1//! object representing a single color in the HSV colorspace with h channel value from 0-360 and s,v channel values from 0-1
2
3const std = @import("std");
4const Self = @This();
5const color = @import("./mod.zig");
6const _x = @import("./_x.zig");
7
8h: f32, // hue [ 0 .. 1 ]
9s: f32, // saturation [ 0 .. 1 ]
10v: f32, // value [ 0 .. 1 ]
11a: f32, // alpha [ 0 .. 1 ]
12
13pub fn initHSVA(h: f32, s: f32, v: f32, a: f32) Self {
14 std.debug.assert(h >= 0.0 and h <= 1.0);
15 std.debug.assert(s >= 0.0 and s <= 1.0);
16 std.debug.assert(v >= 0.0 and v <= 1.0);
17 std.debug.assert(a >= 0.0 and a <= 1.0);
18 return Self{
19 .h = h,
20 .s = s,
21 .v = v,
22 .a = a,
23 };
24}
25
26pub fn eql(x: Self, y: Self) bool {
27 return x.h == y.h and x.s == y.s and x.v == y.v and x.a == y.a;
28}
29
30const M = _x.mixin(@This(), f32, .h, .s, .v);
31pub const to_vec = M.to_vec;
32pub const from_vec = M.from_vec;
33pub const to_array = M.to_array;
34
35// https://en.wikipedia.org/wiki/HSL_and_HSV#HSV_to_RGB
36// https://www.rapidtables.com/convert/color/hsv-to-rgb.html
37pub fn to_srgb(t: Self) color.sRGB {
38 var h, const s, const v, const a = t.to_array();
39 h *= 360.0;
40 h /= 60.0;
41 const c = v * s;
42 const x = c * (1 - @abs(@rem(h, 2.0) - 1.0));
43 const r, const g, const b = blk: {
44 if (h >= 0.0 and h < 1.0) break :blk .{ c, x, 0 };
45 if (h >= 1.0 and h < 2.0) break :blk .{ x, c, 0 };
46 if (h >= 2.0 and h < 3.0) break :blk .{ 0, c, x };
47 if (h >= 3.0 and h < 4.0) break :blk .{ 0, x, c };
48 if (h >= 4.0 and h < 5.0) break :blk .{ x, 0, c };
49 if (h >= 5.0 and h < 6.0) break :blk .{ c, 0, x };
50 unreachable;
51 };
52 const m = v - c;
53 return color.sRGB.from_float(.{ r + m, g + m, b + m, a });
54}