Public Function GetRegionClipSegments( _
   ByVal row As Integer, _
   ByVal segmentsBuffer() As Integer, _
   ByVal segmentsBufferOffset As Integer _
) As Integer

Visual Basic (Usage)	Copy Code
Dim instance As RasterImage Dim row As Integer Dim segmentsBuffer() As Integer Dim segmentsBufferOffset As Integer Dim value As Integer   value = instance.GetRegionClipSegments(row, segmentsBuffer, segmentsBufferOffset)

public int GetRegionClipSegments( 
   int row,
   int[] segmentsBuffer,
   int segmentsBufferOffset
)

public:
int GetRegionClipSegments( 
   int row,
   array<int>^ segmentsBuffer,
   int segmentsBufferOffset
) 

Parameters

row

The number of the row for which to get the segments. The first row is 0, and the last row is 1 less than the image height.

segmentsBuffer

Buffer to be updated with the segments from row contained in the region.

segmentsBufferOffset

Zero based index into segmentsBuffer.

Return Value

This example sets the value of pixels inside a region to half intensity.

Visual Basic

Copy Code

Public Sub GetRegionClipSegmentsExample()    RasterCodecs.Startup()    Dim codecs As RasterCodecs = New RasterCodecs()    Dim srcFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp"    Dim destFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "Image1_GetRegionClipSegments.bmp"    ' Load the image    Dim image As RasterImage = codecs.Load(srcFileName)    ' Add a region to the image    Dim rc As Rectangle = New Rectangle(image.Width \ 3, image.Height \ 3, image.Width \ 3, image.Height \ 3)    image.AddEllipseToRegion(Nothing, rc, RasterRegionCombineMode.Set)    ' Set the pixels inside the region to black    ' Get the maximum number of elements in a row,    ' so we know how big the array of segments should be    Dim maxClipSegments As Integer = image.CalculateRegionMaximumClipSegments()    ' Get the region bounds, so we know which is the first row    Dim rgnBounds As Rectangle = image.GetRegionBounds(Nothing)    ' Allocate an array large enough to store the maximum number of segments.    Dim segmentBuffer As Integer() = New Integer(maxClipSegments - 1) {}    ' Loop through the region rows    Dim y As Integer = rgnBounds.Top    Do While y < rgnBounds.Bottom       ' Get the segments for the row       image.GetRegionClipSegments(y, segmentBuffer, 0)       ' Do something with the pixels       Dim i As Integer = 0       Do While i < maxClipSegments / 2          Dim j As Integer = segmentBuffer(i)          Do While j < segmentBuffer(i + 1)             Dim clr As RasterColor = image.GetPixelColor(y, j)             clr = New RasterColor(clr.R \ 2, clr.G \ 2, clr.B \ 2)             image.SetPixelColor(y, j, clr)             j += 1          Loop          i += 1       Loop       y += 1    Loop    ' Save the image back to file    codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24)    image.Dispose()    codecs.Dispose()    RasterCodecs.Shutdown() End Sub

C#

Copy Code

public void GetRegionClipSegmentsExample()  {     RasterCodecs.Startup();     RasterCodecs codecs = new RasterCodecs();       string srcFileName = LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp";     string destFileName = LeadtoolsExamples.Common.ImagesPath.Path + "Image1_GetRegionClipSegments.bmp";       // Load the image     RasterImage image = codecs.Load(srcFileName);       // Add a region to the image     Rectangle rc = new Rectangle(image.Width / 3, image.Height / 3, image.Width / 3, image.Height / 3);     image.AddEllipseToRegion(null, rc, RasterRegionCombineMode.Set);       // Set the pixels inside the region to black       // Get the maximum number of elements in a row,     // so we know how big the array of segments should be     int maxClipSegments = image.CalculateRegionMaximumClipSegments();       // Get the region bounds, so we know which is the first row     Rectangle rgnBounds = image.GetRegionBounds(null);       // Allocate an array large enough to store the maximum number of segments.     int[] segmentBuffer = new int[maxClipSegments];       // Loop through the region rows     for(int y = rgnBounds.Top; y < rgnBounds.Bottom; y++)     {        // Get the segments for the row        image.GetRegionClipSegments(y, segmentBuffer, 0);          // Do something with the pixels        for(int i = 0; i < maxClipSegments / 2; i++)        {           for(int j = segmentBuffer[i]; j < segmentBuffer[i + 1]; j++)           {              RasterColor clr = image.GetPixelColor(y, j);              clr = new RasterColor(clr.R / 2, clr.G / 2, clr.B / 2);              image.SetPixelColor(y, j, clr);           }        }     }       // Save the image back to file     codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24);       image.Dispose();     codecs.Dispose();     RasterCodecs.Shutdown();  }

To use this method, first call GetRegionBounds with xform set to null (Nothing in Visual Basic), to get the image boundaries. The bounding rectangle will indicate which rows are contained in the region. Go through all the rows contained in the region to get the segments contained in the region.

The segments are returned as an array of pairs of horizontal offsets. The first point in the pair is the beginning of the segment (it is contained in the region). The last point in the pair is the end of the segment. To follow the Windows rules, the end of the segment is the first point NOT CONTAINED in the region.

In most regions, there will be one segment per row. However, some regions can have 0, 1, 2 or more segments.

For example, assume that for a particular row there are two segments. segmentBuffer will be filled with 4 values. Let's call them x0, x1, x2, x3. In this case:

• portion from 0 to x0 - 1 is OUTSIDE the region
• portion from x0 to x1 - 1 is INSIDE the region
• portion from x1 to x2 - 1 is OUTSIDE the region
• portion from x2 to x3 - 1 is INSIDE the region
• portion from x3 to Width - 1 is OUTSIDE the region

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

Reference