[wpilib] Add hex string constructor to Color and Color8Bit (#5063)

Co-authored-by: Tyler Veness <calcmogul@gmail.com>

wpilibc/src/test/native/cpp/util/Color8BitTest.cpp

@@ -0,0 +1,62 @@
+// 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.
+
+#include <gtest/gtest.h>
+
+#include "frc/util/Color8Bit.h"
+
+TEST(Color8BitTest, ConstructDefault) {
+  constexpr frc::Color8Bit color;
+
+  EXPECT_EQ(0, color.red);
+  EXPECT_EQ(0, color.green);
+  EXPECT_EQ(0, color.blue);
+}
+
+TEST(Color8BitTest, ConstructFromInts) {
+  constexpr frc::Color8Bit color{255, 128, 64};
+
+  EXPECT_EQ(255, color.red);
+  EXPECT_EQ(128, color.green);
+  EXPECT_EQ(64, color.blue);
+}
+
+TEST(Color8BitTest, ConstructFromColor) {
+  constexpr frc::Color8Bit color{frc::Color{255, 128, 64}};
+
+  EXPECT_EQ(255, color.red);
+  EXPECT_EQ(128, color.green);
+  EXPECT_EQ(64, color.blue);
+}
+
+TEST(Color8BitTest, ConstructFromHexString) {
+  constexpr frc::Color8Bit color{"#FF8040"};
+
+  EXPECT_EQ(255, color.red);
+  EXPECT_EQ(128, color.green);
+  EXPECT_EQ(64, color.blue);
+
+  // No leading #
+  EXPECT_THROW(frc::Color8Bit{"112233"}, std::invalid_argument);
+
+  // Too long
+  EXPECT_THROW(frc::Color8Bit{"#11223344"}, std::invalid_argument);
+
+  // Invalid hex characters
+  EXPECT_THROW(frc::Color8Bit{"#$$$$$$"}, std::invalid_argument);
+}
+
+TEST(Color8BitTest, ImplicitConversionToColor) {
+  frc::Color color = frc::Color8Bit{255, 128, 64};
+
+  EXPECT_NEAR(1.0, color.red, 1e-2);
+  EXPECT_NEAR(0.5, color.green, 1e-2);
+  EXPECT_NEAR(0.25, color.blue, 1e-2);
+}
+
+TEST(Color8BitTest, ToHexString) {
+  constexpr frc::Color8Bit color{255, 128, 64};
+
+  EXPECT_EQ("#FF8040", color.HexString());
+}

wpilibc/src/test/native/cpp/util/ColorTest.cpp

@@ -0,0 +1,62 @@
+// 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.
+
+#include <gtest/gtest.h>
+
+#include "frc/util/Color.h"
+
+TEST(ColorTest, ConstructDefault) {
+  constexpr frc::Color color;
+
+  EXPECT_DOUBLE_EQ(0.0, color.red);
+  EXPECT_DOUBLE_EQ(0.0, color.green);
+  EXPECT_DOUBLE_EQ(0.0, color.blue);
+}
+
+TEST(ColorTest, ConstructFromDoubles) {
+  constexpr frc::Color color{1.0, 0.5, 0.25};
+
+  EXPECT_NEAR(1.0, color.red, 1e-2);
+  EXPECT_NEAR(0.5, color.green, 1e-2);
+  EXPECT_NEAR(0.25, color.blue, 1e-2);
+}
+
+TEST(ColorTest, ConstructFromInts) {
+  constexpr frc::Color color{255, 128, 64};
+
+  EXPECT_NEAR(1.0, color.red, 1e-2);
+  EXPECT_NEAR(0.5, color.green, 1e-2);
+  EXPECT_NEAR(0.25, color.blue, 1e-2);
+}
+
+TEST(ColorTest, ConstructFromHexString) {
+  constexpr frc::Color color{"#FF8040"};
+
+  EXPECT_NEAR(1.0, color.red, 1e-2);
+  EXPECT_NEAR(0.5, color.green, 1e-2);
+  EXPECT_NEAR(0.25, color.blue, 1e-2);
+
+  // No leading #
+  EXPECT_THROW(frc::Color{"112233"}, std::invalid_argument);
+
+  // Too long
+  EXPECT_THROW(frc::Color{"#11223344"}, std::invalid_argument);
+
+  // Invalid hex characters
+  EXPECT_THROW(frc::Color{"#$$$$$$"}, std::invalid_argument);
+}
+
+TEST(ColorTest, FromHSV) {
+  constexpr frc::Color color = frc::Color::FromHSV(90, 128, 64);
+
+  EXPECT_DOUBLE_EQ(0.1256103515625, color.red);
+  EXPECT_DOUBLE_EQ(0.2510986328125, color.green);
+  EXPECT_DOUBLE_EQ(0.2510986328125, color.blue);
+}
+
+TEST(ColorTest, ToHexString) {
+  constexpr frc::Color color{255, 128, 64};
+
+  EXPECT_EQ("#FF8040", color.HexString());
+}