GemBox.Pdf
  • Overview
  • Examples
  • Free version
  • Support
  • Pricelist

    Show / Hide Table of Contents

    PdfCoonsPatchMeshShading Class

    Namespace:
    GemBox.Pdf.Content.Patterns
    Assembly:
    GemBox.Pdf.dll

    Type 6 shadings (Coons patch meshes) are constructed from one or more color patches, each bounded by four cubic Bézier curves.

    • C#
    • VB.NET
    public sealed class PdfCoonsPatchMeshShading : PdfMeshShading, IEnumerable<PdfMeshPatch>, IEnumerable
    Public NotInheritable Class PdfCoonsPatchMeshShading
        Inherits PdfMeshShading
        Implements IEnumerable(Of PdfMeshPatch), IEnumerable
    Inheritance:
    System.Object
    PdfObject
    PdfContentResource
    PdfShading
    PdfMeshShading
    PdfCoonsPatchMeshShading
    Implements
    System.Collections.Generic.IEnumerable<PdfMeshPatch>
    System.Collections.IEnumerable

    Constructors

    PdfCoonsPatchMeshShading(IList<PdfFunction>, PdfColorSpace)

    Initializes a new instance of the PdfCoonsPatchMeshShading class with an optional ColorSpace.

    The Add(PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint) overload must be used to populate a mesh with a new patch, unconnected to any other. Subsequent, connected, patches can be added with the Add(PdfMeshSharedEdge, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint) overload.

    If the function parameter is omitted or is null, then the PdfMeshVertex(Double, Double, PdfColor) constructor should be used for creating vertices; otherwise, the PdfMeshVertex(Double, Double, Double) constructor should be used. You can use the static method CreateFunction(IList<PdfShadingColor>) to create an interpolation function from two or more PdfShadingColors.

    note

    The Pack(Boolean) method must be used after the mesh is populated to resolve the values of the BitsPerCoordinate, BitsPerComponent, BitsPerFlag, and Decode entries and to serialize the mesh data to the underlying stream.

    • C#
    • VB.NET
    public PdfCoonsPatchMeshShading(IList<PdfFunction> function = null, PdfColorSpace colorSpace = null)
    Public Sub New(function As IList(Of PdfFunction) = Nothing, colorSpace As PdfColorSpace = Nothing)
    Parameters
    function
    System.Collections.Generic.IList<PdfFunction>

    The optional value of the Function entry.

    colorSpace
    PdfColorSpace

    The color space in which color values shall be expressed. If omitted, the DeviceRGB is used.

    PdfCoonsPatchMeshShading(Int32, Int32, Int32, PdfNumberRange, PdfNumberRange, IList<PdfFunction>, PdfColorSpace)

    Initializes a new instance of the PdfCoonsPatchMeshShading class that has the specified mesh data serialization settings and, optionally, ColorSpace.

    The Add(PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint) overload must be used to populate a mesh with a new patch, unconnected to any other. Subsequent, connected, patches can be added with the Add(PdfMeshSharedEdge, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint) overload.

    If the function parameter is omitted or is null, then the PdfMeshVertex(Double, Double, PdfColor) constructor should be used for creating vertices; otherwise, the PdfMeshVertex(Double, Double, Double) constructor should be used. You can use the static method CreateFunction(IList<PdfShadingColor>) to create an interpolation function from two or more PdfShadingColors.

    The Decode entry is set based on the decodeX, decodeY, and ranges of valid color component values specified by the Function's domain or ColorSpace. The Decode for color components can be subsequently updated (it starts with a PdfNumberRange at index 2 in the Decode entry).

    • C#
    • VB.NET
    public PdfCoonsPatchMeshShading(int bitsPerCoordinate, int bitsPerComponent, int bitsPerFlag, PdfNumberRange decodeX, PdfNumberRange decodeY, IList<PdfFunction> function = null, PdfColorSpace colorSpace = null)
    Public Sub New(bitsPerCoordinate As Integer, bitsPerComponent As Integer, bitsPerFlag As Integer, decodeX As PdfNumberRange, decodeY As PdfNumberRange, function As IList(Of PdfFunction) = Nothing, colorSpace As PdfColorSpace = Nothing)
    Parameters
    bitsPerCoordinate
    System.Int32

    The number of bits used to represent each geometric coordinate. The value shall be 1, 2, 4, 8, 12, 16, 24, or 32.

    bitsPerComponent
    System.Int32

    The number of bits used to represent each color component. The value shall be 1, 2, 4, 8, 12, or 16.

    bitsPerFlag
    System.Int32

    The number of bits used to represent the edge flag for each patch. The value of bitsPerFlag shall be 2, 4, or 8, but only the least significant 2 bits in each flag value shall be used.

    decodeX
    PdfNumberRange

    A PdfNumberRange specifying how to map horizontal component of patch coordinates into the appropriate range of values.

    decodeY
    PdfNumberRange

    A PdfNumberRange specifying how to map vertical component of patch coordinates into the appropriate range of values.

    function
    System.Collections.Generic.IList<PdfFunction>

    The optional value of the Function entry.

    colorSpace
    PdfColorSpace

    The color space in which color values shall be expressed. If omitted, the DeviceRGB is used.

    Exceptions
    System.ArgumentOutOfRangeException

    bitsPerCoordinate is not 1, 2, 4, 8, 12, 16, 24, or 32.

    System.ArgumentOutOfRangeException

    bitsPerComponent is not 1, 2, 4, 8, 12, or 16.

    System.ArgumentOutOfRangeException

    bitsPerFlag is not 2, 4, or 8.

    Properties

    BitsPerFlag

    (Required) The number of bits used to represent the edge flag for each patch. The value of BitsPerFlag shall be 2, 4, or 8, but only the least significant 2 bits in each flag value shall be used. The value for the edge flag shall be 0, 1, 2, or 3.

    • C#
    • VB.NET
    public int BitsPerFlag { get; }
    Public ReadOnly Property BitsPerFlag As Integer
    Property Value
    System.Int32

    The number of bits used to represent the edge flag for each patch.

    Exceptions
    System.ArgumentOutOfRangeException

    Argument must be one of the following values: 2, 4, or 8.

    See Also
    PDF Specification ISO 32000-1:2008, section '8.7.4.5.7 Type 6 Shadings (Coons Patch Meshes)'

    ShadingType

    Gets the CoonsPatchMesh value.

    • C#
    • VB.NET
    public override PdfShadingType ShadingType { get; }
    Public Overrides ReadOnly Property ShadingType As PdfShadingType
    Property Value
    PdfShadingType

    The CoonsPatchMesh value.

    Overrides
    PdfShading.ShadingType

    Methods

    Add(PdfMeshSharedEdge, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint)

    Populates a mesh with a subsequent, connected, patch.

    If the edgeFlag is Edge1, then the edge between the second (Vertex03) and the third (Vertex33) (corner) vertex of the previous patch is shared with a subsequent, connected, patch as an edge between its first (Vertex00) and second (Vertex03) (corner) vertex.

    If the edgeFlag is Edge2, then the edge between the third (Vertex33) and the fourth (Vertex30) (corner) vertex of the previous patch is shared with a subsequent, connected, patch as an edge between its first (Vertex00) and second (Vertex03) (corner) vertex.

    If the edgeFlag is Edge3, then the edge between the fourth (Vertex30) and the first (Vertex00) (corner) vertex of the previous patch is shared with a subsequent, connected, patch as an edge between its first (Vertex00) and second (Vertex03) (corner) vertex.

    • C#
    • VB.NET
    public void Add(PdfMeshSharedEdge edgeFlag, PdfPoint point13, PdfPoint point23, PdfMeshVertex vertex33, PdfPoint point32, PdfPoint point31, PdfMeshVertex vertex30, PdfPoint point20, PdfPoint point10)
    Public Sub Add(edgeFlag As PdfMeshSharedEdge, point13 As PdfPoint, point23 As PdfPoint, vertex33 As PdfMeshVertex, point32 As PdfPoint, point31 As PdfPoint, vertex30 As PdfMeshVertex, point20 As PdfPoint, point10 As PdfPoint)
    Parameters
    edgeFlag
    PdfMeshSharedEdge

    The flag specifying the edge of the previous patch that is shared with a subsequent, connected, patch.

    point13
    PdfPoint

    The coordinates of the first control point of a cubic Bézier curve that connects Vertex03 and vertex33.

    point23
    PdfPoint

    The coordinates of the second control point of a cubic Bézier curve that connects Vertex03 and vertex33.

    vertex33
    PdfMeshVertex

    The third (corner) vertex of a new patch.

    point32
    PdfPoint

    The coordinates of the second control point of a cubic Bézier curve that connects vertex30 and vertex33.

    point31
    PdfPoint

    The coordinates of the first control point of a cubic Bézier curve that connects vertex30 and vertex33.

    vertex30
    PdfMeshVertex

    The fourth (corner) vertex of a new patch.

    point20
    PdfPoint

    The coordinates of the second control point of a cubic Bézier curve that connects Vertex00 and vertex30.

    point10
    PdfPoint

    The coordinates of the first control point of a cubic Bézier curve that connects Vertex00 and vertex30.

    Exceptions
    System.ArgumentOutOfRangeException

    edgeFlag must be Edge1, Edge2, or Edge3.

    System.ArgumentException

    The Function entry is set and the IsColorParametric property of vertex33 or vertex30 is false or the Function entry is not set and the IsColorParametric property of vertex33 or vertex30 is true.

    System.ArgumentException

    The Space of the Color of vertex33 or vertex30 is not equal to the shading's ColorSpace.

    System.InvalidOperationException

    This overload cannot be used on an empty mesh. Use the Add(PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint) before.

    Add(PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint)

    Populates a mesh with a new patch, unconnected to any other.

    • C#
    • VB.NET
    public void Add(PdfMeshVertex vertex00, PdfPoint point01, PdfPoint point02, PdfMeshVertex vertex03, PdfPoint point13, PdfPoint point23, PdfMeshVertex vertex33, PdfPoint point32, PdfPoint point31, PdfMeshVertex vertex30, PdfPoint point20, PdfPoint point10)
    Public Sub Add(vertex00 As PdfMeshVertex, point01 As PdfPoint, point02 As PdfPoint, vertex03 As PdfMeshVertex, point13 As PdfPoint, point23 As PdfPoint, vertex33 As PdfMeshVertex, point32 As PdfPoint, point31 As PdfPoint, vertex30 As PdfMeshVertex, point20 As PdfPoint, point10 As PdfPoint)
    Parameters
    vertex00
    PdfMeshVertex

    The first (corner) vertex of a new patch.

    point01
    PdfPoint

    The coordinates of the first control point of a cubic Bézier curve that connects vertex00 and vertex03.

    point02
    PdfPoint

    The coordinates of the second control point of a cubic Bézier curve that connects vertex00 and vertex03.

    vertex03
    PdfMeshVertex

    The second (corner) vertex of a new patch.

    point13
    PdfPoint

    The coordinates of the first control point of a cubic Bézier curve that connects vertex03 and vertex33.

    point23
    PdfPoint

    The coordinates of the second control point of a cubic Bézier curve that connects vertex03 and vertex33.

    vertex33
    PdfMeshVertex

    The third (corner) vertex of a new patch.

    point32
    PdfPoint

    The coordinates of the second control point of a cubic Bézier curve that connects vertex30 and vertex33.

    point31
    PdfPoint

    The coordinates of the first control point of a cubic Bézier curve that connects vertex30 and vertex33.

    vertex30
    PdfMeshVertex

    The fourth (corner) vertex of a new patch.

    point20
    PdfPoint

    The coordinates of the second control point of a cubic Bézier curve that connects vertex00 and vertex30.

    point10
    PdfPoint

    The coordinates of the first control point of a cubic Bézier curve that connects vertex00 and vertex30.

    Exceptions
    System.ArgumentException

    The Function entry is set and the IsColorParametric property of vertex00, vertex03, vertex33, or vertex30 is false or the Function entry is not set and the IsColorParametric property of vertex00, vertex03, vertex33, or vertex30 is true.

    System.ArgumentException

    The Space of the Color of vertex00, vertex03, vertex33, or vertex30 is not equal to the shading's ColorSpace.

    GetEnumerator()

    Returns an enumerator that iterates PdfMeshPatches contained in this PdfCoonsPatchMeshShading.

    • C#
    • VB.NET
    public PdfCoonsPatchMeshShading.Enumerator GetEnumerator()
    Public Function GetEnumerator As PdfCoonsPatchMeshShading.Enumerator
    Returns
    PdfCoonsPatchMeshShading.Enumerator

    A PdfCoonsPatchMeshShading.Enumerator for the PdfCoonsPatchMeshShading.

    Exceptions
    System.InvalidOperationException

    The PdfCoonsPatchMeshShading is empty. Use the Add(PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint, PdfMeshVertex, PdfPoint, PdfPoint) overload to add a PdfMeshPatch.

    Pack(Boolean)

    Packs the mesh data to the underlying PdfStream and, optionally, sets or adjusts the mesh data serialization settings (BitsPerCoordinate, BitsPerComponent, BitsPerFlag, and Decode entries) to the most appropriate values to achieve the best sampled mesh data compaction and resolution, based on the mesh data.

    • C#
    • VB.NET
    public PdfCoonsPatchMeshShading Pack(bool resolveSerializationSettings = true)
    Public Function Pack(resolveSerializationSettings As Boolean = True) As PdfCoonsPatchMeshShading
    Parameters
    resolveSerializationSettings
    System.Boolean

    true to set or adjust the mesh data serialization settings (BitsPerCoordinate, BitsPerComponent, BitsPerFlag, and Decode entries) to the most appropriate values to achieve the best sampled mesh data compaction and resolution, based on the mesh data; otherwise, false.

    Returns
    PdfCoonsPatchMeshShading

    A reference to this PdfCoonsPatchMeshShading instance after the packing operation has completed.

    Exceptions
    System.InvalidOperationException

    Some of the PdfNumberRanges in the Decode entry are too narrow to encode the mesh data. Extend the bounds of those PdfNumberRanges or use the Pack(Boolean) method with a parameter resolveSerializationSettings set to true.

    Inherited Properties

    Background

    (Optional) A color appropriate to the ColorSpace, specifying a single background color. If present, this color shall be used, before any painting operation involving the shading, to fill those portions of the area to be painted that lie outside the bounds of the shading object.

    note

    In the opaque imaging model, the effect is as if the painting operation were performed twice: first with the background color and then with the shading.

    note

    The background color is applied only when the shading is used as part of a PdfShadingPattern, not when it is painted directly with the PdfShadingContent operator.

    (Inherited from PdfShading)

    BitsPerComponent

    (Required) The number of bits used to represent each color component. The value shall be 1, 2, 4, 8, 12, or 16.

    (Inherited from PdfMeshShading)

    BitsPerCoordinate

    (Required) The number of bits used to represent each vertex or geometric coordinate. The value shall be 1, 2, 4, 8, 12, 16, 24, or 32.

    (Inherited from PdfMeshShading)

    BoundingBox

    (Optional) A rectangle giving the left, bottom, right, and top coordinates, respectively, of the shading's bounding box. The coordinates shall be interpreted in the shading's target coordinate space. If present, this bounding box shall be applied as a temporary clipping boundary when the shading is painted, in addition to the current clipping path and any other clipping boundaries in effect at that time.

    (Inherited from PdfShading)

    ColorSpace

    (Required) The color space in which color values shall be expressed. This may be any device, CIE-based, or special color space except a Pattern space. See 8.7.4.4, "Color Space: Special Considerations" for further information.

    (Inherited from PdfShading)

    Decode

    (Required) A collection of PdfNumberRanges specifying how to map vertex or geometric coordinates and color components into the appropriate ranges of values. The decoding method is similar to that used in image dictionaries (see 8.9.5.2, "Decode Arrays"). The ranges shall be specified as follows:

    [(xmin xmax) (ymin ymax) (c1,min c1,max) … (cn,min cn,max)]

    Only one pair of c values shall be specified if a Function entry is present.

    (Inherited from PdfMeshShading)

    Document

    Gets the PdfDocument associated with this PdfContentResource or null if no PdfDocument is associated with this PdfContentResource.

    (Inherited from PdfContentResource)

    Function

    (Optional) A 1-in, n-out function or an array of n 1-in, 1-out functions (where n is the number of color components in the shading dictionary's color space). If this entry is present, the color data for each vertex shall be specified by a single parametric variable rather than by n separate color components. The designated function(s) shall be called with each interpolated value of the parametric variable to determine the actual color at each point. Each input value shall be forced into the range interval specified for the corresponding color component in the shading dictionary's Decode array. Each function's domain shall be a superset of that interval. If the value returned by the function for a given color component is out of range, it shall be adjusted to the nearest valid value.

    This entry shall not be used with an Indexed color space.

    tip

    Use the static method CreateFunction(IList<PdfShadingColor>) to create an interpolation function from two or more PdfShadingColors.

    (Inherited from PdfMeshShading)

    IsAntiAlias

    (Optional) A flag indicating whether to filter the shading function to prevent aliasing artifacts.

    note

    The shading operators sample shading functions at a rate determined by the resolution of the output device. Aliasing can occur if the function is not smooth—that is, if it has a high spatial frequency relative to the sampling rate. Anti-aliasing can be computationally expensive and is usually unnecessary, since most shading functions are smooth enough or are sampled at a high enough frequency to avoid aliasing effects. Anti-aliasing may not be implemented on some output devices, in which case this flag is ignored.

    Default value: false.

    (Inherited from PdfShading)

    Metadata

    (Optional; PDF 1.4) A metadata stream containing metadata for the component.

    (Inherited from PdfObject)

    Inherited Methods

    CreateFunction(System.Collections.Generic.IList<PdfShadingColor>)

    Creates an interpolation function from the specified list of PdfShadingColors.

    Two colors create a PdfExponentialInterpolationFunction and more than two create a PdfStitchingFunction (stitching two or more PdfExponentialInterpolationFunctions).

    The function's Domain is set from the Offset of the first and the last PdfShadingColor.

    (Inherited from PdfShading)

    SetBoundingBox(System.Double, System.Double, System.Double, System.Double)

    Sets the BoundingBox.

    (Inherited from PdfShading)

    Implements

    System.Collections.Generic.IEnumerable<T>
    System.Collections.IEnumerable

    Extension Methods

    PdfObjectExtensions.GetDictionary(PdfObject)
    PdfObjectExtensions.GetOrAddDictionary(PdfObject)
    PdfObjectExtensions.GetArray(PdfObject)

    See Also

    PDF Specification ISO 32000-1:2008, section '8.7.4.5.7 Type 6 Shadings (Coons Patch Meshes)'
    Back to top

    Facebook • Twitter • LinkedIn

    © GemBox Ltd. — All rights reserved.