github.com/onsi/ginkgo@v1.16.6-0.20211118180735-4e1925ba4c95/formatter/colorable_windows.go

/*
These packages are used for colorize on Windows and contributed by mattn.jp@gmail.com

  * go-colorable: <https://github.com/mattn/go-colorable>
  * go-isatty: <https://github.com/mattn/go-isatty>

The MIT License (MIT)

Copyright (c) 2016 Yasuhiro Matsumoto

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

package formatter

import (
	"bytes"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
	"strings"
	"syscall"
	"unsafe"
)

var (
	kernel32                       = syscall.NewLazyDLL("kernel32.dll")
	procGetConsoleScreenBufferInfo = kernel32.NewProc("GetConsoleScreenBufferInfo")
	procSetConsoleTextAttribute    = kernel32.NewProc("SetConsoleTextAttribute")
	procSetConsoleCursorPosition   = kernel32.NewProc("SetConsoleCursorPosition")
	procFillConsoleOutputCharacter = kernel32.NewProc("FillConsoleOutputCharacterW")
	procFillConsoleOutputAttribute = kernel32.NewProc("FillConsoleOutputAttribute")
	procGetConsoleMode             = kernel32.NewProc("GetConsoleMode")
)

func isTerminal(fd uintptr) bool {
	var st uint32
	r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, fd, uintptr(unsafe.Pointer(&st)), 0)
	return r != 0 && e == 0
}

const (
	foregroundBlue      = 0x1
	foregroundGreen     = 0x2
	foregroundRed       = 0x4
	foregroundIntensity = 0x8
	foregroundMask      = (foregroundRed | foregroundBlue | foregroundGreen | foregroundIntensity)
	backgroundBlue      = 0x10
	backgroundGreen     = 0x20
	backgroundRed       = 0x40
	backgroundIntensity = 0x80
	backgroundMask      = (backgroundRed | backgroundBlue | backgroundGreen | backgroundIntensity)
)

type wchar uint16
type short int16
type dword uint32
type word uint16

type coord struct {
	x short
	y short
}

type smallRect struct {
	left   short
	top    short
	right  short
	bottom short
}

type consoleScreenBufferInfo struct {
	size              coord
	cursorPosition    coord
	attributes        word
	window            smallRect
	maximumWindowSize coord
}

type writer struct {
	out     io.Writer
	handle  syscall.Handle
	lastbuf bytes.Buffer
	oldattr word
}

func newColorable(file *os.File) io.Writer {
	if file == nil {
		panic("nil passed instead of *os.File to NewColorable()")
	}

	if isTerminal(file.Fd()) {
		var csbi consoleScreenBufferInfo
		handle := syscall.Handle(file.Fd())
		procGetConsoleScreenBufferInfo.Call(uintptr(handle), uintptr(unsafe.Pointer(&csbi)))
		return &writer{out: file, handle: handle, oldattr: csbi.attributes}
	} else {
		return file
	}
}

var color256 = map[int]int{
	0:   0x000000,
	1:   0x800000,
	2:   0x008000,
	3:   0x808000,
	4:   0x000080,
	5:   0x800080,
	6:   0x008080,
	7:   0xc0c0c0,
	8:   0x808080,
	9:   0xff0000,
	10:  0x00ff00,
	11:  0xffff00,
	12:  0x0000ff,
	13:  0xff00ff,
	14:  0x00ffff,
	15:  0xffffff,
	16:  0x000000,
	17:  0x00005f,
	18:  0x000087,
	19:  0x0000af,
	20:  0x0000d7,
	21:  0x0000ff,
	22:  0x005f00,
	23:  0x005f5f,
	24:  0x005f87,
	25:  0x005faf,
	26:  0x005fd7,
	27:  0x005fff,
	28:  0x008700,
	29:  0x00875f,
	30:  0x008787,
	31:  0x0087af,
	32:  0x0087d7,
	33:  0x0087ff,
	34:  0x00af00,
	35:  0x00af5f,
	36:  0x00af87,
	37:  0x00afaf,
	38:  0x00afd7,
	39:  0x00afff,
	40:  0x00d700,
	41:  0x00d75f,
	42:  0x00d787,
	43:  0x00d7af,
	44:  0x00d7d7,
	45:  0x00d7ff,
	46:  0x00ff00,
	47:  0x00ff5f,
	48:  0x00ff87,
	49:  0x00ffaf,
	50:  0x00ffd7,
	51:  0x00ffff,
	52:  0x5f0000,
	53:  0x5f005f,
	54:  0x5f0087,
	55:  0x5f00af,
	56:  0x5f00d7,
	57:  0x5f00ff,
	58:  0x5f5f00,
	59:  0x5f5f5f,
	60:  0x5f5f87,
	61:  0x5f5faf,
	62:  0x5f5fd7,
	63:  0x5f5fff,
	64:  0x5f8700,
	65:  0x5f875f,
	66:  0x5f8787,
	67:  0x5f87af,
	68:  0x5f87d7,
	69:  0x5f87ff,
	70:  0x5faf00,
	71:  0x5faf5f,
	72:  0x5faf87,
	73:  0x5fafaf,
	74:  0x5fafd7,
	75:  0x5fafff,
	76:  0x5fd700,
	77:  0x5fd75f,
	78:  0x5fd787,
	79:  0x5fd7af,
	80:  0x5fd7d7,
	81:  0x5fd7ff,
	82:  0x5fff00,
	83:  0x5fff5f,
	84:  0x5fff87,
	85:  0x5fffaf,
	86:  0x5fffd7,
	87:  0x5fffff,
	88:  0x870000,
	89:  0x87005f,
	90:  0x870087,
	91:  0x8700af,
	92:  0x8700d7,
	93:  0x8700ff,
	94:  0x875f00,
	95:  0x875f5f,
	96:  0x875f87,
	97:  0x875faf,
	98:  0x875fd7,
	99:  0x875fff,
	100: 0x878700,
	101: 0x87875f,
	102: 0x878787,
	103: 0x8787af,
	104: 0x8787d7,
	105: 0x8787ff,
	106: 0x87af00,
	107: 0x87af5f,
	108: 0x87af87,
	109: 0x87afaf,
	110: 0x87afd7,
	111: 0x87afff,
	112: 0x87d700,
	113: 0x87d75f,
	114: 0x87d787,
	115: 0x87d7af,
	116: 0x87d7d7,
	117: 0x87d7ff,
	118: 0x87ff00,
	119: 0x87ff5f,
	120: 0x87ff87,
	121: 0x87ffaf,
	122: 0x87ffd7,
	123: 0x87ffff,
	124: 0xaf0000,
	125: 0xaf005f,
	126: 0xaf0087,
	127: 0xaf00af,
	128: 0xaf00d7,
	129: 0xaf00ff,
	130: 0xaf5f00,
	131: 0xaf5f5f,
	132: 0xaf5f87,
	133: 0xaf5faf,
	134: 0xaf5fd7,
	135: 0xaf5fff,
	136: 0xaf8700,
	137: 0xaf875f,
	138: 0xaf8787,
	139: 0xaf87af,
	140: 0xaf87d7,
	141: 0xaf87ff,
	142: 0xafaf00,
	143: 0xafaf5f,
	144: 0xafaf87,
	145: 0xafafaf,
	146: 0xafafd7,
	147: 0xafafff,
	148: 0xafd700,
	149: 0xafd75f,
	150: 0xafd787,
	151: 0xafd7af,
	152: 0xafd7d7,
	153: 0xafd7ff,
	154: 0xafff00,
	155: 0xafff5f,
	156: 0xafff87,
	157: 0xafffaf,
	158: 0xafffd7,
	159: 0xafffff,
	160: 0xd70000,
	161: 0xd7005f,
	162: 0xd70087,
	163: 0xd700af,
	164: 0xd700d7,
	165: 0xd700ff,
	166: 0xd75f00,
	167: 0xd75f5f,
	168: 0xd75f87,
	169: 0xd75faf,
	170: 0xd75fd7,
	171: 0xd75fff,
	172: 0xd78700,
	173: 0xd7875f,
	174: 0xd78787,
	175: 0xd787af,
	176: 0xd787d7,
	177: 0xd787ff,
	178: 0xd7af00,
	179: 0xd7af5f,
	180: 0xd7af87,
	181: 0xd7afaf,
	182: 0xd7afd7,
	183: 0xd7afff,
	184: 0xd7d700,
	185: 0xd7d75f,
	186: 0xd7d787,
	187: 0xd7d7af,
	188: 0xd7d7d7,
	189: 0xd7d7ff,
	190: 0xd7ff00,
	191: 0xd7ff5f,
	192: 0xd7ff87,
	193: 0xd7ffaf,
	194: 0xd7ffd7,
	195: 0xd7ffff,
	196: 0xff0000,
	197: 0xff005f,
	198: 0xff0087,
	199: 0xff00af,
	200: 0xff00d7,
	201: 0xff00ff,
	202: 0xff5f00,
	203: 0xff5f5f,
	204: 0xff5f87,
	205: 0xff5faf,
	206: 0xff5fd7,
	207: 0xff5fff,
	208: 0xff8700,
	209: 0xff875f,
	210: 0xff8787,
	211: 0xff87af,
	212: 0xff87d7,
	213: 0xff87ff,
	214: 0xffaf00,
	215: 0xffaf5f,
	216: 0xffaf87,
	217: 0xffafaf,
	218: 0xffafd7,
	219: 0xffafff,
	220: 0xffd700,
	221: 0xffd75f,
	222: 0xffd787,
	223: 0xffd7af,
	224: 0xffd7d7,
	225: 0xffd7ff,
	226: 0xffff00,
	227: 0xffff5f,
	228: 0xffff87,
	229: 0xffffaf,
	230: 0xffffd7,
	231: 0xffffff,
	232: 0x080808,
	233: 0x121212,
	234: 0x1c1c1c,
	235: 0x262626,
	236: 0x303030,
	237: 0x3a3a3a,
	238: 0x444444,
	239: 0x4e4e4e,
	240: 0x585858,
	241: 0x626262,
	242: 0x6c6c6c,
	243: 0x767676,
	244: 0x808080,
	245: 0x8a8a8a,
	246: 0x949494,
	247: 0x9e9e9e,
	248: 0xa8a8a8,
	249: 0xb2b2b2,
	250: 0xbcbcbc,
	251: 0xc6c6c6,
	252: 0xd0d0d0,
	253: 0xdadada,
	254: 0xe4e4e4,
	255: 0xeeeeee,
}

func (w *writer) Write(data []byte) (n int, err error) {
	var csbi consoleScreenBufferInfo
	procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))

	er := bytes.NewBuffer(data)
loop:
	for {
		r1, _, err := procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
		if r1 == 0 {
			break loop
		}

		c1, _, err := er.ReadRune()
		if err != nil {
			break loop
		}
		if c1 != 0x1b {
			fmt.Fprint(w.out, string(c1))
			continue
		}
		c2, _, err := er.ReadRune()
		if err != nil {
			w.lastbuf.WriteRune(c1)
			break loop
		}
		if c2 != 0x5b {
			w.lastbuf.WriteRune(c1)
			w.lastbuf.WriteRune(c2)
			continue
		}

		var buf bytes.Buffer
		var m rune
		for {
			c, _, err := er.ReadRune()
			if err != nil {
				w.lastbuf.WriteRune(c1)
				w.lastbuf.WriteRune(c2)
				w.lastbuf.Write(buf.Bytes())
				break loop
			}
			if ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || c == '@' {
				m = c
				break
			}
			buf.Write([]byte(string(c)))
		}

		var csbi consoleScreenBufferInfo
		switch m {
		case 'A':
			n, err = strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
			csbi.cursorPosition.y -= short(n)
			procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
		case 'B':
			n, err = strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
			csbi.cursorPosition.y += short(n)
			procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
		case 'C':
			n, err = strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
			csbi.cursorPosition.x -= short(n)
			procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
		case 'D':
			n, err = strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			if n, err = strconv.Atoi(buf.String()); err == nil {
				var csbi consoleScreenBufferInfo
				procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
				csbi.cursorPosition.x += short(n)
				procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
			}
		case 'E':
			n, err = strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
			csbi.cursorPosition.x = 0
			csbi.cursorPosition.y += short(n)
			procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
		case 'F':
			n, err = strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
			csbi.cursorPosition.x = 0
			csbi.cursorPosition.y -= short(n)
			procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
		case 'G':
			n, err = strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))
			csbi.cursorPosition.x = short(n)
			procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
		case 'H':
			token := strings.Split(buf.String(), ";")
			if len(token) != 2 {
				continue
			}
			n1, err := strconv.Atoi(token[0])
			if err != nil {
				continue
			}
			n2, err := strconv.Atoi(token[1])
			if err != nil {
				continue
			}
			csbi.cursorPosition.x = short(n2)
			csbi.cursorPosition.x = short(n1)
			procSetConsoleCursorPosition.Call(uintptr(w.handle), *(*uintptr)(unsafe.Pointer(&csbi.cursorPosition)))
		case 'J':
			n, err := strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			var cursor coord
			switch n {
			case 0:
				cursor = coord{x: csbi.cursorPosition.x, y: csbi.cursorPosition.y}
			case 1:
				cursor = coord{x: csbi.window.left, y: csbi.window.top}
			case 2:
				cursor = coord{x: csbi.window.left, y: csbi.window.top}
			}
			var count, written dword
			count = dword(csbi.size.x - csbi.cursorPosition.x + (csbi.size.y-csbi.cursorPosition.y)*csbi.size.x)
			procFillConsoleOutputCharacter.Call(uintptr(w.handle), uintptr(' '), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&written)))
			procFillConsoleOutputAttribute.Call(uintptr(w.handle), uintptr(csbi.attributes), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&written)))
		case 'K':
			n, err := strconv.Atoi(buf.String())
			if err != nil {
				continue
			}
			var cursor coord
			switch n {
			case 0:
				cursor = coord{x: csbi.cursorPosition.x, y: csbi.cursorPosition.y}
			case 1:
				cursor = coord{x: csbi.window.left, y: csbi.window.top + csbi.cursorPosition.y}
			case 2:
				cursor = coord{x: csbi.window.left, y: csbi.window.top + csbi.cursorPosition.y}
			}
			var count, written dword
			count = dword(csbi.size.x - csbi.cursorPosition.x)
			procFillConsoleOutputCharacter.Call(uintptr(w.handle), uintptr(' '), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&written)))
			procFillConsoleOutputAttribute.Call(uintptr(w.handle), uintptr(csbi.attributes), uintptr(count), *(*uintptr)(unsafe.Pointer(&cursor)), uintptr(unsafe.Pointer(&written)))
		case 'm':
			attr := csbi.attributes
			cs := buf.String()
			if cs == "" {
				procSetConsoleTextAttribute.Call(uintptr(w.handle), uintptr(w.oldattr))
				continue
			}
			token := strings.Split(cs, ";")
			for i := 0; i < len(token); i += 1 {
				ns := token[i]
				if n, err = strconv.Atoi(ns); err == nil {
					switch {
					case n == 0 || n == 100:
						attr = w.oldattr
					case 1 <= n && n <= 5:
						attr |= foregroundIntensity
					case n == 7:
						attr = ((attr & foregroundMask) << 4) | ((attr & backgroundMask) >> 4)
					case 22 == n || n == 25 || n == 25:
						attr |= foregroundIntensity
					case n == 27:
						attr = ((attr & foregroundMask) << 4) | ((attr & backgroundMask) >> 4)
					case 30 <= n && n <= 37:
						attr = (attr & backgroundMask)
						if (n-30)&1 != 0 {
							attr |= foregroundRed
						}
						if (n-30)&2 != 0 {
							attr |= foregroundGreen
						}
						if (n-30)&4 != 0 {
							attr |= foregroundBlue
						}
					case n == 38: // set foreground color.
						if i < len(token)-2 && (token[i+1] == "5" || token[i+1] == "05") {
							if n256, err := strconv.Atoi(token[i+2]); err == nil {
								if n256foreAttr == nil {
									n256setup()
								}
								attr &= backgroundMask
								attr |= n256foreAttr[n256]
								i += 2
							}
						} else {
							attr = attr & (w.oldattr & backgroundMask)
						}
					case n == 39: // reset foreground color.
						attr &= backgroundMask
						attr |= w.oldattr & foregroundMask
					case 40 <= n && n <= 47:
						attr = (attr & foregroundMask)
						if (n-40)&1 != 0 {
							attr |= backgroundRed
						}
						if (n-40)&2 != 0 {
							attr |= backgroundGreen
						}
						if (n-40)&4 != 0 {
							attr |= backgroundBlue
						}
					case n == 48: // set background color.
						if i < len(token)-2 && token[i+1] == "5" {
							if n256, err := strconv.Atoi(token[i+2]); err == nil {
								if n256backAttr == nil {
									n256setup()
								}
								attr &= foregroundMask
								attr |= n256backAttr[n256]
								i += 2
							}
						} else {
							attr = attr & (w.oldattr & foregroundMask)
						}
					case n == 49: // reset foreground color.
						attr &= foregroundMask
						attr |= w.oldattr & backgroundMask
					case 90 <= n && n <= 97:
						attr = (attr & backgroundMask)
						attr |= foregroundIntensity
						if (n-90)&1 != 0 {
							attr |= foregroundRed
						}
						if (n-90)&2 != 0 {
							attr |= foregroundGreen
						}
						if (n-90)&4 != 0 {
							attr |= foregroundBlue
						}
					case 100 <= n && n <= 107:
						attr = (attr & foregroundMask)
						attr |= backgroundIntensity
						if (n-100)&1 != 0 {
							attr |= backgroundRed
						}
						if (n-100)&2 != 0 {
							attr |= backgroundGreen
						}
						if (n-100)&4 != 0 {
							attr |= backgroundBlue
						}
					}
					procSetConsoleTextAttribute.Call(uintptr(w.handle), uintptr(attr))
				}
			}
		}
	}
	return len(data) - w.lastbuf.Len(), nil
}

type consoleColor struct {
	rgb       int
	red       bool
	green     bool
	blue      bool
	intensity bool
}

func (c consoleColor) foregroundAttr() (attr word) {
	if c.red {
		attr |= foregroundRed
	}
	if c.green {
		attr |= foregroundGreen
	}
	if c.blue {
		attr |= foregroundBlue
	}
	if c.intensity {
		attr |= foregroundIntensity
	}
	return
}

func (c consoleColor) backgroundAttr() (attr word) {
	if c.red {
		attr |= backgroundRed
	}
	if c.green {
		attr |= backgroundGreen
	}
	if c.blue {
		attr |= backgroundBlue
	}
	if c.intensity {
		attr |= backgroundIntensity
	}
	return
}

var color16 = []consoleColor{
	consoleColor{0x000000, false, false, false, false},
	consoleColor{0x000080, false, false, true, false},
	consoleColor{0x008000, false, true, false, false},
	consoleColor{0x008080, false, true, true, false},
	consoleColor{0x800000, true, false, false, false},
	consoleColor{0x800080, true, false, true, false},
	consoleColor{0x808000, true, true, false, false},
	consoleColor{0xc0c0c0, true, true, true, false},
	consoleColor{0x808080, false, false, false, true},
	consoleColor{0x0000ff, false, false, true, true},
	consoleColor{0x00ff00, false, true, false, true},
	consoleColor{0x00ffff, false, true, true, true},
	consoleColor{0xff0000, true, false, false, true},
	consoleColor{0xff00ff, true, false, true, true},
	consoleColor{0xffff00, true, true, false, true},
	consoleColor{0xffffff, true, true, true, true},
}

type hsv struct {
	h, s, v float32
}

func (a hsv) dist(b hsv) float32 {
	dh := a.h - b.h
	switch {
	case dh > 0.5:
		dh = 1 - dh
	case dh < -0.5:
		dh = -1 - dh
	}
	ds := a.s - b.s
	dv := a.v - b.v
	return float32(math.Sqrt(float64(dh*dh + ds*ds + dv*dv)))
}

func toHSV(rgb int) hsv {
	r, g, b := float32((rgb&0xFF0000)>>16)/256.0,
		float32((rgb&0x00FF00)>>8)/256.0,
		float32(rgb&0x0000FF)/256.0
	min, max := minmax3f(r, g, b)
	h := max - min
	if h > 0 {
		if max == r {
			h = (g - b) / h
			if h < 0 {
				h += 6
			}
		} else if max == g {
			h = 2 + (b-r)/h
		} else {
			h = 4 + (r-g)/h
		}
	}
	h /= 6.0
	s := max - min
	if max != 0 {
		s /= max
	}
	v := max
	return hsv{h: h, s: s, v: v}
}

type hsvTable []hsv

func toHSVTable(rgbTable []consoleColor) hsvTable {
	t := make(hsvTable, len(rgbTable))
	for i, c := range rgbTable {
		t[i] = toHSV(c.rgb)
	}
	return t
}

func (t hsvTable) find(rgb int) consoleColor {
	hsv := toHSV(rgb)
	n := 7
	l := float32(5.0)
	for i, p := range t {
		d := hsv.dist(p)
		if d < l {
			l, n = d, i
		}
	}
	return color16[n]
}

func minmax3f(a, b, c float32) (min, max float32) {
	if a < b {
		if b < c {
			return a, c
		} else if a < c {
			return a, b
		} else {
			return c, b
		}
	} else {
		if a < c {
			return b, c
		} else if b < c {
			return b, a
		} else {
			return c, a
		}
	}
}

var n256foreAttr []word
var n256backAttr []word

func n256setup() {
	n256foreAttr = make([]word, 256)
	n256backAttr = make([]word, 256)
	t := toHSVTable(color16)
	for i, rgb := range color256 {
		c := t.find(rgb)
		n256foreAttr[i] = c.foregroundAttr()
		n256backAttr[i] = c.backgroundAttr()
	}
}