Math and 2D helpers

The engine’s value types for 2D games (ADR 0142). GodotSharp 4.7.2’s C# math (MIT, attributed in each file under MainframeEngine/Src/Math/), so formulas and edge cases match Godot’s.

Type	Notes
System.Numerics.Vector2	the one 2D vector. Vector2Extensions adds Godot’s members as C# 14 extensions: Normalized() (zero stays zero), Length-based helpers (DistanceTo, DirectionTo, MoveToward, LimitLength), Angle, AngleTo, Rotated, Lerp, Slerp, Snapped, Floor/Ceil/Round/Sign/Abs, Clamp, Min/Max, Reflect/Bounce/Slide/Project, Orthogonal, IsEqualApprox; constants Vector2.Up/Down/Left/Right/Inf (Y down) and Vector2.FromAngle
Vector2I, Rect2I	integer vector and rectangle; Vector2I → Vector2 implicit, back explicit (truncates); Rect2I → Rect2 implicit
Rect2, Transform2D	the engine’s own; Transform2D(rotation, origin), transform * point, transform * rect (bounding box)
Color, Colors	float RGBA with Godot’s API (FromHtml/ToHtml, Lerp, Darkened/Lightened, HSV, named colours); converts implicitly to and from Vector4 (the renderers’ form). The 3D material side still uses System.Drawing.Color (files that use both alias it DrawingColor)
Mathf	float maths: Lerp, MoveToward, Wrap, PosMod, Snapped, Clamp, DegToRad, LinearToDb, easing, approximate comparisons
Side	rectangle sides (Rect2I.GrowSide)

Vector2I, Rect2I and Color are built-in value types: [Export] members of these types store as number arrays in .mscene/.mres ([x, y], [x, y, w, h], [r, g, b, a]).

2D helpers

• Label2D: world-space text (font, size, colour, outline, shadow): newlines break lines, Autowrap (Godot’s autowrap_mode: Off, Arbitrary, Word, WordSmart) wraps at Width, lines sit LineSpacing apart (3, Godot’s default) and align horizontally in Width and vertically in Height (GetLines, GetMinimumSize, Size); for prompts, hints and tags that move with the world. Menus and HUDs are UI documents.
• BitMask (ADR 0203; Godot’s BitMap, renamed because Bitmap below differs only by case): a bit grid ported from Godot 4.7.2. CreateFromImageAlpha (a Texture2D, a Bitmap or RGBA8; alpha / 255 > threshold, 0.1), Get/SetBit, SetBitRect, GetTrueBitCount, Resize, GrowMask/ShrinkMask (a disc of radius n inside a rect), OpaqueToPolygons(rect, epsilon = 2) (one outline per 8-connected region, marching squares split where the outline touches itself, then Ramer–Douglas–Peucker; holes are not traced), ConvertToImage, Blit. Built at run time, not saved in scenes. Typical use: a sprite’s alpha → GrowMask → OpaqueToPolygons → a CollisionPolygon2D or a Polygon2D.
• Geometry2D (ADR 0203): Godot’s polygon helpers. MergePolygons, ClipPolygons, IntersectPolygons, ExcludePolygons, ClipPolylineWithPolygon, IntersectPolylineWithPolygon, OffsetPolygon(delta, join), OffsetPolyline(delta, join, end) wrap Clipper2 1.5.4 with Godot’s settings (5 decimals, even-odd, collinear points removed, miter limit 2, arc tolerance 0.25) and return Vector2[][] (holes wind opposite to outlines); TriangulatePolygon is the canvas ear clipper (empty on failure) and IsPolygonClockwise Godot’s (+Y up). GodotGeometryParityTests checks both types against Godot’s output for the same inputs.
• Bitmap: RGBA8 pixels on the CPU (SetPixel, Fill, FromLuminance/FromRed expand one-channel data like an L8/R8 texture samples); Texture2D.FromBitmap uploads it as a data texture, SetPixels(bitmap) refreshes it.
• Time: TicksMsec/TicksUsec (monotonic, since start) and UnixTime (wall clock).