CogDisplay.GetTransform Method

CogDisplay GetTransform Method

Cognex VisionPro 9.8 SR1

Returns the transform from fromSpace to toSpace.

Namespace: Cognex.VisionPro.Display
Assembly: Cognex.VisionPro.Display.Controls (in Cognex.VisionPro.Display.Controls.dll) Version: 75.0.0.0 (75.0.0.0)

Syntax

C++

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public virtual ICogTransform2D GetTransform(
	string toSpace,
	string fromSpace
)

public virtual ICogTransform2D GetTransform(
	string toSpace,
	string fromSpace
)

Public Overridable Function GetTransform ( 
	toSpace As String,
	fromSpace As String
) As ICogTransform2D

Public Overridable Function GetTransform ( 
	toSpace As String,
	fromSpace As String
) As ICogTransform2D

public:
virtual ICogTransform2D^ GetTransform(
	String^ toSpace, 
	String^ fromSpace
)

public:
virtual ICogTransform2D^ GetTransform(
	String^ toSpace, 
	String^ fromSpace
)

Parameters

toSpace: Type: System String
The destination space.

fromSpace: Type: System String
The source space.

Return Value

Type: ICogTransform2D

Exceptions

Exception	Condition
AxHost InvalidActiveXStateException	Thrown when the display control is invalid.

Remarks

GetTransform(String, String) lets you transform locations between the display's coordinate spaces and screen coordinates (which have the special name "*").

The values that you specify for fromSpace and toSpace must be one of the following:

"*"
"#"
a named space in UserPixelTree or UserDisplayTree
a named space in the image being displayed (including "." and "@")

Examples

C++

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private void btnDraw_Click(object sender, System.EventArgs e) {
    CogTransform2DLinear xform;
    CogRectangle aRect;
    CogPointMarker cross = new CogPointMarker();
    double dispX, dispY;
    int    rectIX;

    // Draw a crosshair marker in the center of a rectangle whose coordinate space is "<a href="6511d2e5-0ac6-4821-9069-1cc39c3c0ba5.htm">Cartesian</a>", 
    // but anchor it to the display coordinates ("*") so it does not move when you scroll

    xform = cogDisplay1.GetTransform("*", "Cartesian") as CogTransform2DLinear;

    // Find the interactive rectangle in the graphics group "rect"
    rectIX = cogDisplay1.InteractiveGraphics.FindItem("rect", Cognex.VisionPro.Display.CogDisplayZOrderConstants.Front);
    aRect = cogDisplay1.InteractiveGraphics[rectIX] as CogRectangle;

    // Map the point
    xform.MapPoint(aRect.CenterX, aRect.CenterY, out dispX, out dispY);

    // Draw the cross
    cross.GraphicType = Cognex.VisionPro.CogPointMarkerGraphicTypeConstants.Cross;
    cross.SizeInScreenPixels = 35;
    cross.X = dispX;
    cross.Y = dispY;
    cross.SelectedSpaceName = "*";
    cogDisplay1.StaticGraphics.Add(cross, "cross");
}

private void btnDraw_Click(object sender, System.EventArgs e) {
    CogTransform2DLinear xform;
    CogRectangle aRect;
    CogPointMarker cross = new CogPointMarker();
    double dispX, dispY;
    int    rectIX;

    // Draw a crosshair marker in the center of a rectangle whose coordinate space is "<a href="6511d2e5-0ac6-4821-9069-1cc39c3c0ba5.htm">Cartesian</a>", 
    // but anchor it to the display coordinates ("*") so it does not move when you scroll

    xform = cogDisplay1.GetTransform("*", "Cartesian") as CogTransform2DLinear;

    // Find the interactive rectangle in the graphics group "rect"
    rectIX = cogDisplay1.InteractiveGraphics.FindItem("rect", Cognex.VisionPro.Display.CogDisplayZOrderConstants.Front);
    aRect = cogDisplay1.InteractiveGraphics[rectIX] as CogRectangle;

    // Map the point
    xform.MapPoint(aRect.CenterX, aRect.CenterY, out dispX, out dispY);

    // Draw the cross
    cross.GraphicType = Cognex.VisionPro.CogPointMarkerGraphicTypeConstants.Cross;
    cross.SizeInScreenPixels = 35;
    cross.X = dispX;
    cross.Y = dispY;
    cross.SelectedSpaceName = "*";
    cogDisplay1.StaticGraphics.Add(cross, "cross");
}