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Diffstat (limited to 'libgimpbase/gimpunit.c')
| -rw-r--r-- | libgimpbase/gimpunit.c | 755 |
1 files changed, 755 insertions, 0 deletions
diff --git a/libgimpbase/gimpunit.c b/libgimpbase/gimpunit.c new file mode 100644 index 0000000..e0aa626 --- /dev/null +++ b/libgimpbase/gimpunit.c @@ -0,0 +1,755 @@ +/* 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); + + 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 + */ + +#define GIMP_PARAM_SPEC_UNIT(pspec) (G_TYPE_CHECK_INSTANCE_CAST ((pspec), GIMP_TYPE_PARAM_UNIT, GimpParamSpecUnit)) + +typedef struct _GimpParamSpecUnit GimpParamSpecUnit; + +struct _GimpParamSpecUnit +{ + GParamSpecInt parent_instance; + + gboolean allow_percent; +}; + +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: 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 */ +} |