gpu: Add display transfer rectangles

include/math_util.hpp

@@ -0,0 +1,80 @@
+#pragma once
+#include <array>
+
+namespace Math {
+	// Abstraction for GLSL vectors
+	template <typename T, int size>
+	class Vector {
+		// A GLSL vector can only have 2, 3 or 4 elements
+		static_assert(size == 2 || size == 3 || size == 4);
+		T m_storage[size];
+
+	  public:
+		T& r() { return m_storage[0]; }
+		T& g() { return m_storage[1]; }
+		T& b() {
+			static_assert(size >= 3, "Out of bounds OpenGL::Vector access");
+			return m_storage[2];
+		}
+		T& a() {
+			static_assert(size >= 4, "Out of bounds OpenGL::Vector access");
+			return m_storage[3];
+		}
+
+		T& x() { return r(); }
+		T& y() { return g(); }
+		T& z() { return b(); }
+		T& w() { return a(); }
+		T& operator[](size_t index) { return m_storage[index]; }
+		const T& operator[](size_t index) const { return m_storage[index]; }
+
+		T& u() { return r(); }
+		T& v() { return g(); }
+
+		T& s() { return r(); }
+		T& t() { return g(); }
+		T& p() { return b(); }
+		T& q() { return a(); }
+
+		Vector(std::array<T, size> list) { std::copy(list.begin(), list.end(), &m_storage[0]); }
+
+		Vector() {}
+	};
+
+	using vec2 = Vector<float, 2>;
+	using vec3 = Vector<float, 3>;
+	using vec4 = Vector<float, 4>;
+
+	using dvec2 = Vector<double, 2>;
+	using dvec3 = Vector<double, 3>;
+	using dvec4 = Vector<double, 4>;
+
+	using ivec2 = Vector<int, 2>;
+	using ivec3 = Vector<int, 3>;
+	using ivec4 = Vector<int, 4>;
+
+	using uvec2 = Vector<unsigned int, 2>;
+	using uvec3 = Vector<unsigned int, 3>;
+	using uvec4 = Vector<unsigned int, 4>;
+
+	// A 2D rectangle, meant to be used for stuff like scissor rects or viewport rects
+	// We're never supporting 3D rectangles, because rectangles were never meant to be 3D in the first place
+	template <typename T>
+	struct Rectangle {
+		Vector<T, 2> start;
+		Vector<T, 2> end;
+
+		Rectangle() : start({0}), end({0}) {}
+		Rectangle(T x0, T y0, T x1, T y1) : start({x0, y0}), end({x1, y1}) {}
+
+		T getWidth() const {
+			return std::abs(end.x() - start.x());
+		}
+
+		T getHeight() const {
+			return std::abs(end.y() - start.y());
+		}
+	};
+
+	using Rect = Rectangle<unsigned int>;
+}