LibDraw: Introduce (formerly known as SharedGraphics.)

Instead of LibGUI and WindowServer building their own copies of the drawing
and graphics code, let's it in a separate LibDraw library.

This avoids building the code twice, and will encourage better separation
of concerns. :^)

Libraries/LibDraw/Point.h

@@ -0,0 +1,79 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/LogStream.h>
+
+class Rect;
+struct WSAPI_Point;
+
+class Point {
+public:
+    Point() {}
+    Point(int x, int y)
+        : m_x(x)
+        , m_y(y)
+    {
+    }
+    Point(const WSAPI_Point&);
+
+    int x() const { return m_x; }
+    int y() const { return m_y; }
+
+    void set_x(int x) { m_x = x; }
+    void set_y(int y) { m_y = y; }
+
+    void move_by(int dx, int dy)
+    {
+        m_x += dx;
+        m_y += dy;
+    }
+
+    void move_by(const Point& delta)
+    {
+        move_by(delta.x(), delta.y());
+    }
+
+    Point translated(const Point& delta) const
+    {
+        Point point = *this;
+        point.move_by(delta);
+        return point;
+    }
+
+    Point translated(int dx, int dy) const
+    {
+        Point point = *this;
+        point.move_by(dx, dy);
+        return point;
+    }
+
+    void constrain(const Rect&);
+
+    bool operator==(const Point& other) const
+    {
+        return m_x == other.m_x
+            && m_y == other.m_y;
+    }
+
+    bool operator!=(const Point& other) const
+    {
+        return !(*this == other);
+    }
+
+    Point operator-() const { return { -m_x, -m_y }; }
+    Point operator-(const Point& other) const { return { m_x - other.m_x, m_y - other.m_y }; }
+
+    operator WSAPI_Point() const;
+    String to_string() const { return String::format("[%d,%d]", x(), y()); }
+
+    bool is_null() const { return !m_x && !m_y; }
+
+private:
+    int m_x { 0 };
+    int m_y { 0 };
+};
+
+inline const LogStream& operator<<(const LogStream& stream, const Point& value)
+{
+    return stream << value.to_string();
+}