added more formaters

include/omath/utility/color.hpp

@@ -175,6 +175,16 @@ namespace omath
                             static_cast<int>(m_value.z * 255.f),
                             static_cast<int>(m_value.w * 255.f));
         }
+        [[nodiscard]] std::string to_rgbf_string() const noexcept
+        {
+            return std::format("[r:{}, g:{}, b:{}, a:{}]",
+                            m_value.x, m_value.y, m_value.z, m_value.w);
+        }
+        [[nodiscard]] std::string to_hsv_string() const noexcept
+        {
+            const auto [hue, saturation, value] = to_hsv();
+            return std::format("[h:{}, s:{}, v:{}]", hue, saturation, value);
+        }
         [[nodiscard]] std::wstring to_wstring() const noexcept
         {
             const auto ascii_string = to_string();
@@ -192,23 +202,55 @@ namespace omath
 template<>
 struct std::formatter<omath::Color> // NOLINT(*-dcl58-cpp)
 {
-    [[nodiscard]]
+    enum class ColorFormat { rgb, rgbf, hsv };
-    static constexpr auto parse(const std::format_parse_context& ctx)
+    ColorFormat color_format = ColorFormat::rgb;
+
+    constexpr auto parse(std::format_parse_context& ctx)
     {
-        return ctx.begin();
+        auto it = ctx.begin();
+        const auto end = ctx.end();
+
+        if (it == end || *it == '}')
+            return it;
+
+        const std::string_view spec(it, end);
+
+        if (spec.starts_with("rgbf"))
+        {
+            color_format = ColorFormat::rgbf;
+            return it + 4;
+        }
+        if (spec.starts_with("rgb"))
+        {
+            color_format = ColorFormat::rgb;
+            return it + 3;
+        }
+        if (spec.starts_with("hsv"))
+        {
+            color_format = ColorFormat::hsv;
+            return it + 3;
+        }
+
+        throw std::format_error("Invalid format specifier for omath::Color. Use rgb, rgbf, or hsv.");
     }
 
     template<class FormatContext>
-    [[nodiscard]]
+    auto format(const omath::Color& col, FormatContext& ctx) const
-    static auto format(const omath::Color& col, FormatContext& ctx)
     {
-        if constexpr (std::is_same_v<typename FormatContext::char_type, char>)
+        std::string str;
-            return std::format_to(ctx.out(), "{}", col.to_string());
+        switch (color_format)
-        if constexpr (std::is_same_v<typename FormatContext::char_type, wchar_t>)
+        {
-            return std::format_to(ctx.out(), L"{}", col.to_wstring());
+            case ColorFormat::rgb:  str = col.to_string();      break;
+            case ColorFormat::rgbf: str = col.to_rgbf_string(); break;
+            case ColorFormat::hsv:  str = col.to_hsv_string();  break;
+        }
 
+        if constexpr (std::is_same_v<typename FormatContext::char_type, char>)
+            return std::format_to(ctx.out(), "{}", str);
+        if constexpr (std::is_same_v<typename FormatContext::char_type, wchar_t>)
+            return std::format_to(ctx.out(), L"{}", std::wstring(str.cbegin(), str.cend()));
         if constexpr (std::is_same_v<typename FormatContext::char_type, char8_t>)
-            return std::format_to(ctx.out(), u8"{}", col.to_u8string());
+            return std::format_to(ctx.out(), u8"{}", std::u8string(str.cbegin(), str.cend()));
 
         std::unreachable();
     }

tests/general/unit_test_color_grouped.cpp

@@ -291,3 +291,35 @@ TEST(UnitTestColorGrouped_More2, FormatterUsesToString)
     const auto formatted = std::format("{}", c);
     EXPECT_NE(formatted.find("r:10"), std::string::npos);
 }
+
+TEST(UnitTestColorGrouped_More2, FormatterRgb)
+{
+    constexpr Color c = Color::from_rgba(255, 128, 0, 64);
+    const auto s = std::format("{:rgb}", c);
+    EXPECT_NE(s.find("r:255"), std::string::npos);
+    EXPECT_NE(s.find("g:128"), std::string::npos);
+    EXPECT_NE(s.find("b:0"), std::string::npos);
+    EXPECT_NE(s.find("a:64"), std::string::npos);
+}
+
+TEST(UnitTestColorGrouped_More2, FormatterRgbf)
+{
+    constexpr Color c(0.5f, 0.25f, 1.0f, 0.75f);
+    const auto s = std::format("{:rgbf}", c);
+    EXPECT_NE(s.find("r:"), std::string::npos);
+    EXPECT_NE(s.find("g:"), std::string::npos);
+    EXPECT_NE(s.find("b:"), std::string::npos);
+    EXPECT_NE(s.find("a:"), std::string::npos);
+    // Values should be in [0,1] float range, not 0-255
+    EXPECT_EQ(s.find("r:127"), std::string::npos);
+    EXPECT_EQ(s.find("r:255"), std::string::npos);
+}
+
+TEST(UnitTestColorGrouped_More2, FormatterHsv)
+{
+    const Color c = Color::red();
+    const auto s = std::format("{:hsv}", c);
+    EXPECT_NE(s.find("h:"), std::string::npos);
+    EXPECT_NE(s.find("s:"), std::string::npos);
+    EXPECT_NE(s.find("v:"), std::string::npos);
+}