Unit al5color

Returns the (compiled) version of the addon, in the same format as al_get_allegro_version.

Converts values in HSV color model to RGB color model.

Parameters

h

Color hue angle in the range 0..360.

s

Color saturation in the range 0..1.

v

Color value in the range 0..1.

r

Returns the R (red) value in the range 0..1.

g

Returns the G (green) value in the range 0..1.

b

Returns the B (blue) value in the range 0..1.

See also

al_color_rgb_to_hsv

Given an RGB triplet with components in the range 0..1, returns the hue in degrees from 0..360 and saturation and value in the range 0..1.

al_color_hsv

Returns an ALLEGRO_COLOR structure from HSV (hue, saturation, value) values.

al_color_hsl_to_rgb

Converts values in HSL color model to RGB color model.

Given an RGB triplet with components in the range 0..1, returns the hue in degrees from 0..360 and saturation and lightness in the range 0..1.

See also

al_color_hsl_to_rgb

Converts values in HSL color model to RGB color model.

al_color_hsl

Returns an ALLEGRO_COLOR structure from HSL (hue, saturation, lightness) values.

Given an RGB triplet with components in the range 0..1, returns the hue in degrees from 0..360 and saturation and value in the range 0..1.

See also

al_color_hsv_to_rgb

Converts values in HSV color model to RGB color model.

al_color_hsv

Returns an ALLEGRO_COLOR structure from HSV (hue, saturation, value) values.

Converts values in HSL color model to RGB color model.

Parameters

h

Color hue angle in the range 0..360.

s

Color saturation in the range 0..1.

l

Color lightness in the range 0..1.

r

Returns the R (red) value in the range 0..1.

g

Returns the G (green) value in the range 0..1.

b

Returns the B (blue) value in the range 0..1.

See also

al_color_rgb_to_hsl

Given an RGB triplet with components in the range 0..1, returns the hue in degrees from 0..360 and saturation and lightness in the range 0..1.

al_color_hsl

Returns an ALLEGRO_COLOR structure from HSL (hue, saturation, lightness) values.

al_color_hsv_to_rgb

Converts values in HSV color model to RGB color model.

Given a name, returns the RGB triplet.

The 148 recognized names are:

aliceblue, antiquewhite, aqua, aquamarine, azure, beige, bisque, black, blanchedalmond, blue, blueviolet, brown, burlywood, cadetblue, chartreuse, chocolate, coral, cornflowerblue, cornsilk, crimson, cyan, darkblue, darkcyan, darkgoldenrod, darkgray, darkgreen, darkkhaki, darkmagenta, darkolivegreen, darkorange, darkorchid, darkred, darksalmon, darkseagreen, darkslateblue, darkslategray, darkturquoise, darkviolet, deeppink, deepskyblue, dimgray, dodgerblue, firebrick, floralwhite, forestgreen, fuchsia, gainsboro, ghostwhite, goldenrod, gold, gray, green, greenyellow, honeydew, hotpink, indianred, indigo, ivory, khaki, lavenderblush, lavender, lawngreen, lemonchiffon, lightblue, lightcoral, lightcyan, lightgoldenrodyellow, lightgreen, lightgrey, lightpink, lightsalmon, lightseagreen, lightskyblue, lightslategray, lightsteelblue, lightyellow, lime, limegreen, linen, magenta, maroon, mediumaquamarine, mediumblue, mediumorchid, mediumpurple, mediumseagreen, mediumslateblue, mediumspringgreen, mediumturquoise, mediumvioletred, midnightblue, mintcream, mistyrose, moccasin, avajowhite, navy, oldlace, olive, olivedrab, orange, orangered, orchid, palegoldenrod, palegreen, paleturquoise, palevioletred, papayawhip, peachpuff, peru, pink, plum, powderblue, purple, rebeccapurple, red, rosybrown, royalblue, saddlebrown, salmon, sandybrown, seagreen, seashell, sienna, silver, skyblue, slateblue, slategray, snow, springgreen, steelblue, tan, teal, thistle, tomato, turquoise, violet, wheat, white, whitesmoke, yellow, yellowgreen

They are taken from CSS: https://www.w3.org/TR/css-color-4/.

Note that these 9 colors have two names and so there are only 139 distinct colors: aqua = cyan, darkgray = darkgrey, darkslategray = darkslategrey, dimgray = dimgrey, fuchsia = purple, gray = grey, lightgray = lightgrey, lightslategray = lightslategrey, slategray = slategrey

Parameters

name

The lowercase name of the color.

r

Returns the R (red) value in the range 0..1.

g

Returns the G (green) value in the range 0..1.

b

Returns the B (blue) value in the range 0..1.

Returns

True if a name from the list above was passed, else False.

See also

al_color_name

Returns an ALLEGRO_COLOR with the given name.

al_color_rgb_to_name

Given an RGB triplet with components in the range 0..1, find a color name describing it approximately.

Given an RGB triplet with components in the range 0..1, find a color name describing it approximately.

See also

al_color_name_to_rgb

Given a name, returns the RGB triplet.

al_color_name

Returns an ALLEGRO_COLOR with the given name.

Converts CMYK values to RGB values.

See also

al_color_cmyk

Returns an ALLEGRO_COLOR structure from CMYK values (cyan, magenta, yellow, black).

al_color_rgb_to_cmyk

Each RGB color can be represented in CMYK with a K component of 0 with the following formula:

C = 1 - R
M = 1 - G
Y = 1 - B
K = 0

This function will instead find the representation with the maximal value for K and minimal color components.

Each RGB color can be represented in CMYK with a K component of 0 with the following formula:

C = 1 - R
M = 1 - G
Y = 1 - B
K = 0

This function will instead find the representation with the maximal value for K and minimal color components.

See also

al_color_cmyk

Returns an ALLEGRO_COLOR structure from CMYK values (cyan, magenta, yellow, black).

al_color_cmyk_to_rgb

Converts CMYK values to RGB values.

Converts YUV color values to RGB color space.

See also

al_color_yuv

Returns an ALLEGRO_COLOR structure from YUV values.

al_color_rgb_to_yuv

Converts RGB values to YUV color space.

Converts RGB values to YUV color space.

See also

al_color_yuv

Returns an ALLEGRO_COLOR structure from YUV values.

al_color_yuv_to_rgb

Converts YUV color values to RGB color space.

Creates an HTML-style string representation of an RGB triplet, e.g. #00FAFF.

Example:

VAR
  HTMLstring: STRING;
BEGIN
  HTMLstring := al_color_rgb_to_html (1, 0, 0);

Now HTMLstring will contain "#ff0000".

See also

al_color_html

Interprets an HTML-style hex number (e.g.

al_color_html_to_rgb

Interprets an HTML-style hex number (e.g.

Interprets an HTML-style hex number (e.g. #00FAFF) as a color. The only accepted formats are "#RRGGBB" and "RRGGBB" where R, G, B are hexadecimal digits [0-9A-Fa-f].

Note

the behaviour on invalid strings is different from Allegro 5.0.x.

Returns

True on success, False on failure. On failure all components are set to zero.

See also

al_color_html

Interprets an HTML-style hex number (e.g.

al_color_rgb_to_html

Creates an HTML-style string representation of an RGB triplet, e.g.

Returns an ALLEGRO_COLOR structure from YUV values.

See also

al_color_yuv_to_rgb

Converts YUV color values to RGB color space.

al_color_rgb_to_yuv

Converts RGB values to YUV color space.

Returns an ALLEGRO_COLOR structure from CMYK values (cyan, magenta, yellow, black).

See also

al_color_cmyk_to_rgb

Converts CMYK values to RGB values.

al_color_rgb_to_cmyk

Each RGB color can be represented in CMYK with a K component of 0 with the following formula:

C = 1 - R
M = 1 - G
Y = 1 - B
K = 0

This function will instead find the representation with the maximal value for K and minimal color components.

Returns an ALLEGRO_COLOR structure from HSL (hue, saturation, lightness) values.

Parameters

h

Color hue angle in the range 0..360.

s

Color saturation in the range 0..1.

l

Color lightness in the range 0..1.

See also

al_color_hsl_to_rgb

Converts values in HSL color model to RGB color model.

al_color_hsv

Returns an ALLEGRO_COLOR structure from HSV (hue, saturation, value) values.

Returns an ALLEGRO_COLOR structure from HSV (hue, saturation, value) values.

Parameters

h

Color hue angle in the range 0..360.

s

Color saturation in the range 0..1.

v

Color value in the range 0..1.

See also

al_color_hsv_to_rgb

Converts values in HSV color model to RGB color model.

al_color_hsl

Returns an ALLEGRO_COLOR structure from HSL (hue, saturation, lightness) values.

Returns an ALLEGRO_COLOR with the given name. If the color is not found then black is returned.

See al_color_name_to_rgb for the list of names.

Interprets an HTML-style hex number (e.g. #00FAFF as a color. The accepted format is the same as al_color_html_to_rgb.

Note

the behaviour on invalid strings is different from Allegro 5.0.x.

Returns

the interpreted color, or al_map_rgba (0, 0, 0, 0) if the string could not be parsed.

See also

al_color_html_to_rgb

Interprets an HTML-style hex number (e.g.

al_color_rgb_to_html

Creates an HTML-style string representation of an RGB triplet, e.g.

Converts XYZ color values to RGB color space.

See also

al_color_xyz

Returns an ALLEGRO_COLOR structure from XYZ values.

al_color_rgb_to_xyz

Converts RGB values to XYZ color space.

Converts RGB values to XYZ color space.

See also

al_color_xyz

Returns an ALLEGRO_COLOR structure from XYZ values.

al_color_xyz_to_rgb

Converts XYZ color values to RGB color space.

Returns an ALLEGRO_COLOR structure from XYZ values. The CIE 1931 XYZ color space consists of three components in the range 0..1. The Y component corresponds to luminance and the X and Z components define the color.

RGB components are always assumed to be in sRGB space.

Note

The XYZ color space can represent more colors than are visible in sRGB and therefore conversion may result in RGB values outside of the 0..1 range. You can check for that case with al_is_color_valid.

See also

al_color_xyz_to_rgb

Converts XYZ color values to RGB color space.

al_color_rgb_to_xyz

Converts RGB values to XYZ color space.

Converts CIE L*a*b* color values to RGB color space.

See also

al_color_lab

Returns an ALLEGRO_COLOR structure from CIE L*a*b* values.

al_color_rgb_to_lab

Converts RGB values to L*a*b color space.

Converts RGB values to L*a*b color space.

See also

al_color_lab

Returns an ALLEGRO_COLOR structure from CIE L*a*b* values.

al_color_lab_to_rgb

Converts CIE L*a*b* color values to RGB color space.

Returns an ALLEGRO_COLOR structure from CIE L*a*b* values. The L* component corresponds to luminance from 0..1. The a* and b* components are in the range -1..+1.

Note

The L*a*b* color space can represent more colors than are visible in sRGB and therefore conversion may result in RGB values outside of the 0..1 range. You can check for that case with al_is_color_valid.

Note

In some literature the range of L* is 0 to 100 and a* and b* are from -100 to +100. In that case divide all components by 100 before passing them to this function.

See also

al_color_lab_to_rgb

Converts CIE L*a*b* color values to RGB color space.

al_color_rgb_to_lab

Converts RGB values to L*a*b color space.

Converts xyY color values to RGB color space.

See also

al_color_xyy

Returns an ALLEGRO_COLOR structure from xyY values.

al_color_rgb_to_xyy

Converts RGB values to xyY color space.

Converts RGB values to xyY color space.

See also

al_color_xyy

Returns an ALLEGRO_COLOR structure from xyY values.

al_color_xyy_to_rgb

Converts xyY color values to RGB color space.

Returns an ALLEGRO_COLOR structure from xyY values. The Y component in the xyY color space is the same as the Y in XYZ.

However the x and y values are computed from XYZ like this:

x = X / (X + Y + Z)
y = Y / (X + Y + Z)

See also

al_color_xyy_to_rgb

Converts xyY color values to RGB color space.

al_color_rgb_to_xyy

Converts RGB values to xyY color space.

This function computes the CIEDE2000 color difference between two RGB colors. This is a visually uniform color difference, unlike for example the RGB distance.

When using the RGB distance (Euklidean distance between two RGB triplets) there can be color pairs with the same distance, where the colors of one pair appear to be almost the same color, while the colors of the other pair look quite different. This is improved by using the L*a*b* color space which was designed with perceptual uniformity in mind. However it still is not completely uniform. The CIEDE2000 formula contains some additional transformations to fix that.

The returned color distance is roughly in the range 0 (identical color) to 1 (completely different color) - but values greater than one are possible.

Note

This function uses al_color_lab internally which defines the L component to be in the range 0..1 (and not 0..100 as is sometimes seen).

Converts CIE LCH color values to RGB color space.

See also

al_color_lch

Returns an ALLEGRO_COLOR structure from CIE LCH values.

al_color_rgb_to_lch

Convert RGB values to CIE LCH color space.

Convert RGB values to CIE LCH color space.

See also

al_color_lch

Returns an ALLEGRO_COLOR structure from CIE LCH values.

al_color_lch_to_rgb

Converts CIE LCH color values to RGB color space.

Returns an ALLEGRO_COLOR structure from CIE LCH values. LCH colors are very similar to HSL, with the same meaning of L and H and C corresponding to S. However LCH is more visually uniform. Furthermore, this function expects the angle for H in radians and not in degree.

The CIE LCH color space is a cylindrical representation of the L*a*b* color space. The L component is the same and C and H are computed like this:

C = sqrt (a * a + b * b)
H = atan2 (b, a)

See also

al_color_lch_to_rgb

Converts CIE LCH color values to RGB color space.

al_color_rgb_to_lch

Convert RGB values to CIE LCH color space.

Checks if all components of the color are between 0 and 1. Some of the color conversions in this addon support color spaces with more colors than can be represented in sRGB and when converted to RGB will result in invalid color components outside the 0..1 range.

Converts linear sRGB color values to gamma corrected (i.e. normal) RGB values.

See also

al_color_linear

Returns an ALLEGRO_COLOR structure from linear sRGB values.

al_color_rgb_to_linear

Converts gamma corrected sRGB values (i.e.

Converts gamma corrected sRGB values (i.e. normal RGB) to linear sRGB space.

See also

al_color_linear

Returns an ALLEGRO_COLOR structure from linear sRGB values.

al_color_linear_to_rgb

Converts linear sRGB color values to gamma corrected (i.e.

Returns an ALLEGRO_COLOR structure from linear sRGB values. Allegro RGB values are assumed to be sRGB. The sRGB standard is in wide use by various display devices. It accounts for a standard gamma correction applied to RGB colors before they get displayed.

Gamma correction means if for example we have a medium gray color specified with al_map_rgb_f (0.5,0.5,0.5) then we do not want the monitor to set the pixel to exactly half the physical maximum intensity, but instead to an intensity that appears to be half as bright as the maximum to the person looking at it. In this case that would be closer to 21% of maximum intensity rather than to 50% intensity.

For some applications it may be useful to specify a color in linear sRGB components, in which case you can use this function. For example:

var
  Gray: ALLEGRO_COLOR;
  Htm: String;
begin
  ...
  gray = al_color_linear (0.216, 0.216, 0.216);
  al_color_rgb_to_html (gray.r, gray.g, gray.b, html); { #808080 }
  ...
end.

See also

al_color_linear_to_rgb

Converts linear sRGB color values to gamma corrected (i.e.

al_color_rgb_to_linear

Converts gamma corrected sRGB values (i.e.