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/// A simple float-based color struct. Each component should lie in 0..=1, but it can also be
/// outside that range. If outside, it will be clipped for some operations
#[derive(Debug, Copy, Clone, PartialEq, Default)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct Color {
pub r: f32,
pub g: f32,
pub b: f32,
}
impl Color {
pub const BLACK: Color = Color {
r: 0.0,
g: 0.0,
b: 0.0,
};
pub const WHITE: Color = Color {
r: 1.0,
g: 1.0,
b: 1.0,
};
pub const RED: Color = Color {
r: 1.0,
g: 0.0,
b: 0.0,
};
pub const GREEN: Color = Color {
r: 0.0,
g: 1.0,
b: 0.0,
};
pub const BLUE: Color = Color {
r: 0.0,
g: 0.0,
b: 1.0,
};
pub const CYAN: Color = Color {
r: 0.0,
g: 1.0,
b: 1.0,
};
pub const MAGENTA: Color = Color {
r: 1.0,
g: 0.0,
b: 1.0,
};
pub const YELLOW: Color = Color {
r: 1.0,
g: 1.0,
b: 0.0,
};
/// Create a new color from the given red, green, and blue components
///
/// Examples:
/// ```
/// # use launchy::Color;
/// let lime = Color::new(0.75, 1.0, 0.0);
/// let beige = Color::new(0.96, 0.96, 0.86);
/// ```
pub fn new(r: f32, g: f32, b: f32) -> Self {
Self { r, g, b }
}
/// Creates a color from a hue, starting at 0.0 (red) and ending at 1.0 (red). You can pass in
/// any number though, because the cycle repeats (think the `x` in `sin(x)`)
///
/// ```
/// # use launchy::Color;
/// let red = Color::from_hue(0.0);
/// let orange = Color::from_hue(0.1);
/// let greenish_yellow = Color::from_hue(0.2);
/// let green = Color::from_hue(0.3);
/// let cyan = Color::from_hue(0.4);
/// let light_blue = Color::from_hue(0.5);
/// let blue = Color::from_hue(0.6);
/// let purple = Color::from_hue(0.7);
/// let light_pink = Color::from_hue(0.8);
/// let strong_pink = Color::from_hue(0.9);
/// ```
pub fn from_hue(hue: f32) -> Self {
match hue * 6.0 {
hue if (0.0..1.0).contains(&hue) => Self::new(1.0, hue, 0.0), // red -> yellow
hue if (1.0..2.0).contains(&hue) => Self::new(2.0 - hue, 1.0, 0.0), // yellow -> green
hue if (2.0..3.0).contains(&hue) => Self::new(0.0, 1.0, hue - 2.0), // green -> cyan
hue if (3.0..4.0).contains(&hue) => Self::new(0.0, 4.0 - hue, 1.0), // cyan -> blue
hue if (4.0..5.0).contains(&hue) => Self::new(hue - 4.0, 0.0, 1.0), // blue -> magenta
hue if (5.0..6.0).contains(&hue) => Self::new(1.0, 0.0, 6.0 - hue), // magenta -> red
_ => {
// calculate hue % 1 and then stick the modulo-ed value in
let hue = hue.fract();
let hue = if hue < 0.0 { 1.0 + hue } else { hue };
Self::from_hue(hue)
}
}
}
/// Util function that smoothly interpolates between the following 'keyframes':
/// - 0.00 => green
/// - 0.25 => yellow
/// - 0.50 => red
/// - 0.75 => yellow
/// - 1.00 => green
///
/// and then the cycle continues.
///
/// This function is useful to create a smooth cycling gradient of colors on non-RGB devices
/// such as the Launchpad S.
pub fn red_green_color(hue: f32) -> Self {
let a = |x| {
if x < 0.25 {
4.0 * x
} else if x >= 0.75 {
4.0 - 4.0 * x
} else {
1.0
}
};
let r = a(hue.fract());
let g = a((hue + 0.5).fract());
Self::new(r, g, 0.0)
}
/// Clamp to a range of 0..=1.
///
/// If any component is below 0, it is brought up to 0. If any component is above 1, every
/// component will be multiplied by a certain value so that every component will be at most 1.
///
/// This algorithm ensures that the color hue stays the same, no matter the brightness.
///
/// ```rust
/// # use launchy::Color;
/// assert_eq!(
/// launchy::Color::new(-1.0, 1.0, 3.0).clamp(),
/// launchy::Color::new(0.0, 1.0/3.0, 1.0),
/// );
/// ```
pub fn clamp(self) -> Self {
let Self { r, g, b } = self;
let highest_component = r.max(g).max(b);
let multiplier = if highest_component > 1.0 {
1.0 / highest_component
} else {
1.0
};
let r = f32::clamp(r * multiplier, 0.0, 1.0);
let g = f32::clamp(g * multiplier, 0.0, 1.0);
let b = f32::clamp(b * multiplier, 0.0, 1.0);
Self { r, g, b }
}
/// Return a tuple of color components scaled from 0..=1 to 0..range using the same algorithm
/// as in [`Self::clamp`].
///
/// This function is used by the Canvas implementation of the Launchpads to downscale the
/// high-precision [`Color`]s to their respective color width. For example the Launchpad S only
/// supports four levels of brightness for its red and green component, respectively. Therefore,
/// the Launchpad S calls `.quantize(4)` on a given [`Color`] to derive how that color should be
/// represented on the Launchpad S LEDs.
pub fn quantize(self, range: u8) -> (u8, u8, u8) {
let Self { r, g, b } = self.clamp();
let quantize_component = |c| u8::min((c * range as f32) as u8, range - 1);
(
quantize_component(r),
quantize_component(g),
quantize_component(b),
)
}
/// Mix two colors together. The proportion of the second color is specified by
/// `proportion_of_other`.
///
/// Examples:
/// ```
/// # use launchy::Color;
/// let very_dark_red = Color::RED.mix(Color::BLACK, 0.9);
/// let orange = Color::RED.mix(Color::YELLOW, 0.5);
/// let dark_brown = Color::RED.mix(Color::YELLOW, 0.5).mix(Color::BLACK, 0.7);
/// ```
pub fn mix(self, other: Color, proportion_of_other: f32) -> Color {
other * proportion_of_other + self * (1.0 - proportion_of_other)
}
}
impl std::cmp::Eq for Color {}
impl std::ops::Mul<f32> for Color {
type Output = Self;
fn mul(self, multiplier: f32) -> Self::Output {
Self {
r: self.r * multiplier,
g: self.g * multiplier,
b: self.b * multiplier,
}
}
}
impl std::ops::Div<f32> for Color {
type Output = Self;
fn div(self, multiplier: f32) -> Self::Output {
Self {
r: self.r / multiplier,
g: self.g / multiplier,
b: self.b / multiplier,
}
}
}
impl std::ops::Add for Color {
type Output = Self;
fn add(self, other: Self) -> Self {
Self {
r: self.r + other.r,
g: self.g + other.g,
b: self.b + other.b,
}
}
}
impl std::ops::Sub for Color {
type Output = Self;
fn sub(self, other: Self) -> Self {
Self {
r: self.r - other.r,
g: self.g - other.g,
b: self.b - other.b,
}
}
}
impl std::ops::Add<f32> for Color {
type Output = Self;
fn add(self, addend: f32) -> Self {
Self {
r: self.r + addend,
g: self.g + addend,
b: self.b + addend,
}
}
}
impl std::ops::Sub<f32> for Color {
type Output = Self;
fn sub(self, subtrand /* or something like that */: f32) -> Self {
Self {
r: self.r - subtrand,
g: self.g - subtrand,
b: self.b - subtrand,
}
}
}
impl std::ops::Neg for Color {
type Output = Self;
fn neg(self) -> Self {
Self {
r: -self.r,
g: -self.g,
b: -self.b,
}
}
}
impl std::iter::Sum for Color {
fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
iter.fold(Color::BLACK, |a, b| a + b)
}
}
#[cfg(feature = "embedded-graphics")]
impl From<Color> for embedded_graphics::pixelcolor::Rgb888 {
fn from(color: Color) -> Self {
let (r, g, b) = color.quantize(255);
Self::new(r, g, b)
}
}
#[cfg(feature = "embedded-graphics")]
impl From<embedded_graphics::pixelcolor::Rgb888> for Color {
fn from(color: embedded_graphics::pixelcolor::Rgb888) -> Self {
use embedded_graphics::pixelcolor::RgbColor;
Color::new(
(color.r() as f32 + 0.5) / 256.0,
(color.g() as f32 + 0.5) / 256.0,
(color.b() as f32 + 0.5) / 256.0,
)
}
}