Initial commit.
This commit is contained in:
commit
2077db79b2
202
LICENSE
Normal file
202
LICENSE
Normal file
@ -0,0 +1,202 @@
|
|||||||
|
|
||||||
|
Apache License
|
||||||
|
Version 2.0, January 2004
|
||||||
|
http://www.apache.org/licenses/
|
||||||
|
|
||||||
|
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
|
||||||
|
|
||||||
|
1. Definitions.
|
||||||
|
|
||||||
|
"License" shall mean the terms and conditions for use, reproduction,
|
||||||
|
and distribution as defined by Sections 1 through 9 of this document.
|
||||||
|
|
||||||
|
"Licensor" shall mean the copyright owner or entity authorized by
|
||||||
|
the copyright owner that is granting the License.
|
||||||
|
|
||||||
|
"Legal Entity" shall mean the union of the acting entity and all
|
||||||
|
other entities that control, are controlled by, or are under common
|
||||||
|
control with that entity. For the purposes of this definition,
|
||||||
|
"control" means (i) the power, direct or indirect, to cause the
|
||||||
|
direction or management of such entity, whether by contract or
|
||||||
|
otherwise, or (ii) ownership of fifty percent (50%) or more of the
|
||||||
|
outstanding shares, or (iii) beneficial ownership of such entity.
|
||||||
|
|
||||||
|
"You" (or "Your") shall mean an individual or Legal Entity
|
||||||
|
exercising permissions granted by this License.
|
||||||
|
|
||||||
|
"Source" form shall mean the preferred form for making modifications,
|
||||||
|
including but not limited to software source code, documentation
|
||||||
|
source, and configuration files.
|
||||||
|
|
||||||
|
"Object" form shall mean any form resulting from mechanical
|
||||||
|
transformation or translation of a Source form, including but
|
||||||
|
not limited to compiled object code, generated documentation,
|
||||||
|
and conversions to other media types.
|
||||||
|
|
||||||
|
"Work" shall mean the work of authorship, whether in Source or
|
||||||
|
Object form, made available under the License, as indicated by a
|
||||||
|
copyright notice that is included in or attached to the work
|
||||||
|
(an example is provided in the Appendix below).
|
||||||
|
|
||||||
|
"Derivative Works" shall mean any work, whether in Source or Object
|
||||||
|
form, that is based on (or derived from) the Work and for which the
|
||||||
|
editorial revisions, annotations, elaborations, or other modifications
|
||||||
|
represent, as a whole, an original work of authorship. For the purposes
|
||||||
|
of this License, Derivative Works shall not include works that remain
|
||||||
|
separable from, or merely link (or bind by name) to the interfaces of,
|
||||||
|
the Work and Derivative Works thereof.
|
||||||
|
|
||||||
|
"Contribution" shall mean any work of authorship, including
|
||||||
|
the original version of the Work and any modifications or additions
|
||||||
|
to that Work or Derivative Works thereof, that is intentionally
|
||||||
|
submitted to Licensor for inclusion in the Work by the copyright owner
|
||||||
|
or by an individual or Legal Entity authorized to submit on behalf of
|
||||||
|
the copyright owner. For the purposes of this definition, "submitted"
|
||||||
|
means any form of electronic, verbal, or written communication sent
|
||||||
|
to the Licensor or its representatives, including but not limited to
|
||||||
|
communication on electronic mailing lists, source code control systems,
|
||||||
|
and issue tracking systems that are managed by, or on behalf of, the
|
||||||
|
Licensor for the purpose of discussing and improving the Work, but
|
||||||
|
excluding communication that is conspicuously marked or otherwise
|
||||||
|
designated in writing by the copyright owner as "Not a Contribution."
|
||||||
|
|
||||||
|
"Contributor" shall mean Licensor and any individual or Legal Entity
|
||||||
|
on behalf of whom a Contribution has been received by Licensor and
|
||||||
|
subsequently incorporated within the Work.
|
||||||
|
|
||||||
|
2. Grant of Copyright License. Subject to the terms and conditions of
|
||||||
|
this License, each Contributor hereby grants to You a perpetual,
|
||||||
|
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
|
||||||
|
copyright license to reproduce, prepare Derivative Works of,
|
||||||
|
publicly display, publicly perform, sublicense, and distribute the
|
||||||
|
Work and such Derivative Works in Source or Object form.
|
||||||
|
|
||||||
|
3. Grant of Patent License. Subject to the terms and conditions of
|
||||||
|
this License, each Contributor hereby grants to You a perpetual,
|
||||||
|
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
|
||||||
|
(except as stated in this section) patent license to make, have made,
|
||||||
|
use, offer to sell, sell, import, and otherwise transfer the Work,
|
||||||
|
where such license applies only to those patent claims licensable
|
||||||
|
by such Contributor that are necessarily infringed by their
|
||||||
|
Contribution(s) alone or by combination of their Contribution(s)
|
||||||
|
with the Work to which such Contribution(s) was submitted. If You
|
||||||
|
institute patent litigation against any entity (including a
|
||||||
|
cross-claim or counterclaim in a lawsuit) alleging that the Work
|
||||||
|
or a Contribution incorporated within the Work constitutes direct
|
||||||
|
or contributory patent infringement, then any patent licenses
|
||||||
|
granted to You under this License for that Work shall terminate
|
||||||
|
as of the date such litigation is filed.
|
||||||
|
|
||||||
|
4. Redistribution. You may reproduce and distribute copies of the
|
||||||
|
Work or Derivative Works thereof in any medium, with or without
|
||||||
|
modifications, and in Source or Object form, provided that You
|
||||||
|
meet the following conditions:
|
||||||
|
|
||||||
|
(a) You must give any other recipients of the Work or
|
||||||
|
Derivative Works a copy of this License; and
|
||||||
|
|
||||||
|
(b) You must cause any modified files to carry prominent notices
|
||||||
|
stating that You changed the files; and
|
||||||
|
|
||||||
|
(c) You must retain, in the Source form of any Derivative Works
|
||||||
|
that You distribute, all copyright, patent, trademark, and
|
||||||
|
attribution notices from the Source form of the Work,
|
||||||
|
excluding those notices that do not pertain to any part of
|
||||||
|
the Derivative Works; and
|
||||||
|
|
||||||
|
(d) If the Work includes a "NOTICE" text file as part of its
|
||||||
|
distribution, then any Derivative Works that You distribute must
|
||||||
|
include a readable copy of the attribution notices contained
|
||||||
|
within such NOTICE file, excluding those notices that do not
|
||||||
|
pertain to any part of the Derivative Works, in at least one
|
||||||
|
of the following places: within a NOTICE text file distributed
|
||||||
|
as part of the Derivative Works; within the Source form or
|
||||||
|
documentation, if provided along with the Derivative Works; or,
|
||||||
|
within a display generated by the Derivative Works, if and
|
||||||
|
wherever such third-party notices normally appear. The contents
|
||||||
|
of the NOTICE file are for informational purposes only and
|
||||||
|
do not modify the License. You may add Your own attribution
|
||||||
|
notices within Derivative Works that You distribute, alongside
|
||||||
|
or as an addendum to the NOTICE text from the Work, provided
|
||||||
|
that such additional attribution notices cannot be construed
|
||||||
|
as modifying the License.
|
||||||
|
|
||||||
|
You may add Your own copyright statement to Your modifications and
|
||||||
|
may provide additional or different license terms and conditions
|
||||||
|
for use, reproduction, or distribution of Your modifications, or
|
||||||
|
for any such Derivative Works as a whole, provided Your use,
|
||||||
|
reproduction, and distribution of the Work otherwise complies with
|
||||||
|
the conditions stated in this License.
|
||||||
|
|
||||||
|
5. Submission of Contributions. Unless You explicitly state otherwise,
|
||||||
|
any Contribution intentionally submitted for inclusion in the Work
|
||||||
|
by You to the Licensor shall be under the terms and conditions of
|
||||||
|
this License, without any additional terms or conditions.
|
||||||
|
Notwithstanding the above, nothing herein shall supersede or modify
|
||||||
|
the terms of any separate license agreement you may have executed
|
||||||
|
with Licensor regarding such Contributions.
|
||||||
|
|
||||||
|
6. Trademarks. This License does not grant permission to use the trade
|
||||||
|
names, trademarks, service marks, or product names of the Licensor,
|
||||||
|
except as required for reasonable and customary use in describing the
|
||||||
|
origin of the Work and reproducing the content of the NOTICE file.
|
||||||
|
|
||||||
|
7. Disclaimer of Warranty. Unless required by applicable law or
|
||||||
|
agreed to in writing, Licensor provides the Work (and each
|
||||||
|
Contributor provides its Contributions) on an "AS IS" BASIS,
|
||||||
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
|
||||||
|
implied, including, without limitation, any warranties or conditions
|
||||||
|
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
|
||||||
|
PARTICULAR PURPOSE. You are solely responsible for determining the
|
||||||
|
appropriateness of using or redistributing the Work and assume any
|
||||||
|
risks associated with Your exercise of permissions under this License.
|
||||||
|
|
||||||
|
8. Limitation of Liability. In no event and under no legal theory,
|
||||||
|
whether in tort (including negligence), contract, or otherwise,
|
||||||
|
unless required by applicable law (such as deliberate and grossly
|
||||||
|
negligent acts) or agreed to in writing, shall any Contributor be
|
||||||
|
liable to You for damages, including any direct, indirect, special,
|
||||||
|
incidental, or consequential damages of any character arising as a
|
||||||
|
result of this License or out of the use or inability to use the
|
||||||
|
Work (including but not limited to damages for loss of goodwill,
|
||||||
|
work stoppage, computer failure or malfunction, or any and all
|
||||||
|
other commercial damages or losses), even if such Contributor
|
||||||
|
has been advised of the possibility of such damages.
|
||||||
|
|
||||||
|
9. Accepting Warranty or Additional Liability. While redistributing
|
||||||
|
the Work or Derivative Works thereof, You may choose to offer,
|
||||||
|
and charge a fee for, acceptance of support, warranty, indemnity,
|
||||||
|
or other liability obligations and/or rights consistent with this
|
||||||
|
License. However, in accepting such obligations, You may act only
|
||||||
|
on Your own behalf and on Your sole responsibility, not on behalf
|
||||||
|
of any other Contributor, and only if You agree to indemnify,
|
||||||
|
defend, and hold each Contributor harmless for any liability
|
||||||
|
incurred by, or claims asserted against, such Contributor by reason
|
||||||
|
of your accepting any such warranty or additional liability.
|
||||||
|
|
||||||
|
END OF TERMS AND CONDITIONS
|
||||||
|
|
||||||
|
APPENDIX: How to apply the Apache License to your work.
|
||||||
|
|
||||||
|
To apply the Apache License to your work, attach the following
|
||||||
|
boilerplate notice, with the fields enclosed by brackets "[]"
|
||||||
|
replaced with your own identifying information. (Don't include
|
||||||
|
the brackets!) The text should be enclosed in the appropriate
|
||||||
|
comment syntax for the file format. We also recommend that a
|
||||||
|
file or class name and description of purpose be included on the
|
||||||
|
same "printed page" as the copyright notice for easier
|
||||||
|
identification within third-party archives.
|
||||||
|
|
||||||
|
Copyright [yyyy] [name of copyright owner]
|
||||||
|
|
||||||
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
|
you may not use this 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.
|
||||||
174
oklab.go
Normal file
174
oklab.go
Normal file
@ -0,0 +1,174 @@
|
|||||||
|
// Based on: https://bottosson.github.io/posts/oklab/
|
||||||
|
//
|
||||||
|
// OkLab first defines a transform from xyz, and multiplies by this matrix:
|
||||||
|
// [+0.8189330101, +0.3618667424, -0.1288597137]
|
||||||
|
// [+0.0329845436, +0.9293118715, +0.0361456387]
|
||||||
|
// [+0.0482003018, +0.2643662691, +0.633851707 ]
|
||||||
|
//
|
||||||
|
// Wikipedia lists this matrix for converting from linear sRGB to D65 CIE XYZ, so
|
||||||
|
// I'm considering it canonical:
|
||||||
|
// [+0.4124, +0.3576, +0.1805]
|
||||||
|
// [+0.2126, +0.7152, +0.0722]
|
||||||
|
// [+0.0193, +0.1192, +0.9505]
|
||||||
|
//
|
||||||
|
// Combined, we get:
|
||||||
|
// [+0.41217385032507, +0.5362974607032, +0.05146302925248]
|
||||||
|
// [+0.21187214048845, +0.6807476834212, +0.10740645682645]
|
||||||
|
// [+0.08831541121808, +0.2818663070584, +0.63026344660742]
|
||||||
|
//
|
||||||
|
// And its inverse:
|
||||||
|
// [+4.0767584135565013494237930518854, -3.3072279873944731418619352916485, +0.230721459944885632473018834049 ]
|
||||||
|
// [-1.2681810851624033989047813181437, +2.6092932102856398573991970933594, -0.3411121165477535569679616041822]
|
||||||
|
// [-0.0040984077180314400491332639337372, -0.70350366010241732765095902557887, +1.7068604529788013559365593912662]
|
||||||
|
//
|
||||||
|
// After a non-linear transformation (cube root), OkLab applies a second matrix:
|
||||||
|
// [+0.2104542553, +0.793617785, -0.0040720468]
|
||||||
|
// [+1.9779984951, -2.428592205, +0.4505937099]
|
||||||
|
// [+0.0259040371, +0.7827717662, -0.808675766 ]
|
||||||
|
//
|
||||||
|
// And its inverse:
|
||||||
|
// [+0.99999999845051981426207542502031, +0.39633779217376785682345989261573, +0.21580375806075880342314146183004 ]
|
||||||
|
// [+1.0000000088817607767160752456705, -0.10556134232365634941095687705472, -0.063854174771705903405254198817796]
|
||||||
|
// [+1.0000000546724109177012928651534, -0.089484182094965759689052745863391, -1.2914855378640917399489287529148 ]
|
||||||
|
//
|
||||||
|
// It should be noted that the numbers in the first column were supposed to be 1, and other implementations skip
|
||||||
|
// multiplying by that column altogether. I however am insane, and shall continue barging forward.
|
||||||
|
|
||||||
|
package oklab
|
||||||
|
|
||||||
|
import (
|
||||||
|
"image/color"
|
||||||
|
"math"
|
||||||
|
)
|
||||||
|
|
||||||
|
type Color struct {
|
||||||
|
Lightness, ChromaA, ChromaB, A float64
|
||||||
|
}
|
||||||
|
|
||||||
|
func linearize(c uint32) float64 {
|
||||||
|
l := float64(c) / 0xffff
|
||||||
|
|
||||||
|
if l <= 0.039285714285714285714285714285714 {
|
||||||
|
return l / 12.923210180787861094641554898407
|
||||||
|
}
|
||||||
|
|
||||||
|
return math.Pow((l+0.055)/1.055, 2.4)
|
||||||
|
}
|
||||||
|
|
||||||
|
func delinearize(l float64) uint32 {
|
||||||
|
switch {
|
||||||
|
case l <= 0:
|
||||||
|
return 0
|
||||||
|
case l <= 0.0030399346397784299969770436366690:
|
||||||
|
return uint32(l*846922.57919793247683733430026710 + 0.5)
|
||||||
|
case l >= 1:
|
||||||
|
return 0xffff
|
||||||
|
default:
|
||||||
|
return uint32(69139.425*math.Pow(l, 1/2.4) - 3603.925)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// FromNRGBA create an OkLab color from non-pre-multiplied RGBA.
|
||||||
|
func FromNRGBA(r, g, b, a uint32) Color {
|
||||||
|
rLin, gLin, bLin := linearize(r), linearize(g), linearize(b)
|
||||||
|
|
||||||
|
l := math.Cbrt(0.41217385032507*rLin + 0.5362974607032*gLin + 0.05146302925248*bLin)
|
||||||
|
m := math.Cbrt(0.21187214048845*rLin + 0.6807476834212*gLin + 0.10740645682645*bLin)
|
||||||
|
s := math.Cbrt(0.08831541121808*rLin + 0.2818663070584*gLin + 0.63026344660742*bLin)
|
||||||
|
|
||||||
|
return Color{
|
||||||
|
0.2104542553*l + 0.793617785*m - 0.0040720468*s,
|
||||||
|
1.9779984951*l - 2.428592205*m + 0.4505937099*s,
|
||||||
|
0.0259040371*l + 0.7827717662*m - 0.808675766*s,
|
||||||
|
float64(a) / float64(0xffff),
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// FromRGBA create an OkLab color from pre-multiplied RGBA.
|
||||||
|
func FromRGBA(r, g, b, a uint32) Color {
|
||||||
|
switch a {
|
||||||
|
case 0xffff:
|
||||||
|
// do nothing.
|
||||||
|
case 0:
|
||||||
|
// completely transparent, color information was lost.
|
||||||
|
// pretend it was gray.
|
||||||
|
r, g, b = 0x7fff, 0x7fff, 0x7fff
|
||||||
|
default:
|
||||||
|
// un-premultiply rgb.
|
||||||
|
//
|
||||||
|
// Note that I'm rounding up here, which is the opposite of what the NRGBA/NRGBA64 colors do,
|
||||||
|
// which may be a bug as RGBA64->NRGBA64->RGBA64 is lossy.
|
||||||
|
r = (r*0xffff + a - 1) / a
|
||||||
|
g = (g*0xffff + a - 1) / a
|
||||||
|
b = (b*0xffff + a - 1) / a
|
||||||
|
}
|
||||||
|
|
||||||
|
return FromNRGBA(r, g, b, a)
|
||||||
|
}
|
||||||
|
|
||||||
|
func cube(v float64) float64 {
|
||||||
|
return v * v * v
|
||||||
|
}
|
||||||
|
|
||||||
|
// NRGBA converts to non-premultiplied RGBA.
|
||||||
|
func (c Color) NRGBA() (r, g, b, a uint32) {
|
||||||
|
l := cube(0.99999999845051981426207542502031*c.Lightness + 0.39633779217376785682345989261573*c.ChromaA + 0.21580375806075880342314146183004*c.ChromaB)
|
||||||
|
m := cube(1.0000000088817607767160752456705*c.Lightness - 0.10556134232365634941095687705472*c.ChromaA - 0.063854174771705903405254198817796*c.ChromaB)
|
||||||
|
s := cube(1.0000000546724109177012928651534*c.Lightness - 0.089484182094965759689052745863391*c.ChromaA - 1.2914855378640917399489287529148*c.ChromaB)
|
||||||
|
|
||||||
|
r = delinearize(4.0767584135565013494237930518854*l - 3.3072279873944731418619352916485*m + 0.230721459944885632473018834049*s)
|
||||||
|
g = delinearize(-1.2681810851624033989047813181437*l + 2.6092932102856398573991970933594*m - 0.3411121165477535569679616041822*s)
|
||||||
|
b = delinearize(-0.0040984077180314400491332639337372*l - 0.70350366010241732765095902557887*m + 1.7068604529788013559365593912662*s)
|
||||||
|
a = uint32(c.A*0xffff + 0.5)
|
||||||
|
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
// RGBA converts to premultiplied RGBA.
|
||||||
|
func (c Color) RGBA() (r, g, b, a uint32) {
|
||||||
|
r, g, b, a = c.NRGBA()
|
||||||
|
|
||||||
|
r = r * a / 0xffff
|
||||||
|
g = g * a / 0xffff
|
||||||
|
b = b * a / 0xffff
|
||||||
|
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
func sqr(a float64) float64 {
|
||||||
|
return a * a
|
||||||
|
}
|
||||||
|
|
||||||
|
func Distance(a, b Color) float64 {
|
||||||
|
dL := a.Lightness*a.A - b.Lightness*b.A
|
||||||
|
da := a.ChromaA*a.A - b.ChromaA*b.A
|
||||||
|
db := a.ChromaB*a.A - b.ChromaB*b.A
|
||||||
|
dA := a.A - b.A
|
||||||
|
|
||||||
|
return math.Sqrt(max(sqr(dL), sqr(dL+dA)) + max(sqr(da), sqr(da+dA)) + max(sqr(db), sqr(db+dA)))
|
||||||
|
//return math.Sqrt((sqr(dL)+sqr(da)+sqr(db))*(a.A*b.A) + sqr(dA))
|
||||||
|
}
|
||||||
|
|
||||||
|
func okLabModel(c color.Color) color.Color {
|
||||||
|
switch c := c.(type) {
|
||||||
|
case Color:
|
||||||
|
return c
|
||||||
|
|
||||||
|
// Special handling for color.NRGBA and color.NRGBA64
|
||||||
|
case color.NRGBA:
|
||||||
|
return FromNRGBA(uint32(c.R)*0x101, uint32(c.G)*0x101, uint32(c.B)*0x101, uint32(c.A)*0x101)
|
||||||
|
|
||||||
|
case color.NRGBA64:
|
||||||
|
return FromNRGBA(uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A))
|
||||||
|
|
||||||
|
// This isn't a standard interface, but I'm going to check for it regardless.
|
||||||
|
case interface{ NRGBA() (r, g, b, a uint32) }:
|
||||||
|
return FromNRGBA(c.NRGBA())
|
||||||
|
|
||||||
|
default:
|
||||||
|
return FromRGBA(c.RGBA())
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// Implements a color model for converting arbitrary colors to OKLab.
|
||||||
|
var Model = color.ModelFunc(okLabModel)
|
||||||
195
oklab_test.go
Normal file
195
oklab_test.go
Normal file
@ -0,0 +1,195 @@
|
|||||||
|
package oklab
|
||||||
|
|
||||||
|
import (
|
||||||
|
"image/color"
|
||||||
|
"math"
|
||||||
|
"reflect"
|
||||||
|
"testing"
|
||||||
|
)
|
||||||
|
|
||||||
|
func TestColor_NRGBA(t *testing.T) {
|
||||||
|
// Not checking the whole space because that would be slow, and alpha is given less resolution in this test.
|
||||||
|
// The increments were chosen because they're factors of 0xffff, so we'll end on the maximum value.
|
||||||
|
for a := uint32(0); a < 0x10000; a += 4369 {
|
||||||
|
for b := uint32(0); b < 0x10000; b += 1285 {
|
||||||
|
for g := uint32(0); g < 0x10000; g += 1285 {
|
||||||
|
for r := uint32(0); r < 0x10000; r += 1285 {
|
||||||
|
_r, _g, _b, _a := FromNRGBA(r, g, b, a).NRGBA()
|
||||||
|
|
||||||
|
if r != _r || g != _g || b != _b || a != _a {
|
||||||
|
t.Errorf("NRGBA(0x%04x,0x%04x,0x%04x,0x%04x) -> OkLab -> NRGBA(0x%04x,0x%04x,0x%04x,0x%04x)", r, g, b, a, _r, _g, _b, _a)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestColor_RGBA(t *testing.T) {
|
||||||
|
// This is similar to the NRGBA test, except the components step by a/17 instead of a fixed 1285.
|
||||||
|
// a/17 was chosen because 17 is a factor of 4369, so the components will end equalling a.
|
||||||
|
for a := uint32(0); a < 0x10000; a += 4369 {
|
||||||
|
step := max(1, a/17)
|
||||||
|
for b := uint32(0); b <= a; b += step {
|
||||||
|
for g := uint32(0); g <= a; g += step {
|
||||||
|
for r := uint32(0); r <= a; r += step {
|
||||||
|
_r, _g, _b, _a := FromRGBA(r, g, b, a).RGBA()
|
||||||
|
|
||||||
|
if r != _r || g != _g || b != _b || a != _a {
|
||||||
|
t.Errorf("RGBA(0x%04x,0x%04x,0x%04x,0x%04x) -> OkLab -> RGBA(0x%04x,0x%04x,0x%04x,0x%04x)", r, g, b, a, _r, _g, _b, _a)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func Test_delinearize(t *testing.T) {
|
||||||
|
for c := uint32(0); c < 0x10000; c++ {
|
||||||
|
got := delinearize(linearize(c))
|
||||||
|
if got != c {
|
||||||
|
t.Errorf("delinearize(linearize(0x%04x)) != 0x%04x", c, got)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// The NRGBA and NRGBA64 models don't have sensible ways to recover transparent colors from types it
|
||||||
|
// doesn't know about, so I'm going to help them out.
|
||||||
|
func fixedNRGBAModel(c color.Color) color.Color {
|
||||||
|
if c, ok := c.(interface{ NRGBA() (r, g, b, a uint32) }); ok {
|
||||||
|
r, g, b, a := c.NRGBA()
|
||||||
|
return color.NRGBA{R: uint8(r >> 8), G: uint8(g >> 8), B: uint8(b >> 8), A: uint8(a >> 8)}
|
||||||
|
}
|
||||||
|
|
||||||
|
return color.NRGBAModel.Convert(c)
|
||||||
|
}
|
||||||
|
|
||||||
|
func fixedNRGBA64Model(c color.Color) color.Color {
|
||||||
|
if c, ok := c.(interface{ NRGBA() (r, g, b, a uint32) }); ok {
|
||||||
|
r, g, b, a := c.NRGBA()
|
||||||
|
return color.NRGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: uint16(a)}
|
||||||
|
}
|
||||||
|
|
||||||
|
return color.NRGBA64Model.Convert(c)
|
||||||
|
}
|
||||||
|
|
||||||
|
func Test_Model(t *testing.T) {
|
||||||
|
// test to make sure we can reproduce some test colors.
|
||||||
|
// In particular, I want to make sure the colors can be recovered from transparent NRGBA and NRGBA64.
|
||||||
|
for _, tt := range [...]struct {
|
||||||
|
name string
|
||||||
|
color color.Color
|
||||||
|
model color.Model
|
||||||
|
}{
|
||||||
|
{
|
||||||
|
"OkLab: nop",
|
||||||
|
Color{math.Inf(1), math.Inf(-1), math.MaxFloat64, 0},
|
||||||
|
Model,
|
||||||
|
}, {
|
||||||
|
"NRGBA: opaque Sapphire",
|
||||||
|
color.NRGBA{R: 0x0f, G: 0x52, B: 0xba, A: 0xff},
|
||||||
|
color.ModelFunc(fixedNRGBAModel),
|
||||||
|
}, {
|
||||||
|
"NRGBA: translucent Orchid",
|
||||||
|
color.NRGBA{R: 0xda, G: 0x70, B: 0xd6, A: 0x7f},
|
||||||
|
color.ModelFunc(fixedNRGBAModel),
|
||||||
|
}, {
|
||||||
|
"NRGBA: invisible Floral White",
|
||||||
|
color.NRGBA{R: 0xff, G: 0xfa, B: 0xf0, A: 0x00},
|
||||||
|
color.ModelFunc(fixedNRGBAModel),
|
||||||
|
}, {
|
||||||
|
"NRGBA64: opaque Amethyst",
|
||||||
|
color.NRGBA64{R: 0x9999, G: 0x6666, B: 0xcccc, A: 0xffff},
|
||||||
|
color.ModelFunc(fixedNRGBA64Model),
|
||||||
|
}, {
|
||||||
|
"NRGBA64: translucent Smoke",
|
||||||
|
color.NRGBA64{R: 0xf5f5, G: 0xf5f5, B: 0xf5f5, A: 0x7fff},
|
||||||
|
color.ModelFunc(fixedNRGBA64Model),
|
||||||
|
}, {
|
||||||
|
"NRGBA64: invisible Emerald",
|
||||||
|
color.NRGBA64{R: 0x5050, G: 0xC8C8, B: 0x7878, A: 0x0000},
|
||||||
|
color.ModelFunc(fixedNRGBA64Model),
|
||||||
|
}, {
|
||||||
|
"RGBA64: opaque Chartreuse",
|
||||||
|
color.RGBA64{R: 0xb2b2, G: 0xd6d6, B: 0x3f3f, A: 0xffff},
|
||||||
|
color.RGBA64Model,
|
||||||
|
}, {
|
||||||
|
"RGBA64: transparent Mauveine",
|
||||||
|
color.RGBA64{R: 0x577c, G: 0x013e, B: 0x602b, A: 0x9e37},
|
||||||
|
color.RGBA64Model,
|
||||||
|
}, {
|
||||||
|
"RGBA64: invisible nothing",
|
||||||
|
color.RGBA64{R: 0x0, G: 0x0, B: 0x0, A: 0x0},
|
||||||
|
color.RGBA64Model,
|
||||||
|
}, {
|
||||||
|
"RGBA: opaque Chartreuse",
|
||||||
|
color.RGBA{R: 0xb2, G: 0xd6, B: 0x3f, A: 0xff},
|
||||||
|
color.RGBAModel,
|
||||||
|
}, {
|
||||||
|
"RGBA: transparent Mauveine",
|
||||||
|
color.RGBA{R: 0x57, G: 0x01, B: 0x60, A: 0x9e},
|
||||||
|
color.RGBAModel,
|
||||||
|
}, {
|
||||||
|
"RGBA: invisible nothing",
|
||||||
|
color.RGBA{R: 0x0, G: 0x0, B: 0x0, A: 0x0},
|
||||||
|
color.RGBAModel,
|
||||||
|
},
|
||||||
|
} {
|
||||||
|
t.Run(tt.name, func(t *testing.T) {
|
||||||
|
c := Model.Convert(tt.color).(Color)
|
||||||
|
|
||||||
|
if got := tt.model.Convert(c); !reflect.DeepEqual(got, tt.color) {
|
||||||
|
t.Errorf("%#+v -> %#+v -> %#+v, want %#+v", tt.color, c, got, tt.color)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
})
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestDistance(t *testing.T) {
|
||||||
|
colours := []Color{
|
||||||
|
FromNRGBA(0xffff, 0xffff, 0xffff, 0xffff),
|
||||||
|
FromNRGBA(0xffff, 0xffff, 0xffff, 0x7fff),
|
||||||
|
FromNRGBA(0xffff, 0xffff, 0xffff, 0x0000),
|
||||||
|
FromNRGBA(0x0000, 0x0000, 0x0000, 0xffff),
|
||||||
|
FromNRGBA(0x0000, 0x0000, 0x0000, 0x7fff),
|
||||||
|
FromNRGBA(0x0000, 0x0000, 0x0000, 0x0000),
|
||||||
|
}
|
||||||
|
|
||||||
|
for i, c0 := range colours {
|
||||||
|
for j, c1 := range colours {
|
||||||
|
d := Distance(c0, c1)
|
||||||
|
|
||||||
|
if i == j || (c0.A == 0 && c1.A == 0) {
|
||||||
|
// if they're the same color, or both are completely transparent,
|
||||||
|
// they should be perceived as identical.
|
||||||
|
|
||||||
|
if d != 0 {
|
||||||
|
t.Errorf("Distance(%v, %v) = %v, want 0", c0, c1, d)
|
||||||
|
}
|
||||||
|
} else {
|
||||||
|
// otherwise, there should be some kind of difference between them.
|
||||||
|
if d <= 0 {
|
||||||
|
t.Errorf("Distance(%v, %v) = %v, want > 0", c0, c1, d)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
mid := Color{
|
||||||
|
Lightness: (c0.Lightness + c1.Lightness) * 0.5,
|
||||||
|
ChromaA: (c0.ChromaA + c1.ChromaA) * 0.5,
|
||||||
|
ChromaB: (c0.ChromaB + c1.ChromaB) * 0.5,
|
||||||
|
A: (c0.A + c1.A) * 0.5,
|
||||||
|
}
|
||||||
|
|
||||||
|
// traveling from c0 to c1 via mid can't possibly be
|
||||||
|
// shorter than traveling from c0 to c1 directly.
|
||||||
|
d2 := Distance(c0, mid) + Distance(mid, c1)
|
||||||
|
if d2 < d {
|
||||||
|
t.Errorf("Distance(%v, %v)+Distance(%v, %v) < Distance(%v, %v), want %f >= %f", c0, mid, mid, c1, c0, c1, d2, d)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
Loading…
x
Reference in New Issue
Block a user