Clamp to prevent overflow when interpolating between two gradient stops.

pcwalton · pcwalton · commit 1570c3821705 · 2020-07-16T10:37:31.000-07:00
Closes #397.
diff --git a/content/src/gradient.rs b/content/src/gradient.rs
@@ -166,10 +166,8 @@ impl Gradient {
             return lower_stop.color;
         }
 
-        lower_stop.color
-                  .to_f32()
-                  .lerp(upper_stop.color.to_f32(), (t - lower_stop.offset) / denom)
-                  .to_u8()
+        let ratio = ((t - lower_stop.offset) / denom).min(1.0);
+        lower_stop.color.to_f32().lerp(upper_stop.color.to_f32(), ratio).to_u8()
     }
 
     #[inline]

Original file line number	Diff line number	Diff line change
`@@ -166,10 +166,8 @@ impl Gradient {`
`166`	`166`	`return lower_stop.color;`
`167`	`167`	`}`
`168`	`168`
`169`		`- lower_stop.color`
`170`		`- .to_f32()`
`171`		`- .lerp(upper_stop.color.to_f32(), (t - lower_stop.offset) / denom)`
`172`		`- .to_u8()`
	`169`	`+ let ratio = ((t - lower_stop.offset) / denom).min(1.0);`
	`170`	`+ lower_stop.color.to_f32().lerp(upper_stop.color.to_f32(), ratio).to_u8()`
`173`	`171`	`}`
`174`	`172`
`175`	`173`	`#[inline]`