Explicit color conversion methods (#10321)

# Objective

Closes #10319 

## Changelog
* Added a new `Color::rgba_from_array([f32; 4]) -> Color` method.
* Added a new `Color::rgb_from_array([f32; 3]) -> Color` method.
* Added a new `Color::rgba_linear_from_array([f32; 4]) -> Color` method.
* Added a new `Color::rgb_linear_from_array([f32; 3]) -> Color` method.
* Added a new `Color::hsla_from_array([f32; 4]) -> Color` method.
* Added a new `Color::hsl_from_array([f32; 3]) -> Color` method.
* Added a new `Color::lcha_from_array([f32; 4]) -> Color` method.
* Added a new `Color::lch_from_array([f32; 3]) -> Color` method.
* Added a new `Color::rgba_to_vec4(&self) -> Vec4` method.
* Added a new `Color::rgba_to_array(&self) -> [f32; 4]` method.
* Added a new `Color::rgb_to_vec3(&self) -> Vec3` method.
* Added a new `Color::rgb_to_array(&self) -> [f32; 3]` method.
* Added a new `Color::rgba_linear_to_vec4(&self) -> Vec4` method.
* Added a new `Color::rgba_linear_to_array(&self) -> [f32; 4]` method.
* Added a new `Color::rgb_linear_to_vec3(&self) -> Vec3` method.
* Added a new `Color::rgb_linear_to_array(&self) -> [f32; 3]` method.
* Added a new `Color::hsla_to_vec4(&self) -> Vec4` method.
* Added a new `Color::hsla_to_array(&self) -> [f32; 4]` method.
* Added a new `Color::hsl_to_vec3(&self) -> Vec3` method.
* Added a new `Color::hsl_to_array(&self) -> [f32; 3]` method.
* Added a new `Color::lcha_to_vec4(&self) -> Vec4` method.
* Added a new `Color::lcha_to_array(&self) -> [f32; 4]` method.
* Added a new `Color::lch_to_vec3(&self) -> Vec3` method.
* Added a new `Color::lch_to_array(&self) -> [f32; 3]` method.

## Migration Guide
`Color::from(Vec4)` is now `Color::rgba_from_array(impl Into<[f32; 4]>)`
`Vec4::from(Color)` is now `Color::rgba_to_vec4(&self)`

Before:
```rust
let color_vec4 = Vec4::new(0.5, 0.5, 0.5);
let color_from_vec4 = Color::from(color_vec4);

let color_array = [0.5, 0.5, 0.5];
let color_from_array = Color::from(color_array);
```
After:
```rust
let color_vec4 = Vec4::new(0.5, 0.5, 0.5);
let color_from_vec4 = Color::rgba_from_array(color_vec4);

let color_array = [0.5, 0.5, 0.5];
let color_from_array = Color::rgba_from_array(color_array);
```

crates/bevy_gltf/src/loader.rs

@@ -998,7 +998,7 @@ fn load_node(
                 gltf::khr_lights_punctual::Kind::Directional => {
                     let mut entity = parent.spawn(DirectionalLightBundle {
                         directional_light: DirectionalLight {
-                            color: Color::from(light.color()),
+                            color: Color::rgb_from_array(light.color()),
                             // NOTE: KHR_punctual_lights defines the intensity units for directional
                             // lights in lux (lm/m^2) which is what we need.
                             illuminance: light.intensity(),
@@ -1018,7 +1018,7 @@ fn load_node(
                 gltf::khr_lights_punctual::Kind::Point => {
                     let mut entity = parent.spawn(PointLightBundle {
                         point_light: PointLight {
-                            color: Color::from(light.color()),
+                            color: Color::rgb_from_array(light.color()),
                             // NOTE: KHR_punctual_lights defines the intensity units for point lights in
                             // candela (lm/sr) which is luminous intensity and we need luminous power.
                             // For a point light, luminous power = 4 * pi * luminous intensity
@@ -1044,7 +1044,7 @@ fn load_node(
                 } => {
                     let mut entity = parent.spawn(SpotLightBundle {
                         spot_light: SpotLight {
-                            color: Color::from(light.color()),
+                            color: Color::rgb_from_array(light.color()),
                             // NOTE: KHR_punctual_lights defines the intensity units for spot lights in
                             // candela (lm/sr) which is luminous intensity and we need luminous power.
                             // For a spot light, we map luminous power = 4 * pi * luminous intensity

crates/bevy_render/src/color/mod.rs

@@ -5,7 +5,7 @@ pub use colorspace::*;
 use bevy_math::{Vec3, Vec4};
 use bevy_reflect::{Reflect, ReflectDeserialize, ReflectSerialize};
 use serde::{Deserialize, Serialize};
-use std::ops::{Add, AddAssign, Mul, MulAssign};
+use std::ops::{Add, Mul, MulAssign};
 use thiserror::Error;
 
 #[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize, Reflect)]
@@ -1102,69 +1102,184 @@ impl Color {
             }
         }
     }
-}
 
-impl Default for Color {
-    fn default() -> Self {
-        Color::WHITE
+    /// New `Color` from `[f32; 4]` (or a type that can be converted into them) with RGB representation in sRGB colorspace.
+    #[inline]
+    pub fn rgba_from_array(arr: impl Into<[f32; 4]>) -> Self {
+        let [r, g, b, a]: [f32; 4] = arr.into();
+        Color::rgba(r, g, b, a)
     }
-}
 
-impl AddAssign<Color> for Color {
-    fn add_assign(&mut self, rhs: Color) {
-        match self {
+    /// New `Color` from `[f32; 3]` (or a type that can be converted into them) with RGB representation in sRGB colorspace.
+    #[inline]
+    pub fn rgb_from_array(arr: impl Into<[f32; 3]>) -> Self {
+        let [r, g, b]: [f32; 3] = arr.into();
+        Color::rgb(r, g, b)
+    }
+
+    /// New `Color` from `[f32; 4]` (or a type that can be converted into them) with RGB representation in linear RGB colorspace.
+    #[inline]
+    pub fn rgba_linear_from_array(arr: impl Into<[f32; 4]>) -> Self {
+        let [r, g, b, a]: [f32; 4] = arr.into();
+        Color::rgba_linear(r, g, b, a)
+    }
+
+    /// New `Color` from `[f32; 3]` (or a type that can be converted into them) with RGB representation in linear RGB colorspace.
+    #[inline]
+    pub fn rgb_linear_from_array(arr: impl Into<[f32; 3]>) -> Self {
+        let [r, g, b]: [f32; 3] = arr.into();
+        Color::rgb_linear(r, g, b)
+    }
+
+    /// New `Color` from `[f32; 4]` (or a type that can be converted into them) with HSL representation in sRGB colorspace.
+    #[inline]
+    pub fn hsla_from_array(arr: impl Into<[f32; 4]>) -> Self {
+        let [h, s, l, a]: [f32; 4] = arr.into();
+        Color::hsla(h, s, l, a)
+    }
+
+    /// New `Color` from `[f32; 3]` (or a type that can be converted into them) with HSL representation in sRGB colorspace.
+    #[inline]
+    pub fn hsl_from_array(arr: impl Into<[f32; 3]>) -> Self {
+        let [h, s, l]: [f32; 3] = arr.into();
+        Color::hsl(h, s, l)
+    }
+
+    /// New `Color` from `[f32; 4]` (or a type that can be converted into them) with LCH representation in sRGB colorspace.
+    #[inline]
+    pub fn lcha_from_array(arr: impl Into<[f32; 4]>) -> Self {
+        let [l, c, h, a]: [f32; 4] = arr.into();
+        Color::lcha(l, c, h, a)
+    }
+
+    /// New `Color` from `[f32; 3]` (or a type that can be converted into them) with LCH representation in sRGB colorspace.
+    #[inline]
+    pub fn lch_from_array(arr: impl Into<[f32; 3]>) -> Self {
+        let [l, c, h]: [f32; 3] = arr.into();
+        Color::lch(l, c, h)
+    }
+
+    /// Convert `Color` to RGBA and return as `Vec4`.
+    #[inline]
+    pub fn rgba_to_vec4(&self) -> Vec4 {
+        let color = self.as_rgba();
+        match color {
             Color::Rgba {
                 red,
                 green,
                 blue,
                 alpha,
-            } => {
-                let rhs = rhs.as_rgba_f32();
-                *red += rhs[0];
-                *green += rhs[1];
-                *blue += rhs[2];
-                *alpha += rhs[3];
-            }
+            } => Vec4::new(red, green, blue, alpha),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Convert `Color` to RGBA and return as `Vec3`.
+    #[inline]
+    pub fn rgb_to_vec3(&self) -> Vec3 {
+        let color = self.as_rgba();
+        match color {
+            Color::Rgba {
+                red, green, blue, ..
+            } => Vec3::new(red, green, blue),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Convert `Color` to linear RGBA and return as `Vec4`.
+    #[inline]
+    pub fn rgba_linear_to_vec4(&self) -> Vec4 {
+        let color = self.as_rgba_linear();
+        match color {
             Color::RgbaLinear {
                 red,
                 green,
                 blue,
                 alpha,
-            } => {
-                let rhs = rhs.as_linear_rgba_f32();
-                *red += rhs[0];
-                *green += rhs[1];
-                *blue += rhs[2];
-                *alpha += rhs[3];
-            }
+            } => Vec4::new(red, green, blue, alpha),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Convert `Color` to linear RGBA and return as `Vec3`.
+    #[inline]
+    pub fn rgb_linear_to_vec3(&self) -> Vec3 {
+        let color = self.as_rgba_linear();
+        match color {
+            Color::RgbaLinear {
+                red, green, blue, ..
+            } => Vec3::new(red, green, blue),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Convert `Color` to HSLA and return as `Vec4`.
+    #[inline]
+    pub fn hsla_to_vec4(&self) -> Vec4 {
+        let color = self.as_hsla();
+        match color {
             Color::Hsla {
                 hue,
                 saturation,
                 lightness,
                 alpha,
-            } => {
-                let rhs = rhs.as_hsla_f32();
-                *hue += rhs[0];
-                *saturation += rhs[1];
-                *lightness += rhs[2];
-                *alpha += rhs[3];
-            }
+            } => Vec4::new(hue, saturation, lightness, alpha),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Convert `Color` to HSLA and return as `Vec3`.
+    #[inline]
+    pub fn hsl_to_vec3(&self) -> Vec3 {
+        let color = self.as_hsla();
+        match color {
+            Color::Hsla {
+                hue,
+                saturation,
+                lightness,
+                ..
+            } => Vec3::new(hue, saturation, lightness),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Convert `Color` to LCHA and return as `Vec4`.
+    #[inline]
+    pub fn lcha_to_vec4(&self) -> Vec4 {
+        let color = self.as_lcha();
+        match color {
             Color::Lcha {
                 lightness,
                 chroma,
                 hue,
                 alpha,
-            } => {
-                let rhs = rhs.as_lcha_f32();
-                *lightness += rhs[0];
-                *chroma += rhs[1];
-                *hue += rhs[2];
-                *alpha += rhs[3];
-            }
+            } => Vec4::new(lightness, chroma, hue, alpha),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Convert `Color` to LCHA and return as `Vec3`.
+    #[inline]
+    pub fn lch_to_vec3(&self) -> Vec3 {
+        let color = self.as_lcha();
+        match color {
+            Color::Lcha {
+                lightness,
+                chroma,
+                hue,
+                ..
+            } => Vec3::new(lightness, chroma, hue),
+            _ => unreachable!(),
         }
     }
 }
 
+impl Default for Color {
+    fn default() -> Self {
+        Color::WHITE
+    }
+}
+
 impl Add<Color> for Color {
     type Output = Color;
 
@@ -1219,7 +1334,6 @@ impl Add<Color> for Color {
                 alpha,
             } => {
                 let rhs = rhs.as_lcha_f32();
-
                 Color::Lcha {
                     lightness: lightness + rhs[0],
                     chroma: chroma + rhs[1],
@@ -1231,53 +1345,6 @@ impl Add<Color> for Color {
     }
 }
 
-impl AddAssign<Vec4> for Color {
-    fn add_assign(&mut self, rhs: Vec4) {
-        let rhs: Color = rhs.into();
-        *self += rhs;
-    }
-}
-
-impl Add<Vec4> for Color {
-    type Output = Color;
-
-    fn add(self, rhs: Vec4) -> Self::Output {
-        let rhs: Color = rhs.into();
-        self + rhs
-    }
-}
-
-impl From<Color> for [f32; 4] {
-    fn from(color: Color) -> Self {
-        color.as_rgba_f32()
-    }
-}
-
-impl From<[f32; 4]> for Color {
-    fn from([r, g, b, a]: [f32; 4]) -> Self {
-        Color::rgba(r, g, b, a)
-    }
-}
-
-impl From<[f32; 3]> for Color {
-    fn from([r, g, b]: [f32; 3]) -> Self {
-        Color::rgb(r, g, b)
-    }
-}
-
-impl From<Color> for Vec4 {
-    fn from(color: Color) -> Self {
-        let color: [f32; 4] = color.into();
-        Vec4::new(color[0], color[1], color[2], color[3])
-    }
-}
-
-impl From<Vec4> for Color {
-    fn from(vec4: Vec4) -> Self {
-        Color::rgba(vec4.x, vec4.y, vec4.z, vec4.w)
-    }
-}
-
 impl From<Color> for wgpu::Color {
     fn from(color: Color) -> Self {
         if let Color::RgbaLinear {
@@ -1909,15 +1976,15 @@ mod tests {
     #[test]
     fn conversions_vec4() {
         let starting_vec4 = Vec4::new(0.4, 0.5, 0.6, 1.0);
-        let starting_color = Color::from(starting_vec4);
+        let starting_color = Color::rgba_from_array(starting_vec4);
 
-        assert_eq!(starting_vec4, Vec4::from(starting_color));
+        assert_eq!(starting_vec4, starting_color.rgba_to_vec4());
 
         let transformation = Vec4::new(0.5, 0.5, 0.5, 1.0);
 
         assert_eq!(
             starting_color * transformation,
-            Color::from(starting_vec4 * transformation),
+            Color::rgba_from_array(starting_vec4 * transformation)
         );
     }
 

examples/ui/ui_material.rs

@@ -17,7 +17,7 @@ fn update(time: Res<Time>, mut ui_materials: ResMut<Assets<CustomUiMaterial>>) {
     for (_, material) in ui_materials.iter_mut() {
         // rainbow color effect
         let new_color = Color::hsl((time.elapsed_seconds() * 60.0) % 360.0, 1., 0.5);
-        material.color = new_color.into();
+        material.color = new_color.rgba_to_vec4();
     }
 }
 
@@ -45,7 +45,7 @@ fn setup(mut commands: Commands, mut ui_materials: ResMut<Assets<CustomUiMateria
                     ..default()
                 },
                 material: ui_materials.add(CustomUiMaterial {
-                    color: Color::WHITE.into(),
+                    color: Color::WHITE.rgba_to_vec4(),
                 }),
                 ..default()
             });