Struct ViewportPoint

Namespace

FlowGraph.Core.Coordinates

Assembly

FlowGraph.Core.dll

A point in viewport coordinate space (screen/control coordinates).

Viewport coordinates represent positions within the visible canvas control. (0,0) is the top-left of the canvas control, and values increase to the right and down. These coordinates change as the user pans and zooms - a node at canvas (100, 200) will appear at different viewport positions depending on the current zoom/pan state.

When to use:

• Auto-pan edge detection (checking if cursor is near viewport edges)
• Fixed UI positioning (tooltips, menus that don't pan/zoom)
• Direct rendering to DrawingContext (after converting from canvas)
• Viewport bounds calculations

Important: Viewport coordinates assume (0,0) is at the canvas control's origin. If the canvas is embedded in a larger control with margins/toolbars, you may need to account for offsets when converting from parent control coordinates.

public readonly record struct ViewportPoint : IEquatable<ViewportPoint>

Implements

IEquatable<ViewportPoint>

Inherited Members

ValueType.Equals(object)

ValueType.GetHashCode()

object.Equals(object, object)

object.GetType()

object.ReferenceEquals(object, object)

Extension Methods

AvaloniaCoordinateExtensions.ToAvalonia(ViewportPoint)

Constructors

ViewportPoint(double, double)

A point in viewport coordinate space (screen/control coordinates).

Viewport coordinates represent positions within the visible canvas control. (0,0) is the top-left of the canvas control, and values increase to the right and down. These coordinates change as the user pans and zooms - a node at canvas (100, 200) will appear at different viewport positions depending on the current zoom/pan state.

When to use:

• Auto-pan edge detection (checking if cursor is near viewport edges)
• Fixed UI positioning (tooltips, menus that don't pan/zoom)
• Direct rendering to DrawingContext (after converting from canvas)
• Viewport bounds calculations

Important: Viewport coordinates assume (0,0) is at the canvas control's origin. If the canvas is embedded in a larger control with margins/toolbars, you may need to account for offsets when converting from parent control coordinates.

public ViewportPoint(double X, double Y)

Parameters

X double

Y double

Properties

X

public double X { get; init; }

Property Value

double

Y

public double Y { get; init; }

Property Value

double

Zero

The origin point (0, 0) in viewport space.

public static ViewportPoint Zero { get; }

Property Value

ViewportPoint

Methods

DistanceSquaredTo(ViewportPoint)

Calculates the squared distance to another point (faster than DistanceTo).

public double DistanceSquaredTo(ViewportPoint other)

Parameters

other ViewportPoint

Returns

double

DistanceTo(ViewportPoint)

Calculates the distance to another point.

public double DistanceTo(ViewportPoint other)

Parameters

other ViewportPoint

Returns

double

GetEdgePanDirection(ViewportRect, double)

Gets the direction(s) in which this point is near the edge.

public ViewportVector GetEdgePanDirection(ViewportRect bounds, double edgeDistance)

Parameters

bounds ViewportRect

The viewport bounds to check against.

edgeDistance double

The distance from edge to trigger.

Returns

ViewportVector

A vector indicating the pan direction (negative = pan in that direction).

IsNearEdge(ViewportRect, double)

Checks if this point is within a distance from an edge of a bounding box. Useful for auto-pan edge detection.

public bool IsNearEdge(ViewportRect bounds, double edgeDistance)

Parameters

bounds ViewportRect

The viewport bounds to check against.

edgeDistance double

The distance from edge to trigger.

Returns

bool

True if the point is within edgeDistance of any edge.

ToString()

Returns the fully qualified type name of this instance.

public override string ToString()

Returns

string

The fully qualified type name.

Operators

operator +(ViewportPoint, ViewportVector)

Adds a vector to this point, producing a new point.

public static ViewportPoint operator +(ViewportPoint point, ViewportVector vector)

Parameters

point ViewportPoint

vector ViewportVector

Returns

ViewportPoint

operator -(ViewportPoint, ViewportPoint)

Calculates the vector between two points.

public static ViewportVector operator -(ViewportPoint a, ViewportPoint b)

Parameters

a ViewportPoint

b ViewportPoint

Returns

ViewportVector

operator -(ViewportPoint, ViewportVector)

Subtracts a vector from this point, producing a new point.

public static ViewportPoint operator -(ViewportPoint point, ViewportVector vector)

Parameters

point ViewportPoint

vector ViewportVector

Returns

ViewportPoint