Files
HellionChat/HellionChat/Util/ColourUtil.cs
T

82 lines
2.7 KiB
C#
Executable File

using System.Buffers.Binary;
using System.Numerics;
namespace HellionChat.Util;
internal static class ColourUtil {
private static (byte r, byte g, byte b) RgbaToRgbComponents(uint rgba)
{
var r = (byte) ((rgba & 0xFF000000) >> 24);
var g = (byte) ((rgba & 0xFF0000) >> 16);
var b = (byte) ((rgba & 0xFF00) >> 8);
return (r, g, b);
}
internal static uint RgbaToAbgr(uint rgba) => BinaryPrimitives.ReverseEndianness(rgba);
internal static Vector3 RgbaToVector3(uint rgba)
{
var (r, g, b) = RgbaToRgbComponents(rgba);
return new Vector3((float) r / 255, (float) g / 255, (float) b / 255);
}
internal static uint Vector3ToRgba(Vector3 col)
{
return ComponentsToRgba(
(byte) Math.Round(col.X * 255),
(byte) Math.Round(col.Y * 255),
(byte) Math.Round(col.Z * 255)
);
}
internal static uint Vector4ToAbgr(Vector4 col)
{
return RgbaToAbgr(ComponentsToRgba(
(byte) Math.Round(col.X * 255),
(byte) Math.Round(col.Y * 255),
(byte) Math.Round(col.Z * 255),
(byte) Math.Round(col.W * 255)
));
}
public static unsafe uint ArgbToRgba(uint x)
{
var buf = (byte*)&x;
(buf[1], buf[2], buf[3], buf[0]) = (buf[0], buf[1], buf[2], buf[3]);
return x;
}
internal static uint ComponentsToRgba(byte red, byte green, byte blue, byte alpha = 0xFF)
=> alpha | (uint) (red << 24) | (uint) (green << 16) | (uint) (blue << 8);
internal static uint AdjustBrightness(uint abgr, float factor)
{
var a = (byte) ((abgr & 0xFF000000) >> 24);
var b = (byte) ((abgr & 0x00FF0000) >> 16);
var g = (byte) ((abgr & 0x0000FF00) >> 8);
var r = (byte) (abgr & 0x000000FF);
var nr = (byte) Math.Clamp(r * factor, 0f, 255f);
var ng = (byte) Math.Clamp(g * factor, 0f, 255f);
var nb = (byte) Math.Clamp(b * factor, 0f, 255f);
return ((uint) a << 24) | ((uint) nb << 16) | ((uint) ng << 8) | nr;
}
public static uint HexToRgba(string hex)
{
ArgumentNullException.ThrowIfNull(hex);
var s = hex.StartsWith('#') ? hex[1..] : hex;
if (s.Length != 6 && s.Length != 8)
throw new FormatException($"Hex colour must be 6 or 8 hex digits, got {s.Length}: '{hex}'");
if (!uint.TryParse(s, System.Globalization.NumberStyles.HexNumber, System.Globalization.CultureInfo.InvariantCulture, out var value))
throw new FormatException($"Hex colour '{hex}' is not a valid hexadecimal value");
if (s.Length == 6)
value = (value << 8) | 0xFFu; // RRGGBB → RRGGBBFF
return value;
}
}