[wpiutil] Move Color and Color8Bit from wpilib to wpiutil (#8437)

Removes one of the org.wpilib.util package conflicts for modularization.

Only a few minor tweaks were required to remove the wpimath dependency.

wpiutil/src/main/native/include/wpi/util/Color8Bit.hpp

@@ -0,0 +1,134 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#pragma once
+
+#include <algorithm>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+
+#include <fmt/format.h>
+
+#include "wpi/util/Color.hpp"
+#include "wpi/util/StringExtras.hpp"
+#include "wpi/util/ct_string.hpp"
+
+namespace wpi::util {
+
+/**
+ * Represents colors that can be used with Addressable LEDs.
+ */
+class Color8Bit {
+ public:
+  /**
+   * Constructs a default color (black).
+   */
+  constexpr Color8Bit() = default;
+
+  /**
+   * Constructs a Color8Bit.
+   *
+   * @param r Red value (0-255)
+   * @param g Green value (0-255)
+   * @param b Blue value (0-255)
+   */
+  constexpr Color8Bit(int r, int g, int b)
+      : red(std::clamp(r, 0, 255)),
+        green(std::clamp(g, 0, 255)),
+        blue(std::clamp(b, 0, 255)) {}
+
+  /**
+   * Constructs a Color8Bit from a Color.
+   *
+   * @param color The color
+   */
+  constexpr Color8Bit(const Color& color)  // NOLINT
+      : red(color.red * 255),
+        green(color.green * 255),
+        blue(color.blue * 255) {}
+
+  /**
+   * Constructs a Color8Bit from a hex string.
+   *
+   * @param hexString a string of the format <tt>\#RRGGBB</tt>
+   * @throws std::invalid_argument if the hex string is invalid.
+   */
+  explicit constexpr Color8Bit(std::string_view hexString) {
+    if (hexString.length() != 7 || !hexString.starts_with("#") ||
+        !wpi::util::isHexDigit(hexString[1]) ||
+        !wpi::util::isHexDigit(hexString[2]) ||
+        !wpi::util::isHexDigit(hexString[3]) ||
+        !wpi::util::isHexDigit(hexString[4]) ||
+        !wpi::util::isHexDigit(hexString[5]) ||
+        !wpi::util::isHexDigit(hexString[6])) {
+      throw std::invalid_argument(
+          fmt::format("Invalid hex string for Color \"{}\"", hexString));
+    }
+
+    red = wpi::util::hexDigitValue(hexString[1]) * 16 +
+          wpi::util::hexDigitValue(hexString[2]);
+    green = wpi::util::hexDigitValue(hexString[3]) * 16 +
+            wpi::util::hexDigitValue(hexString[4]);
+    blue = wpi::util::hexDigitValue(hexString[5]) * 16 +
+           wpi::util::hexDigitValue(hexString[6]);
+  }
+
+  constexpr bool operator==(const Color8Bit&) const = default;
+
+  constexpr operator Color() const {  // NOLINT
+    return Color(red / 255.0, green / 255.0, blue / 255.0);
+  }
+
+  /**
+   * Create a Color8Bit from a hex string.
+   *
+   * @param hexString a string of the format <tt>\#RRGGBB</tt>
+   * @return Color8Bit object from hex string.
+   * @throws std::invalid_argument if the hex string is invalid.
+   */
+  static constexpr Color8Bit FromHexString(std::string_view hexString) {
+    if (hexString.length() != 7 || !hexString.starts_with("#") ||
+        !wpi::util::isHexDigit(hexString[1]) ||
+        !wpi::util::isHexDigit(hexString[2]) ||
+        !wpi::util::isHexDigit(hexString[3]) ||
+        !wpi::util::isHexDigit(hexString[4]) ||
+        !wpi::util::isHexDigit(hexString[5]) ||
+        !wpi::util::isHexDigit(hexString[6])) {
+      throw std::invalid_argument(
+          fmt::format("Invalid hex string for Color \"{}\"", hexString));
+    }
+
+    int r = wpi::util::hexDigitValue(hexString[0]) * 16 +
+            wpi::util::hexDigitValue(hexString[1]);
+    int g = wpi::util::hexDigitValue(hexString[2]) * 16 +
+            wpi::util::hexDigitValue(hexString[3]);
+    int b = wpi::util::hexDigitValue(hexString[4]) * 16 +
+            wpi::util::hexDigitValue(hexString[5]);
+    return Color8Bit{r, g, b};
+  }
+
+  /**
+   * Return this color represented as a hex string.
+   *
+   * @return a string of the format <tt>\#RRGGBB</tt>
+   */
+  constexpr auto HexString() const {
+    return wpi::util::ct_string<char, std::char_traits<char>, 7>{
+        {'#', wpi::util::hexdigit(red / 16), wpi::util::hexdigit(red % 16),
+         wpi::util::hexdigit(green / 16), wpi::util::hexdigit(green % 16),
+         wpi::util::hexdigit(blue / 16), wpi::util::hexdigit(blue % 16)}};
+  }
+
+  /// Red component (0-255).
+  int red = 0;
+
+  /// Green component (0-255).
+  int green = 0;
+
+  /// Blue component (0-255).
+  int blue = 0;
+};
+
+}  // namespace wpi::util