Styles, colors and color maps

Style

By default, the drawn shapes will have a black edge and no fill. a StyleProperties object can be passed as an additionnal argument to change it.

Predefined styles are available in the StyleProperties class:

inside() : black edge, green fill
outside() : black edge, cyan fill
boundary() : black edge, yellow fill

A StyleProperties object is composed of two Color objects, one for the edge and one for the fill. Three constructors are available:

default_style = StyleProperties() # default
edge_style = StyleProperties(Color.red()) # edge only
edge_fill_style = StyleProperties([Color.blue(),Color.green()]) # edge and fill

StyleProperties default_style;
StyleProperties edge_style(Color::red()); // edge only
StyleProperties edge_fill_style({Color::blue(),Color::green()}); // edge and fill

It can also be deduced from one or two Color objects.

fig.draw_box([[2.2,2.5],[2.2,2.5]]) # Default style
fig.draw_box([[2.2,2.5],[2.2,2.5]],StyleProperties.inside()) # black edge, green fill
fig.draw_box([[2.2,2.5],[2.2,2.5]],Color.red()) # red edge, no fill
fig.draw_box([[2.2,2.5],[2.2,2.5]],[Color.blue(),Color.green()]) # blue edge, green fill

fig.draw_box({{2.2,2.5},{2.2,2.5}}); // Default style
fig.draw_box({{2.2,2.5},{2.2,2.5}},StyleProperties::inside()); // black edge, green fill
fig.draw_box({{2.2,2.5},{2.2,2.5}},Color::red()); // red edge, no fill
fig.draw_box({{2.2,2.5},{2.2,2.5}},{Color::blue(),Color::green()}); // blue edge, green fill

Colors

Predefined colors are available in the Color class. Each of the static methods can take an argument to define the transparency of the color between 0 (full transparency) and 1 (full opacity).

Color.none() # transparent
Color.black() # black
Color.white() # white
Color.green() # green
Color.blue() # blue
Color.cyan() # cyan
Color.yellow() # yellow
Color.red() # red
Color.dark_gray() # dark gray
Color.purple() # purple
Color.dark_green() # dark green

Color::none(); // transparent
Color::black(); // black
Color::white(); // white
Color::green(); // green
Color::blue(); // blue
Color::cyan(); // cyan
Color::yellow(); // yellow
Color::red(); // red
Color::dark_gray(); // dark gray
Color::purple(); // purple
Color::dark_green(); // dark green

Custom colors can be defined in the RGB or HSV color spaces. An enumaration Model is used to make the distinction between the two.

Model.RGB # RGB color space
Model.HSV # HSV color space

Model::RGB; // RGB color space
Model::HSV; // HSV color space

A getter model() is available, and the methods rgb() and hsv() are used to do the conversion between the two color spaces.

If the color is in RGB the red, green, blue and alpha values are between 0 and 255. If the color is in HSV the hue value is between 0 and 360 while the saturation, value and alpha values are between 0 and 100.

The Color class constructor can take different arguments:

No argument : black color
An array of 3 floats and a Model (default is RGB): the RGB or HSV values
An array of 4 floats and a Model (default is RGB): the RGBA or HSVA values and the transparency
A list of 3 or 4 floats and a Model (default is RGB): the RGB, HSV, RGBA or HSVA values
A string : the html representation of the color (e.g. “#FF0000” for red)

Additionnal methods are available for any useful purpose:

hex_str() : the html representation of the color
vec() : the RGBA or HSVA values in a vector

Color creation example :

# predefined colors without and with opacity
fig.draw_point([2,2], [Color.red(),Color.yellow(0.5)])
# HTML color without and with opacity
fig.draw_box([[2.4,2.9],[2.4,2.9]],[Color("#da3907"),Color("#da390755")])
# HSV color without and with opacity
fig.draw_box([[2.6,3.1],[2.6,3.1]],[Color([108,90,78],Model.HSV),Color([108,90,78,20],Model.HSV)])
# RGB color auto cast from list without and with opacity
fig.draw_box([[2.,2.3],[2.6,2.9]],[[255,0,255],[255,0,255,100]])

// predefined colors without and with opacity
fig.draw_point({2,2}, {Color::red(),Color::yellow(0.5)});
// HTML color without and with opacity
fig2.draw_box({{2.4,2.9},{2.4,2.9}},{Color("#da3907"),Color("#da390755")});
// HSV color without and with opacity
fig2.draw_box({{2.6,3.1},{2.6,3.1}},{Color({108,90,78},Model::HSV),Color({108,90,78,20},Model::HSV)});

Color maps

Color maps are used to convert a scalar value (between 0 and 1) to a color. The ColorMap class provides a set of predefined color maps:

basic() : the default ColorMap
haxby() : the Haxby color map
rainbow() : the rainbow color map
blue_tube() : a blue color map, used mainly for tubes
red_tube() : a red color map, used mainly for tubes

These five color maps are displayed below:

The method color() is used to get the color corresponding to a scalar value. The argument is a float between 0 and 1.

As for the Color class, the ColorMap also has a Model (RGB or HSV) and an associated getter model(). The default Model is RGB.

You can also create your own color map :

# Create a custom color map
custom_map = ColorMap(Model.RGB)
custom_map[0] = Color([255,0,0])
custom_map[0.5] = Color([0,255,0])
custom_map[1] = Color([0,0,255])

// Create a custom color map
ColorMap custom_map (Model::RGB);
custom_map[0] = Color({255,0,0});
custom_map[0.5] = Color({0,255,0});
custom_map[1] = Color({0,0,255});

Note that you can add RGB and HSV colors to the same color map. The model of the color map will define the interpolation space.