nano-color

nano-color

HSV <-> RGB colors conversion utility library. HSV filter, coloring filter, gradients generating.

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Functions

Common parameter names

• R,G,B,A -- integer channel value (0..255);
• h -- hue value (0..359);
• s,v,a -- saturation, volume, alpha value (0..1);
• g -- gamma value;
• RGB -- [ R, G, B ];
• RGBA -- [ R, G, B, A ];
• IRGBA -- 0xRRGGBBAA;
• IRGB -- 0xRRGGBB;
• data -- array of bytes;
• addr -- offset in an array of bytes.

setGamma(g)

set Gamma correction value

rgb2hsv(R,G,B)

Converts RGB to HSV. Returns array [ h, s, v ].

hsv2rgb(h,s,v)

Returns [ R, G, B ].

hsva2rgba(h,s,v,a)

Returns [ R, G, B, A ].

rgba2hsva(R,G,B,A)

Returns [ h, s, v, a ].

rgb2hex(RGB)

Return CSS hex color string -- '#RRGGBB'.

rgba2hex(RGBA)

Return SVN hex color string -- '#RRGGBBAA'.

hex2rgb(h)

Returns [ R, G, B ]. Eats '#RGB', '#RGBA', '#RRGGBB' and '#RRGGBBAA' formats.

hex2rgba(hex)

Returns [ R, G, B, A ]. Eats '#RGB', '#RGBA', '#RRGGBB' and '#RRGGBBAA' formats.

rgb2array(IRGB)

Returns [ R, G, B ].

rgba2array(IRGBA)

Returns [ R, G, B, A ].

hsva2irgba(h,s,v,a)

Returns 0xRRGGBBAA.

put_rgb(data, addr, RGBA)

Put or mix in RGBA to the RGB bitmap array (data).

put_rgba(data, addr, RGBA)

Put or mix in RGBA to the RGBA bitmap array (data).

hsv_filter(data, addr, h, s, v)

Applyes HSV filter to the bitmap pixel.

colorify_filter(data, addr, h, s, v)

Applyes Colorify filter to the bitmap pixel.

There are special case for v < 0. A result volume will be calculated by the formula (.21*r + .72*g + .07*b) * -val.

gradient(first_pos, last_pos, stops, fn)

• {stops} -- Object with color stops like:

{ 0: '#000', 4000: '#1234', 6000: 0x33445566, 10000: [ 255, 255, 255, 255 ] }

where, keys of object should be numeric value in bounds between 0 and 10000, that means from 0 to 1.0.

• {fn(position, RGBA)} -- callback function

Example:

> var c = require('nano-color');
c.gradient(0, 10, {
		0: '#000',
		4000: '#1234',
		6000: 0x33445566,
		10000: [ 255, 255, 255, 255 ]
	}, function (pos, RGBA) {
		console.log('%s: [ %s ]', pos, RGBA.join(', '));
	});

will produce console output:

0: [ 0, 0, 0, 255 ]
1: [ 4, 9, 13, 208 ]
2: [ 9, 17, 26, 162 ]
3: [ 13, 26, 38, 115 ]
4: [ 17, 34, 51, 68 ]
4: [ 17, 34, 51, 68 ]
5: [ 34, 51, 68, 85 ]
6: [ 51, 68, 85, 102 ]
6: [ 51, 68, 85, 102 ]
7: [ 102, 115, 128, 140 ]
8: [ 153, 162, 170, 179 ]
9: [ 204, 208, 213, 217 ]
10: [ 255, 255, 255, 255 ]