decorations: Decoration Positioner (#3800)

src/helpers/Box.cpp

@@ -96,6 +96,15 @@ CBox& CBox::scaleFromCenter(double scale) {
     return *this;
 }
 
+CBox& CBox::expand(const double& value) {
+    x -= value;
+    y -= value;
+    w += value * 2.0;
+    h += value * 2.0;
+
+    return *this;
+}
+
 CBox CBox::roundInternal() {
     float newW = x + w - std::floor(x);
     float newH = y + h - std::floor(y);
@@ -110,3 +119,7 @@ Vector2D CBox::pos() const {
 Vector2D CBox::size() const {
     return {w, h};
 }
+
+SWindowDecorationExtents CBox::extentsFrom(const CBox& small) {
+    return {{small.x - x, small.y - y}, {w - small.w - (small.x - x), h - small.h - (small.y - y)}};
+}

src/helpers/Box.hpp

@@ -39,26 +39,29 @@ class CBox {
         h = size.y;
     }
 
-    wlr_box  wlr();
-    wlr_box* pWlr();
+    wlr_box                  wlr();
+    wlr_box*                 pWlr();
 
-    CBox&    applyFromWlr();
-    CBox&    scale(double scale);
-    CBox&    scaleFromCenter(double scale);
-    CBox&    scale(const Vector2D& scale);
-    CBox&    translate(const Vector2D& vec);
-    CBox&    round();
-    CBox&    transform(const wl_output_transform t, double w, double h);
-    CBox&    addExtents(const SWindowDecorationExtents& e);
+    CBox&                    applyFromWlr();
+    CBox&                    scale(double scale);
+    CBox&                    scaleFromCenter(double scale);
+    CBox&                    scale(const Vector2D& scale);
+    CBox&                    translate(const Vector2D& vec);
+    CBox&                    round();
+    CBox&                    transform(const wl_output_transform t, double w, double h);
+    CBox&                    addExtents(const SWindowDecorationExtents& e);
+    CBox&                    expand(const double& value);
 
-    Vector2D middle() const;
-    Vector2D pos() const;
-    Vector2D size() const;
+    SWindowDecorationExtents extentsFrom(const CBox&); // this is the big box
 
-    bool     containsPoint(const Vector2D& vec) const;
-    bool     empty() const;
+    Vector2D                 middle() const;
+    Vector2D                 pos() const;
+    Vector2D                 size() const;
 
-    double   x = 0, y = 0;
+    bool                     containsPoint(const Vector2D& vec) const;
+    bool                     empty() const;
+
+    double                   x = 0, y = 0;
     union {
         double w;
         double width;

src/helpers/Region.cpp

@@ -21,8 +21,8 @@ CRegion::CRegion(wlr_box* box) {
     pixman_region32_init_rect(&m_rRegion, box->x, box->y, box->width, box->height);
 }
 
-CRegion::CRegion(CBox* box) {
-    pixman_region32_init_rect(&m_rRegion, box->x, box->y, box->w, box->h);
+CRegion::CRegion(const CBox& box) {
+    pixman_region32_init_rect(&m_rRegion, box.x, box.y, box.w, box.h);
 }
 
 CRegion::CRegion(pixman_box32_t* box) {
@@ -63,6 +63,11 @@ CRegion& CRegion::add(double x, double y, double w, double h) {
     return *this;
 }
 
+CRegion& CRegion::add(const CBox& other) {
+    pixman_region32_union_rect(&m_rRegion, &m_rRegion, other.x, other.y, other.w, other.h);
+    return *this;
+}
+
 CRegion& CRegion::subtract(const CRegion& other) {
     pixman_region32_subtract(&m_rRegion, &m_rRegion, const_cast<CRegion*>(&other)->pixman());
     return *this;

src/helpers/Region.hpp

@@ -17,7 +17,7 @@ class CRegion {
     /* Create from a wlr_box */
     CRegion(wlr_box* box);
     /* Create from a CBox */
-    CRegion(CBox* box);
+    CRegion(const CBox& box);
     /* Create from a pixman_box32_t */
     CRegion(pixman_box32_t* box);
 
@@ -40,6 +40,7 @@ class CRegion {
     CRegion&                    set(const CRegion& other);
     CRegion&                    add(const CRegion& other);
     CRegion&                    add(double x, double y, double w, double h);
+    CRegion&                    add(const CBox& other);
     CRegion&                    subtract(const CRegion& other);
     CRegion&                    intersect(const CRegion& other);
     CRegion&                    intersect(double x, double y, double w, double h);

src/helpers/Vector2D.cpp

@@ -28,6 +28,10 @@ Vector2D Vector2D::floor() const {
     return Vector2D(std::floor(x), std::floor(y));
 }
 
+Vector2D Vector2D::round() const {
+    return Vector2D(std::round(x), std::round(y));
+}
+
 Vector2D Vector2D::clamp(const Vector2D& min, const Vector2D& max) const {
     return Vector2D(std::clamp(this->x, min.x, max.x < min.x ? INFINITY : max.x), std::clamp(this->y, min.y, max.y < min.y ? INFINITY : max.y));
 }

src/helpers/Vector2D.hpp

@@ -61,6 +61,7 @@ class Vector2D {
     Vector2D clamp(const Vector2D& min, const Vector2D& max = Vector2D()) const;
 
     Vector2D floor() const;
+    Vector2D round() const;
 
     bool     inTriangle(const Vector2D& p1, const Vector2D& p2, const Vector2D& p3) const;
 };