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// Copyright 2016 The TCell Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use file except in compliance with the License.
// You may obtain a copy of the license at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tcell
import (
"github.com/lucasb-eyer/go-colorful"
"math"
)
// FindColor attempts to find a given color, or the best match possible for it,
// from the palette given. This is an expensive operation, so results should
// be cached by the caller.
func FindColor(c Color, palette []Color) Color {
match := ColorDefault
dist := float64(0)
r, g, b := c.RGB()
c1 := colorful.Color{
R: float64(r) / 255.0,
G: float64(g) / 255.0,
B: float64(b) / 255.0,
}
for _, d := range palette {
r, g, b = d.RGB()
c2 := colorful.Color{
R: float64(r) / 255.0,
G: float64(g) / 255.0,
B: float64(b) / 255.0,
}
// CIE94 is more accurate, but really really expensive.
nd := c1.DistanceCIE76(c2)
if math.IsNaN(nd) {
nd = math.Inf(1)
}
if match == ColorDefault || nd < dist {
match = d
dist = nd
}
}
return match
}
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