From 291bb4de2a2e5940fbebd8d400f35c1fc3b0c7a2 Mon Sep 17 00:00:00 2001
From: Ben Bridle <bridle.benjamin@gmail.com>
Date: Sun, 24 Dec 2023 21:07:11 +1300
Subject: First commit

---
 src/internal.rs | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 src/internal.rs

(limited to 'src/internal.rs')

diff --git a/src/internal.rs b/src/internal.rs
new file mode 100644
index 0000000..ca099a2
--- /dev/null
+++ b/src/internal.rs
@@ -0,0 +1,90 @@
+pub trait Internal: Copy + Clone + PartialEq + std::ops::Sub<Output = Self> {
+    const MIN: Self;
+    const MAX: Self;
+
+    fn clamp(self) -> Self;
+    fn as_u8(self) -> u8;
+    fn as_f32(self) -> f32;
+    fn as_f64(self) -> f64;
+
+    fn mul_u8(self, value: u8) -> u8;
+    fn mul_u16(self, value: u16) -> u16;
+    fn mul_u32(self, value: u32) -> u32;
+    fn mul_f32(self, value: f32) -> f32;
+    fn mul_f64(self, value: f64) -> f64;
+}
+
+impl Internal for u8 {
+    const MIN: Self = u8::MIN;
+    const MAX: Self = u8::MAX;
+
+    fn clamp(self) -> Self {
+        self
+    }
+    fn as_u8(self) -> u8 {
+        self
+    }
+    fn as_f32(self) -> f32 {
+        self as f32 / u8::MAX as f32
+    }
+    fn as_f64(self) -> f64 {
+        self as f64 / u8::MAX as f64
+    }
+
+    fn mul_u8(self, value: u8) -> u8 {
+        (value as u16 * self as u16 / 255u16) as u8
+    }
+    fn mul_u16(self, value: u16) -> u16 {
+        (value as u32 * self as u32 / 255u32) as u16
+    }
+    fn mul_u32(self, value: u32) -> u32 {
+        (value as u64 * self as u64 / 255u64) as u32
+    }
+    fn mul_f32(self, value: f32) -> f32 {
+        value * self.as_f32()
+    }
+    fn mul_f64(self, value: f64) -> f64 {
+        value * self.as_f64()
+    }
+}
+
+macro_rules! impl_for_float {
+    ($type:ty) => {
+        impl Internal for $type {
+            const MIN: Self = 0.0;
+            const MAX: Self = 1.0;
+
+            fn clamp(self) -> Self {
+                <$type>::clamp(self, <Self as Internal>::MIN, <Self as Internal>::MAX)
+            }
+            fn as_u8(self) -> u8 {
+                (self * 255.0) as u8
+            }
+            fn as_f32(self) -> f32 {
+                self as f32
+            }
+            fn as_f64(self) -> f64 {
+                self as f64
+            }
+
+            fn mul_u8(self, value: u8) -> u8 {
+                (value as Self * self) as u8
+            }
+            fn mul_u16(self, value: u16) -> u16 {
+                (value as Self * self).round() as u16
+            }
+            fn mul_u32(self, value: u32) -> u32 {
+                (value as Self * self).round() as u32
+            }
+            fn mul_f32(self, value: f32) -> f32 {
+                value * self.as_f32()
+            }
+            fn mul_f64(self, value: f64) -> f64 {
+                value * self.as_f64()
+            }
+        }
+    };
+}
+
+impl_for_float!(f32);
+impl_for_float!(f64);
-- 
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