ref(event): split Size into two Points (one for the size and one for the anchor / origin)

src/input.zig

@@ -1,11 +1,11 @@
 //! Input module for `zterm`. Contains structs to represent key events and mouse events.
 const std = @import("std");
 
-const Size = @import("size.zig").Size;
+const Point = @import("point.zig").Point;
 
 pub const Mouse = packed struct {
-    col: u16,
-    row: u16,
+    x: u16,
+    y: u16,
     button: Button,
     kind: Kind,
 
@@ -35,9 +35,9 @@ pub const Mouse = packed struct {
         return std.meta.eql(this, other);
     }
 
-    pub fn in(this: @This(), size: Size) bool {
-        return this.col >= size.anchor.col and this.col <= size.cols + size.anchor.col and
-            this.row >= size.anchor.row and this.row <= size.rows + size.anchor.row;
+    pub fn in(this: @This(), origin: Point, size: Point) bool {
+        return this.x >= origin.x and this.x <= size.x + origin.x and
+            this.y >= origin.y and this.y <= size.y + origin.y;
     }
 };