color-management: implement set_tf_power

src/cmm/cmm_eotf.rs

@@ -9,4 +9,28 @@ pub enum Eotf {
     Log100,
     Log316,
     St428,
+    Pow(EotfPow),
+}
+
+const MUL: u32 = 10_000;
+const MUL_F32: f32 = MUL as f32;
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, Ord, PartialOrd)]
+pub struct EotfPow(pub u32);
+
+impl EotfPow {
+    pub const MIN: Self = Self(10_000);
+    pub const LINEAR: Self = Self(10_000);
+    pub const GAMMA22: Self = Self(22_000);
+    pub const GAMMA24: Self = Self(24_000);
+    pub const GAMMA28: Self = Self(28_000);
+    pub const MAX: Self = Self(100_000);
+
+    pub fn eotf_f32(self) -> f32 {
+        self.0 as f32 / MUL_F32
+    }
+
+    pub fn inv_eotf_f32(self) -> f32 {
+        MUL_F32 / self.0 as f32
+    }
 }