GimpRGB: GIMP Color Library Reference Manual

+ + +

GimpRGB

GimpRGB — Definitions and Functions relating to RGB colors.

Functions

++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

+void +	+gimp_rgb_set () +
+void +	+gimp_rgb_set_alpha () +
+void +	+gimp_rgb_set_pixel () +
+void +	+gimp_rgb_get_pixel () +
+void +	+gimp_rgb_set_uchar () +
+void +	+gimp_rgb_get_uchar () +
+gboolean +	+gimp_rgb_parse_name () +
+gboolean +	+gimp_rgb_parse_hex () +
+gboolean +	+gimp_rgb_parse_css () +
+gint +	+gimp_rgb_list_names () +
+void +	+gimp_rgb_add () +
+void +	+gimp_rgb_subtract () +
+void +	+gimp_rgb_multiply () +
+gdouble +	+gimp_rgb_distance () +
+gdouble +	+gimp_rgb_max () +
+gdouble +	+gimp_rgb_min () +
+void +	+gimp_rgb_clamp () +
+void +	+gimp_rgb_gamma () +
+gdouble +	+gimp_rgb_luminance () +
+guchar +	+gimp_rgb_luminance_uchar () +
+gdouble +	+gimp_rgb_intensity () +
+guchar +	+gimp_rgb_intensity_uchar () +
+void +	+gimp_rgb_composite () +
+void +	+gimp_rgba_set () +
+void +	+gimp_rgba_set_pixel () +
+void +	+gimp_rgba_get_pixel () +
+void +	+gimp_rgba_set_uchar () +
+void +	+gimp_rgba_get_uchar () +
+gboolean +	+gimp_rgba_parse_css () +
+void +	+gimp_rgba_add () +
+void +	+gimp_rgba_subtract () +
+void +	+gimp_rgba_multiply () +
+gdouble +	+gimp_rgba_distance () +
#define	+GIMP_RGB_LUMINANCE() +
#define	+GIMP_RGB_INTENSITY() +
+GParamSpec * +	+gimp_param_spec_rgb () +
+void +	+gimp_param_spec_rgb_get_default () +
+gboolean +	+gimp_param_spec_rgb_has_alpha () +
#define	+GIMP_VALUE_HOLDS_RGB() +
+void +	+gimp_value_get_rgb () +
+void +	+gimp_value_set_rgb () +

Types and Values

++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

struct	GimpRGB
enum	GimpRGBCompositeMode
#define	GIMP_RGB_LUMINANCE_RED
#define	GIMP_RGB_LUMINANCE_GREEN
#define	GIMP_RGB_LUMINANCE_BLUE
#define	GIMP_RGB_INTENSITY_RED
#define	GIMP_RGB_INTENSITY_GREEN
#define	GIMP_RGB_INTENSITY_BLUE
#define	GIMP_TYPE_RGB
#define	GIMP_TYPE_PARAM_RGB

Description

Definitions and Functions relating to RGB colors.

Functions

gimp_rgb_set ()

void
+gimp_rgb_set (GimpRGB *rgb,
+              gdouble red,
+              gdouble green,
+              gdouble blue);

Sets the red, green and blue components of rgb + and leaves the +alpha component unchanged. The color values should be between 0.0 +and 1.0 but there is no check to enforce this and the values are +set exactly as they are passed in.

Parameters

+++++ + + + + + + + + + + + + + + + + + + + + + + +

rgb	a GimpRGB struct
red	the red component
green	the green component
blue	the blue component

gimp_rgb_set_alpha ()

void
+gimp_rgb_set_alpha (GimpRGB *rgb,
+                    gdouble alpha);

Sets the alpha component of rgb + and leaves the RGB components unchanged.

Parameters

+++++ + + + + + + + + + + + + +

rgb	a GimpRGB struct
alpha	the alpha component

gimp_rgb_set_pixel ()

void
+gimp_rgb_set_pixel (GimpRGB *rgb,
+                    const Babl *format,
+                    gconstpointer pixel);

Sets the red, green and blue components of rgb + from the color +stored in pixel +. The pixel format of pixel + is determined by +format +.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgb	a GimpRGB struct
format	a Babl format
pixel	pointer to the source pixel

Since: 2.10

gimp_rgb_get_pixel ()

void
+gimp_rgb_get_pixel (const GimpRGB *rgb,
+                    const Babl *format,
+                    gpointer pixel);

Writes the red, green, blue and alpha components of rgb + to the +color stored in pixel +. The pixel format of pixel + is determined by +format +.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgb	a GimpRGB struct
format	a Babl format
pixel	pointer to the destination pixel

Since: 2.10

gimp_rgb_set_uchar ()

void
+gimp_rgb_set_uchar (GimpRGB *rgb,
+                    guchar red,
+                    guchar green,
+                    guchar blue);

Sets the red, green and blue components of rgb + from 8bit values +(0 to 255) and leaves the alpha component unchanged.

Parameters

+++++ + + + + + + + + + + + + + + + + + + + + + + +

rgb	a GimpRGB struct
red	the red component
green	the green component
blue	the blue component

gimp_rgb_get_uchar ()

void
+gimp_rgb_get_uchar (const GimpRGB *rgb,
+                    guchar *red,
+                    guchar *green,
+                    guchar *blue);

gimp_rgb_parse_name ()

gboolean
+gimp_rgb_parse_name (GimpRGB *rgb,
+                     const gchar *name,
+                     gint len);

Attempts to parse a color name. This function accepts SVG 1.0 +color keywords.

This function does not touch the alpha component of rgb +.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgb	a GimpRGB struct used to return the parsed color
name	a color name (in UTF-8 encoding)
len	the length of `name` +, in bytes. or -1 if `name` +is nul-terminated

Returns

TRUE if name +was parsed successfully and rgb +has +been set, FALSE otherwise

Since: 2.2

gimp_rgb_parse_hex ()

gboolean
+gimp_rgb_parse_hex (GimpRGB *rgb,
+                    const gchar *hex,
+                    gint len);

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 +.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgb	a GimpRGB struct used to return the parsed color
hex	a string describing a color in hexadecimal notation
len	the length of `hex` +, in bytes. or -1 if `hex` +is nul-terminated

Returns

TRUE if hex +was parsed successfully and rgb +has +been set, FALSE otherwise

Since: 2.2

gimp_rgb_parse_css ()

gboolean
+gimp_rgb_parse_css (GimpRGB *rgb,
+                    const gchar *css,
+                    gint len);

Attempts to parse a string describing an RGB 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 gimp_rgb_parse_hex() +(#ff0000) or a color name as parsed by +gimp_rgb_parse_name() (red).

This function does not touch the alpha component of rgb +.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgb	a GimpRGB struct used to return the parsed color
css	a string describing a color in CSS notation
len	the length of `hex` +, in bytes. or -1 if `hex` +is nul-terminated

Returns

TRUE if css +was parsed successfully and rgb +has been +set, FALSE otherwise

Since: 2.2

gimp_rgb_list_names ()

gint
+gimp_rgb_list_names (const gchar ***names,
+                     GimpRGB **colors);

Returns the list of SVG 1.0 color +keywords that is used by gimp_rgb_parse_name().

The returned strings are const and must not be freed. Only the two +arrays are allocated dynamically. You must call g_free() on the +names + and colors + arrays when they are not any longer needed.

Parameters

+++++ + + + + + + + + + + + + +

names	return location for an array of color names
colors	return location for an array of GimpRGB structs

Returns

the number of named colors +(i.e. the length of the returned arrays)

Since: 2.2

gimp_rgb_add ()

void
+gimp_rgb_add (GimpRGB *rgb1,
+              const GimpRGB *rgb2);

gimp_rgb_subtract ()

void
+gimp_rgb_subtract (GimpRGB *rgb1,
+                   const GimpRGB *rgb2);

gimp_rgb_multiply ()

void
+gimp_rgb_multiply (GimpRGB *rgb1,
+                   gdouble factor);

gimp_rgb_distance ()

gdouble
+gimp_rgb_distance (const GimpRGB *rgb1,
+                   const GimpRGB *rgb2);

gimp_rgb_max ()

gdouble
+gimp_rgb_max (const GimpRGB *rgb);

gimp_rgb_min ()

gdouble
+gimp_rgb_min (const GimpRGB *rgb);

gimp_rgb_clamp ()

void
+gimp_rgb_clamp (GimpRGB *rgb);

gimp_rgb_gamma ()

void
+gimp_rgb_gamma (GimpRGB *rgb,
+                gdouble gamma);

gimp_rgb_luminance ()

gdouble
+gimp_rgb_luminance (const GimpRGB *rgb);

Parameters

+++++ + + + + + +

rgb

a GimpRGB struct

Returns

the luminous intensity of the range from 0.0 to 1.0.

Since: 2.4

gimp_rgb_luminance_uchar ()

guchar
+gimp_rgb_luminance_uchar (const GimpRGB *rgb);

Parameters

+++++ + + + + + +

rgb

a GimpRGB struct

Returns

the luminous intensity in the range from 0 to 255.

Since: 2.4

gimp_rgb_intensity ()

gdouble
+gimp_rgb_intensity (const GimpRGB *rgb);

gimp_rgb_intensity is deprecated and should not be used in newly-written code.

This function is deprecated! Use gimp_rgb_luminance() instead.

Parameters

+++++ + + + + + +

rgb

a GimpRGB struct

Returns

the intensity in the range from 0.0 to 1.0.

gimp_rgb_intensity_uchar ()

guchar
+gimp_rgb_intensity_uchar (const GimpRGB *rgb);

gimp_rgb_intensity_uchar is deprecated and should not be used in newly-written code.

This function is deprecated! Use gimp_rgb_luminance_uchar() instead.

Parameters

+++++ + + + + + +

rgb

a GimpRGB struct

Returns

the intensity in the range from 0 to 255.

gimp_rgb_composite ()

void
+gimp_rgb_composite (GimpRGB *color1,
+                    const GimpRGB *color2,
+                    GimpRGBCompositeMode mode);

gimp_rgba_set ()

void
+gimp_rgba_set (GimpRGB *rgba,
+               gdouble red,
+               gdouble green,
+               gdouble blue,
+               gdouble alpha);

Sets the red, green, blue and alpha components of rgb +. The values +should be between 0.0 and 1.0 but there is no check to enforce this +and the values are set exactly as they are passed in.

Parameters

+++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + +

rgba	a GimpRGB struct
red	the red component
green	the green component
blue	the blue component
alpha	the alpha component

gimp_rgba_set_pixel ()

void
+gimp_rgba_set_pixel (GimpRGB *rgba,
+                     const Babl *format,
+                     gconstpointer pixel);

Sets the red, green, blue and alpha components of rgba + from the +color stored in pixel +. The pixel format of pixel + is determined +by format +.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgba	a GimpRGB struct
format	a Babl format
pixel	pointer to the source pixel

Since: 2.10

gimp_rgba_get_pixel ()

void
+gimp_rgba_get_pixel (const GimpRGB *rgba,
+                     const Babl *format,
+                     gpointer pixel);

Writes the red, green, blue and alpha components of rgba + to the +color stored in pixel +. The pixel format of pixel + is determined by +format +.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgba	a GimpRGB struct
format	a Babl format
pixel	pointer to the destination pixel

Since: 2.10

gimp_rgba_set_uchar ()

void
+gimp_rgba_set_uchar (GimpRGB *rgba,
+                     guchar red,
+                     guchar green,
+                     guchar blue,
+                     guchar alpha);

Sets the red, green, blue and alpha components of rgb + from 8bit +values (0 to 255).

Parameters

+++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + +

rgba	a GimpRGB struct
red	the red component
green	the green component
blue	the blue component
alpha	the alpha component

gimp_rgba_get_uchar ()

void
+gimp_rgba_get_uchar (const GimpRGB *rgba,
+                     guchar *red,
+                     guchar *green,
+                     guchar *blue,
+                     guchar *alpha);

gimp_rgba_parse_css ()

gboolean
+gimp_rgba_parse_css (GimpRGB *rgba,
+                     const gchar *css,
+                     gint len);

Similar to gimp_rgb_parse_css() but handles RGB colors with alpha +channel in the numerical CSS notation (rgba(255,0,0,255) +or rgba(100%,0%,0%,1000%)).

It doesn't handle the hexadecimal notation or color names because +they leave the alpha channel unspecified.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

rgba	a GimpRGB struct used to return the parsed color
css	a string describing a color in CSS notation
len	the length of `hex` +, in bytes. or -1 if `hex` +is nul-terminated

Returns

TRUE if css +was parsed successfully and rgb +has been +set, FALSE otherwise

Since: 2.2

gimp_rgba_add ()

void
+gimp_rgba_add (GimpRGB *rgba1,
+               const GimpRGB *rgba2);

gimp_rgba_subtract ()

void
+gimp_rgba_subtract (GimpRGB *rgba1,
+                    const GimpRGB *rgba2);

gimp_rgba_multiply ()

void
+gimp_rgba_multiply (GimpRGB *rgba,
+                    gdouble factor);

gimp_rgba_distance ()

gdouble
+gimp_rgba_distance (const GimpRGB *rgba1,
+                    const GimpRGB *rgba2);

GIMP_RGB_LUMINANCE()

#define             GIMP_RGB_LUMINANCE(r,g,b)

GIMP_RGB_INTENSITY()

#define             GIMP_RGB_INTENSITY(r,g,b)

GIMP_RGB_INTENSITY is deprecated and should not be used in newly-written code.

gimp_param_spec_rgb ()

GParamSpec *
+gimp_param_spec_rgb (const gchar *name,
+                     const gchar *nick,
+                     const gchar *blurb,
+                     gboolean has_alpha,
+                     const GimpRGB *default_value,
+                     GParamFlags flags);

Creates a param spec to hold an GimpRGB value. +See g_param_spec_internal() for more information.

Parameters

+++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

name	Canonical name of the param
nick	Nickname of the param
blurb	Brief description of param.
has_alpha	`TRUE` if the alpha channel has relevance.
default_value	Value to use if none is assigned.
flags	a combination of GParamFlags

Returns

a newly allocated GParamSpec instance

Since: 2.4

gimp_param_spec_rgb_get_default ()

void
+gimp_param_spec_rgb_get_default (GParamSpec *pspec,
+                                 GimpRGB *default_value);

Returns the pspec +'s default color value.

Parameters

+++++ + + + + + + + + + + + + +

pspec	a GimpParamSpecRGB.
default_value	return location for `pspec` +'s default value

Since: 2.10.14

gimp_param_spec_rgb_has_alpha ()

gboolean
+gimp_param_spec_rgb_has_alpha (GParamSpec *pspec);

Parameters

+++++ + + + + + +

pspec

a GParamSpec to hold an GimpRGB value.

Returns

TRUE if the alpha channel is relevant.

Since: 2.4

GIMP_VALUE_HOLDS_RGB()

#define GIMP_VALUE_HOLDS_RGB(value) (G_TYPE_CHECK_VALUE_TYPE ((value), GIMP_TYPE_RGB))
+

gimp_value_get_rgb ()

void
+gimp_value_get_rgb (const GValue *value,
+                    GimpRGB *rgb);

gimp_value_set_rgb ()

void
+gimp_value_set_rgb (GValue *value,
+                    const GimpRGB *rgb);

Types and Values

struct GimpRGB

struct GimpRGB {
+  gdouble r, g, b, a;
+};
+

Used to keep RGB and RGBA colors. All components are in a range of +[0.0..1.0].

Members

+++++ + + + + + + + + + + + + + + + + + + + + + + +

gdouble `r`;	the red component
gdouble `g`;	the green component
gdouble `b`;	the blue component
gdouble `a`;	the alpha component

enum GimpRGBCompositeMode

Members

+++++ + + + + + + + + + + + + + + + + + +

GIMP_RGB_COMPOSITE_NONE	+ don't do compositing +
GIMP_RGB_COMPOSITE_NORMAL	+ composite on top +
GIMP_RGB_COMPOSITE_BEHIND	+ composite behind +

GIMP_RGB_LUMINANCE_RED

#define GIMP_RGB_LUMINANCE_RED    (0.22248840)
+

GIMP_RGB_LUMINANCE_GREEN

#define GIMP_RGB_LUMINANCE_GREEN  (0.71690369)
+

GIMP_RGB_LUMINANCE_BLUE

#define GIMP_RGB_LUMINANCE_BLUE   (0.06060791)
+

GIMP_RGB_INTENSITY_RED

#define GIMP_RGB_INTENSITY_RED    (0.30)
+

GIMP_RGB_INTENSITY_RED is deprecated and should not be used in newly-written code.

GIMP_RGB_INTENSITY_GREEN

#define GIMP_RGB_INTENSITY_GREEN  (0.59)
+

GIMP_RGB_INTENSITY_GREEN is deprecated and should not be used in newly-written code.

GIMP_RGB_INTENSITY_BLUE

#define GIMP_RGB_INTENSITY_BLUE   (0.11)
+

GIMP_RGB_INTENSITY_BLUE is deprecated and should not be used in newly-written code.

GIMP_TYPE_RGB

#define GIMP_TYPE_RGB               (gimp_rgb_get_type ())
+

GIMP_TYPE_PARAM_RGB

#define GIMP_TYPE_PARAM_RGB           (gimp_param_rgb_get_type ())
+