Reorganise sRGB module a little

src/image/srgb.rs

@@ -2,6 +2,13 @@ use super::*;
 
 use ccvl_proc_macros::Pixel;
 
+#[derive(Clone, Copy, Debug, PartialEq, Pixel)]
+pub struct SRGB {
+    pub r: f32,
+    pub g: f32,
+    pub b: f32,
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Pixel)]
 pub struct SRGBA {
     pub r: f32,
@@ -10,13 +17,6 @@ pub struct SRGBA {
     pub a: f32,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Pixel)]
-pub struct SRGB {
-    pub r: f32,
-    pub g: f32,
-    pub b: f32,
-}
-
 const CUTOFF: f32 = 4.05e-2;
 const LINEAR_DIVISOR: f32 = 12.92;
 const SHIFT: f32 = 5.5e-2;
@@ -46,12 +46,6 @@ impl SRGBA {
     }
 }
 
-impl Into<SRGB> for SRGBA {
-    fn into(self) -> SRGB {
-        SRGB::new(self.r, self.g, self.b)
-    }
-}
-
 impl SRGB {
     pub fn new(r: f32, g: f32, b: f32) -> Self {
         Self { r, g, b }
@@ -64,6 +58,12 @@ impl Into<SRGBA> for SRGB {
     }
 }
 
+impl From<SRGBA> for SRGB {
+    fn from(rgba: SRGBA) -> Self {
+        Self::new(rgba.r, rgba.g, rgba.b)
+    }
+}
+
 impl Into<LinearRGB> for SRGB {
     fn into(self) -> LinearRGB {
         LinearRGB::new(
@@ -84,6 +84,18 @@ impl From<LinearRGB> for SRGB {
     }
 }
 
+impl Into<LinearRGB> for SRGBA {
+	fn into(self) -> LinearRGB {
+		SRGB::from(self).into()
+	}
+}
+
+impl From<LinearRGB> for SRGBA {
+	fn from(linear: LinearRGB) -> Self {
+		SRGB::from(linear).into()
+	}
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;