0,
1.0, NULL);
(*colors)[i] = color;
}
}
return names;
}
/**
* gimp_color_parse_css_substring: (skip)
* @css: (array length=len): a string describing a color in CSS notation
* @len: the length of @css, in bytes. or -1 if @css is nul-terminated
*
* Attempts to parse a string describing an sRGB color in CSS notation. This can
* be either a numerical representation (`rgb(255,0,0)` or `rgb(100%,0%,0%)`) or
* a hexadecimal notation as parsed by [func@color_parse_hex] (`##ff0000`) or a
* color name as parsed by [func@color_parse_name] (`red`).
*
* Additionally the `rgba()`, `hsl()` and `hsla()` functions are supported too.
*
* Returns: (transfer full): a newly allocated [class@Gegl.Color] if @css was
* parsed successfully, %NULL otherwise
*
* Since: 2.2
**/
GeglColor *
gimp_color_parse_css_substring (const gchar *css,
gint len)
{
gchar *tmp;
GeglColor *color;
g_return_val_if_fail (css != NULL, FALSE);
tmp = gimp_color_parse_strip (css, len);
if (g_strcmp0 (tmp, "transparent") == 0)
color = gegl_color_new ("transparent");
else
color = gimp_color_parse_css_internal (tmp);
g_free (tmp);
return color;
}
/**
* gimp_color_parse_hex_substring: (skip)
* @hex: (array length=len): a string describing a color in hexadecimal notation
* @len: the length of @hex, in bytes. or -1 if @hex is nul-terminated
*
* Attempts to parse a string describing an RGB color in hexadecimal
* notation (optionally prefixed with a '#').
*
* This function does not touch the alpha component of @rgb.
*
* Returns: (transfer full): a newly allocated color representing @hex.
*
* Since: 2.2
**/
GeglColor *
gimp_color_parse_hex_substring (const gchar *hex,
gint len)
{
GeglColor *result;
gchar *tmp;
g_return_val_if_fail (hex != NULL, FALSE);
tmp = gimp_color_parse_strip (hex, len);
result = gimp_color_parse_hex_internal (tmp);
g_free (tmp);
return result;
}
/**
* gimp_color_parse_name_substring: (skip)
* @name: (array length=len): a color name (in UTF-8 encoding)
* @len: the length of @name, in bytes. or -1 if @name is nul-terminated
*
* Attempts to parse a color name. This function accepts [SVG 1.1 color
* keywords](https://www.w3.org/TR/SVG11/types.html#ColorKeywords).
*
* Returns: (transfer full): a sRGB color as defined in "4.4. Recognized color
* keyword names" list of SVG 1.1 specification, if @name was parsed
* successfully, %NULL otherwise
*
* Since: 2.2
**/
GeglColor *
gimp_color_parse_name_substring (const gchar *name,
gint len)
{
gchar *tmp;
GeglColor *result;
g_return_val_if_fail (name != NULL, FALSE);
tmp = gimp_color_parse_strip (name, len);
result = gimp_color_parse_name_internal (tmp);
g_free (tmp);
return result;
}
/* Private functions. */
static GeglColor *
gimp_color_parse_name_internal (const gchar *name)
{
/* GeglColor also has name reading support. It supports HTML 4.01 standard
* whereas here we have SVG 1.0 name support. Moreover we support a lot more
* colors.
*/
ColorEntry *entry = bsearch (name, named_colors,
G_N_ELEMENTS (named_colors), sizeof (ColorEntry),
gimp_color_entry_compare);
if (entry)
{
GeglColor *color = gegl_color_new (NULL);
gegl_color_set_rgba_with_space (color, (gdouble) entry->red / 255.0,
(gdouble) entry->green / 255.0, (gdouble) entry->blue / 255.0,
1.0, NULL);
return color;
}
return NULL;
}
static GeglColor *
gimp_color_parse_hex_internal (const gchar *hex)
{
GeglColor *color;
gint i;
gsize len;
gdouble val[3];
if (hex[0] == '#')
hex++;
len = strlen (hex);
/* TODO: current implementation has 2 issues:
* 1. It doesn't support the alpha channel, even though CSS spec now has
* support for it with either 8 or 4 digits.
* 2. The spec has nothing about channels on 3 or 4 digits, which we support
* here (for higher precision?). Is this format really supported somewhere?
* Do we want to keep this?
* See: https://drafts.csswg.org/css-color/#hex-notation
*/
if (len % 3 || len < 3 || len > 12)
return NULL;
len /= 3;
for (i = 0; i < 3; i++, hex += len)
{
if (! gimp_color_parse_hex_component (hex, len, val + i))
return NULL;
}
color = gegl_color_new (NULL);
gegl_color_set_pixel (color, babl_format ("R'G'B' double"), val);
return color;
}
static GeglColor *
gimp_color_parse_css_numeric (const gchar *css)
{
GeglColor *color;
gdouble values[4];
gboolean alpha;
gboolean hsl;
gint i;
if (css[0] == 'r' && css[1] == 'g' && css[2] == 'b')
hsl = FALSE;
else if (css[0] == 'h' && css[1] == 's' && css[2] == 'l')
hsl = TRUE;
else
g_return_val_if_reached (NULL);
if (css[3] == 'a' && css[4] == '(')
alpha = TRUE;
else if (css[3] == '(')
alpha = FALSE;
else
g_return_val_if_reached (NULL);
css += (alpha ? 5 : 4);
for (i = 0; i < (alpha ? 4 : 3); i++)
{
const gchar *end = css;
while (*end && *end != ',' && *end != '%' && *end != ')')
end++;
if (i == 3 || *end == '%')
{
values[i] = g_ascii_strtod (css, (gchar **) &end);
if (errno == ERANGE)
return FALSE;
if (*end == '%')
{
end++;
values[i] /= 100.0;
}
}
else
{
glong value = strtol (css, (gchar **) &end, 10);
if (errno == ERANGE)
return FALSE;
if (hsl)
values[i] = value / (i == 0 ? 360.0 : 100.0);
else
values[i] = value / 255.0;
}
/* CSS Color specs indicates:
* > Values outside these ranges are not invalid, but are clamped to the
* > ranges defined here at parsed-value time.
* See: https://drafts.csswg.org/css-color/#rgb-functions
* So even though we might hope being able to reach non-sRGB colors when
* using the percentage syntax, the spec explicitly forbids it.
*/
values[i] = CLAMP (values[i], 0.0, 1.0);
while (*end == ',' || g_ascii_isspace (*end))
end++;
css = end;
}
if (*css != ')')
return NULL;
color = gegl_color_new (NULL);
if (hsl)
{
gfloat values_f[4];
for (i = 0; i < (alpha ? 4 : 3); i++)
values_f[i] = (gfloat) values[i];
if (alpha)
gegl_color_set_pixel (color, babl_format ("HSLA float"), values_f);
else
gegl_color_set_pixel (color, babl_format ("HSL float"), values_f);
}
else
{
if (alpha)
gegl_color_set_pixel (color, babl_format ("R'G'B'A double"), values);
else
gegl_color_set_pixel (color, babl_format ("R'G'B' double"), values);
}
return color;
}
static GeglColor *
gimp_color_parse_css_internal (const gchar *css)
{
if (css[0] == '#')
{
return gimp_color_parse_hex_internal (css);
}
else if (strncmp (css, "rgb(", 4) == 0 ||
strncmp (css, "hsl(", 4) == 0 ||
strncmp (css, "rgba(", 5) == 0 ||
strncmp (css, "hsla(", 5) == 0)
{
return gimp_color_parse_css_numeric (css);
}
else
{
return gimp_color_parse_name_internal (css);
}
}
static gchar *
gimp_color_parse_strip (const gchar *str,
gint len)
{
gchar *result;
while (len > 0 && g_ascii_isspace (*str))
{
str++;
len--;
}
if (len < 0)
{
while (g_ascii_isspace (*str))
str++;
len = strlen (str);
}
while (len > 0 && g_ascii_isspace (str[len - 1]))
len--;
result = g_malloc (len + 1);
memcpy (result, str, len);
result[len] = '\0';
return result;
}
static gint
gimp_color_entry_compare (gconstpointer a,
gconstpointer b)
{
const gchar *name = a;
const ColorEntry *entry = b;
return g_ascii_strcasecmp (name, entry->name);
}
static gboolean
gimp_color_parse_hex_component (const gchar *hex,
gint len,
gdouble *value)
{
gint i;
guint c = 0;
for (i = 0; i < len; i++, hex++)
{
if (!*hex || !g_ascii_isxdigit (*hex))
return FALSE;
c = (c << 4) | g_ascii_xdigit_value (*hex);
}
switch (len)
{
case 1: *value = (gdouble) c / 15.0; break;
case 2: *value = (gdouble) c / 255.0; break;
case 3: *value = (gdouble) c / 4095.0; break;
case 4: *value = (gdouble) c / 65535.0; break;
default:
g_return_val_if_reached (FALSE);
}
return TRUE;
}
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