1 files changed, 148 insertions, 0 deletions
diff --git a/src/brussel.common/Color.hpp b/src/brussel.common/Color.hpp
new file mode 100644
index 0000000..ef0c5a9
--- /dev/null
+++ b/src/brussel.common/Color.hpp
@@ -0,0 +1,148 @@
+#pragma once
+
+#include "Utils.hpp"
+
+#include <algorithm>
+#include <cstdint>
+#include <glm/glm.hpp>
+#include <limits>
+
+class HsvColor;
+class RgbaColor {
+public:
+	uint8_t r;
+	uint8_t g;
+	uint8_t b;
+	uint8_t a;
+
+public:
+	constexpr RgbaColor() noexcept
+		: r{ 255 }
+		, g{ 255 }
+		, b{ 255 }
+		, a{ 255 } {
+	}
+
+	constexpr RgbaColor(float r, float g, float b, float a = 1.0f) noexcept
+		: r{ static_cast<uint8_t>(r * 255.0f) }
+		, g{ static_cast<uint8_t>(g * 255.0f) }
+		, b{ static_cast<uint8_t>(b * 255.0f) }
+		, a{ static_cast<uint8_t>(a * 255.0f) } {
+	}
+
+	constexpr RgbaColor(int r, int g, int b, int a = 255) noexcept
+		: r{ static_cast<uint8_t>(r & 0xFF) }
+		, g{ static_cast<uint8_t>(g & 0xFF) }
+		, b{ static_cast<uint8_t>(b & 0xFF) }
+		, a{ static_cast<uint8_t>(a & 0xFF) } {
+	}
+
+	constexpr RgbaColor(uint32_t rgba) noexcept
+		: r{ static_cast<uint8_t>((rgba >> 0) & 0xFF) }
+		, g{ static_cast<uint8_t>((rgba >> 8) & 0xFF) }
+		, b{ static_cast<uint8_t>((rgba >> 16) & 0xFF) }
+		, a{ static_cast<uint8_t>((rgba >> 24) & 0xFF) } {
+	}
+
+	constexpr uint32_t GetScalar() const noexcept {
+		uint32_t res = 0;
+		res |= r << 0;
+		res |= g << 8;
+		res |= b << 16;
+		res |= a << 24;
+		return res;
+	}
+
+	constexpr void SetScalar(uint32_t scalar) noexcept {
+		r = (scalar >> 0) & 0xFF;
+		g = (scalar >> 8) & 0xFF;
+		b = (scalar >> 16) & 0xFF;
+		a = (scalar >> 24) & 0xFF;
+	}
+
+	constexpr float GetNormalizedRed() const noexcept {
+		return r / 255.0f;
+	}
+
+	constexpr float GetNormalizedGreen() const noexcept {
+		return g / 255.0f;
+	}
+
+	constexpr float GetNormalizedBlue() const noexcept {
+		return b / 255.0f;
+	}
+
+	constexpr float GetNormalizedAlpha() const noexcept {
+		return a / 255.0f;
+	}
+
+	constexpr glm::ivec4 ToIVec() const noexcept {
+		return { r, g, b, a };
+	}
+
+	constexpr glm::vec4 ToVec() const noexcept {
+		return { GetNormalizedRed(), GetNormalizedGreen(), GetNormalizedBlue(), GetNormalizedAlpha() };
+	}
+
+	// Forward declaring because cyclic reference between RgbaColor and HsvColor
+	constexpr HsvColor ToHsv() const noexcept;
+
+	friend constexpr bool operator==(const RgbaColor&, const RgbaColor&) noexcept = default;
+};
+
+constexpr RgbaColor kXAxisColor(0xFF, 0x80, 0x80, 0xFF);
+constexpr RgbaColor kYAxisColor(0x80, 0xFF, 0x80, 0xFF);
+constexpr RgbaColor kZAxisColor(0x80, 0x80, 0xFF, 0xFF);
+
+class HsvColor {
+public:
+	float h;
+	float s;
+	float v;
+	float a;
+
+public:
+	constexpr HsvColor() noexcept
+		: h{ 0.0f }
+		, s{ 0.0f }
+		, v{ 1.0f }
+		, a{ 1.0f } {
+	}
+
+	constexpr HsvColor(float h, float s, float v, float a) noexcept
+		: h{ h }
+		, s{ s }
+		, v{ v }
+		, a{ a } {
+	}
+
+	// Forward declaring because cyclic reference between RgbaColor and HsvColor
+	constexpr RgbaColor ToRgba() const noexcept;
+};
+
+constexpr HsvColor RgbaColor::ToHsv() const noexcept {
+	float r = GetNormalizedRed();
+	float g = GetNormalizedBlue();
+	float b = GetNormalizedGreen();
+	float a = GetNormalizedAlpha();
+
+	auto p = g < b ? glm::vec4(b, g, -1, 2.0f / 3.0f) : glm::vec4(g, b, 0, -1.0f / 3.0f);
+	auto q = r < p.x ? glm::vec4(p.x, p.y, p.w, r) : glm::vec4(r, p.y, p.z, p.x);
+	float c = q.x - std::min(q.w, q.y);
+	float h = Utils::Abs((q.w - q.y) / (6 * c + std::numeric_limits<float>::epsilon()) + q.z);
+
+	glm::vec3 hcv{ h, c, q.x };
+	float s = hcv.y / (hcv.z + std::numeric_limits<float>::epsilon());
+	return HsvColor(hcv.x, s, hcv.z, a);
+}
+
+constexpr RgbaColor HsvColor::ToRgba() const noexcept {
+	float r = Utils::Abs(h * 6 - 3) - 1;
+	float g = 2 - Utils::Abs(h * 6 - 2);
+	float b = 2 - Utils::Abs(h * 6 - 4);
+
+	auto rgb = glm::vec3{ std::clamp(r, 0.0f, 1.0f), std::clamp(g, 0.0f, 1.0f), std::clamp(b, 0.0f, 1.0f) };
+	auto vc = (rgb - glm::vec3{ 0, 0, 0 }) * s + glm::vec3{ 1, 1, 1 } * v;
+
+	return RgbaColor(vc.x, vc.y, vc.z, a);
+}