[color] Fix HLS to RGB colorspace conversion

The HLS to RGB conversion in case the S value is zero is:

  R = G = B = luminance

ClutterColor uses a byte (0 to 255) for the R, G and B channels
encoding, while luminance is expressed using a floating point value
in the closed interval [0, 1]; thus the case above becomes:

  R = G = B = (luminance * 255)

The clutter_color_from_hls() code is missing the final step of
de-normalizing the luminance value, and so it breaks the roundtrip
colorspace conversion between RGB and HLS.

Fixes bug:

  http://bugzilla.openedhand.com/show_bug.cgi?id=1695
This commit is contained in:
Emmanuele Bassi 2009-07-27 12:04:40 +01:00
parent db2fda9c43
commit ad7dcc9896

View File

@ -244,15 +244,10 @@ clutter_color_from_hls (ClutterColor *color,
hue /= 360.0;
if (luminance == 0)
{
color->red = color->green = color->blue = 0;
return;
}
if (saturation == 0)
{
color->red = color->green = color->blue = luminance;
color->red = color->green = color->blue = (luminance * 255);
return;
}
@ -271,6 +266,7 @@ clutter_color_from_hls (ClutterColor *color,
{
if (tmp3[i] < 0)
tmp3[i] += 1.0;
if (tmp3[i] > 1)
tmp3[i] -= 1.0;
@ -284,9 +280,9 @@ clutter_color_from_hls (ClutterColor *color,
clr[i] = tmp1;
}
color->red = clr[0] * 255.0;
color->red = clr[0] * 255.0;
color->green = clr[1] * 255.0;
color->blue = clr[2] * 255.0;
color->blue = clr[2] * 255.0;
}
/**