added function and ud-literal to convert hex color codes to glm::vec4 and ImColor

src/mirrage/gui/include/mirrage/gui/gui.hpp

@@ -14,12 +14,38 @@
 #include <glm/vec2.hpp>
 #include <glm/vec4.hpp>
 
+
+#define IM_VEC2_CLASS_EXTRA              \
+	constexpr ImVec2(const glm::vec2& f) \
+	{                                    \
+		x = f.x;                         \
+		y = f.y;                         \
+	}                                    \
+	constexpr operator glm::vec2() const { return glm::vec2(x, y); }
+#define IM_VEC4_CLASS_EXTRA              \
+	constexpr ImVec4(const glm::vec4& f) \
+	{                                    \
+		x = f.x;                         \
+		y = f.y;                         \
+		z = f.z;                         \
+		w = f.w;                         \
+	}                                    \
+	constexpr operator glm::vec4() const { return glm::vec4(x, y, z, w); }
+
 #include <imgui.h>
 
 #include <cstdint>
 #include <memory>
 
 
+namespace mirrage::gui::literals {
+	inline ImColor operator"" _imcolor(const char* str, std::size_t len)
+	{
+		auto c = mirrage::util::hex_to_color(str, len);
+		return {std::pow(c.r, 2.2f), std::pow(c.g, 2.2f), std::pow(c.b, 2.2f), c.a};
+	}
+} // namespace mirrage::gui::literals
+
 namespace ImGui {
 	inline constexpr float SIZE_AUTO = 0.0f;
 

src/mirrage/utils/include/mirrage/utils/units.hpp

@@ -7,9 +7,11 @@
 
 #pragma once
 
+#include <mirrage/utils/log.hpp>
+
+#include <glm/glm.hpp>
 #include <glm/gtc/constants.hpp>
 #include <glm/gtx/rotate_vector.hpp>
-#include <glm/vec2.hpp>
 
 #include <cmath>
 #include <type_traits>
@@ -27,6 +29,68 @@ namespace mirrage::util {
 	using Rgba = glm::vec4;
 	using Rgb  = glm::vec3;
 
+	// hex code to color conversion
+	namespace detail {
+		constexpr auto constexpr_strlen(const char* str)
+		{
+			auto len = std::size_t(0);
+			while(*str != '\0')
+				str++;
+
+			return len;
+		}
+
+		constexpr auto hex_char_to_byte(char c)
+		{
+			auto b = std::int32_t(c & 0b1111);
+			return c > '9' ? b + 0b1001 : b;
+		}
+	} // namespace detail
+
+	inline auto hex_to_color(const char* color, std::size_t len) -> Rgba
+	{
+		// skip leading #
+		if(*color == '#') {
+			color++;
+			len--;
+		}
+
+		auto result = glm::vec4(1, 1, 1, 1);
+
+		switch(len) {
+			case 3:
+			case 4:
+				for(auto i = 0; i < int(len); i++)
+					result[i] = detail::hex_char_to_byte(color[i]) / 255.f;
+				break;
+
+			case 6:
+			case 8:
+				for(auto i = 0; i < int(len) / 2; i++)
+					result[i] = (detail::hex_char_to_byte(color[i * 2]) << 4
+					             | detail::hex_char_to_byte(color[i * 2]))
+					            / 255.f;
+
+				break;
+
+			default: MIRRAGE_FAIL("Invalid input to hex_to_vec4: " << color);
+		}
+
+		return result;
+	}
+
+	[[nodiscard]] inline auto hex_to_color(const std::string& str) -> Rgba
+	{
+		return hex_to_color(str.c_str(), str.length());
+	}
+
+	[[nodiscard]] inline auto hex_to_color(const char* str) -> Rgba
+	{
+		return hex_to_color(str, detail::constexpr_strlen(str));
+	}
+
+
+
 	template <class S>
 	struct Value_type {
 	  protected:
@@ -416,6 +480,11 @@ namespace mirrage::util {
 		constexpr Force operator"" _kn(long double v) { return Force(static_cast<float>(v * 1000)); }
 		constexpr Force operator"" _kn(unsigned long long v) { return Force(static_cast<float>(v * 1000)); }
 
+		inline glm::vec4 operator"" _color(const char* str, std::size_t len)
+		{
+			return hex_to_color(str, len);
+		}
+
 		constexpr Time         second   = 1_s;
 		constexpr Time_squared second_2 = 1_s * 1_s;
 		constexpr Time         minute   = 1_min;