ui: replace lookup tables with algorithm

The algorithm for computing the [16,256) range of the `standard' 256
colors comes from 256colors.pl from XFree86's xterm tree, which appears
to have given rise to the standard colors.

1 files changed, 44 insertions, 269 deletions

diff --git a/ui-curses.c b/ui-curses.c
index 3d2040d..52b11fc 100644
--- a/ui-curses.c
+++ b/ui-curses.c
@@ -124,129 +124,6 @@ typedef struct {
 	unsigned char b;
 } Color;
 
-static const Color color_from_256[] = {
-	{   0, 0x00, 0x00, 0x00 }, {   1, 0x00, 0x00, 0x5f },
-	{   2, 0x00, 0x00, 0x87 }, {   3, 0x00, 0x00, 0xaf },
-	{   4, 0x00, 0x00, 0xd7 }, {   5, 0x00, 0x00, 0xff },
-	{   6, 0x00, 0x5f, 0x00 }, {   7, 0x00, 0x5f, 0x5f },
-	{   8, 0x00, 0x5f, 0x87 }, {   9, 0x00, 0x5f, 0xaf },
-	{  10, 0x00, 0x5f, 0xd7 }, {  11, 0x00, 0x5f, 0xff },
-	{  12, 0x00, 0x87, 0x00 }, {  13, 0x00, 0x87, 0x5f },
-	{  14, 0x00, 0x87, 0x87 }, {  15, 0x00, 0x87, 0xaf },
-	{  16, 0x00, 0x87, 0xd7 }, {  17, 0x00, 0x87, 0xff },
-	{  18, 0x00, 0xaf, 0x00 }, {  19, 0x00, 0xaf, 0x5f },
-	{  20, 0x00, 0xaf, 0x87 }, {  21, 0x00, 0xaf, 0xaf },
-	{  22, 0x00, 0xaf, 0xd7 }, {  23, 0x00, 0xaf, 0xff },
-	{  24, 0x00, 0xd7, 0x00 }, {  25, 0x00, 0xd7, 0x5f },
-	{  26, 0x00, 0xd7, 0x87 }, {  27, 0x00, 0xd7, 0xaf },
-	{  28, 0x00, 0xd7, 0xd7 }, {  29, 0x00, 0xd7, 0xff },
-	{  30, 0x00, 0xff, 0x00 }, {  31, 0x00, 0xff, 0x5f },
-	{  32, 0x00, 0xff, 0x87 }, {  33, 0x00, 0xff, 0xaf },
-	{  34, 0x00, 0xff, 0xd7 }, {  35, 0x00, 0xff, 0xff },
-	{  36, 0x5f, 0x00, 0x00 }, {  37, 0x5f, 0x00, 0x5f },
-	{  38, 0x5f, 0x00, 0x87 }, {  39, 0x5f, 0x00, 0xaf },
-	{  40, 0x5f, 0x00, 0xd7 }, {  41, 0x5f, 0x00, 0xff },
-	{  42, 0x5f, 0x5f, 0x00 }, {  43, 0x5f, 0x5f, 0x5f },
-	{  44, 0x5f, 0x5f, 0x87 }, {  45, 0x5f, 0x5f, 0xaf },
-	{  46, 0x5f, 0x5f, 0xd7 }, {  47, 0x5f, 0x5f, 0xff },
-	{  48, 0x5f, 0x87, 0x00 }, {  49, 0x5f, 0x87, 0x5f },
-	{  50, 0x5f, 0x87, 0x87 }, {  51, 0x5f, 0x87, 0xaf },
-	{  52, 0x5f, 0x87, 0xd7 }, {  53, 0x5f, 0x87, 0xff },
-	{  54, 0x5f, 0xaf, 0x00 }, {  55, 0x5f, 0xaf, 0x5f },
-	{  56, 0x5f, 0xaf, 0x87 }, {  57, 0x5f, 0xaf, 0xaf },
-	{  58, 0x5f, 0xaf, 0xd7 }, {  59, 0x5f, 0xaf, 0xff },
-	{  60, 0x5f, 0xd7, 0x00 }, {  61, 0x5f, 0xd7, 0x5f },
-	{  62, 0x5f, 0xd7, 0x87 }, {  63, 0x5f, 0xd7, 0xaf },
-	{  64, 0x5f, 0xd7, 0xd7 }, {  65, 0x5f, 0xd7, 0xff },
-	{  66, 0x5f, 0xff, 0x00 }, {  67, 0x5f, 0xff, 0x5f },
-	{  68, 0x5f, 0xff, 0x87 }, {  69, 0x5f, 0xff, 0xaf },
-	{  70, 0x5f, 0xff, 0xd7 }, {  71, 0x5f, 0xff, 0xff },
-	{  72, 0x87, 0x00, 0x00 }, {  73, 0x87, 0x00, 0x5f },
-	{  74, 0x87, 0x00, 0x87 }, {  75, 0x87, 0x00, 0xaf },
-	{  76, 0x87, 0x00, 0xd7 }, {  77, 0x87, 0x00, 0xff },
-	{  78, 0x87, 0x5f, 0x00 }, {  79, 0x87, 0x5f, 0x5f },
-	{  80, 0x87, 0x5f, 0x87 }, {  81, 0x87, 0x5f, 0xaf },
-	{  82, 0x87, 0x5f, 0xd7 }, {  83, 0x87, 0x5f, 0xff },
-	{  84, 0x87, 0x87, 0x00 }, {  85, 0x87, 0x87, 0x5f },
-	{  86, 0x87, 0x87, 0x87 }, {  87, 0x87, 0x87, 0xaf },
-	{  88, 0x87, 0x87, 0xd7 }, {  89, 0x87, 0x87, 0xff },
-	{  90, 0x87, 0xaf, 0x00 }, {  91, 0x87, 0xaf, 0x5f },
-	{  92, 0x87, 0xaf, 0x87 }, {  93, 0x87, 0xaf, 0xaf },
-	{  94, 0x87, 0xaf, 0xd7 }, {  95, 0x87, 0xaf, 0xff },
-	{  96, 0x87, 0xd7, 0x00 }, {  97, 0x87, 0xd7, 0x5f },
-	{  98, 0x87, 0xd7, 0x87 }, {  99, 0x87, 0xd7, 0xaf },
-	{ 100, 0x87, 0xd7, 0xd7 }, { 101, 0x87, 0xd7, 0xff },
-	{ 102, 0x87, 0xff, 0x00 }, { 103, 0x87, 0xff, 0x5f },
-	{ 104, 0x87, 0xff, 0x87 }, { 105, 0x87, 0xff, 0xaf },
-	{ 106, 0x87, 0xff, 0xd7 }, { 107, 0x87, 0xff, 0xff },
-	{ 108, 0xaf, 0x00, 0x00 }, { 109, 0xaf, 0x00, 0x5f },
-	{ 110, 0xaf, 0x00, 0x87 }, { 111, 0xaf, 0x00, 0xaf },
-	{ 112, 0xaf, 0x00, 0xd7 }, { 113, 0xaf, 0x00, 0xff },
-	{ 114, 0xaf, 0x5f, 0x00 }, { 115, 0xaf, 0x5f, 0x5f },
-	{ 116, 0xaf, 0x5f, 0x87 }, { 117, 0xaf, 0x5f, 0xaf },
-	{ 118, 0xaf, 0x5f, 0xd7 }, { 119, 0xaf, 0x5f, 0xff },
-	{ 120, 0xaf, 0x87, 0x00 }, { 121, 0xaf, 0x87, 0x5f },
-	{ 122, 0xaf, 0x87, 0x87 }, { 123, 0xaf, 0x87, 0xaf },
-	{ 124, 0xaf, 0x87, 0xd7 }, { 125, 0xaf, 0x87, 0xff },
-	{ 126, 0xaf, 0xaf, 0x00 }, { 127, 0xaf, 0xaf, 0x5f },
-	{ 128, 0xaf, 0xaf, 0x87 }, { 129, 0xaf, 0xaf, 0xaf },
-	{ 130, 0xaf, 0xaf, 0xd7 }, { 131, 0xaf, 0xaf, 0xff },
-	{ 132, 0xaf, 0xd7, 0x00 }, { 133, 0xaf, 0xd7, 0x5f },
-	{ 134, 0xaf, 0xd7, 0x87 }, { 135, 0xaf, 0xd7, 0xaf },
-	{ 136, 0xaf, 0xd7, 0xd7 }, { 137, 0xaf, 0xd7, 0xff },
-	{ 138, 0xaf, 0xff, 0x00 }, { 139, 0xaf, 0xff, 0x5f },
-	{ 140, 0xaf, 0xff, 0x87 }, { 141, 0xaf, 0xff, 0xaf },
-	{ 142, 0xaf, 0xff, 0xd7 }, { 143, 0xaf, 0xff, 0xff },
-	{ 144, 0xd7, 0x00, 0x00 }, { 145, 0xd7, 0x00, 0x5f },
-	{ 146, 0xd7, 0x00, 0x87 }, { 147, 0xd7, 0x00, 0xaf },
-	{ 148, 0xd7, 0x00, 0xd7 }, { 149, 0xd7, 0x00, 0xff },
-	{ 150, 0xd7, 0x5f, 0x00 }, { 151, 0xd7, 0x5f, 0x5f },
-	{ 152, 0xd7, 0x5f, 0x87 }, { 153, 0xd7, 0x5f, 0xaf },
-	{ 154, 0xd7, 0x5f, 0xd7 }, { 155, 0xd7, 0x5f, 0xff },
-	{ 156, 0xd7, 0x87, 0x00 }, { 157, 0xd7, 0x87, 0x5f },
-	{ 158, 0xd7, 0x87, 0x87 }, { 159, 0xd7, 0x87, 0xaf },
-	{ 160, 0xd7, 0x87, 0xd7 }, { 161, 0xd7, 0x87, 0xff },
-	{ 162, 0xd7, 0xaf, 0x00 }, { 163, 0xd7, 0xaf, 0x5f },
-	{ 164, 0xd7, 0xaf, 0x87 }, { 165, 0xd7, 0xaf, 0xaf },
-	{ 166, 0xd7, 0xaf, 0xd7 }, { 167, 0xd7, 0xaf, 0xff },
-	{ 168, 0xd7, 0xd7, 0x00 }, { 169, 0xd7, 0xd7, 0x5f },
-	{ 170, 0xd7, 0xd7, 0x87 }, { 171, 0xd7, 0xd7, 0xaf },
-	{ 172, 0xd7, 0xd7, 0xd7 }, { 173, 0xd7, 0xd7, 0xff },
-	{ 174, 0xd7, 0xff, 0x00 }, { 175, 0xd7, 0xff, 0x5f },
-	{ 176, 0xd7, 0xff, 0x87 }, { 177, 0xd7, 0xff, 0xaf },
-	{ 178, 0xd7, 0xff, 0xd7 }, { 179, 0xd7, 0xff, 0xff },
-	{ 180, 0xff, 0x00, 0x00 }, { 181, 0xff, 0x00, 0x5f },
-	{ 182, 0xff, 0x00, 0x87 }, { 183, 0xff, 0x00, 0xaf },
-	{ 184, 0xff, 0x00, 0xd7 }, { 185, 0xff, 0x00, 0xff },
-	{ 186, 0xff, 0x5f, 0x00 }, { 187, 0xff, 0x5f, 0x5f },
-	{ 188, 0xff, 0x5f, 0x87 }, { 189, 0xff, 0x5f, 0xaf },
-	{ 190, 0xff, 0x5f, 0xd7 }, { 191, 0xff, 0x5f, 0xff },
-	{ 192, 0xff, 0x87, 0x00 }, { 193, 0xff, 0x87, 0x5f },
-	{ 194, 0xff, 0x87, 0x87 }, { 195, 0xff, 0x87, 0xaf },
-	{ 196, 0xff, 0x87, 0xd7 }, { 197, 0xff, 0x87, 0xff },
-	{ 198, 0xff, 0xaf, 0x00 }, { 199, 0xff, 0xaf, 0x5f },
-	{ 200, 0xff, 0xaf, 0x87 }, { 201, 0xff, 0xaf, 0xaf },
-	{ 202, 0xff, 0xaf, 0xd7 }, { 203, 0xff, 0xaf, 0xff },
-	{ 204, 0xff, 0xd7, 0x00 }, { 205, 0xff, 0xd7, 0x5f },
-	{ 206, 0xff, 0xd7, 0x87 }, { 207, 0xff, 0xd7, 0xaf },
-	{ 208, 0xff, 0xd7, 0xd7 }, { 209, 0xff, 0xd7, 0xff },
-	{ 210, 0xff, 0xff, 0x00 }, { 211, 0xff, 0xff, 0x5f },
-	{ 212, 0xff, 0xff, 0x87 }, { 213, 0xff, 0xff, 0xaf },
-	{ 214, 0xff, 0xff, 0xd7 }, { 215, 0xff, 0xff, 0xff },
-	{ 216, 0x08, 0x08, 0x08 }, { 217, 0x12, 0x12, 0x12 },
-	{ 218, 0x1c, 0x1c, 0x1c }, { 219, 0x26, 0x26, 0x26 },
-	{ 220, 0x30, 0x30, 0x30 }, { 221, 0x3a, 0x3a, 0x3a },
-	{ 222, 0x44, 0x44, 0x44 }, { 223, 0x4e, 0x4e, 0x4e },
-	{ 224, 0x58, 0x58, 0x58 }, { 225, 0x62, 0x62, 0x62 },
-	{ 226, 0x6c, 0x6c, 0x6c }, { 227, 0x76, 0x76, 0x76 },
-	{ 228, 0x80, 0x80, 0x80 }, { 229, 0x8a, 0x8a, 0x8a },
-	{ 230, 0x94, 0x94, 0x94 }, { 231, 0x9e, 0x9e, 0x9e },
-	{ 232, 0xa8, 0xa8, 0xa8 }, { 233, 0xb2, 0xb2, 0xb2 },
-	{ 234, 0xbc, 0xbc, 0xbc }, { 235, 0xc6, 0xc6, 0xc6 },
-	{ 236, 0xd0, 0xd0, 0xd0 }, { 237, 0xda, 0xda, 0xda },
-	{ 238, 0xe4, 0xe4, 0xe4 }, { 239, 0xee, 0xee, 0xee },
-};
-
 #define MAX_COLOR_CLOBBER (240)
 static short color_clobber_idx = 0;
 static uint32_t clobbering_colors[MAX_COLOR_CLOBBER];
@@ -272,20 +149,35 @@ static int color_compare(const void *lhs0, const void *rhs0) {
 	return 0;
 }
 
+/* Calculate r,g,b components of one of the standard upper 240 colors */
+static void get_6cube_rgb(unsigned int n, int *r, int *g, int *b)
+{
+	if (n < 16) {
+		return;
+	} else if (n < 232) {
+		n -= 16;
+		*r = (n / 36) ? (n / 36) * 40 + 55 : 0;
+		*g = ((n / 6) % 6) ? ((n / 6) % 6) * 40 + 55 : 0;
+		*b = (n % 6) ? (n % 6) * 40 + 55 : 0;
+	} else if (n < 256) {
+		n -= 232;
+		*r = n * 10 + 8;
+		*g = n * 10 + 8;
+		*b = n * 10 + 8;
+	}
+}
+
 /* Reset color to xterm-style defaults via init_color and 6x6 cube */
 static void reset_color_by_6cube(unsigned int n)
 {
-	/* n should be in [0, 240) */
+	/* n should be in [16, 256) */
 	if (n >= MAX_COLOR_CLOBBER)
 		return;
 
-	unsigned int r6 = n / 36;
-	unsigned int g6 = (n / 6) % 6;
-	unsigned int b6 = n % 6;
-	unsigned int r = r6 ? (1000 * (r6 * 40 + 55)) / 0xff : 0;
-	unsigned int g = g6 ? (1000 * (g6 * 40 + 55)) / 0xff : 0;
-	unsigned int b = b6 ? (1000 * (b6 * 40 + 55)) / 0xff : 0;
-	init_color(16 + n, r, g, b);
+	int r = 0, g = 0, b = 0;
+	get_6cube_rgb(n, &r, &g, &b);
+	init_color(n, (r * 1000) / 0xff, (g * 1000) / 0xff,
+	           (b * 1000) / 0xff);
 }
 
 /* Reset every overwritten color to the standard-ish color cube */
@@ -294,7 +186,7 @@ static void undo_palette(void)
 	for (short i = 0; i < MAX_COLOR_CLOBBER; ++i) {
 		if (!clobbering_colors[i])
 			break;
-		reset_color_by_6cube(i);
+		reset_color_by_6cube(i + 16);
 	}
 }
 
@@ -337,129 +229,6 @@ static int color_find_rgb(unsigned char r, unsigned char g, unsigned char b)
 		return i + 16;
 	}
 
-	static const Color color_to_256[] = {
-		{   0, 0x00, 0x00, 0x00 }, {   1, 0x00, 0x00, 0x5f },
-		{   2, 0x00, 0x00, 0x87 }, {   3, 0x00, 0x00, 0xaf },
-		{   4, 0x00, 0x00, 0xd7 }, {   5, 0x00, 0x00, 0xff },
-		{   6, 0x00, 0x5f, 0x00 }, {   7, 0x00, 0x5f, 0x5f },
-		{   8, 0x00, 0x5f, 0x87 }, {   9, 0x00, 0x5f, 0xaf },
-		{  10, 0x00, 0x5f, 0xd7 }, {  11, 0x00, 0x5f, 0xff },
-		{  12, 0x00, 0x87, 0x00 }, {  13, 0x00, 0x87, 0x5f },
-		{  14, 0x00, 0x87, 0x87 }, {  15, 0x00, 0x87, 0xaf },
-		{  16, 0x00, 0x87, 0xd7 }, {  17, 0x00, 0x87, 0xff },
-		{  18, 0x00, 0xaf, 0x00 }, {  19, 0x00, 0xaf, 0x5f },
-		{  20, 0x00, 0xaf, 0x87 }, {  21, 0x00, 0xaf, 0xaf },
-		{  22, 0x00, 0xaf, 0xd7 }, {  23, 0x00, 0xaf, 0xff },
-		{  24, 0x00, 0xd7, 0x00 }, {  25, 0x00, 0xd7, 0x5f },
-		{  26, 0x00, 0xd7, 0x87 }, {  27, 0x00, 0xd7, 0xaf },
-		{  28, 0x00, 0xd7, 0xd7 }, {  29, 0x00, 0xd7, 0xff },
-		{  30, 0x00, 0xff, 0x00 }, {  31, 0x00, 0xff, 0x5f },
-		{  32, 0x00, 0xff, 0x87 }, {  33, 0x00, 0xff, 0xaf },
-		{  34, 0x00, 0xff, 0xd7 }, {  35, 0x00, 0xff, 0xff },
-		{ 216, 0x08, 0x08, 0x08 }, { 217, 0x12, 0x12, 0x12 },
-		{ 218, 0x1c, 0x1c, 0x1c }, { 219, 0x26, 0x26, 0x26 },
-		{ 220, 0x30, 0x30, 0x30 }, { 221, 0x3a, 0x3a, 0x3a },
-		{ 222, 0x44, 0x44, 0x44 }, { 223, 0x4e, 0x4e, 0x4e },
-		{ 224, 0x58, 0x58, 0x58 }, {  36, 0x5f, 0x00, 0x00 },
-		{  37, 0x5f, 0x00, 0x5f }, {  38, 0x5f, 0x00, 0x87 },
-		{  39, 0x5f, 0x00, 0xaf }, {  40, 0x5f, 0x00, 0xd7 },
-		{  41, 0x5f, 0x00, 0xff }, {  42, 0x5f, 0x5f, 0x00 },
-		{  43, 0x5f, 0x5f, 0x5f }, {  44, 0x5f, 0x5f, 0x87 },
-		{  45, 0x5f, 0x5f, 0xaf }, {  46, 0x5f, 0x5f, 0xd7 },
-		{  47, 0x5f, 0x5f, 0xff }, {  48, 0x5f, 0x87, 0x00 },
-		{  49, 0x5f, 0x87, 0x5f }, {  50, 0x5f, 0x87, 0x87 },
-		{  51, 0x5f, 0x87, 0xaf }, {  52, 0x5f, 0x87, 0xd7 },
-		{  53, 0x5f, 0x87, 0xff }, {  54, 0x5f, 0xaf, 0x00 },
-		{  55, 0x5f, 0xaf, 0x5f }, {  56, 0x5f, 0xaf, 0x87 },
-		{  57, 0x5f, 0xaf, 0xaf }, {  58, 0x5f, 0xaf, 0xd7 },
-		{  59, 0x5f, 0xaf, 0xff }, {  60, 0x5f, 0xd7, 0x00 },
-		{  61, 0x5f, 0xd7, 0x5f }, {  62, 0x5f, 0xd7, 0x87 },
-		{  63, 0x5f, 0xd7, 0xaf }, {  64, 0x5f, 0xd7, 0xd7 },
-		{  65, 0x5f, 0xd7, 0xff }, {  66, 0x5f, 0xff, 0x00 },
-		{  67, 0x5f, 0xff, 0x5f }, {  68, 0x5f, 0xff, 0x87 },
-		{  69, 0x5f, 0xff, 0xaf }, {  70, 0x5f, 0xff, 0xd7 },
-		{  71, 0x5f, 0xff, 0xff }, { 225, 0x62, 0x62, 0x62 },
-		{ 226, 0x6c, 0x6c, 0x6c }, { 227, 0x76, 0x76, 0x76 },
-		{ 228, 0x80, 0x80, 0x80 }, {  72, 0x87, 0x00, 0x00 },
-		{  73, 0x87, 0x00, 0x5f }, {  74, 0x87, 0x00, 0x87 },
-		{  75, 0x87, 0x00, 0xaf }, {  76, 0x87, 0x00, 0xd7 },
-		{  77, 0x87, 0x00, 0xff }, {  78, 0x87, 0x5f, 0x00 },
-		{  79, 0x87, 0x5f, 0x5f }, {  80, 0x87, 0x5f, 0x87 },
-		{  81, 0x87, 0x5f, 0xaf }, {  82, 0x87, 0x5f, 0xd7 },
-		{  83, 0x87, 0x5f, 0xff }, {  84, 0x87, 0x87, 0x00 },
-		{  85, 0x87, 0x87, 0x5f }, {  86, 0x87, 0x87, 0x87 },
-		{  87, 0x87, 0x87, 0xaf }, {  88, 0x87, 0x87, 0xd7 },
-		{  89, 0x87, 0x87, 0xff }, {  90, 0x87, 0xaf, 0x00 },
-		{  91, 0x87, 0xaf, 0x5f }, {  92, 0x87, 0xaf, 0x87 },
-		{  93, 0x87, 0xaf, 0xaf }, {  94, 0x87, 0xaf, 0xd7 },
-		{  95, 0x87, 0xaf, 0xff }, {  96, 0x87, 0xd7, 0x00 },
-		{  97, 0x87, 0xd7, 0x5f }, {  98, 0x87, 0xd7, 0x87 },
-		{  99, 0x87, 0xd7, 0xaf }, { 100, 0x87, 0xd7, 0xd7 },
-		{ 101, 0x87, 0xd7, 0xff }, { 102, 0x87, 0xff, 0x00 },
-		{ 103, 0x87, 0xff, 0x5f }, { 104, 0x87, 0xff, 0x87 },
-		{ 105, 0x87, 0xff, 0xaf }, { 106, 0x87, 0xff, 0xd7 },
-		{ 107, 0x87, 0xff, 0xff }, { 229, 0x8a, 0x8a, 0x8a },
-		{ 230, 0x94, 0x94, 0x94 }, { 231, 0x9e, 0x9e, 0x9e },
-		{ 232, 0xa8, 0xa8, 0xa8 }, { 108, 0xaf, 0x00, 0x00 },
-		{ 109, 0xaf, 0x00, 0x5f }, { 110, 0xaf, 0x00, 0x87 },
-		{ 111, 0xaf, 0x00, 0xaf }, { 112, 0xaf, 0x00, 0xd7 },
-		{ 113, 0xaf, 0x00, 0xff }, { 114, 0xaf, 0x5f, 0x00 },
-		{ 115, 0xaf, 0x5f, 0x5f }, { 116, 0xaf, 0x5f, 0x87 },
-		{ 117, 0xaf, 0x5f, 0xaf }, { 118, 0xaf, 0x5f, 0xd7 },
-		{ 119, 0xaf, 0x5f, 0xff }, { 120, 0xaf, 0x87, 0x00 },
-		{ 121, 0xaf, 0x87, 0x5f }, { 122, 0xaf, 0x87, 0x87 },
-		{ 123, 0xaf, 0x87, 0xaf }, { 124, 0xaf, 0x87, 0xd7 },
-		{ 125, 0xaf, 0x87, 0xff }, { 126, 0xaf, 0xaf, 0x00 },
-		{ 127, 0xaf, 0xaf, 0x5f }, { 128, 0xaf, 0xaf, 0x87 },
-		{ 129, 0xaf, 0xaf, 0xaf }, { 130, 0xaf, 0xaf, 0xd7 },
-		{ 131, 0xaf, 0xaf, 0xff }, { 132, 0xaf, 0xd7, 0x00 },
-		{ 133, 0xaf, 0xd7, 0x5f }, { 134, 0xaf, 0xd7, 0x87 },
-		{ 135, 0xaf, 0xd7, 0xaf }, { 136, 0xaf, 0xd7, 0xd7 },
-		{ 137, 0xaf, 0xd7, 0xff }, { 138, 0xaf, 0xff, 0x00 },
-		{ 139, 0xaf, 0xff, 0x5f }, { 140, 0xaf, 0xff, 0x87 },
-		{ 141, 0xaf, 0xff, 0xaf }, { 142, 0xaf, 0xff, 0xd7 },
-		{ 143, 0xaf, 0xff, 0xff }, { 233, 0xb2, 0xb2, 0xb2 },
-		{ 234, 0xbc, 0xbc, 0xbc }, { 235, 0xc6, 0xc6, 0xc6 },
-		{ 236, 0xd0, 0xd0, 0xd0 }, { 144, 0xd7, 0x00, 0x00 },
-		{ 145, 0xd7, 0x00, 0x5f }, { 146, 0xd7, 0x00, 0x87 },
-		{ 147, 0xd7, 0x00, 0xaf }, { 148, 0xd7, 0x00, 0xd7 },
-		{ 149, 0xd7, 0x00, 0xff }, { 150, 0xd7, 0x5f, 0x00 },
-		{ 151, 0xd7, 0x5f, 0x5f }, { 152, 0xd7, 0x5f, 0x87 },
-		{ 153, 0xd7, 0x5f, 0xaf }, { 154, 0xd7, 0x5f, 0xd7 },
-		{ 155, 0xd7, 0x5f, 0xff }, { 156, 0xd7, 0x87, 0x00 },
-		{ 157, 0xd7, 0x87, 0x5f }, { 158, 0xd7, 0x87, 0x87 },
-		{ 159, 0xd7, 0x87, 0xaf }, { 160, 0xd7, 0x87, 0xd7 },
-		{ 161, 0xd7, 0x87, 0xff }, { 162, 0xd7, 0xaf, 0x00 },
-		{ 163, 0xd7, 0xaf, 0x5f }, { 164, 0xd7, 0xaf, 0x87 },
-		{ 165, 0xd7, 0xaf, 0xaf }, { 166, 0xd7, 0xaf, 0xd7 },
-		{ 167, 0xd7, 0xaf, 0xff }, { 168, 0xd7, 0xd7, 0x00 },
-		{ 169, 0xd7, 0xd7, 0x5f }, { 170, 0xd7, 0xd7, 0x87 },
-		{ 171, 0xd7, 0xd7, 0xaf }, { 172, 0xd7, 0xd7, 0xd7 },
-		{ 173, 0xd7, 0xd7, 0xff }, { 174, 0xd7, 0xff, 0x00 },
-		{ 175, 0xd7, 0xff, 0x5f }, { 176, 0xd7, 0xff, 0x87 },
-		{ 177, 0xd7, 0xff, 0xaf }, { 178, 0xd7, 0xff, 0xd7 },
-		{ 179, 0xd7, 0xff, 0xff }, { 237, 0xda, 0xda, 0xda },
-		{ 238, 0xe4, 0xe4, 0xe4 }, { 239, 0xee, 0xee, 0xee },
-		{ 180, 0xff, 0x00, 0x00 }, { 181, 0xff, 0x00, 0x5f },
-		{ 182, 0xff, 0x00, 0x87 }, { 183, 0xff, 0x00, 0xaf },
-		{ 184, 0xff, 0x00, 0xd7 }, { 185, 0xff, 0x00, 0xff },
-		{ 186, 0xff, 0x5f, 0x00 }, { 187, 0xff, 0x5f, 0x5f },
-		{ 188, 0xff, 0x5f, 0x87 }, { 189, 0xff, 0x5f, 0xaf },
-		{ 190, 0xff, 0x5f, 0xd7 }, { 191, 0xff, 0x5f, 0xff },
-		{ 192, 0xff, 0x87, 0x00 }, { 193, 0xff, 0x87, 0x5f },
-		{ 194, 0xff, 0x87, 0x87 }, { 195, 0xff, 0x87, 0xaf },
-		{ 196, 0xff, 0x87, 0xd7 }, { 197, 0xff, 0x87, 0xff },
-		{ 198, 0xff, 0xaf, 0x00 }, { 199, 0xff, 0xaf, 0x5f },
-		{ 200, 0xff, 0xaf, 0x87 }, { 201, 0xff, 0xaf, 0xaf },
-		{ 202, 0xff, 0xaf, 0xd7 }, { 203, 0xff, 0xaf, 0xff },
-		{ 204, 0xff, 0xd7, 0x00 }, { 205, 0xff, 0xd7, 0x5f },
-		{ 206, 0xff, 0xd7, 0x87 }, { 207, 0xff, 0xd7, 0xaf },
-		{ 208, 0xff, 0xd7, 0xd7 }, { 209, 0xff, 0xd7, 0xff },
-		{ 210, 0xff, 0xff, 0x00 }, { 211, 0xff, 0xff, 0x5f },
-		{ 212, 0xff, 0xff, 0x87 }, { 213, 0xff, 0xff, 0xaf },
-		{ 214, 0xff, 0xff, 0xd7 }, { 215, 0xff, 0xff, 0xff },
-	};
-
 	static const unsigned char color_256_to_16[256] = {
 		 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
 		 0,  4,  4,  4, 12, 12,  2,  6,  4,  4, 12, 12,  2,  2,  6,  4,
@@ -479,29 +248,35 @@ static int color_find_rgb(unsigned char r, unsigned char g, unsigned char b)
 		 8,  8,  8,  8,  7,  7,  7,  7,  7,  7, 15, 15, 15, 15, 15, 15
 	};
 
-	Color rgb = { .r = r, .g = g, .b = b };
-	const Color *found = bsearch(&rgb, color_to_256, LENGTH(color_to_256),
-	    sizeof color_to_256[0], color_compare);
-
-	if (!found) {
+	int i = 0;
+	if ((!r || (r - 55) % 40 == 0) &&
+	    (!g || (g - 55) % 40 == 0) &&
+	    (!b || (b - 55) % 40 == 0)) {
+		i = 16;
+		i += r ? ((r - 55) / 40) * 36 : 0;
+		i += g ? ((g - 55) / 40) * 6 : 0;
+		i += g ? ((b - 55) / 40) : 0;
+	} else if (r == g && g == b && (r - 8) % 10 == 0 && r < 239) {
+		i = 232 + ((r - 8) / 10);
+	} else {
 		unsigned lowest = UINT_MAX;
-		found = color_from_256;
-		for (int i = 0; i < 240; i++) {
-			int dr = (int)color_from_256[i].r - r;
-			int dg = (int)color_from_256[i].g - g;
-			int db = (int)color_from_256[i].b - b;
-
+		for (int j = 16; j < 256; ++j) {
+			int jr = 0, jg = 0, jb = 0;
+			get_6cube_rgb(j, &jr, &jg, &jb);
+			int dr = jr - r;
+			int dg = jg - g;
+			int db = jb - b;
 			unsigned int distance = dr * dr + dg * dg + db * db;
 			if (distance < lowest) {
 				lowest = distance;
-				found = &color_from_256[i];
+				i = j;
 			}
 		}
 	}
 
 	if (COLORS <= 16)
-		return color_256_to_16[found->i + 16];
-	return found->i + 16;
+		return color_256_to_16[i];
+	return i;
 }
 
 /* Convert color from string. */