pub trait FromColorUnclampedMut<T>where
T: ?Sized + FromColorUnclampedMut<Self>,{
// Required method
fn from_color_unclamped_mut(
color: &mut T,
) -> FromColorUnclampedMutGuard<'_, Self, T>;
}Expand description
Temporarily convert colors in place, without clamping.
It allows colors to be converted without using more additional memory than what is necessary for the conversion, itself. The conversion will however have to be reverted at some point, since the memory space is borrowed and has to be restored to its original format. This is enforced by a scope guard that does the opposite conversion when it’s dropped.
See also IntoColorUnclampedMut and FromColorMut.
use palette::{convert::FromColorUnclampedMut, ShiftHueAssign, Srgb, Hsv};
let mut rgb = [
Srgb::new(1.0, 0.0, 0.0),
Srgb::new(0.0, 1.0, 0.0),
Srgb::new(0.0, 0.0, 1.0),
];
{
let mut hsv = <[Hsv]>::from_color_unclamped_mut(&mut rgb);
// All of the colors in `rgb` have been converted to `Hsv`:
assert_eq!(
*hsv,
[
Hsv::new(0.0, 1.0, 1.0),
Hsv::new(120.0, 1.0, 1.0),
Hsv::new(240.0, 1.0, 1.0),
]
);
hsv.shift_hue_assign(60.0);
} // The guard is dropped here and the colors are restored to `Srgb`.
// Notice how the colors in `rgb` have changed:
assert_eq!(
rgb,
[
Srgb::new(1.0, 1.0, 0.0),
Srgb::new(0.0, 1.0, 1.0),
Srgb::new(1.0, 0.0, 1.0),
]
);The scope guard, FromColorUnclampedMutGuard, has a few extra methods
that can make multiple conversion steps more efficient. One of those is
FromColorUnclampedMutGuard::then_into_color_unclamped_mut, which works
like IntoColorUnclampedMut::into_color_unclamped_mut, but does not add
an extra step when restoring to the original color type. This example will
convert Srgb → Hsv → Hsl → Srgb instead of Srgb → Hsv → Hsl → Hsv → Srgb:
use palette::{convert::FromColorUnclampedMut, ShiftHueAssign, LightenAssign, Srgb, Hsv, Hsl};
let mut rgb = [
Srgb::new(1.0, 0.0, 0.0),
Srgb::new(0.0, 1.0, 0.0),
Srgb::new(0.0, 0.0, 1.0),
];
{
let mut hsv = <[Hsv]>::from_color_unclamped_mut(&mut rgb);
hsv.shift_hue_assign(60.0);
let mut hsl = hsv.then_into_color_unclamped_mut::<[Hsl]>();
hsl.lighten_assign(0.5);
} // `then_into_color_unclamped_mut` makes the guard restore directly to `Srgb` here.
// Notice how the colors in `rgb` have changed:
assert_eq!(
rgb,
[
Srgb::new(1.0, 1.0, 0.5),
Srgb::new(0.5, 1.0, 1.0),
Srgb::new(1.0, 0.5, 1.0),
]
);§Note
The reused memory space could end up with unexpected values if the
conversion panics or if the scope guard’s drop function doesn’t run. The
default implementations of FromColorUnclampedMut uses ArrayCast, which
is only implemented for color types that can safely accept and recover from
any value. Other color types will have to provide their own implementations
that can handle this case.
Required Methods§
sourcefn from_color_unclamped_mut(
color: &mut T,
) -> FromColorUnclampedMutGuard<'_, Self, T>
fn from_color_unclamped_mut( color: &mut T, ) -> FromColorUnclampedMutGuard<'_, Self, T>
Temporarily convert from another color type in place, without clamping.
This reuses the memory space, and the returned scope guard will restore the converted colors to their original type when it’s dropped.