THotPDF.RegisterDeviceN Method

Declares a PDF 1.3+ DeviceN color space backed by N user-supplied spot inks (ISO 32000-1 8.6.6.5). Generalises RegisterSeparation from one colorant to many: six-color printing, metallic / fluorescent inks, custom PDF/X ink mixes, or any N-channel ink set.

function RegisterDeviceN(const ColorantNames: array of AnsiString; const AlternateCS: AnsiString; const TintC1Matrix: array of Extended): AnsiString;

AnsiString RegisterDeviceN(const AnsiString* ColorantNames, int ColorantNameCount, const AnsiString& AlternateCS, const Extended* TintC1Matrix, int TintC1MatrixCount);

DeviceN takes N tint operands in [0..1], one per colorant, and computes M output components in AlternateCS using a linear weighted-blend tint transform that HotPDF builds internally as a PostScript-calculator Function Type 4. The output for channel m is the sum over all colorants n of tint[n] * TintC1Matrix[n*M + m], clamped to [0..1] by the rendering pipeline.

ColorantNames - array of N ink names. Each entry is written as a PDF name; spaces are escaped to #20 per PDF 1.7 7.3.5. The special name 'None' marks an unused colorant slot. The name list defines the N input dimensions of the resulting color space.

AlternateCS - 'DeviceGray' (M = 1), 'DeviceRGB' (M = 3), or 'DeviceCMYK' (M = 4). Any other value raises an exception.

TintC1Matrix - row-major N * M Extended array. Row n column m is colorant n's contribution to AlternateCS channel m at full strength (tint[n] = 1.0) with all other tints at zero. Length must be exactly Length(ColorantNames) * M.

Return value: an auto-generated name (DevN1, DevN2, ...). Returns an empty string when StrictVersionLock is on and the active Version is below PDF 1.3 (otherwise the document version auto-bumps to 1.3).

Code Example

// Two-colorant DeviceN over DeviceRGB. Colorant 0 ('Red') is pure
// red at full strength, colorant 1 ('Blue') is pure blue. Mixing
// (0.5, 0.5) yields a 50/50 blend; (1, 1) saturates to magenta.
var
  CSName: AnsiString;
  Mat: array[0..5] of Extended;
begin
  HPDF.Version := pdf14;
  HPDF.BeginDoc;
  Mat[0] := 1.0; Mat[1] := 0.0; Mat[2] := 0.0;  // Red row     -> (1, 0, 0)
  Mat[3] := 0.0; Mat[4] := 0.0; Mat[5] := 1.0;  // Blue row    -> (0, 0, 1)
  CSName := HPDF.RegisterDeviceN(
    ['Red', 'Blue'], 'DeviceRGB', Mat);
  HPDF.CurrentPage.SetFillColorSpace(CSName);
  HPDF.CurrentPage.SetFillColor([0.5, 0.5]);   // mid-purple
  HPDF.CurrentPage.Rectangle(60, 60, 200, 100);
  HPDF.CurrentPage.Fill;
  HPDF.EndDoc;
end;