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gimp/libgimpbase/gimpunit.c

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/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* gimpunit.c
* Copyright (C) 2003 Michael Natterer <mitch@gimp.org>
*
* 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
* Lesser 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 <math.h>
#include <string.h>
#include <glib-object.h>
#include "gimpbasetypes.h"
#include "gimpbase-private.h"
#include "gimpunit.h"
/**
* SECTION: gimpunit
* @title: gimpunit
* @short_description: Provides a collection of predefined units and
* functions for creating user-defined units.
* @see_also: #GimpUnitMenu, #GimpSizeEntry.
*
* Provides a collection of predefined units and functions for
* creating user-defined units.
**/
static void unit_to_string (const GValue *src_value,
GValue *dest_value);
static void string_to_unit (const GValue *src_value,
GValue *dest_value);
GType
gimp_unit_get_type (void)
{
static GType unit_type = 0;
if (! unit_type)
{
const GTypeInfo type_info = { 0, };
unit_type = g_type_register_static (G_TYPE_INT, "GimpUnit",
&type_info, 0);
g_value_register_transform_func (unit_type, G_TYPE_STRING,
unit_to_string);
g_value_register_transform_func (G_TYPE_STRING, unit_type,
string_to_unit);
}
return unit_type;
}
static void
unit_to_string (const GValue *src_value,
GValue *dest_value)
{
GimpUnit unit = (GimpUnit) g_value_get_int (src_value);
g_value_set_string (dest_value, gimp_unit_get_identifier (unit));
}
static void
string_to_unit (const GValue *src_value,
GValue *dest_value)
{
const gchar *str;
gint num_units;
gint i;
str = g_value_get_string (src_value);
if (!str || !*str)
goto error;
num_units = gimp_unit_get_number_of_units ();
for (i = GIMP_UNIT_PIXEL; i < num_units; i++)
if (strcmp (str, gimp_unit_get_identifier (i)) == 0)
break;
if (i == num_units)
{
if (strcmp (str, gimp_unit_get_identifier (GIMP_UNIT_PERCENT)) == 0)
i = GIMP_UNIT_PERCENT;
else
goto error;
}
g_value_set_int (dest_value, i);
return;
error:
g_warning ("Can't convert string '%s' to GimpUnit.", str);
}
/**
* gimp_unit_get_number_of_units:
*
* Returns the number of units which are known to the #GimpUnit system.
*
* Returns: The number of defined units.
**/
gint
gimp_unit_get_number_of_units (void)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_number_of_units != NULL,
GIMP_UNIT_END);
return _gimp_unit_vtable.unit_get_number_of_units ();
}
/**
* gimp_unit_get_number_of_built_in_units:
*
* Returns the number of #GimpUnit's which are hardcoded in the unit system
* (UNIT_INCH, UNIT_MM, UNIT_POINT, UNIT_PICA and the two "pseudo unit"
* UNIT_PIXEL).
*
* Returns: The number of built-in units.
**/
gint
gimp_unit_get_number_of_built_in_units (void)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_number_of_built_in_units
!= NULL, GIMP_UNIT_END);
return _gimp_unit_vtable.unit_get_number_of_built_in_units ();
}
/**
* gimp_unit_new:
* @identifier: The unit's identifier string.
* @factor: The unit's factor (how many units are in one inch).
* @digits: The unit's suggested number of digits (see gimp_unit_get_digits()).
* @symbol: The symbol of the unit (e.g. "''" for inch).
* @abbreviation: The abbreviation of the unit.
* @singular: The singular form of the unit.
* @plural: The plural form of the unit.
*
* Returns the integer ID of the new #GimpUnit.
*
* Note that a new unit is always created with its deletion flag
* set to %TRUE. You will have to set it to %FALSE with
* gimp_unit_set_deletion_flag() to make the unit definition persistent.
*
* Returns: The ID of the new unit.
**/
GimpUnit
gimp_unit_new (gchar *identifier,
gdouble factor,
gint digits,
gchar *symbol,
gchar *abbreviation,
gchar *singular,
gchar *plural)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_new != NULL, GIMP_UNIT_INCH);
return _gimp_unit_vtable.unit_new (identifier, factor, digits,
symbol, abbreviation, singular, plural);
}
/**
* gimp_unit_get_deletion_flag:
* @unit: The unit you want to know the @deletion_flag of.
*
* Returns: The unit's @deletion_flag.
**/
gboolean
gimp_unit_get_deletion_flag (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_deletion_flag != NULL, FALSE);
return _gimp_unit_vtable.unit_get_deletion_flag (unit);
}
/**
* gimp_unit_set_deletion_flag:
* @unit: The unit you want to set the @deletion_flag for.
* @deletion_flag: The new deletion_flag.
*
* Sets a #GimpUnit's @deletion_flag. If the @deletion_flag of a unit is
* %TRUE when GIMP exits, this unit will not be saved in the users's
* "unitrc" file.
*
* Trying to change the @deletion_flag of a built-in unit will be silently
* ignored.
**/
void
gimp_unit_set_deletion_flag (GimpUnit unit,
gboolean deletion_flag)
{
g_return_if_fail (_gimp_unit_vtable.unit_set_deletion_flag != NULL);
_gimp_unit_vtable.unit_set_deletion_flag (unit, deletion_flag);
}
/**
* gimp_unit_get_factor:
* @unit: The unit you want to know the factor of.
*
* A #GimpUnit's @factor is defined to be:
*
* distance_in_units == (@factor * distance_in_inches)
*
* Returns 0 for @unit == GIMP_UNIT_PIXEL.
*
* Returns: The unit's factor.
**/
gdouble
gimp_unit_get_factor (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_factor != NULL, 1.0);
if (unit == GIMP_UNIT_PIXEL)
return 0.0;
return _gimp_unit_vtable.unit_get_factor (unit);
}
/**
* gimp_unit_get_digits:
* @unit: The unit you want to know the digits.
*
* Returns the number of digits set for @unit.
* Built-in units' accuracy is approximately the same as an inch with
* two digits. User-defined units can suggest a different accuracy.
*
* Note: the value is as-set by defaults or by the user and does not
* necessary provide enough precision on high-resolution images.
* When the information is needed for a specific image, the use of
* gimp_unit_get_scaled_digits() may be more appropriate.
*
* Returns 0 for @unit == GIMP_UNIT_PIXEL.
*
* Returns: The suggested number of digits.
**/
gint
gimp_unit_get_digits (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_digits != NULL, 2);
return _gimp_unit_vtable.unit_get_digits (unit);
}
/**
* gimp_unit_get_scaled_digits:
* @unit: The unit you want to know the digits.
* @resolution: the resolution in PPI.
*
* Returns the number of digits a @unit field should provide to get
* enough accuracy so that every pixel position shows a different
* value from neighboring pixels.
*
* Note: when needing digit accuracy to display a diagonal distance,
* the @resolution may not correspond to the image's horizontal or
* vertical resolution, but instead to the result of:
* `distance_in_pixel / distance_in_inch`.
*
* Returns: The suggested number of digits.
**/
gint
gimp_unit_get_scaled_digits (GimpUnit unit,
gdouble resolution)
{
gint digits;
g_return_val_if_fail (_gimp_unit_vtable.unit_get_digits != NULL, 2);
digits = ceil (log10 (1.0 /
gimp_pixels_to_units (1.0, unit, resolution)));
return MAX (digits, gimp_unit_get_digits (unit));
}
/**
* gimp_unit_get_identifier:
* @unit: The unit you want to know the identifier of.
*
* This is an untranslated string and must not be changed or freed.
*
* Returns: The unit's identifier.
**/
const gchar *
gimp_unit_get_identifier (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_identifier != NULL, NULL);
return _gimp_unit_vtable.unit_get_identifier (unit);
}
/**
* gimp_unit_get_symbol:
* @unit: The unit you want to know the symbol of.
*
* This is e.g. "''" for UNIT_INCH.
*
* NOTE: This string must not be changed or freed.
*
* Returns: The unit's symbol.
**/
const gchar *
gimp_unit_get_symbol (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_symbol != NULL, NULL);
return _gimp_unit_vtable.unit_get_symbol (unit);
}
/**
* gimp_unit_get_abbreviation:
* @unit: The unit you want to know the abbreviation of.
*
* For built-in units, this function returns the translated abbreviation
* of the unit.
*
* NOTE: This string must not be changed or freed.
*
* Returns: The unit's abbreviation.
**/
const gchar *
gimp_unit_get_abbreviation (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_abbreviation != NULL, NULL);
return _gimp_unit_vtable.unit_get_abbreviation (unit);
}
/**
* gimp_unit_get_singular:
* @unit: The unit you want to know the singular form of.
*
* For built-in units, this function returns the translated singular form
* of the unit's name.
*
* NOTE: This string must not be changed or freed.
*
* Returns: The unit's singular form.
**/
const gchar *
gimp_unit_get_singular (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_singular != NULL, NULL);
return _gimp_unit_vtable.unit_get_singular (unit);
}
/**
* gimp_unit_get_plural:
* @unit: The unit you want to know the plural form of.
*
* For built-in units, this function returns the translated plural form
* of the unit's name.
*
* NOTE: This string must not be changed or freed.
*
* Returns: The unit's plural form.
**/
const gchar *
gimp_unit_get_plural (GimpUnit unit)
{
g_return_val_if_fail (_gimp_unit_vtable.unit_get_plural != NULL, NULL);
return _gimp_unit_vtable.unit_get_plural (unit);
}
static gint print (gchar *buf,
gint len,
gint start,
const gchar *fmt,
...) G_GNUC_PRINTF (4, 5);
static gint
print (gchar *buf,
gint len,
gint start,
const gchar *fmt,
...)
{
va_list args;
gint printed;
va_start (args, fmt);
printed = g_vsnprintf (buf + start, len - start, fmt, args);
if (printed < 0)
printed = len - start;
va_end (args);
return printed;
}
/**
* gimp_unit_format_string:
* @format: A printf-like format string which is used to create the unit
* string.
* @unit: A unit.
*
* The @format string supports the following percent expansions:
*
* <informaltable pgwide="1" frame="none" role="enum">
* <tgroup cols="2"><colspec colwidth="1*"/><colspec colwidth="8*"/>
* <tbody>
* <row>
* <entry>% f</entry>
* <entry>Factor (how many units make up an inch)</entry>
* </row>
* <row>
* <entry>% y</entry>
* <entry>Symbol (e.g. "''" for GIMP_UNIT_INCH)</entry>
* </row>
* <row>
* <entry>% a</entry>
* <entry>Abbreviation</entry>
* </row>
* <row>
* <entry>% s</entry>
* <entry>Singular</entry>
* </row>
* <row>
* <entry>% p</entry>
* <entry>Plural</entry>
* </row>
* <row>
* <entry>%%</entry>
* <entry>Literal percent</entry>
* </row>
* </tbody>
* </tgroup>
* </informaltable>
*
* Returns: A newly allocated string with above percent expressions
* replaced with the resp. strings for @unit.
*
* Since: 2.8
**/
gchar *
gimp_unit_format_string (const gchar *format,
GimpUnit unit)
{
gchar buffer[1024];
gint i = 0;
g_return_val_if_fail (format != NULL, NULL);
g_return_val_if_fail (unit == GIMP_UNIT_PERCENT ||
(unit >= GIMP_UNIT_PIXEL &&
unit < gimp_unit_get_number_of_units ()), NULL);
while (i < (sizeof (buffer) - 1) && *format)
{
switch (*format)
{
case '%':
format++;
switch (*format)
{
case 0:
g_warning ("%s: unit-menu-format string ended within %%-sequence",
G_STRFUNC);
break;
case '%':
buffer[i++] = '%';
break;
case 'f': /* factor (how many units make up an inch) */
i += print (buffer, sizeof (buffer), i, "%f",
gimp_unit_get_factor (unit));
break;
case 'y': /* symbol ("''" for inch) */
i += print (buffer, sizeof (buffer), i, "%s",
gimp_unit_get_symbol (unit));
break;
case 'a': /* abbreviation */
i += print (buffer, sizeof (buffer), i, "%s",
gimp_unit_get_abbreviation (unit));
break;
case 's': /* singular */
i += print (buffer, sizeof (buffer), i, "%s",
gimp_unit_get_singular (unit));
break;
case 'p': /* plural */
i += print (buffer, sizeof (buffer), i, "%s",
gimp_unit_get_plural (unit));
break;
default:
g_warning ("%s: unit-menu-format contains unknown format "
"sequence '%%%c'", G_STRFUNC, *format);
break;
}
break;
default:
buffer[i++] = *format;
break;
}
format++;
}
buffer[MIN (i, sizeof (buffer) - 1)] = 0;
return g_strdup (buffer);
}
/*
* GIMP_TYPE_PARAM_UNIT
*/
static void gimp_param_unit_class_init (GParamSpecClass *class);
static gboolean gimp_param_unit_value_validate (GParamSpec *pspec,
GValue *value);
/**
* gimp_param_unit_get_type:
*
* Reveals the object type
*
* Returns: the #GType for a unit param object
*
* Since: 2.4
**/
GType
gimp_param_unit_get_type (void)
{
static GType spec_type = 0;
if (! spec_type)
{
const GTypeInfo type_info =
{
sizeof (GParamSpecClass),
NULL, NULL,
(GClassInitFunc) gimp_param_unit_class_init,
NULL, NULL,
sizeof (GimpParamSpecUnit),
0, NULL, NULL
};
spec_type = g_type_register_static (G_TYPE_PARAM_INT,
"GimpParamUnit",
&type_info, 0);
}
return spec_type;
}
static void
gimp_param_unit_class_init (GParamSpecClass *class)
{
class->value_type = GIMP_TYPE_UNIT;
class->value_validate = gimp_param_unit_value_validate;
}
static gboolean
gimp_param_unit_value_validate (GParamSpec *pspec,
GValue *value)
{
GParamSpecInt *ispec = G_PARAM_SPEC_INT (pspec);
GimpParamSpecUnit *uspec = GIMP_PARAM_SPEC_UNIT (pspec);
gint oval = value->data[0].v_int;
if (!(uspec->allow_percent && value->data[0].v_int == GIMP_UNIT_PERCENT))
{
value->data[0].v_int = CLAMP (value->data[0].v_int,
ispec->minimum,
gimp_unit_get_number_of_units () - 1);
}
return value->data[0].v_int != oval;
}
/**
* gimp_param_spec_unit:
* @name: Canonical name of the param
* @nick: Nickname of the param
* @blurb: Brief description of param.
* @allow_pixels: Whether "pixels" is an allowed unit.
* @allow_percent: Whether "percent" is an allowed unit.
* @default_value: Unit to use if none is assigned.
* @flags: a combination of #GParamFlags
*
* Creates a param spec to hold a units param.
* See g_param_spec_internal() for more information.
*
* Returns: (transfer full): a newly allocated #GParamSpec instance
*
* Since: 2.4
**/
GParamSpec *
gimp_param_spec_unit (const gchar *name,
const gchar *nick,
const gchar *blurb,
gboolean allow_pixels,
gboolean allow_percent,
GimpUnit default_value,
GParamFlags flags)
{
GimpParamSpecUnit *pspec;
GParamSpecInt *ispec;
pspec = g_param_spec_internal (GIMP_TYPE_PARAM_UNIT,
name, nick, blurb, flags);
ispec = G_PARAM_SPEC_INT (pspec);
ispec->default_value = default_value;
ispec->minimum = allow_pixels ? GIMP_UNIT_PIXEL : GIMP_UNIT_INCH;
ispec->maximum = GIMP_UNIT_PERCENT - 1;
pspec->allow_percent = allow_percent;
return G_PARAM_SPEC (pspec);
}
/**
* gimp_pixels_to_units:
* @pixels: value in pixels
* @unit: unit to convert to
* @resolution: resolution in DPI
*
* Converts a @value specified in pixels to @unit.
*
* Returns: @pixels converted to units.
*
* Since: 2.8
**/
gdouble
gimp_pixels_to_units (gdouble pixels,
GimpUnit unit,
gdouble resolution)
{
if (unit == GIMP_UNIT_PIXEL)
return pixels;
return pixels * gimp_unit_get_factor (unit) / resolution;
}
/**
* gimp_units_to_pixels:
* @value: value in units
* @unit: unit of @value
* @resolution: resloution in DPI
*
* Converts a @value specified in @unit to pixels.
*
* Returns: @value converted to pixels.
*
* Since: 2.8
**/
gdouble
gimp_units_to_pixels (gdouble value,
GimpUnit unit,
gdouble resolution)
{
if (unit == GIMP_UNIT_PIXEL)
return value;
return value * resolution / gimp_unit_get_factor (unit);
}
/**
* gimp_units_to_points:
* @value: value in units
* @unit: unit of @value
* @resolution: resloution in DPI
*
* Converts a @value specified in @unit to points.
*
* Returns: @value converted to points.
*
* Since: 2.8
**/
gdouble
gimp_units_to_points (gdouble value,
GimpUnit unit,
gdouble resolution)
{
if (unit == GIMP_UNIT_POINT)
return value;
if (unit == GIMP_UNIT_PIXEL)
return (value * gimp_unit_get_factor (GIMP_UNIT_POINT) / resolution);
return (value *
gimp_unit_get_factor (GIMP_UNIT_POINT) / gimp_unit_get_factor (unit));
}
/**
* gimp_unit_is_metric:
* @unit: The unit
*
* Checks if the given @unit is metric. A simplistic test is used
* that looks at the unit's factor and checks if it is 2.54 multiplied
* by some common powers of 10. Currently it checks for mm, cm, dm, m.
*
* See also: gimp_unit_get_factor()
*
* Returns: %TRUE if the @unit is metric.
*
* Since: 2.10
**/
gboolean
gimp_unit_is_metric (GimpUnit unit)
{
gdouble factor;
if (unit == GIMP_UNIT_MM)
return TRUE;
factor = gimp_unit_get_factor (unit);
if (factor == 0.0)
return FALSE;
return ((ABS (factor - 0.0254) < 1e-7) || /* m */
(ABS (factor - 0.254) < 1e-6) || /* dm */
(ABS (factor - 2.54) < 1e-5) || /* cm */
(ABS (factor - 25.4) < 1e-4)); /* mm */
}
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