GraphicsPathIterator::Enumerate method (gdipluspath.h)

Article
02/22/2024

The GraphicsPathIterator::Enumerate method copies the path's data points to a PointF array and copies the path's point types to a BYTE array.

Syntax

INT Enumerate(
  [out] PointF *points,
  [out] BYTE   *types,
  [in]  INT    count
);

Parameters

[out] points

Type: PointF*

Pointer to an array that receives the path's data points.

[out] types

Type: BYTE*

Pointer to an array that receives the path's point types.

[in] count

Type: INT

Integer that specifies the number of elements in the points array. This is the same as the number of elements in the types array.

Return value

Type: INT

This method returns the number of points retrieved.

Remarks

This GraphicsPathIterator object is associated with a GraphicsPath object. That GraphicsPath object has an array of points and an array of types. Each element in the array of types is a byte that specifies the point type and a set of flags for the corresponding element in the array of points. Possible point types and flags are listed in the PathPointType enumeration.

You can call the GraphicsPathIterator::GetCount method to determine the number of data points in the path. The points parameter points to a buffer that receives the data points, and the types parameter points to a buffer that receives the types. Before you call the GraphicsPathIterator::Enumerate method, you must allocate memory for those buffers. The size of the points buffer should be the return value of GraphicsPathIterator::GetCount multiplied by sizeof(PointF). The size of the types buffer should be the return value of GraphicsPathIterator::GetCount.

Examples

The following example creates a GraphicsPath object and adds three lines to the path. The code creates a GraphicsPathIterator object and calls its GraphicsPathIterator::Enumerate method to retrieve the path's data points and point types. Then the code displays the count returned by the GraphicsPathIterator::Enumerate method.


#define BUFFER_SIZE 30
TCHAR numPointsEnum[BUFFER_SIZE];

// Add some lines to a path.
Point pts[] = {Point(20, 20), 
                Point(100, 20), 
                Point(100, 50), 
                Point(20, 50)};
GraphicsPath path;
path.AddLines(pts, 4);

// Create a GraphicsPathIterator object, and associate it with the path.
GraphicsPathIterator pathIterator(&path);

// Create destination arrays, and copy the path data to them.
UINT c = pathIterator.GetCount();
PointF* pEnumPoints = new PointF[c]; 
BYTE* pTypes = new BYTE[c];
INT count = pathIterator.Enumerate(pEnumPoints, pTypes, c);

// Confirm that the points were enumerated.
StringCchPrintf(
   numPointsEnum, BUFFER_SIZE, TEXT("%d points were enumerated."), count);

MessageBox(hWnd, numPointsEnum, TEXT("Enumerate"), NULL);

delete[] pEnumPoints;
delete[] pTypes;

Requirements

Requirement	Value
Minimum supported client	Windows XP, Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	gdipluspath.h (include Gdiplus.h)
Library	Gdiplus.lib
DLL	Gdiplus.dll