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// Copyright ©2015 The Gonum Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Copyright ©2011-2012 The bíogo Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package palette
import (
"image/color"
"testing"
)
func withinEpsilon(a, b, epsilon uint32) bool {
d := int64(a) - int64(b)
if d < 0 {
d = -d
}
return d <= int64(epsilon)
}
func TestColor(t *testing.T) {
for r := 0; r < 256; r += 5 {
for g := 0; g < 256; g += 5 {
for b := 0; b < 256; b += 5 {
col := color.RGBA{uint8(r), uint8(g), uint8(b), 0}
cDirectR, cDirectG, cDirectB, cDirectA := col.RGBA()
hsva := rgbaToHsva(col.RGBA())
if hsva.H < 0 || hsva.H > 1 {
t.Errorf("unexpected values for H: want [0, 1] got:%f", hsva.H)
}
if hsva.S < 0 || hsva.S > 1 {
t.Errorf("unexpected values for S: want [0, 1] got:%f", hsva.S)
}
if hsva.V < 0 || hsva.V > 1 {
t.Errorf("unexpected values for V: want [0, 1] got:%f", hsva.V)
}
cFromHSVR, cFromHSVG, cFromHSVB, cFromHSVA := hsva.RGBA()
if cFromHSVR < 0 || cFromHSVR > 0xFFFF {
t.Errorf("unexpected values for H: want [0x0, 0xFFFF] got:%f", hsva.H)
}
if cFromHSVG < 0 || cFromHSVG > 0xFFFF {
t.Errorf("unexpected values for S: want [0x0, 0xFFFF] got:%f", hsva.S)
}
if cFromHSVB < 0 || cFromHSVB > 0xFFFF {
t.Errorf("unexpected values for V: want [0x0, 0xFFFF] got:%f", hsva.V)
}
if cFromHSVA < 0 || cFromHSVA > 0xFFFF {
t.Errorf("unexpected values for V: want [0x0, 0xFFFF] got:%f", hsva.V)
}
back := rgbaToHsva(color.RGBA{uint8(cFromHSVR >> 8), uint8(cFromHSVG >> 8), uint8(cFromHSVB >> 8), uint8(cFromHSVA)}.RGBA())
if hsva != back {
t.Errorf("roundtrip error: got:%#v want:%#v", back, hsva)
}
const epsilon = 1
if !withinEpsilon(cFromHSVR, cDirectR, epsilon) {
t.Errorf("roundtrip error for R: got:%d want:%d", cFromHSVR, cDirectR)
}
if !withinEpsilon(cFromHSVG, cDirectG, epsilon) {
t.Errorf("roundtrip error for G: got:%d want:%d %d", cFromHSVG, cDirectG, cFromHSVG-cDirectG)
}
if !withinEpsilon(cFromHSVB, cDirectB, epsilon) {
t.Errorf("roundtrip error for B: got:%d want:%d", cFromHSVB, cDirectB)
}
if cFromHSVA != cDirectA {
t.Errorf("roundtrip error for A: got:%d want:%d", cFromHSVA, cDirectA)
}
if t.Failed() {
return
}
}
}
}
}
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