Added proper hit test with rotation and pivoting

include/utils.h

@@ -80,6 +80,7 @@ struct Line {
   Vec2<float> start;
   Vec2<float> end;
 
+  Line() = default;
   Line(Vec2<float> start, Vec2<float> end) : start(start), end(end) {}
 
   bool intersects(const Line &other) const {
@@ -98,7 +99,7 @@ struct Line {
 struct Rect {
   Line diagonal; // from top-left to bottom-right
 
-  Rect(Vec2<float> a, Vec2<float> b) : diagonal(a, b) {
+  Rect(Vec2<float> a, Vec2<float> b) {
     diagonal.start = {
       MIN(a.x, b.x),
       MIN(a.y, b.y)
@@ -109,7 +110,11 @@ struct Rect {
     };
   }
 
-  static Rect from_size(Vec2<float> position, Vec2<float> size) {
+  static Rect from(Vec2<float> size) {
+    return Rect({0, 0}, size);
+  }
+
+  static Rect from(Vec2<float> position, Vec2<float> size) {
     return Rect(position, position + size);
   }