THotPDF.RegisterImageTilingPattern Method

Registers a coloured PDF tiling pattern whose cell reuses one existing image XObject across one or more independently clipped affine placements

Declaration

function RegisterImageTilingPattern(ImageIndex: Integer; BBoxLLx,
  BBoxLLy, BBoxURx, BBoxURy: Single; XStep, YStep: Single;
  const Placements: THPDFImageTilingPlacements;
  TilingType: THPDFTilingPatternType;
  const PatternMatrix: THPDFAffineMatrix): AnsiString; overload;

function RegisterImageTilingPattern(ImageIndex: Integer; BBoxLLx,
  BBoxLLy, BBoxURx, BBoxURy: Single; XStep, YStep: Single;
  const Placements: THPDFImageTilingPlacements;
  TilingType: THPDFTilingPatternType;
  const PatternMatrix: THPDFAffineMatrix;
  UseImageSoftMask: boolean): AnsiString; overload;

Unit

HPDFDoc

Parameters

ImageIndex selects an image previously returned by AddImage or an equivalent image-registration API
BBoxLLx, BBoxLLy, BBoxURx, and BBoxURy define the finite positive pattern-cell bounds
XStep and YStep define finite non-zero cell spacing
Placements supplies 1 to 1024 finite invertible matrices with finite positive clipping rectangles
TilingType selects the PDF tiling placement rule
PatternMatrix maps pattern coordinates into the parent content stream default coordinate system
UseImageSoftMask reuses the selected image's grayscale /SMask XObject as the cell image

Behaviour

The method emits one image XObject resource in the pattern dictionary and invokes it from every placement, so repeated and mirrored cells do not duplicate image bytes

Each placement is isolated by q and Q, clipped before its matrix is concatenated, and serialized with locale-independent PDF numbers

The soft-mask overload links one existing alpha image under a stable SMIm resource name, allowing repeated and reflected alpha cells without duplicating or decoding image bytes

The method raises ERangeError for invalid image indices, placement counts, clipping rectangles, matrices, bounds, steps, or pattern matrices

Return value