# mxGeometry

Extends mxRectangle to represent the geometry of a cell.

For vertices, the geometry consists of the x- and y-location, and the width and height.  For edges, the geometry consists of the optional terminal- and control points.  The terminal points are only required if an edge is unconnected, and are stored in the sourcePoint and targetPoint variables, respectively.

#### Example

If an edge is unconnected, that is, it has no source or target terminal, then a geometry with terminal points for a new edge can be defined as follows.

```geometry.setTerminalPoint(new mxPoint(x1, y1), true);
geometry.points = [new mxPoint(x2, y2)];
geometry.setTerminalPoint(new mxPoint(x3, y3), false);```

Control points are used regardless of the connected state of an edge and may be ignored or interpreted differently depending on the edge’s mxEdgeStyle.

To disable automatic reset of control points after a cell has been moved or resized, the the <mxGraph.resizeEdgesOnMove> and mxGraph.resetEdgesOnResize may be used.

#### Edge Labels

Using the x- and y-coordinates of a cell’s geometry, it is possible to position the label on edges on a specific location on the actual edge shape as it appears on the screen.  The x-coordinate of an edge’s geometry is used to describe the distance from the center of the edge from -1 to 1 with 0 being the center of the edge and the default value.  The y-coordinate of an edge’s geometry is used to describe the absolute, orthogonal distance in pixels from that point.  In addition, the mxGeometry.offset is used as an absolute offset vector from the resulting point.

This coordinate system is applied if relative is true, otherwise the offset defines the absolute vector from the edge’s center point to the label and the values for <x> and <y> are ignored.

The width and height parameter for edge geometries can be used to set the label width and height (eg. for word wrapping).

#### Ports

The term “port” refers to a relatively positioned, connectable child cell, which is used to specify the connection between the parent and another cell in the graph.  Ports are typically modeled as vertices with relative geometries.

#### Offsets

The offset field is interpreted in 3 different ways, depending on the cell and the geometry.  For edges, the offset defines the absolute offset for the edge label.  For relative geometries, the offset defines the absolute offset for the origin (top, left corner) of the vertex, otherwise the offset defines the absolute offset for the label inside the vertex or group.

Summary
 mxGeometry Extends mxRectangle to represent the geometry of a cell. Functions mxGeometry Constructs a new object to describe the size and location of a vertex or the control points of an edge. Variables TRANSLATE_CONTROL_POINTS Global switch to translate the points in translate. alternateBounds Stores alternate values for x, y, width and height in a rectangle. sourcePoint Defines the source mxPoint of the edge. targetPoint Defines the target mxPoint of the edge. points Array of mxPoints which specifies the control points along the edge. offset For edges, this holds the offset (in pixels) from the position defined by and on the edge. relative Specifies if the coordinates in the geometry are to be interpreted as relative coordinates. Functions swap Swaps the x, y, width and height with the values stored in alternateBounds and puts the previous values into alternateBounds as a rectangle. getTerminalPoint Returns the mxPoint representing the source or target point of this edge. setTerminalPoint Sets the sourcePoint or targetPoint to the given mxPoint and returns the new point. rotate Rotates the geometry by the given angle around the given center. translate Translates the geometry by the specified amount. scale Scales the geometry by the given amount. equals Returns true if the given object equals this geometry.

### mxGeometry

 function mxGeometry( x, y, width, height )

Constructs a new object to describe the size and location of a vertex or the control points of an edge.

### TRANSLATE_CONTROL_POINTS

 mxGeometry.prototype.TRANSLATE_CONTROL_POINTS

Global switch to translate the points in translate.  Default is true.

### alternateBounds

 mxGeometry.prototype.alternateBounds

Stores alternate values for x, y, width and height in a rectangle.  See swap to exchange the values.  Default is null.

### sourcePoint

 mxGeometry.prototype.sourcePoint

Defines the source mxPoint of the edge.  This is used if the corresponding edge does not have a source vertex.  Otherwise it is ignored.  Default is null.

### targetPoint

 mxGeometry.prototype.targetPoint

Defines the target mxPoint of the edge.  This is used if the corresponding edge does not have a target vertex.  Otherwise it is ignored.  Default is null.

### points

 mxGeometry.prototype.points

Array of mxPoints which specifies the control points along the edge.  These points are the intermediate points on the edge, for the endpoints use targetPoint and sourcePoint or set the terminals of the edge to a non-null value.  Default is null.

### offset

 mxGeometry.prototype.offset

For edges, this holds the offset (in pixels) from the position defined by <x> and <y> on the edge.  For relative geometries (for vertices), this defines the absolute offset from the point defined by the relative coordinates.  For absolute geometries (for vertices), this defines the offset for the label.  Default is null.

### relative

 mxGeometry.prototype.relative

Specifies if the coordinates in the geometry are to be interpreted as relative coordinates.  For edges, this is used to define the location of the edge label relative to the edge as rendered on the display.  For vertices, this specifies the relative location inside the bounds of the parent cell.

If this is false, then the coordinates are relative to the origin of the parent cell or, for edges, the edge label position is relative to the center of the edge as rendered on screen.

Default is false.

### swap

 mxGeometry.prototype.swap = function()

Swaps the x, y, width and height with the values stored in alternateBounds and puts the previous values into alternateBounds as a rectangle.  This operation is carried-out in-place, that is, using the existing geometry instance.  If this operation is called during a graph model transactional change, then the geometry should be cloned before calling this method and setting the geometry of the cell using mxGraphModel.setGeometry.

### getTerminalPoint

 mxGeometry.prototype.getTerminalPoint = function( isSource )

Returns the mxPoint representing the source or target point of this edge.  This is only used if the edge has no source or target vertex.

#### Parameters

 isSource Boolean that specifies if the source or target point should be returned.

### setTerminalPoint

 mxGeometry.prototype.setTerminalPoint = function( point, isSource )

Sets the sourcePoint or targetPoint to the given mxPoint and returns the new point.

#### Parameters

 point Point to be used as the new source or target point. isSource Boolean that specifies if the source or target point should be set.

### rotate

 mxGeometry.prototype.rotate = function( angle, cx )

Rotates the geometry by the given angle around the given center.  That is, <x> and <y> of the geometry, the sourcePoint, targetPoint and all points are translated by the given amount.  <x> and <y> are only translated if relative is false.

#### Parameters

 angle Number that specifies the rotation angle in degrees. cx mxPoint that specifies the center of the rotation.

### translate

 mxGeometry.prototype.translate = function( dx, dy )

Translates the geometry by the specified amount.  That is, <x> and <y> of the geometry, the sourcePoint, targetPoint and all points are translated by the given amount.  <x> and <y> are only translated if relative is false.  If TRANSLATE_CONTROL_POINTS is false, then points are not modified by this function.

#### Parameters

 dx Number that specifies the x-coordinate of the translation. dy Number that specifies the y-coordinate of the translation.

### scale

 mxGeometry.prototype.scale = function( sx, sy, fixedAspect )

Scales the geometry by the given amount.  That is, <x> and <y> of the geometry, the sourcePoint, targetPoint and all points are scaled by the given amount.  <x>, <y>, <width> and <height> are only scaled if relative is false.  If <fixedAspect> is true, then the smaller value is used to scale the width and the height.

#### Parameters

 sx Number that specifies the horizontal scale factor. sy Number that specifies the vertical scale factor. fixedAspect Optional boolean to keep the aspect ratio fixed.

### equals

 mxGeometry.prototype.equals = function( obj )

Returns true if the given object equals this geometry.

Extends mxPoint to implement a 2-dimensional rectangle with double precision coordinates.
 function mxGeometry( x, y, width, height )
Constructs a new object to describe the size and location of a vertex or the control points of an edge.
 mxGeometry.prototype.TRANSLATE_CONTROL_POINTS
Global switch to translate the points in translate.
 mxGeometry.prototype.alternateBounds
Stores alternate values for x, y, width and height in a rectangle.
 mxGeometry.prototype.sourcePoint
Defines the source mxPoint of the edge.
Implements a 2-dimensional vector with double precision coordinates.
 mxGeometry.prototype.targetPoint
Defines the target mxPoint of the edge.
 mxGeometry.prototype.points
Array of mxPoints which specifies the control points along the edge.
 mxGeometry.prototype.offset
For edges, this holds the offset (in pixels) from the position defined by x and y on the edge.
 mxGeometry.prototype.relative
Specifies if the coordinates in the geometry are to be interpreted as relative coordinates.
 mxGeometry.prototype.swap = function()
Swaps the x, y, width and height with the values stored in alternateBounds and puts the previous values into alternateBounds as a rectangle.
 mxGeometry.prototype.getTerminalPoint = function( isSource )
Returns the mxPoint representing the source or target point of this edge.
 mxGeometry.prototype.setTerminalPoint = function( point, isSource )
Sets the sourcePoint or targetPoint to the given mxPoint and returns the new point.
 mxGeometry.prototype.rotate = function( angle, cx )
Rotates the geometry by the given angle around the given center.
 mxGeometry.prototype.translate = function( dx, dy )
Translates the geometry by the specified amount.
 mxGeometry.prototype.scale = function( sx, sy, fixedAspect )
Scales the geometry by the given amount.
 mxGeometry.prototype.equals = function( obj )
Returns true if the given object equals this geometry.
Provides various edge styles to be used as the values for mxConstants.STYLE_EDGE in a cell style.
 mxGraph.prototype.resetEdgesOnResize
Specifies if edge control points should be reset after the resize of a connected cell.
 mxGraphModel.prototype.setGeometry = function( cell, geometry )
Sets the mxGeometry of the given mxCell.