From 37d0005a9e651f366076c930019464d162506a57 Mon Sep 17 00:00:00 2001 From: Oliver Kiddle Date: Mon, 5 Nov 2018 22:24:05 +0100 Subject: 43747: new module to map colours from hex triplets to the nearest matching colour --- Src/Modules/nearcolor.c | 178 ++++++++++++++++++++++++++++++++++++++++++++++ Src/Modules/nearcolor.mdd | 5 ++ 2 files changed, 183 insertions(+) create mode 100644 Src/Modules/nearcolor.c create mode 100644 Src/Modules/nearcolor.mdd (limited to 'Src/Modules') diff --git a/Src/Modules/nearcolor.c b/Src/Modules/nearcolor.c new file mode 100644 index 000000000..2a763d470 --- /dev/null +++ b/Src/Modules/nearcolor.c @@ -0,0 +1,178 @@ +#include "nearcolor.mdh" +#include "nearcolor.pro" + +#include + +struct cielab { + float L, a, b; +}; +typedef struct cielab *Cielab; + +static float +deltae(Cielab lab1, Cielab lab2) +{ + /* taking square root unnecessary as we're just comparing values */ + return powf(lab1->L - lab2->L, 2) + + powf(lab1->a - lab2->a, 2) + + powf(lab1->b - lab2->b, 2); +} + +static void +RGBtoLAB(int red, int green, int blue, Cielab lab) +{ + float R = (float)red / 255.0; + float G = (float)green / 255.0; + float B = (float)blue / 255.0; + R = 100.0 * (R > 0.04045 ? powf((R + 0.055) / 1.055, 2.4) : R / 12.92); + G = 100.0 * (G > 0.04045 ? powf((G + 0.055) / 1.055, 2.4) : G / 12.92); + B = 100.0 * (B > 0.04045 ? powf((B + 0.055) / 1.055, 2.4) : B / 12.92); + + /* Observer. = 2 degrees, Illuminant = D65 */ + float X = (R * 0.4124 + G * 0.3576 + B * 0.1805) / 95.047; + float Y = (R * 0.2126 + G * 0.7152 + B * 0.0722) / 100.0; + float Z = (R * 0.0193 + G * 0.1192 + B * 0.9505) / 108.883; + + X = (X > 0.008856) ? powf(X, 1.0/3.0) : (7.787 * X) + (16.0 / 116.0); + Y = (Y > 0.008856) ? powf(Y, 1.0/3.0) : (7.787 * Y) + (16.0 / 116.0); + Z = (Z > 0.008856) ? powf(Z, 1.0/3.0) : (7.787 * Z) + (16.0 / 116.0); + + lab->L = (116.0 * Y) - 16.0; + lab->a = 500.0 * (X - Y); + lab->b = 200.0 * (Y - Z); +} + +static int +mapRGBto88(int red, int green, int blue) +{ + int component[] = { 0, 0x8b, 0xcd, 0xff, 0x2e, 0x5c, 0x8b, 0xa2, 0xb9, 0xd0, 0xe7 }; + struct cielab orig, next; + float nextl, bestl = -1; + int r, g, b; + int comp_r = 0, comp_g = 0, comp_b = 0; + + /* Get original value */ + RGBtoLAB(red, green, blue, &orig); + + /* try every one of the 72 colours */ + for (r = 0; r < 11; r++) { + for (g = 0; g <= 3; g++) { + for (b = 0; b <= 3; b++) { + if (r > 3) g = b = r; /* advance inner loops to the block of greys */ + RGBtoLAB(component[r], component[g], component[b], &next); + nextl = deltae(&orig, &next); + if (nextl < bestl || bestl < 0) { + bestl = nextl; + comp_r = r; + comp_g = g; + comp_b = b; + } + } + } + } + + return (comp_r > 3) ? 77 + comp_r : + 16 + (comp_r * 16) + (comp_g * 4) + comp_b; +} + +/* + * Convert RGB to nearest colour in the 256 colour range + */ +static int +mapRGBto256(int red, int green, int blue) +{ + int component[] = { + 0, 0x5f, 0x87, 0xaf, 0xd7, 0xff, + 0x8, 0x12, 0x1c, 0x26, 0x30, 0x3a, 0x44, 0x4e, + 0x58, 0x62, 0x6c, 0x76, 0x80, 0x8a, 0x94, 0x9e, + 0xa8, 0xb2, 0xbc, 0xc6, 0xd0, 0xda, 0xe4, 0xee + }; + struct cielab orig, next; + float nextl, bestl = -1; + int r, g, b; + int comp_r = 0, comp_g = 0, comp_b = 0; + + /* Get original value */ + RGBtoLAB(red, green, blue, &orig); + + for (r = 0; r < sizeof(component)/sizeof(*component); r++) { + for (g = 0; g <= 5; g++) { + for (b = 0; b <= 5; b++) { + if (r > 5) g = b = r; /* advance inner loops to the block of greys */ + RGBtoLAB(component[r], component[g], component[b], &next); + nextl = deltae(&orig, &next); + if (nextl < bestl || bestl < 0) { + bestl = nextl; + comp_r = r; + comp_g = g; + comp_b = b; + } + } + } + } + + return (comp_r > 5) ? 226 + comp_r : + 16 + (comp_r * 36) + (comp_g * 6) + comp_b; +} + +static int +getnearestcolor(UNUSED(Hookdef dummy), Color_rgb col) +{ + if (tccolours == 256) + return mapRGBto256(col->red, col->green, col->blue); + if (tccolours == 88) + return mapRGBto88(col->red, col->green, col->blue); + return 0; +} + +static struct features module_features = { + NULL, 0, + NULL, 0, + NULL, 0, + NULL, 0, + 0 +}; + +/**/ +int +setup_(UNUSED(Module m)) +{ + return 0; +} + +/**/ +int +features_(Module m, char ***features) +{ + *features = featuresarray(m, &module_features); + return 0; +} + +/**/ +int +enables_(Module m, int **enables) +{ + return handlefeatures(m, &module_features, enables); +} + +/**/ +int +boot_(Module m) +{ + addhookfunc("get_color_attr", (Hookfn) getnearestcolor); + return 0; +} + +/**/ +int +cleanup_(Module m) +{ + deletehookfunc("get_color_attr", (Hookfn) getnearestcolor); + return setfeatureenables(m, &module_features, NULL); +} + +/**/ +int +finish_(UNUSED(Module m)) +{ + return 0; +} diff --git a/Src/Modules/nearcolor.mdd b/Src/Modules/nearcolor.mdd new file mode 100644 index 000000000..2fcdaf04e --- /dev/null +++ b/Src/Modules/nearcolor.mdd @@ -0,0 +1,5 @@ +name=zsh/nearcolor +link=dynamic +load=no + +objects="nearcolor.o" -- cgit 1.4.1