Gdk.Color render_foreground(ContrastPaletteColor symbol)
{
return(Contrast.RenderForegroundColor(get_background(), symbol));
}
Gdk.Color render_foreground(ContrastPaletteColor symbol)
{
return Contrast.RenderForegroundColor(get_background(), symbol);
}
/* Creates a specific color value for a foreground color, optimizing for
* maximum readability against the background.
*/
public static Gdk.Color RenderForegroundColor(Gdk.Color background, ContrastPaletteColor color)
{
float L, a, b;
int max_color;
float max_dist;
float[,] points = new float[8,3];
float ld, cd;
int i;
Gdk.Color rcolor = new Gdk.Color();
rgb_to_lab(background.Red, background.Green, background.Blue, out L, out a, out b);
points[0,0] = color_regions[(int)color,0];
points[0,1] = color_regions[(int)color,2];
points[0,2] = color_regions[(int)color,4];
points[1,0] = color_regions[(int)color,0];
points[1,1] = color_regions[(int)color,2];
points[1,2] = color_regions[(int)color,5];
points[2,0] = color_regions[(int)color,0];
points[2,1] = color_regions[(int)color,3];
points[2,2] = color_regions[(int)color,4];
points[3,0] = color_regions[(int)color,0];
points[3,1] = color_regions[(int)color,3];
points[3,2] = color_regions[(int)color,5];
points[4,0] = color_regions[(int)color,1];
points[4,1] = color_regions[(int)color,2];
points[4,2] = color_regions[(int)color,4];
points[5,0] = color_regions[(int)color,1];
points[5,1] = color_regions[(int)color,2];
points[5,2] = color_regions[(int)color,5];
points[6,0] = color_regions[(int)color,1];
points[6,1] = color_regions[(int)color,3];
points[6,2] = color_regions[(int)color,4];
points[7,0] = color_regions[(int)color,1];
points[7,1] = color_regions[(int)color,3];
points[7,2] = color_regions[(int)color,5];
max_dist = 0;
max_color = 0;
for (i = 0; i < 8; i++) {
float dist = lab_distance(L, a, b, points[i,0], points[i,1], points[i,2]);
if (dist > max_dist) {
max_dist = dist;
max_color = i;
}
}
/* If the luminosity distance is really short, extend the vector further
* out. This may push it outside the bounds of the region that a color
* is specified in, but it keeps things readable when the background and
* foreground are really close.
*/
ld = Math.Abs(L - points[max_color,0]);
cd = (float) Math.Sqrt (Math.Pow (Math.Abs (a - points[max_color,1]), 2.0f) + Math.Pow (Math.Abs (b - points[max_color,2]), 2.0f));
if ((ld < 10.0f) && (cd < 60.0f)) {
float dL, da, db;
dL = points[max_color,0] - L;
da = points[max_color,1] - a;
db = points[max_color,2] - b;
points[max_color,0] = L + (dL * 4.0f);
points[max_color,1] = a + (da * 1.5f);
points[max_color,2] = b + (db * 1.5f);
}
rcolor.Pixel = 0;
lab_to_rgb(points[max_color,0], points[max_color,1], points[max_color,2], out rcolor.Red, out rcolor.Green, out rcolor.Blue);
return rcolor;
}
/* Creates a specific color value for a foreground color, optimizing for
* maximum readability against the background.
*/
public static Color RenderForegroundColor(Color background, ContrastPaletteColor color)
{
float L, a, b;
int max_color;
float max_dist;
float[,] points = new float[8, 3];
float ld, cd;
int i;
rgb_to_lab((ushort)(background.R * 255), (ushort)(background.G * 255),
(ushort)(background.B * 255), out L, out a, out b);
points[0, 0] = color_regions[(int)color, 0];
points[0, 1] = color_regions[(int)color, 2];
points[0, 2] = color_regions[(int)color, 4];
points[1, 0] = color_regions[(int)color, 0];
points[1, 1] = color_regions[(int)color, 2];
points[1, 2] = color_regions[(int)color, 5];
points[2, 0] = color_regions[(int)color, 0];
points[2, 1] = color_regions[(int)color, 3];
points[2, 2] = color_regions[(int)color, 4];
points[3, 0] = color_regions[(int)color, 0];
points[3, 1] = color_regions[(int)color, 3];
points[3, 2] = color_regions[(int)color, 5];
points[4, 0] = color_regions[(int)color, 1];
points[4, 1] = color_regions[(int)color, 2];
points[4, 2] = color_regions[(int)color, 4];
points[5, 0] = color_regions[(int)color, 1];
points[5, 1] = color_regions[(int)color, 2];
points[5, 2] = color_regions[(int)color, 5];
points[6, 0] = color_regions[(int)color, 1];
points[6, 1] = color_regions[(int)color, 3];
points[6, 2] = color_regions[(int)color, 4];
points[7, 0] = color_regions[(int)color, 1];
points[7, 1] = color_regions[(int)color, 3];
points[7, 2] = color_regions[(int)color, 5];
max_dist = 0;
max_color = 0;
for (i = 0; i < 8; i++)
{
float dist = lab_distance(L, a, b, points[i, 0], points[i, 1], points[i, 2]);
if (dist > max_dist)
{
max_dist = dist;
max_color = i;
}
}
/* If the luminosity distance is really short, extend the vector further
* out. This may push it outside the bounds of the region that a color
* is specified in, but it keeps things readable when the background and
* foreground are really close.
*/
ld = Math.Abs(L - points[max_color, 0]);
cd = (float)Math.Sqrt(Math.Pow(Math.Abs(a - points[max_color, 1]), 2.0f) + Math.Pow(Math.Abs(b - points[max_color, 2]), 2.0f));
if ((ld < 10.0f) && (cd < 60.0f))
{
float dL, da, db;
dL = points[max_color, 0] - L;
da = points[max_color, 1] - a;
db = points[max_color, 2] - b;
points[max_color, 0] = L + (dL * 4.0f);
points[max_color, 1] = a + (da * 1.5f);
points[max_color, 2] = b + (db * 1.5f);
}
ushort red, green, blue;
lab_to_rgb(points[max_color, 0], points[max_color, 1], points[max_color, 2], out red, out green, out blue);
return(new Color(red / 255.0, green / 255.0, blue / 255.0));
}
