Matrix::TransformVectors Method (array<Point>^)
Applies only the scale and rotate components of this Matrix to the specified array of points.
Assembly: System.Drawing (in System.Drawing.dll)
The following code example is designed for use with Windows Forms, and it requires PaintEventArgse, an Paint event object. The code performs the following actions:
Creates an array of points that form a rectangle.
Draws this array of points to the screen prior to applying a scaling transform (the blue rectangle).
Creates a matrix and scales it by 3 in the x-axis and 2 in the y-axis, and translates it by 100 in both axes.
Lists the matrix elements to the screen.
Applies this matrix transform to the array of points.
Draws the transformed array to the screen (the red rectangle).
Notice that the red rectangle has been scaled by a factor of 3 in the x-axis and by 2 in the y-axis, including the upper left-hand corner of the rectangle (the beginning point of the rectangle) but the translation vector (the last two elements of the matrix) is ignored.
public: void TransformVectorsExample( PaintEventArgs^ e ) { Pen^ myPen = gcnew Pen( Color::Blue,1.0f ); Pen^ myPen2 = gcnew Pen( Color::Red,1.0f ); // Create an array of points. array<Point>^ myArray = {Point(20,20),Point(120,20),Point(120,120),Point(20,120),Point(20,20)}; // Draw the Points to the screen before applying the // transform. e->Graphics->DrawLines( myPen, myArray ); // Create a matrix, scale it, and translate it. Matrix^ myMatrix = gcnew Matrix; myMatrix->Scale( 3, 2, MatrixOrder::Append ); myMatrix->Translate( 100, 100, MatrixOrder::Append ); // List the matrix elements to the screen. ListMatrixElements( e, myMatrix, "Scaled and Translated Matrix", 6, 20 ); // Apply the transform to the array. myMatrix->TransformVectors( myArray ); // Draw the Points to the screen again after applying the // transform. e->Graphics->DrawLines( myPen2, myArray ); } //------------------------------------------------------- // This function is a helper function to // list the contents of a matrix. //------------------------------------------------------- void ListMatrixElements( PaintEventArgs^ e, Matrix^ matrix, String^ matrixName, int numElements, int y ) { // Set up variables for drawing the array // of points to the screen. int i; float x = 20,X = 200; System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",8 ); SolidBrush^ myBrush = gcnew SolidBrush( Color::Black ); // Draw the matrix name to the screen. e->Graphics->DrawString( String::Concat( matrixName, ": " ), myFont, myBrush, (float)x, (float)y ); // Draw the set of path points and types to the screen. for ( i = 0; i < numElements; i++ ) { e->Graphics->DrawString( String::Concat( matrix->Elements[ i ], ", " ), myFont, myBrush, (float)X, (float)y ); X += 30; } }
Available since 1.1