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/Rect.h

@@ -0,0 +1,252 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/LogStream.h>
+#include <LibDraw/Point.h>
+#include <LibDraw/Size.h>
+#include <LibDraw/TextAlignment.h>
+
+struct WSAPI_Rect;
+
+class Rect {
+public:
+    Rect() {}
+    Rect(int x, int y, int width, int height)
+        : m_location(x, y)
+        , m_size(width, height)
+    {
+    }
+    Rect(const Point& location, const Size& size)
+        : m_location(location)
+        , m_size(size)
+    {
+    }
+    Rect(const Rect& other)
+        : m_location(other.m_location)
+        , m_size(other.m_size)
+    {
+    }
+
+    Rect(const WSAPI_Rect&);
+
+    bool is_null() const
+    {
+        return width() == 0 && height() == 0;
+    }
+
+    bool is_empty() const
+    {
+        return width() <= 0 || height() <= 0;
+    }
+
+    void move_by(int dx, int dy)
+    {
+        m_location.move_by(dx, dy);
+    }
+
+    void move_by(const Point& delta)
+    {
+        m_location.move_by(delta);
+    }
+
+    Point center() const
+    {
+        return { x() + width() / 2, y() + height() / 2 };
+    }
+
+    void set_location(const Point& location)
+    {
+        m_location = location;
+    }
+
+    void set_size(const Size& size)
+    {
+        m_size = size;
+    }
+
+    void set_size(int width, int height)
+    {
+        m_size.set_width(width);
+        m_size.set_height(height);
+    }
+
+    void inflate(int w, int h)
+    {
+        set_x(x() - w / 2);
+        set_width(width() + w);
+        set_y(y() - h / 2);
+        set_height(height() + h);
+    }
+
+    void shrink(int w, int h)
+    {
+        set_x(x() + w / 2);
+        set_width(width() - w);
+        set_y(y() + h / 2);
+        set_height(height() - h);
+    }
+
+    Rect shrunken(int w, int h) const
+    {
+        Rect rect = *this;
+        rect.shrink(w, h);
+        return rect;
+    }
+
+    Rect inflated(int w, int h) const
+    {
+        Rect rect = *this;
+        rect.inflate(w, h);
+        return rect;
+    }
+
+    Rect translated(int dx, int dy) const
+    {
+        Rect rect = *this;
+        rect.move_by(dx, dy);
+        return rect;
+    }
+
+    Rect translated(const Point& delta) const
+    {
+        Rect rect = *this;
+        rect.move_by(delta);
+        return rect;
+    }
+
+    bool contains(int x, int y) const
+    {
+        return x >= m_location.x() && x <= right() && y >= m_location.y() && y <= bottom();
+    }
+
+    bool contains(const Point& point) const
+    {
+        return contains(point.x(), point.y());
+    }
+
+    bool contains(const Rect& other) const
+    {
+        return left() <= other.left()
+            && right() >= other.right()
+            && top() <= other.top()
+            && bottom() >= other.bottom();
+    }
+
+    int left() const { return x(); }
+    int right() const { return x() + width() - 1; }
+    int top() const { return y(); }
+    int bottom() const { return y() + height() - 1; }
+
+    void set_left(int left)
+    {
+        set_x(left);
+    }
+
+    void set_top(int top)
+    {
+        set_y(top);
+    }
+
+    void set_right(int right)
+    {
+        set_width(right - x() + 1);
+    }
+
+    void set_bottom(int bottom)
+    {
+        set_height(bottom - y() + 1);
+    }
+
+    bool intersects(const Rect& other) const
+    {
+        return left() <= other.right()
+            && other.left() <= right()
+            && top() <= other.bottom()
+            && other.top() <= bottom();
+    }
+
+    int x() const { return location().x(); }
+    int y() const { return location().y(); }
+    int width() const { return m_size.width(); }
+    int height() const { return m_size.height(); }
+
+    void set_x(int x) { m_location.set_x(x); }
+    void set_y(int y) { m_location.set_y(y); }
+    void set_width(int width) { m_size.set_width(width); }
+    void set_height(int height) { m_size.set_height(height); }
+
+    Point location() const { return m_location; }
+    Size size() const { return m_size; }
+
+    Vector<Rect, 4> shatter(const Rect& hammer) const;
+
+    operator WSAPI_Rect() const;
+
+    bool operator==(const Rect& other) const
+    {
+        return m_location == other.m_location
+            && m_size == other.m_size;
+    }
+
+    void intersect(const Rect&);
+
+    static Rect intersection(const Rect& a, const Rect& b)
+    {
+        Rect r(a);
+        r.intersect(b);
+        return r;
+    }
+
+    Rect intersected(const Rect& other) const
+    {
+        return intersection(*this, other);
+    }
+
+    Rect united(const Rect&) const;
+
+    Point top_left() const { return { left(), top() }; }
+    Point top_right() const { return { right(), top() }; }
+    Point bottom_left() const { return { left(), bottom() }; }
+    Point bottom_right() const { return { right(), bottom() }; }
+
+    void align_within(const Rect&, TextAlignment);
+
+    void center_within(const Rect& other)
+    {
+        center_horizontally_within(other);
+        center_vertically_within(other);
+    }
+
+    void center_horizontally_within(const Rect& other)
+    {
+        set_x(other.center().x() - width() / 2);
+    }
+
+    void center_vertically_within(const Rect& other)
+    {
+        set_y(other.center().y() - height() / 2);
+    }
+
+    String to_string() const { return String::format("[%d,%d %dx%d]", x(), y(), width(), height()); }
+
+private:
+    Point m_location;
+    Size m_size;
+};
+
+inline void Point::constrain(const Rect& rect)
+{
+    if (x() < rect.left())
+        set_x(rect.left());
+    else if (x() > rect.right())
+        set_x(rect.right());
+    if (y() < rect.top())
+        set_y(rect.top());
+    else if (y() > rect.bottom())
+        set_y(rect.bottom());
+}
+
+inline const LogStream& operator<<(const LogStream& stream, const Rect& value)
+{
+    return stream << value.to_string();
+}