doodle::Color Class Reference

Color is a color represented with four unsigned bytes. More...

#include <doodle/color.hpp>

Public Member Functions
constexpr	Color () noexcept=default
	The default color is black with full opacity. More...
constexpr	Color (double grey, double alpha=255) noexcept
	Note that if only one value is provided to Color, it will be interpreted as a grayscale value. Add a second value, and it will be used for alpha transparency. More...
constexpr	Color (double red, double green, double blue, double alpha=255) noexcept
	When three values are specified, they are interpreted as RGB. Adding a fourth value applies alpha transparency. More...

Public Attributes
double	red = 0
double	green = 0
double	blue = 0
double	alpha = 255

Detailed Description

Color is a color represented with four unsigned bytes.

It has the red, green, blue, and alpha color channels in the range of 0 to 255, where 255 is full intensity of the color channel, 128 is roughly half intensity and 0 is no intensity of the color channel. The alpha channel doesn't contribute light intensity but is used to define transparency. The alpha value also uses the range 0 to 255 to set the amount of transparency. The value 0 defines the color as entirely transparent (it won't display), the value 255 is entirely opaque, and the values between these extremes cause the colors to mix on the screen.

#include <doodle/doodle.hpp>
using namespace doodle;
int main(void)
{
    create_window(100, 100);
    set_outline_width(3.0);
    Color squareColor{100, 50, 150};
    while (!is_window_closed())
    {
        update_window();
        clear_background(255);
        no_fill();
        set_outline_color(0);
        draw_ellipse(0, 0, 80.f);
        squareColor.alpha = 128 + 128.0 * std::sin(ElapsedTime);
        set_fill_color(squareColor);
        no_outline();
        draw_rectangle(-Width / 2.0 + 13, -Height / 2.0 + 13, Width - 26.0, Height - 26.0);
    }
    return 0;
}

Definition at line 52 of file color.hpp.

Constructor & Destructor Documentation

Color() [1/3]

constexpr doodle::Color::Color ( )

constexprdefaultnoexcept

The default color is black with full opacity.

#include <doodle/doodle.hpp>
using namespace doodle;
int main(void)
{
    create_window(100, 100);
    no_outline();
    while (!is_window_closed())
    {
        update_window();
        clear_background(220);
        set_fill_color(Color{}); // default is black color
        draw_ellipse(0, 0, 35);
    }
    return 0;
}

Color() [2/3]

constexpr doodle::Color::Color ( double  grey, double  alpha = 255  )

inlineexplicitconstexprnoexcept

Note that if only one value is provided to Color, it will be interpreted as a grayscale value. Add a second value, and it will be used for alpha transparency.

Parameters

grey	number specifying value between white and black
alpha	alpha value relative to color range 0-255

#include <doodle/doodle.hpp>
using namespace doodle;
int main(void)
{
    create_window(100, 100);
    no_outline();
    while (!is_window_closed())
    {
        update_window();
        clear_background(Color{220});
        set_fill_color(Color{255});
        draw_rectangle(-20, -20, 35, 35);
        set_fill_color(Color{100, 128});
        draw_rectangle(0, 0, 35, 35);
    }
    return 0;
}

Definition at line 111 of file color.hpp.

            : red(grey), green(grey), blue(grey), alpha(alpha)
        {
        }

Color() [3/3]

constexpr doodle::Color::Color ( double  red, double  green, double  blue, double  alpha = 255  )

inlineconstexprnoexcept

When three values are specified, they are interpreted as RGB. Adding a fourth value applies alpha transparency.

Parameters

red	red value relative to the color range 0-255
green	value relative to the color range 0-255
blue	value relative to the color range 0-255
alpha	alpha value relative to color range 0-255

#include <doodle/doodle.hpp>
using namespace doodle;
int main(void)
{
    create_window(100, 100);
    no_outline();
    constexpr Color yellow{255, 204, 0};
    constexpr Color transparent_green{220, 236, 165, 120};
    while (!is_window_closed())
    {
        update_window();
        clear_background(220);
        set_fill_color(yellow);
        draw_ellipse(-20, 20, 80);
        set_fill_color(transparent_green);
        draw_ellipse(15, -15, 80);
    }
    return 0;
}

Definition at line 147 of file color.hpp.

            : red(red), green(green), blue(blue), alpha(alpha)
        {
        }

Member Data Documentation

alpha

double doodle::Color::alpha = 255

Definition at line 58 of file color.hpp.

blue

double doodle::Color::blue = 0

Definition at line 57 of file color.hpp.

green

double doodle::Color::green = 0

Definition at line 56 of file color.hpp.

red

double doodle::Color::red = 0

Definition at line 55 of file color.hpp.

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The documentation for this class was generated from the following file:

• include/doodle/color.hpp