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