/src/gdal/alg/gdalrasterpolygonenumerator.cpp

Source
/******************************************************************************
 *
 * Project:  GDAL
 * Purpose:  Raster Polygon Enumerator
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2008, Frank Warmerdam
 * Copyright (c) 2015, Even Rouault <even.rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_port.h"
#include "gdal_alg_priv.h"

#include <cstddef>
#include <limits>

#include "cpl_conv.h"
#include "cpl_error.h"

/*! @cond Doxygen_Suppress */

/************************************************************************/
/*                    GDALRasterPolygonEnumeratorT()                    */
/************************************************************************/

template <class DataType, class EqualityTest>
GDALRasterPolygonEnumeratorT<
    DataType, EqualityTest>::GDALRasterPolygonEnumeratorT(int nConnectednessIn)
    : nConnectedness(nConnectednessIn)

{
    CPLAssert(nConnectedness == 4 || nConnectedness == 8);
}

/************************************************************************/
/*                   ~GDALRasterPolygonEnumeratorT()                    */
/************************************************************************/

template <class DataType, class EqualityTest>
GDALRasterPolygonEnumeratorT<DataType,
                             EqualityTest>::~GDALRasterPolygonEnumeratorT()

{
    Clear();
}

/************************************************************************/
/*                               Clear()                                */
/************************************************************************/

template <class DataType, class EqualityTest>
void GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::Clear()

{
    CPLFree(panPolyIdMap);
    CPLFree(panPolyValue);

    panPolyIdMap = nullptr;
    panPolyValue = nullptr;

    nNextPolygonId = 0;
    nPolyAlloc = 0;
}

/************************************************************************/
/*                            MergePolygon()                            */
/*                                                                      */
/*      Update the polygon map to indicate the merger of two polygons.  */
/************************************************************************/

template <class DataType, class EqualityTest>
void GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::MergePolygon(
    int nSrcId, int nDstIdInit)

{
    // Figure out the final dest id.
    int nDstIdFinal = nDstIdInit;
    while (panPolyIdMap[nDstIdFinal] != nDstIdFinal)
        nDstIdFinal = panPolyIdMap[nDstIdFinal];

    // Map the whole intermediate chain to it.
    int nDstIdCur = nDstIdInit;
    while (panPolyIdMap[nDstIdCur] != nDstIdCur)
    {
        int nNextDstId = panPolyIdMap[nDstIdCur];
        panPolyIdMap[nDstIdCur] = nDstIdFinal;
        nDstIdCur = nNextDstId;
    }

    // And map the whole source chain to it too (can be done in one pass).
    while (panPolyIdMap[nSrcId] != nSrcId)
    {
        int nNextSrcId = panPolyIdMap[nSrcId];
        panPolyIdMap[nSrcId] = nDstIdFinal;
        nSrcId = nNextSrcId;
    }
    panPolyIdMap[nSrcId] = nDstIdFinal;
}

/************************************************************************/
/*                             NewPolygon()                             */
/*                                                                      */
/*      Allocate a new polygon id, and reallocate the polygon maps      */
/*      if needed.                                                      */
/************************************************************************/

template <class DataType, class EqualityTest>
int GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::NewPolygon(
    DataType nValue)

{
    if (nNextPolygonId == std::numeric_limits<int>::max())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "GDALRasterPolygonEnumeratorT::NewPolygon(): maximum number "
                 "of polygons reached");
        return -1;
    }
    if (nNextPolygonId >= nPolyAlloc)
    {
        int nPolyAllocNew;
        if (nPolyAlloc < (std::numeric_limits<int>::max() - 20) / 2)
            nPolyAllocNew = nPolyAlloc * 2 + 20;
        else
            nPolyAllocNew = std::numeric_limits<int>::max();
#if SIZEOF_VOIDP == 4
        if (nPolyAllocNew >
                static_cast<int>(std::numeric_limits<size_t>::max() /
                                 sizeof(GInt32)) ||
            nPolyAllocNew >
                static_cast<int>(std::numeric_limits<size_t>::max() /
                                 sizeof(DataType)))
        {
            CPLError(CE_Failure, CPLE_OutOfMemory,
                     "GDALRasterPolygonEnumeratorT::NewPolygon(): too many "
                     "polygons");
            return -1;
        }
#endif
        auto panPolyIdMapNew = static_cast<GInt32 *>(
            VSI_REALLOC_VERBOSE(panPolyIdMap, nPolyAllocNew * sizeof(GInt32)));
        auto panPolyValueNew = static_cast<DataType *>(VSI_REALLOC_VERBOSE(
            panPolyValue, nPolyAllocNew * sizeof(DataType)));
        if (panPolyIdMapNew == nullptr || panPolyValueNew == nullptr)
        {
            VSIFree(panPolyIdMapNew);
            VSIFree(panPolyValueNew);
            return -1;
        }
        panPolyIdMap = panPolyIdMapNew;
        panPolyValue = panPolyValueNew;
        nPolyAlloc = nPolyAllocNew;
    }

    const int nPolyId = nNextPolygonId;
    panPolyIdMap[nPolyId] = nPolyId;
    panPolyValue[nPolyId] = nValue;
    nNextPolygonId++;

    return nPolyId;
}

/************************************************************************/
/*                           CompleteMerges()                           */
/*                                                                      */
/*      Make a pass through the maps, ensuring every polygon id         */
/*      points to the final id it should use, not an intermediate       */
/*      value.                                                          */
/************************************************************************/

template <class DataType, class EqualityTest>
void GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::CompleteMerges()

{
    int nFinalPolyCount = 0;

    for (int iPoly = 0; iPoly < nNextPolygonId; iPoly++)
    {
        // Figure out the final id.
        int nId = panPolyIdMap[iPoly];
        while (nId != panPolyIdMap[nId])
        {
            nId = panPolyIdMap[nId];
        }

        // Then map the whole intermediate chain to it.
        int nIdCur = panPolyIdMap[iPoly];
        panPolyIdMap[iPoly] = nId;
        while (nIdCur != panPolyIdMap[nIdCur])
        {
            int nNextId = panPolyIdMap[nIdCur];
            panPolyIdMap[nIdCur] = nId;
            nIdCur = nNextId;
        }

        if (panPolyIdMap[iPoly] == iPoly)
            nFinalPolyCount++;
    }

    CPLDebug("GDALRasterPolygonEnumerator",
             "Counted %d polygon fragments forming %d final polygons.",
             nNextPolygonId, nFinalPolyCount);
}

/************************************************************************/
/*                            ProcessLine()                             */
/*                                                                      */
/*      Assign ids to polygons, one line at a time.                     */
/************************************************************************/

template <class DataType, class EqualityTest>
bool GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::ProcessLine(
    DataType *panLastLineVal, DataType *panThisLineVal, GInt32 *panLastLineId,
    GInt32 *panThisLineId, int nXSize)

{
    EqualityTest eq;

    /* -------------------------------------------------------------------- */
    /*      Special case for the first line.                                */
    /* -------------------------------------------------------------------- */
    if (panLastLineVal == nullptr)
    {
        for (int i = 0; i < nXSize; i++)
        {
            if (panThisLineVal[i] == GP_NODATA_MARKER)
            {
                panThisLineId[i] = -1;
            }
            else if (i == 0 ||
                     !(eq.operator()(panThisLineVal[i], panThisLineVal[i - 1])))
            {
                panThisLineId[i] = NewPolygon(panThisLineVal[i]);
                if (panThisLineId[i] < 0)
                    return false;
            }
            else
            {
                panThisLineId[i] = panThisLineId[i - 1];
            }
        }

        return true;
    }

    /* -------------------------------------------------------------------- */
    /*      Process each pixel comparing to the previous pixel, and to      */
    /*      the last line.                                                  */
    /* -------------------------------------------------------------------- */
    for (int i = 0; i < nXSize; i++)
    {
        if (panThisLineVal[i] == GP_NODATA_MARKER)
        {
            panThisLineId[i] = -1;
        }
        else if (i > 0 &&
                 eq.operator()(panThisLineVal[i], panThisLineVal[i - 1]))
        {
            panThisLineId[i] = panThisLineId[i - 1];

            if (eq.operator()(panLastLineVal[i], panThisLineVal[i]) &&
                (panPolyIdMap[panLastLineId[i]] !=
                 panPolyIdMap[panThisLineId[i]]))
            {
                MergePolygon(panLastLineId[i], panThisLineId[i]);
            }

            if (nConnectedness == 8 &&
                eq.operator()(panLastLineVal[i - 1], panThisLineVal[i]) &&
                (panPolyIdMap[panLastLineId[i - 1]] !=
                 panPolyIdMap[panThisLineId[i]]))
            {
                MergePolygon(panLastLineId[i - 1], panThisLineId[i]);
            }

            if (nConnectedness == 8 && i < nXSize - 1 &&
                eq.operator()(panLastLineVal[i + 1], panThisLineVal[i]) &&
                (panPolyIdMap[panLastLineId[i + 1]] !=
                 panPolyIdMap[panThisLineId[i]]))
            {
                MergePolygon(panLastLineId[i + 1], panThisLineId[i]);
            }
        }
        else if (eq.operator()(panLastLineVal[i], panThisLineVal[i]))
        {
            panThisLineId[i] = panLastLineId[i];
        }
        else if (i > 0 && nConnectedness == 8 &&
                 eq.operator()(panLastLineVal[i - 1], panThisLineVal[i]))
        {
            panThisLineId[i] = panLastLineId[i - 1];

            if (i < nXSize - 1 &&
                eq.operator()(panLastLineVal[i + 1], panThisLineVal[i]) &&
                (panPolyIdMap[panLastLineId[i + 1]] !=
                 panPolyIdMap[panThisLineId[i]]))
            {
                MergePolygon(panLastLineId[i + 1], panThisLineId[i]);
            }
        }
        else if (i < nXSize - 1 && nConnectedness == 8 &&
                 eq.operator()(panLastLineVal[i + 1], panThisLineVal[i]))
        {
            panThisLineId[i] = panLastLineId[i + 1];
        }
        else
        {
            panThisLineId[i] = NewPolygon(panThisLineVal[i]);
            if (panThisLineId[i] < 0)
                return false;
        }
    }
    return true;
}

template class GDALRasterPolygonEnumeratorT<std::int64_t, IntEqualityTest>;

template class GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>;

template class GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>;

/*! @endcond */

Coverage Report

Created: 2026-02-14 06:52

Line	Count	Source
1		/******************************************************************************
2		*
3		* Project: GDAL
4		* Purpose: Raster Polygon Enumerator
5		* Author: Frank Warmerdam, warmerdam@pobox.com
6		*
7		******************************************************************************
8		* Copyright (c) 2008, Frank Warmerdam
9		* Copyright (c) 2015, Even Rouault <even.rouault at spatialys.com>
10		*
11		* SPDX-License-Identifier: MIT
12		****************************************************************************/
13
14		#include "cpl_port.h"
15		#include "gdal_alg_priv.h"
16
17		#include <cstddef>
18		#include <limits>
19
20		#include "cpl_conv.h"
21		#include "cpl_error.h"
22
23		/! @cond Doxygen_Suppress /
24
25		/************************************************************************/
26		/* GDALRasterPolygonEnumeratorT() */
27		/************************************************************************/
28
29		template <class DataType, class EqualityTest>
30		GDALRasterPolygonEnumeratorT<
31		DataType, EqualityTest>::GDALRasterPolygonEnumeratorT(int nConnectednessIn)
32	0	: nConnectedness(nConnectednessIn)
33
34	0	{
35	0	CPLAssert(nConnectedness == 4 \|\| nConnectedness == 8);
36	0	} Unexecuted instantiation: GDALRasterPolygonEnumeratorT<long, IntEqualityTest>::GDALRasterPolygonEnumeratorT(int) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>::GDALRasterPolygonEnumeratorT(int) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>::GDALRasterPolygonEnumeratorT(int)
37
38		/************************************************************************/
39		/* ~GDALRasterPolygonEnumeratorT() */
40		/************************************************************************/
41
42		template <class DataType, class EqualityTest>
43		GDALRasterPolygonEnumeratorT<DataType,
44		EqualityTest>::~GDALRasterPolygonEnumeratorT()
45
46	0	{
47	0	Clear();
48	0	} Unexecuted instantiation: GDALRasterPolygonEnumeratorT<long, IntEqualityTest>::~GDALRasterPolygonEnumeratorT() Unexecuted instantiation: GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>::~GDALRasterPolygonEnumeratorT() Unexecuted instantiation: GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>::~GDALRasterPolygonEnumeratorT()
49
50		/************************************************************************/
51		/* Clear() */
52		/************************************************************************/
53
54		template <class DataType, class EqualityTest>
55		void GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::Clear()
56
57	0	{
58	0	CPLFree(panPolyIdMap);
59	0	CPLFree(panPolyValue);
60
61	0	panPolyIdMap = nullptr;
62	0	panPolyValue = nullptr;
63
64	0	nNextPolygonId = 0;
65	0	nPolyAlloc = 0;
66	0	} Unexecuted instantiation: GDALRasterPolygonEnumeratorT<long, IntEqualityTest>::Clear() Unexecuted instantiation: GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>::Clear() Unexecuted instantiation: GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>::Clear()
67
68		/************************************************************************/
69		/* MergePolygon() */
70		/* */
71		/* Update the polygon map to indicate the merger of two polygons. */
72		/************************************************************************/
73
74		template <class DataType, class EqualityTest>
75		void GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::MergePolygon(
76		int nSrcId, int nDstIdInit)
77
78	0	{
79		// Figure out the final dest id.
80	0	int nDstIdFinal = nDstIdInit;
81	0	while (panPolyIdMap[nDstIdFinal] != nDstIdFinal)
82	0	nDstIdFinal = panPolyIdMap[nDstIdFinal];
83
84		// Map the whole intermediate chain to it.
85	0	int nDstIdCur = nDstIdInit;
86	0	while (panPolyIdMap[nDstIdCur] != nDstIdCur)
87	0	{
88	0	int nNextDstId = panPolyIdMap[nDstIdCur];
89	0	panPolyIdMap[nDstIdCur] = nDstIdFinal;
90	0	nDstIdCur = nNextDstId;
91	0	}
92
93		// And map the whole source chain to it too (can be done in one pass).
94	0	while (panPolyIdMap[nSrcId] != nSrcId)
95	0	{
96	0	int nNextSrcId = panPolyIdMap[nSrcId];
97	0	panPolyIdMap[nSrcId] = nDstIdFinal;
98	0	nSrcId = nNextSrcId;
99	0	}
100	0	panPolyIdMap[nSrcId] = nDstIdFinal;
101	0	} Unexecuted instantiation: GDALRasterPolygonEnumeratorT<long, IntEqualityTest>::MergePolygon(int, int) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>::MergePolygon(int, int) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>::MergePolygon(int, int)
102
103		/************************************************************************/
104		/* NewPolygon() */
105		/* */
106		/* Allocate a new polygon id, and reallocate the polygon maps */
107		/* if needed. */
108		/************************************************************************/
109
110		template <class DataType, class EqualityTest>
111		int GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::NewPolygon(
112		DataType nValue)
113
114	0	{
115	0	if (nNextPolygonId == std::numeric_limits<int>::max())
116	0	{
117	0	CPLError(CE_Failure, CPLE_AppDefined,
118	0	"GDALRasterPolygonEnumeratorT::NewPolygon(): maximum number "
119	0	"of polygons reached");
120	0	return -1;
121	0	}
122	0	if (nNextPolygonId >= nPolyAlloc)
123	0	{
124	0	int nPolyAllocNew;
125	0	if (nPolyAlloc < (std::numeric_limits<int>::max() - 20) / 2)
126	0	nPolyAllocNew = nPolyAlloc * 2 + 20;
127	0	else
128	0	nPolyAllocNew = std::numeric_limits<int>::max();
129		#if SIZEOF_VOIDP == 4
130		if (nPolyAllocNew >
131		static_cast<int>(std::numeric_limits<size_t>::max() /
132		sizeof(GInt32)) \|\|
133		nPolyAllocNew >
134		static_cast<int>(std::numeric_limits<size_t>::max() /
135		sizeof(DataType)))
136		{
137		CPLError(CE_Failure, CPLE_OutOfMemory,
138		"GDALRasterPolygonEnumeratorT::NewPolygon(): too many "
139		"polygons");
140		return -1;
141		}
142		#endif
143	0	auto panPolyIdMapNew = static_cast<GInt32 *>(
144	0	VSI_REALLOC_VERBOSE(panPolyIdMap, nPolyAllocNew * sizeof(GInt32)));
145	0	auto panPolyValueNew = static_cast<DataType *>(VSI_REALLOC_VERBOSE(
146	0	panPolyValue, nPolyAllocNew * sizeof(DataType)));
147	0	if (panPolyIdMapNew == nullptr \|\| panPolyValueNew == nullptr)
148	0	{
149	0	VSIFree(panPolyIdMapNew);
150	0	VSIFree(panPolyValueNew);
151	0	return -1;
152	0	}
153	0	panPolyIdMap = panPolyIdMapNew;
154	0	panPolyValue = panPolyValueNew;
155	0	nPolyAlloc = nPolyAllocNew;
156	0	}
157
158	0	const int nPolyId = nNextPolygonId;
159	0	panPolyIdMap[nPolyId] = nPolyId;
160	0	panPolyValue[nPolyId] = nValue;
161	0	nNextPolygonId++;
162
163	0	return nPolyId;
164	0	} Unexecuted instantiation: GDALRasterPolygonEnumeratorT<long, IntEqualityTest>::NewPolygon(long) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>::NewPolygon(float) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>::NewPolygon(double)
165
166		/************************************************************************/
167		/* CompleteMerges() */
168		/* */
169		/* Make a pass through the maps, ensuring every polygon id */
170		/* points to the final id it should use, not an intermediate */
171		/* value. */
172		/************************************************************************/
173
174		template <class DataType, class EqualityTest>
175		void GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::CompleteMerges()
176
177	0	{
178	0	int nFinalPolyCount = 0;
179
180	0	for (int iPoly = 0; iPoly < nNextPolygonId; iPoly++)
181	0	{
182		// Figure out the final id.
183	0	int nId = panPolyIdMap[iPoly];
184	0	while (nId != panPolyIdMap[nId])
185	0	{
186	0	nId = panPolyIdMap[nId];
187	0	}
188
189		// Then map the whole intermediate chain to it.
190	0	int nIdCur = panPolyIdMap[iPoly];
191	0	panPolyIdMap[iPoly] = nId;
192	0	while (nIdCur != panPolyIdMap[nIdCur])
193	0	{
194	0	int nNextId = panPolyIdMap[nIdCur];
195	0	panPolyIdMap[nIdCur] = nId;
196	0	nIdCur = nNextId;
197	0	}
198
199	0	if (panPolyIdMap[iPoly] == iPoly)
200	0	nFinalPolyCount++;
201	0	}
202
203	0	CPLDebug("GDALRasterPolygonEnumerator",
204	0	"Counted %d polygon fragments forming %d final polygons.",
205	0	nNextPolygonId, nFinalPolyCount);
206	0	} Unexecuted instantiation: GDALRasterPolygonEnumeratorT<long, IntEqualityTest>::CompleteMerges() Unexecuted instantiation: GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>::CompleteMerges() Unexecuted instantiation: GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>::CompleteMerges()
207
208		/************************************************************************/
209		/* ProcessLine() */
210		/* */
211		/* Assign ids to polygons, one line at a time. */
212		/************************************************************************/
213
214		template <class DataType, class EqualityTest>
215		bool GDALRasterPolygonEnumeratorT<DataType, EqualityTest>::ProcessLine(
216		DataType panLastLineVal, DataType panThisLineVal, GInt32 *panLastLineId,
217		GInt32 *panThisLineId, int nXSize)
218
219	0	{
220	0	EqualityTest eq;
221
222		/* -------------------------------------------------------------------- */
223		/* Special case for the first line. */
224		/* -------------------------------------------------------------------- */
225	0	if (panLastLineVal == nullptr)
226	0	{
227	0	for (int i = 0; i < nXSize; i++)
228	0	{
229	0	if (panThisLineVal[i] == GP_NODATA_MARKER)
230	0	{
231	0	panThisLineId[i] = -1;
232	0	}
233	0	else if (i == 0 \|\|
234	0	!(eq.operator()(panThisLineVal[i], panThisLineVal[i - 1])))
235	0	{
236	0	panThisLineId[i] = NewPolygon(panThisLineVal[i]);
237	0	if (panThisLineId[i] < 0)
238	0	return false;
239	0	}
240	0	else
241	0	{
242	0	panThisLineId[i] = panThisLineId[i - 1];
243	0	}
244	0	}
245
246	0	return true;
247	0	}
248
249		/* -------------------------------------------------------------------- */
250		/* Process each pixel comparing to the previous pixel, and to */
251		/* the last line. */
252		/* -------------------------------------------------------------------- */
253	0	for (int i = 0; i < nXSize; i++)
254	0	{
255	0	if (panThisLineVal[i] == GP_NODATA_MARKER)
256	0	{
257	0	panThisLineId[i] = -1;
258	0	}
259	0	else if (i > 0 &&
260	0	eq.operator()(panThisLineVal[i], panThisLineVal[i - 1]))
261	0	{
262	0	panThisLineId[i] = panThisLineId[i - 1];
263
264	0	if (eq.operator()(panLastLineVal[i], panThisLineVal[i]) &&
265	0	(panPolyIdMap[panLastLineId[i]] !=
266	0	panPolyIdMap[panThisLineId[i]]))
267	0	{
268	0	MergePolygon(panLastLineId[i], panThisLineId[i]);
269	0	}
270
271	0	if (nConnectedness == 8 &&
272	0	eq.operator()(panLastLineVal[i - 1], panThisLineVal[i]) &&
273	0	(panPolyIdMap[panLastLineId[i - 1]] !=
274	0	panPolyIdMap[panThisLineId[i]]))
275	0	{
276	0	MergePolygon(panLastLineId[i - 1], panThisLineId[i]);
277	0	}
278
279	0	if (nConnectedness == 8 && i < nXSize - 1 &&
280	0	eq.operator()(panLastLineVal[i + 1], panThisLineVal[i]) &&
281	0	(panPolyIdMap[panLastLineId[i + 1]] !=
282	0	panPolyIdMap[panThisLineId[i]]))
283	0	{
284	0	MergePolygon(panLastLineId[i + 1], panThisLineId[i]);
285	0	}
286	0	}
287	0	else if (eq.operator()(panLastLineVal[i], panThisLineVal[i]))
288	0	{
289	0	panThisLineId[i] = panLastLineId[i];
290	0	}
291	0	else if (i > 0 && nConnectedness == 8 &&
292	0	eq.operator()(panLastLineVal[i - 1], panThisLineVal[i]))
293	0	{
294	0	panThisLineId[i] = panLastLineId[i - 1];
295
296	0	if (i < nXSize - 1 &&
297	0	eq.operator()(panLastLineVal[i + 1], panThisLineVal[i]) &&
298	0	(panPolyIdMap[panLastLineId[i + 1]] !=
299	0	panPolyIdMap[panThisLineId[i]]))
300	0	{
301	0	MergePolygon(panLastLineId[i + 1], panThisLineId[i]);
302	0	}
303	0	}
304	0	else if (i < nXSize - 1 && nConnectedness == 8 &&
305	0	eq.operator()(panLastLineVal[i + 1], panThisLineVal[i]))
306	0	{
307	0	panThisLineId[i] = panLastLineId[i + 1];
308	0	}
309	0	else
310	0	{
311	0	panThisLineId[i] = NewPolygon(panThisLineVal[i]);
312	0	if (panThisLineId[i] < 0)
313	0	return false;
314	0	}
315	0	}
316	0	return true;
317	0	} Unexecuted instantiation: GDALRasterPolygonEnumeratorT<long, IntEqualityTest>::ProcessLine(long, long, int, int, int) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>::ProcessLine(float, float, int, int, int) Unexecuted instantiation: GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>::ProcessLine(double, double, int, int, int)
318
319		template class GDALRasterPolygonEnumeratorT<std::int64_t, IntEqualityTest>;
320
321		template class GDALRasterPolygonEnumeratorT<float, FloatEqualityTest>;
322
323		template class GDALRasterPolygonEnumeratorT<double, DoubleEqualityTest>;
324
325		/! @endcond /