rt::color compose(const rt::color& c1, const rt::color& c2) {
rt::color inv_c1(255-c1.get_red(), 255-c1.get_green(), 255-c1.get_blue(), 255-c1.get_alpha());
return rt::color(
c2.get_red()-std::min(inv_c1.get_red(), c2.get_red()),
c2.get_green()-std::min(inv_c1.get_green(), c2.get_green()),
c2.get_blue()-std::min(inv_c1.get_blue(), c2.get_blue())
);
}
Light Light::reflect_on(const rt::color& color) const {
return Light(
color.get_red() / 255.0 * red,
color.get_green() / 255.0 * green,
color.get_blue() / 255.0 * blue
);
}
Light::Light(const rt::color& color) :
red(light_component_of_color_component(color.get_red())),
green(light_component_of_color_component(color.get_green())),
blue(light_component_of_color_component(color.get_blue())) {
}