CTMHelper (Apache FOP Core 2.11 API)
Date: 2025-04-24

org.apache.fop.render.pdf

## Class CTMHelper

- java.lang.Object
- - org.apache.fop.render.pdf.CTMHelper

-     public final class CTMHelper
      extends Object

  CTMHelper converts FOP transformation matrices to those suitable for use by the PDFRenderer. The e and f elements of the matrix will be divided by 1000 as FOP uses millipoints as it's default user space and PDF uses points.
  See Also:
    `CTM`

- - ### Method Summary

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `static double[]` | `toPDFArray(CTM sourceMatrix)` Creates an array of six doubles from the source CTM.
    `static CTM` | `toPDFCTM(CTM sourceMatrix)` Creates a new CTM based in the sourceMatrix.
    `static String` | `toPDFString(AffineTransform transform, boolean convertMillipoints)` Converts the AffineTransform instance to a string for use in the PDFRenderer cm operations.
    `static String` | `toPDFString(CTM sourceMatrix)` Converts the sourceMatrix to a string for use in the PDFRenderer cm operations.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Method Detail

    - #### toPDFString

          public static String toPDFString(CTM sourceMatrix)

      Converts the sourceMatrix to a string for use in the PDFRenderer cm operations.

      For example:

              org.apache.fop.area.CTM ctm =
                    new org.apache.fop.area.CTM(1.0, 0.0, 0.0, 1.0, 1000.0, 1000.0);
              String pdfMatrix =  org.apache.fop.render.pdf.CTMHelper.toPDFString(ctm);

      will return the string "`1.0 0.0 0.0 1.0 1.0 1.0`".
      Parameters:
        `sourceMatrix` - - The matrix to convert.
      Returns:
        a space seperated string containing the matrix elements.

    - #### toPDFString

          public static String toPDFString(AffineTransform transform,
                                           boolean convertMillipoints)

      Converts the AffineTransform instance to a string for use in the PDFRenderer cm operations.

      Parameters:
        `transform` - The matrix to convert.
        `convertMillipoints` - Indicates that the matrix needs to be converted from millipoints to points.
      Returns:
        a space seperated string containing the matrix elements.

    - #### toPDFCTM

          public static CTM toPDFCTM(CTM sourceMatrix)

      Creates a new CTM based in the sourceMatrix.

      For example:

              org.apache.fop.area.CTM inCTM =
                    new org.apache.fop.area.CTM(1.0, 0.0, 0.0, 1.0, 1000.0, 1000.0);
              org.apache.fop.area.CTM outCTM =
                    org.apache.fop.render.pdf.CTMHelper.toPDFCTM(ctm);

      will return a new CTM where a == 1.0, b == 0.0, c == 0.0, d == 1.0, e == 1.0 and f == 1.0.
      Parameters:
        `sourceMatrix` - - The matrix to convert.
      Returns:
        a new converted matrix.

    - #### toPDFArray

          public static double[] toPDFArray(CTM sourceMatrix)

      Creates an array of six doubles from the source CTM.

      For example:

              org.apache.fop.area.CTM inCTM =
                    new org.apache.fop.area.CTM(1.0, 0.0, 0.0, 1.0, 1000.0, 1000.0);
              double matrix[] = org.apache.fop.render.pdf.CTMHelper.toPDFArray(ctm);

      will return a new array where matrix[0] == 1.0, matrix[1] == 0.0, matrix[2] == 0.0, matrix[3] == 1.0, matrix[4] == 1.0 and matrix[5] == 1.0.
      Parameters:
        `sourceMatrix` - - The matrix to convert.
      Returns:
        an array of doubles containing the converted matrix.

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