Overhaul Rect2 & Rect2i Documentation

doc/classes/Rect2.xml

@@ -4,10 +4,10 @@
 		A 2D axis-aligned bounding box using floating-point coordinates.
 	</brief_description>
 	<description>
-		[Rect2] consists of a position, a size, and several utility functions. It is typically used for fast overlap tests.
-		It uses floating-point coordinates. If you need integer coordinates, use [Rect2i] instead.
-		The 3D counterpart to [Rect2] is [AABB].
-		Negative values for [member size] are not supported and will not work for most methods. Use [method abs] to get a Rect2 with a positive size.
+		The [Rect2] built-in [Variant] type represents an axis-aligned rectangle in a 2D space. It is defined by its [member position] and [member size], which are [Vector2]. It is frequently used for fast overlap tests (see [method intersects]). Although [Rect2] itself is axis-aligned, it can be combined with [Transform2D] to represent a rotated or skewed rectangle.
+		For integer coordinates, use [Rect2i]. The 3D equivalent to [Rect2] is [AABB].
+		[b]Note:[/b] Negative values for [member size] are not supported. With negative size, most [Rect2] methods do not work correctly. Use [method abs] to get an equivalent [Rect2] with a non-negative size.
+		[b]Note:[/b] In a boolean context, a [Rect2] evaluates to [code]false[/code] if both [member position] and [member size] are zero (equal to [constant Vector2.ZERO]). Otherwise, it always evaluates to [code]true[/code].
 	</description>
 	<tutorials>
 		<link title="Math documentation index">$DOCS_URL/tutorials/math/index.html</link>
@@ -18,7 +18,7 @@
 		<constructor name="Rect2">
 			<return type="Rect2" />
 			<description>
-				Constructs a default-initialized [Rect2] with default (zero) values of [member position] and [member size].
+				Constructs a [Rect2] with its [member position] and [member size] set to [constant Vector2.ZERO].
 			</description>
 		</constructor>
 		<constructor name="Rect2">
@@ -40,7 +40,7 @@
 			<param index="0" name="position" type="Vector2" />
 			<param index="1" name="size" type="Vector2" />
 			<description>
-				Constructs a [Rect2] by position and size.
+				Constructs a [Rect2] by [param position] and [param size].
 			</description>
 		</constructor>
 		<constructor name="Rect2">
@@ -50,63 +50,83 @@
 			<param index="2" name="width" type="float" />
 			<param index="3" name="height" type="float" />
 			<description>
-				Constructs a [Rect2] by x, y, width, and height.
+				Constructs a [Rect2] by setting its [member position] to ([param x], [param y]), and its [member size] to ([param width], [param height]).
 			</description>
 		</constructor>
 	</constructors>
 	<methods>
 		<method name="abs" qualifiers="const">
 			<return type="Rect2" />
 			<description>
-				Returns a [Rect2] with equivalent position and area, modified so that the top-left corner is the origin and [code]width[/code] and [code]height[/code] are positive.
+				Returns a [Rect2] equivalent to this rectangle, with its width and height modified to be non-negative values, and with its [member position] being the top-left corner of the rectangle.
+				[codeblocks]
+				[gdscript]
+				var rect = Rect2(25, 25, -100, -50)
+				var absolute = rect.abs() # absolute is Rect2(-75, -25, 100, 50)
+				[/gdscript]
+				[csharp]
+				var rect = new Rect2(25, 25, -100, -50);
+				var absolute = rect.Abs(); // absolute is Rect2(-75, -25, 100, 50)
+				[/csharp]
+				[/codeblocks]
+				[b]Note:[/b] It's recommended to use this method when [member size] is negative, as most other methods in Godot assume that the [member position] is the top-left corner, and the [member end] is the bottom-right corner.
 			</description>
 		</method>
 		<method name="encloses" qualifiers="const">
 			<return type="bool" />
 			<param index="0" name="b" type="Rect2" />
 			<description>
-				Returns [code]true[/code] if this [Rect2] completely encloses another one.
+				Returns [code]true[/code] if this rectangle [i]completely[/i] encloses the [param b] rectangle.
 			</description>
 		</method>
 		<method name="expand" qualifiers="const">
 			<return type="Rect2" />
 			<param index="0" name="to" type="Vector2" />
 			<description>
-				Returns a copy of this [Rect2] expanded to include a given point.
-				[b]Example:[/b]
+				Returns a copy of this rectangle expanded to include the given [param to] point, if necessary.
 				[codeblocks]
 				[gdscript]
-				# position (-3, 2), size (1, 1)
-				var rect = Rect2(Vector2(-3, 2), Vector2(1, 1))
-				# position (-3, -1), size (3, 4), so we fit both rect and Vector2(0, -1)
-				var rect2 = rect.expand(Vector2(0, -1))
+				var rect = Rect2(0, 0, 5, 2)
+
+				rect = rect.expand(Vector2(10, 0)) # rect is Rect2(0, 0, 10, 2)
+				rect = rect.expand(Vector2(-5, 5)) # rect is Rect2(-5, 0, 10, 5)
 				[/gdscript]
 				[csharp]
-				// position (-3, 2), size (1, 1)
-				var rect = new Rect2(new Vector2(-3, 2), new Vector2(1, 1));
-				// position (-3, -1), size (3, 4), so we fit both rect and Vector2(0, -1)
-				var rect2 = rect.Expand(new Vector2(0, -1));
+				var rect = new Rect2(0, 0, 5, 2);
+
+				rect = rect.Expand(new Vector2(10, 0)); // rect is Rect2(0, 0, 10, 2)
+				rect = rect.Expand(new Vector2(-5, 5)); // rect is Rect2(-5, 0, 10, 5)
 				[/csharp]
 				[/codeblocks]
 			</description>
 		</method>
 		<method name="get_area" qualifiers="const">
 			<return type="float" />
 			<description>
-				Returns the area of the [Rect2]. See also [method has_area].
+				Returns the rectangle's area. This is equivalent to [code]size.x * size.y[/code]. See also [method has_area].
 			</description>
 		</method>
 		<method name="get_center" qualifiers="const">
 			<return type="Vector2" />
 			<description>
-				Returns the center of the [Rect2], which is equal to [member position] + ([member size] / 2).
+				Returns the center point of the rectangle. This is the same as [code]position + (size / 2.0)[/code].
 			</description>
 		</method>
 		<method name="grow" qualifiers="const">
 			<return type="Rect2" />
 			<param index="0" name="amount" type="float" />
 			<description>
-				Returns a copy of the [Rect2] grown by the specified [param amount] on all sides.
+				Returns a copy of this rectangle extended on all sides by the given [param amount]. A negative [param amount] shrinks the rectangle instead. See also [method grow_individual] and [method grow_side].
+				[codeblocks]
+				[gdscript]
+				var a = Rect2(4, 4, 8, 8).grow(4) # a is Rect2(0, 0, 16, 16)
+				var b = Rect2(0, 0, 8, 4).grow(2) # b is Rect2(-2, -2, 12, 8)
+				[/gdscript]
+				[csharp]
+				var a = new Rect2(4, 4, 8, 8).Grow(4); // a is Rect2(0, 0, 16, 16)
+				var b = new Rect2(0, 0, 8, 4).Grow(2); // b is Rect2(-2, -2, 12, 8)
+				[/csharp]
+				[/codeblocks]
 			</description>
 		</method>
 		<method name="grow_individual" qualifiers="const">
@@ -116,87 +136,100 @@
 			<param index="2" name="right" type="float" />
 			<param index="3" name="bottom" type="float" />
 			<description>
-				Returns a copy of the [Rect2] grown by the specified amount on each side individually.
+				Returns a copy of this rectangle with its [param left], [param top], [param right], and [param bottom] sides extended by the given amounts. Negative values shrink the sides, instead. See also [method grow] and [method grow_side].
 			</description>
 		</method>
 		<method name="grow_side" qualifiers="const">
 			<return type="Rect2" />
 			<param index="0" name="side" type="int" />
 			<param index="1" name="amount" type="float" />
 			<description>
-				Returns a copy of the [Rect2] grown by the specified [param amount] on the specified [enum Side].
+				Returns a copy of this rectangle with its [param side] extended by the given [param amount] (see [enum Side] constants). A negative [param amount] shrinks the rectangle, instead. See also [method grow] and [method grow_individual].
 			</description>
 		</method>
 		<method name="has_area" qualifiers="const">
 			<return type="bool" />
 			<description>
-				Returns [code]true[/code] if the [Rect2] has area, and [code]false[/code] if the [Rect2] is linear, empty, or has a negative [member size]. See also [method get_area].
+				Returns [code]true[/code] if this rectangle has positive width and height. See also [method get_area].
 			</description>
 		</method>
 		<method name="has_point" qualifiers="const">
 			<return type="bool" />
 			<param index="0" name="point" type="Vector2" />
 			<description>
-				Returns [code]true[/code] if the [Rect2] contains a point. By convention, the right and bottom edges of the [Rect2] are considered exclusive, so points on these edges are [b]not[/b] included.
-				[b]Note:[/b] This method is not reliable for [Rect2] with a [i]negative size[/i]. Use [method abs] to get a positive sized equivalent rectangle to check for contained points.
+				Returns [code]true[/code] if the rectangle contains the given [param point]. By convention, points on the right and bottom edges are [b]not[/b] included.
+				[b]Note:[/b] This method is not reliable for [Rect2] with a [i]negative[/i] [member size]. Use [method abs] first to get a valid rectangle.
 			</description>
 		</method>
 		<method name="intersection" qualifiers="const">
 			<return type="Rect2" />
 			<param index="0" name="b" type="Rect2" />
 			<description>
-				Returns the intersection of this [Rect2] and [param b].
-				If the rectangles do not intersect, an empty [Rect2] is returned.
+				Returns the intersection between this rectangle and [param b]. If the rectangles do not intersect, returns an empty [Rect2].
+				[codeblocks]
+				[gdscript]
+				var rect1 = Rect2(0, 0, 5, 10)
+				var rect2 = Rect2(2, 0, 8, 4)
+
+				var a = rect1.intersection(rect2) # a is Rect2(2, 0, 3, 4)
+				[/gdscript]
+				[csharp]
+				var rect1 = new Rect2(0, 0, 5, 10);
+				var rect2 = new Rect2(2, 0, 8, 4);
+
+				var a = rect1.Intersection(rect2); // a is Rect2(2, 0, 3, 4)
+				[/csharp]
+				[/codeblocks]
+				[b]Note:[/b] If you only need to know whether two rectangles are overlapping, use [method intersects], instead.
 			</description>
 		</method>
 		<method name="intersects" qualifiers="const">
 			<return type="bool" />
 			<param index="0" name="b" type="Rect2" />
 			<param index="1" name="include_borders" type="bool" default="false" />
 			<description>
-				Returns [code]true[/code] if the [Rect2] overlaps with [param b] (i.e. they have at least one point in common).
-				If [param include_borders] is [code]true[/code], they will also be considered overlapping if their borders touch, even without intersection.
+				Returns [code]true[/code] if this rectangle overlaps with the [param b] rectangle. The edges of both rectangles are excluded, unless [param include_borders] is [code]true[/code].
 			</description>
 		</method>
 		<method name="is_equal_approx" qualifiers="const">
 			<return type="bool" />
 			<param index="0" name="rect" type="Rect2" />
 			<description>
-				Returns [code]true[/code] if this [Rect2] and [param rect] are approximately equal, by calling [code]is_equal_approx[/code] on each component.
+				Returns [code]true[/code] if this rectangle and [param rect] are approximately equal, by calling [method Vector2.is_equal_approx] on the [member position] and the [member size].
 			</description>
 		</method>
 		<method name="is_finite" qualifiers="const">
 			<return type="bool" />
 			<description>
-				Returns [code]true[/code] if this [Rect2] is finite, by calling [method @GlobalScope.is_finite] on each component.
+				Returns [code]true[/code] if this rectangle's values are finite, by calling [method Vector2.is_finite] on the [member position] and the [member size].
 			</description>
 		</method>
 		<method name="merge" qualifiers="const">
 			<return type="Rect2" />
 			<param index="0" name="b" type="Rect2" />
 			<description>
-				Returns a larger [Rect2] that contains this [Rect2] and [param b].
+				Returns a [Rect2] that encloses both this rectangle and [param b] around the edges. See also [method encloses].
 			</description>
 		</method>
 	</methods>
 	<members>
 		<member name="end" type="Vector2" setter="" getter="" default="Vector2(0, 0)">
-			Ending corner. This is calculated as [code]position + size[/code]. Setting this value will change the size.
+			The ending point. This is usually the bottom-right corner of the rectangle, and is equivalent to [code]position + size[/code]. Setting this point affects the [member size].
 		</member>
 		<member name="position" type="Vector2" setter="" getter="" default="Vector2(0, 0)">
-			Beginning corner. Typically has values lower than [member end].
+			The origin point. This is usually the top-left corner of the rectangle.
 		</member>
 		<member name="size" type="Vector2" setter="" getter="" default="Vector2(0, 0)">
-			Size from [member position] to [member end]. Typically, all components are positive.
-			If the size is negative, you can use [method abs] to fix it.
+			The rectangle's width and height, starting from [member position]. Setting this value also affects the [member end] point.
+			[b]Note:[/b] It's recommended setting the width and height to non-negative values, as most methods in Godot assume that the [member position] is the top-left corner, and the [member end] is the bottom-right corner. To get an equivalent rectangle with non-negative size, use [method abs].
 		</member>
 	</members>
 	<operators>
 		<operator name="operator !=">
 			<return type="bool" />
 			<param index="0" name="right" type="Rect2" />
 			<description>
-				Returns [code]true[/code] if the rectangles are not equal.
+				Returns [code]true[/code] if the [member position] or [member size] of both rectangles are not equal.
 				[b]Note:[/b] Due to floating-point precision errors, consider using [method is_equal_approx] instead, which is more reliable.
 			</description>
 		</operator>
@@ -211,7 +244,7 @@
 			<return type="bool" />
 			<param index="0" name="right" type="Rect2" />
 			<description>
-				Returns [code]true[/code] if the rectangles are exactly equal.
+				Returns [code]true[/code] if both [member position] and [member size] of the rectangles are exactly equal, respectively.
 				[b]Note:[/b] Due to floating-point precision errors, consider using [method is_equal_approx] instead, which is more reliable.
 			</description>
 		</operator>