BuildSystem: Cleanup userspace directory layout

userspace programs are now in userspace/programs
userspace tests are now in userspace/tests

This makes listing userspace projects much cleaner. Libraries were
already separated to their own directory, so other programs should also.

userspace/programs/WindowServer/Utils.h

@@ -0,0 +1,80 @@
+#pragma once
+
+#include <BAN/Math.h>
+#include <BAN/Optional.h>
+
+#include <stdint.h>
+
+struct Position
+{
+	int32_t x;
+	int32_t y;
+};
+
+struct Rectangle
+{
+	int32_t x;
+	int32_t y;
+	int32_t width;
+	int32_t height;
+
+	bool contains(Position position) const
+	{
+		if (position.x < x || position.x >= x + width)
+			return false;
+		if (position.y < y || position.y >= y + height)
+			return false;
+		return true;
+	}
+
+	BAN::Optional<Rectangle> get_overlap(Rectangle other) const
+	{
+		const auto min_x = BAN::Math::max(x, other.x);
+		const auto min_y = BAN::Math::max(y, other.y);
+		const auto max_x = BAN::Math::min(x + width, other.x + other.width);
+		const auto max_y = BAN::Math::min(y + height, other.y + other.height);
+		if (min_x >= max_x || min_y >= max_y)
+			return {};
+		return Rectangle {
+			.x = min_x,
+			.y = min_y,
+			.width = max_x - min_x,
+			.height = max_y - min_y,
+		};
+	}
+
+	Rectangle get_bounding_box(Rectangle other) const
+	{
+		const auto min_x = BAN::Math::min(x, other.x);
+		const auto min_y = BAN::Math::min(y, other.y);
+		const auto max_x = BAN::Math::max(x + width, other.x + other.width);
+		const auto max_y = BAN::Math::max(y + height, other.y + other.height);
+		return Rectangle {
+			.x = min_x,
+			.y = min_y,
+			.width = max_x - min_x,
+			.height = max_y - min_y,
+		};
+	}
+
+	bool operator==(const Rectangle& other) const
+	{
+		return x == other.x && y == other.y && width == other.width && height == other.height;
+	}
+
+};
+
+struct Circle
+{
+	int32_t x;
+	int32_t y;
+	int32_t radius;
+
+	bool contains(Position position) const
+	{
+		int32_t dx = position.x - x;
+		int32_t dy = position.y - y;
+		return dx * dx + dy * dy <= radius * radius;
+	}
+
+};