Color

RGBA color struct with utility methods and named color constants.

Header: #include <asw/modules/color.h>
Namespace: asw

Color Struct

struct Color {
  uint8_t r, g, b, a;
};

Constructors

Color();                                        // Black, fully opaque (0,0,0,255)
Color(uint8_t r, uint8_t g, uint8_t b, uint8_t a = 255);

Static Constructors

from_float

static Color from_float(float r, float g, float b, float a = 1.0F);

Create a color from float values (0.0 - 1.0).

from_hex

static Color from_hex(const std::string& hex);

Create a color from a hex string. Supports #RRGGBB and #RRGGBBAA formats. Returns opaque black on invalid input, including hex digits that are not valid.

to_fcolor

FColor to_fcolor() const;

Convert to an FColor, with each channel from 0.0 to 1.0. asw::FColor is an alias of SDL_FColor, for SDL functions that take float colors.

to_channel

static uint8_t to_channel(float value);

Round a 0 - 255 channel value and clamp it into range. Use it instead of static_cast<uint8_t>, which is undefined for values out of range.

Methods

lighten

Color lighten(float percentage) const;

Lighten the color by a percentage (0.0 - 1.0). Values outside this range are clamped. Alpha does not change.

darken

Color darken(float percentage) const;

Darken the color by a percentage (0.0 - 1.0). Values outside this range are clamped. Alpha does not change.

lerp

Color lerp(const Color& color, float t) const;

Mix toward another color, including alpha. t goes from 0.0 (this color) to 1.0 (color). Values outside this range are clamped.

blend

Color blend(const Color& color) const;

Alpha-blend this color over another.

invert

Color invert() const;

Return the inverted color (preserves alpha).

grayscale

Color grayscale() const;

Convert to grayscale using perceptual luminance weights.

with_alpha

Color with_alpha(uint8_t alpha) const;

Return a copy with a different alpha value.

Named Constants

Available in the asw::color namespace.

Basic Colors

black, silver, gray, white, maroon, red, purple, fuchsia, green, lime, olive, yellow, navy, blue, teal, aqua

Extended Colors

All CSS named colors are available, including: coral, crimson, cyan, darkblue, dodgerblue, gold, hotpink, indigo, ivory, khaki, lavender, magenta, orange, pink, salmon, skyblue, tomato, turquoise, violet, and many more.

Special

Constant	Value
asw::color::transparent	#00000000 (fully transparent)

Example

// Construct colors
asw::Color red(255, 0, 0);
asw::Color semi = asw::Color(255, 255, 255, 128);
auto sky = asw::Color::from_hex("#87CEEB");
auto half = asw::Color::from_float(1.0f, 0.5f, 0.0f, 0.5f);

// Use named constants
asw::draw::rect_fill(quad, asw::color::coral);
asw::draw::circle_fill(pos, 10.0f, asw::color::white.with_alpha(128));

// Color manipulation
auto lighter = asw::color::blue.lighten(0.3f);
auto darker = asw::color::red.darken(0.5f);
auto gray = asw::color::green.grayscale();
auto inverted = asw::color::yellow.invert();

// Fade from red to transparent blue over a particle's life
auto fade = asw::color::red.lerp(asw::color::blue.with_alpha(0), age / lifetime);