-
-
Notifications
You must be signed in to change notification settings - Fork 3k
/
qgsrastercalculator.cpp
673 lines (588 loc) · 22.3 KB
/
qgsrastercalculator.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
/***************************************************************************
qgsrastercalculator.cpp - description
-----------------------
begin : September 28th, 2010
copyright : (C) 2010 by Marco Hugentobler
email : marco dot hugentobler at sourcepole dot ch
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#include "qgsgdalutils.h"
#include "qgsrastercalculator.h"
#include "qgsrasterdataprovider.h"
#include "qgsrasterinterface.h"
#include "qgsrasterlayer.h"
#include "qgsrastermatrix.h"
#include "qgsrasterprojector.h"
#include "qgsfeedback.h"
#include "qgsogrutils.h"
#include "qgsproject.h"
#include <QFile>
#include <cpl_string.h>
#include <gdalwarper.h>
#ifdef HAVE_OPENCL
#include "qgsopenclutils.h"
#include "qgsgdalutils.h"
#endif
QgsRasterCalculator::QgsRasterCalculator( const QString &formulaString, const QString &outputFile, const QString &outputFormat,
const QgsRectangle &outputExtent, int nOutputColumns, int nOutputRows, const QVector<QgsRasterCalculatorEntry> &rasterEntries )
: mFormulaString( formulaString )
, mOutputFile( outputFile )
, mOutputFormat( outputFormat )
, mOutputRectangle( outputExtent )
, mNumOutputColumns( nOutputColumns )
, mNumOutputRows( nOutputRows )
, mRasterEntries( rasterEntries )
{
//default to first layer's crs
mOutputCrs = mRasterEntries.at( 0 ).raster->crs();
}
QgsRasterCalculator::QgsRasterCalculator( const QString &formulaString, const QString &outputFile, const QString &outputFormat,
const QgsRectangle &outputExtent, const QgsCoordinateReferenceSystem &outputCrs, int nOutputColumns, int nOutputRows, const QVector<QgsRasterCalculatorEntry> &rasterEntries )
: mFormulaString( formulaString )
, mOutputFile( outputFile )
, mOutputFormat( outputFormat )
, mOutputRectangle( outputExtent )
, mOutputCrs( outputCrs )
, mNumOutputColumns( nOutputColumns )
, mNumOutputRows( nOutputRows )
, mRasterEntries( rasterEntries )
{
}
QgsRasterCalculator::Result QgsRasterCalculator::processCalculation( QgsFeedback *feedback )
{
mLastError.clear();
//prepare search string / tree
std::unique_ptr< QgsRasterCalcNode > calcNode( QgsRasterCalcNode::parseRasterCalcString( mFormulaString, mLastError ) );
if ( !calcNode )
{
//error
return ParserError;
}
// Check input layers and bands
for ( const auto &entry : qgis::as_const( mRasterEntries ) )
{
if ( !entry.raster ) // no raster layer in entry
{
mLastError = QObject::tr( "No raster layer for entry %1" ).arg( entry.ref );
return InputLayerError;
}
if ( entry.bandNumber <= 0 || entry.bandNumber > entry.raster->bandCount() )
{
mLastError = QObject::tr( "Band number %1 is not valid for entry %2" ).arg( entry.bandNumber ).arg( entry.ref );
return BandError;
}
}
#ifdef HAVE_OPENCL
// Check for matrix nodes, GPU implementation does not support them
QList<const QgsRasterCalcNode *> nodeList;
if ( QgsOpenClUtils::enabled() && QgsOpenClUtils::available() && calcNode->findNodes( QgsRasterCalcNode::Type::tMatrix ).isEmpty() )
return processCalculationGPU( std::move( calcNode ), feedback );
#endif
//open output dataset for writing
GDALDriverH outputDriver = openOutputDriver();
if ( !outputDriver )
{
mLastError = QObject::tr( "Could not obtain driver for %1" ).arg( mOutputFormat );
return CreateOutputError;
}
gdal::dataset_unique_ptr outputDataset( openOutputFile( outputDriver ) );
if ( !outputDataset )
{
mLastError = QObject::tr( "Could not create output %1" ).arg( mOutputFile );
return CreateOutputError;
}
GDALSetProjection( outputDataset.get(), mOutputCrs.toWkt().toLocal8Bit().data() );
GDALRasterBandH outputRasterBand = GDALGetRasterBand( outputDataset.get(), 1 );
float outputNodataValue = -FLT_MAX;
GDALSetRasterNoDataValue( outputRasterBand, outputNodataValue );
// Check if we need to read the raster as a whole (which is memory inefficient
// and not interruptable by the user) by checking if any raster matrix nodes are
// in the expression
bool requiresMatrix = ! calcNode->findNodes( QgsRasterCalcNode::Type::tMatrix ).isEmpty();
// Take the fast route (process one line at a time) if we can
if ( ! requiresMatrix )
{
// Map of raster names -> blocks
std::map<QString, std::unique_ptr<QgsRasterBlock>> inputBlocks;
std::map<QString, QgsRasterCalculatorEntry> uniqueRasterEntries;
for ( const auto &r : calcNode->findNodes( QgsRasterCalcNode::Type::tRasterRef ) )
{
QString layerRef( r->toString().remove( 0, 1 ) );
layerRef.chop( 1 );
if ( ! inputBlocks.count( layerRef ) )
{
for ( const auto &ref : mRasterEntries )
{
if ( ref.ref == layerRef )
{
uniqueRasterEntries[layerRef] = ref;
inputBlocks[layerRef ] = qgis::make_unique<QgsRasterBlock>();
}
}
}
}
//read / write line by line
QMap<QString, QgsRasterBlock * > _rasterData;
// Cast to float
std::vector<float> castedResult;
castedResult.reserve( static_cast<size_t>( mNumOutputColumns ) );
auto rowHeight = mOutputRectangle.height() / mNumOutputRows;
for ( size_t row = 0; row < static_cast<size_t>( mNumOutputRows ); ++row )
{
if ( feedback )
{
feedback->setProgress( 100.0 * static_cast< double >( row ) / mNumOutputRows );
}
if ( feedback && feedback->isCanceled() )
{
break;
}
// Calculates the rect for a single row read
QgsRectangle rect( mOutputRectangle );
rect.setYMaximum( rect.yMaximum() - rowHeight * row );
rect.setYMinimum( rect.yMaximum() - rowHeight );
// Read rows into input blocks
for ( auto &layerRef : inputBlocks )
{
QgsRasterCalculatorEntry ref = uniqueRasterEntries[layerRef.first];
if ( uniqueRasterEntries[layerRef.first].raster->crs() != mOutputCrs )
{
QgsRasterProjector proj;
proj.setCrs( ref.raster->crs(), mOutputCrs );
proj.setInput( ref.raster->dataProvider() );
proj.setPrecision( QgsRasterProjector::Exact );
layerRef.second.reset( proj.block( ref.bandNumber, rect, mNumOutputColumns, 1 ) );
}
else
{
inputBlocks[layerRef.first].reset( ref.raster->dataProvider()->block( ref.bandNumber, rect, mNumOutputColumns, 1 ) );
}
}
QgsRasterMatrix resultMatrix;
resultMatrix.setNodataValue( outputNodataValue );
_rasterData.clear();
for ( const auto &layerRef : inputBlocks )
{
_rasterData.insert( layerRef.first, inputBlocks[layerRef.first].get() );
}
if ( calcNode->calculate( _rasterData, resultMatrix, 0 ) )
{
// write scanline to the dataset
for ( size_t i = 0; i < static_cast<size_t>( mNumOutputColumns ); i++ )
{
castedResult[i] = static_cast<float>( resultMatrix.data()[i] );
}
if ( GDALRasterIO( outputRasterBand, GF_Write, 0, row, mNumOutputColumns, 1, castedResult.data(), mNumOutputColumns, 1, GDT_Float32, 0, 0 ) != CE_None )
{
QgsDebugMsg( QStringLiteral( "RasterIO error!" ) );
}
}
}
if ( feedback )
{
feedback->setProgress( 100.0 );
}
}
else // Original code (memory inefficient route)
{
QMap< QString, QgsRasterBlock * > inputBlocks;
QVector<QgsRasterCalculatorEntry>::const_iterator it = mRasterEntries.constBegin();
for ( ; it != mRasterEntries.constEnd(); ++it )
{
std::unique_ptr< QgsRasterBlock > block;
// if crs transform needed
if ( it->raster->crs() != mOutputCrs )
{
QgsRasterProjector proj;
proj.setCrs( it->raster->crs(), mOutputCrs );
proj.setInput( it->raster->dataProvider() );
proj.setPrecision( QgsRasterProjector::Exact );
QgsRasterBlockFeedback *rasterBlockFeedback = new QgsRasterBlockFeedback();
QObject::connect( feedback, &QgsFeedback::canceled, rasterBlockFeedback, &QgsRasterBlockFeedback::cancel );
block.reset( proj.block( it->bandNumber, mOutputRectangle, mNumOutputColumns, mNumOutputRows, rasterBlockFeedback ) );
if ( rasterBlockFeedback->isCanceled() )
{
qDeleteAll( inputBlocks );
return Canceled;
}
}
else
{
block.reset( it->raster->dataProvider()->block( it->bandNumber, mOutputRectangle, mNumOutputColumns, mNumOutputRows ) );
}
if ( block->isEmpty() )
{
mLastError = QObject::tr( "Could not allocate required memory for %1" ).arg( it->ref );
qDeleteAll( inputBlocks );
return MemoryError;
}
inputBlocks.insert( it->ref, block.release() );
}
QgsRasterMatrix resultMatrix;
resultMatrix.setNodataValue( outputNodataValue );
//read / write line by line
for ( int i = 0; i < mNumOutputRows; ++i )
{
if ( feedback )
{
feedback->setProgress( 100.0 * static_cast< double >( i ) / mNumOutputRows );
}
if ( feedback && feedback->isCanceled() )
{
break;
}
if ( calcNode->calculate( inputBlocks, resultMatrix, i ) )
{
bool resultIsNumber = resultMatrix.isNumber();
float *calcData = new float[mNumOutputColumns];
for ( int j = 0; j < mNumOutputColumns; ++j )
{
calcData[j] = ( float )( resultIsNumber ? resultMatrix.number() : resultMatrix.data()[j] );
}
//write scanline to the dataset
if ( GDALRasterIO( outputRasterBand, GF_Write, 0, i, mNumOutputColumns, 1, calcData, mNumOutputColumns, 1, GDT_Float32, 0, 0 ) != CE_None )
{
QgsDebugMsg( QStringLiteral( "RasterIO error!" ) );
}
delete[] calcData;
}
}
if ( feedback )
{
feedback->setProgress( 100.0 );
}
//close datasets and release memory
calcNode.reset();
qDeleteAll( inputBlocks );
inputBlocks.clear();
}
if ( feedback && feedback->isCanceled() )
{
//delete the dataset without closing (because it is faster)
gdal::fast_delete_and_close( outputDataset, outputDriver, mOutputFile );
return Canceled;
}
return Success;
}
#ifdef HAVE_OPENCL
QgsRasterCalculator::Result QgsRasterCalculator::processCalculationGPU( std::unique_ptr< QgsRasterCalcNode > calcNode, QgsFeedback *feedback )
{
QString cExpression( calcNode->toString( true ) );
QList<const QgsRasterCalcNode *> nodeList( calcNode->findNodes( QgsRasterCalcNode::Type::tRasterRef ) );
QSet<QString> capturedTexts;
for ( const auto &r : qgis::as_const( nodeList ) )
{
QString s( r->toString().remove( 0, 1 ) );
s.chop( 1 );
capturedTexts.insert( s );
}
// Extract all references
struct LayerRef
{
QString name;
int band;
QgsRasterLayer *layer = nullptr;
QString varName;
QString typeName;
size_t index;
size_t bufferSize;
size_t dataSize;
};
// Collects all layers, band, name, varName and size information
std::vector<LayerRef> inputRefs;
size_t refCounter = 0;
for ( const auto &r : capturedTexts )
{
if ( r.startsWith( '"' ) )
continue;
QStringList parts( r.split( '@' ) );
if ( parts.count() != 2 )
continue;
bool ok = false;
LayerRef entry;
entry.name = r;
entry.band = parts[1].toInt( &ok );
for ( const auto &ref : mRasterEntries )
{
if ( ref.ref == entry.name )
entry.layer = ref.raster;
}
if ( !( entry.layer && entry.layer->dataProvider() && ok ) )
continue;
entry.dataSize = entry.layer->dataProvider()->dataTypeSize( entry.band );
switch ( entry.layer->dataProvider()->dataType( entry.band ) )
{
case Qgis::DataType::Byte:
entry.typeName = QStringLiteral( "unsigned char" );
break;
case Qgis::DataType::UInt16:
entry.typeName = QStringLiteral( "unsigned int" );
break;
case Qgis::DataType::Int16:
entry.typeName = QStringLiteral( "short" );
break;
case Qgis::DataType::UInt32:
entry.typeName = QStringLiteral( "unsigned int" );
break;
case Qgis::DataType::Int32:
entry.typeName = QStringLiteral( "int" );
break;
case Qgis::DataType::Float32:
entry.typeName = QStringLiteral( "float" );
break;
// FIXME: not sure all OpenCL implementations support double
// maybe safer to fall back to the CPU implementation
// after a compatibility check
case Qgis::DataType::Float64:
entry.typeName = QStringLiteral( "double" );
break;
default:
return BandError;
}
entry.bufferSize = entry.dataSize * mNumOutputColumns;
entry.index = refCounter;
entry.varName = QStringLiteral( "input_raster_%1_band_%2" )
.arg( refCounter++ )
.arg( entry.band );
inputRefs.push_back( entry );
}
// Prepare context and queue
cl::Context ctx( QgsOpenClUtils::context() );
cl::CommandQueue queue( QgsOpenClUtils::commandQueue() );
// Create the C expression
std::vector<cl::Buffer> inputBuffers;
inputBuffers.reserve( inputRefs.size() );
QStringList inputArgs;
for ( const auto &ref : inputRefs )
{
cExpression.replace( QStringLiteral( "\"%1\"" ).arg( ref.name ), QStringLiteral( "%1[i]" ).arg( ref.varName ) );
inputArgs.append( QStringLiteral( "__global %1 *%2" )
.arg( ref.typeName )
.arg( ref.varName ) );
inputBuffers.push_back( cl::Buffer( ctx, CL_MEM_READ_ONLY, ref.bufferSize, nullptr, nullptr ) );
}
//qDebug() << cExpression;
// Create the program
QString programTemplate( R"CL(
// Inputs:
##INPUT_DESC##
// Expression: ##EXPRESSION_ORIGINAL##
__kernel void rasterCalculator( ##INPUT##
__global float *resultLine
)
{
// Get the index of the current element
const int i = get_global_id(0);
// Expression
resultLine[i] = ##EXPRESSION##;
}
)CL" );
QStringList inputDesc;
for ( const auto &ref : inputRefs )
{
inputDesc.append( QStringLiteral( " // %1 = %2" ).arg( ref.varName ).arg( ref.name ) );
}
programTemplate = programTemplate.replace( QStringLiteral( "##INPUT_DESC##" ), inputDesc.join( '\n' ) );
programTemplate = programTemplate.replace( QStringLiteral( "##INPUT##" ), inputArgs.length() ? ( inputArgs.join( ',' ).append( ',' ) ) : QChar( ' ' ) );
programTemplate = programTemplate.replace( QStringLiteral( "##EXPRESSION##" ), cExpression );
programTemplate = programTemplate.replace( QStringLiteral( "##EXPRESSION_ORIGINAL##" ), calcNode->toString( ) );
// qDebug() << programTemplate;
// Create a program from the kernel source
cl::Program program( QgsOpenClUtils::buildProgram( programTemplate, QgsOpenClUtils::ExceptionBehavior::Throw ) );
// Create the buffers, output is float32 (4 bytes)
// We assume size of float = 4 because that's the size used by OpenCL and IEEE 754
Q_ASSERT( sizeof( float ) == 4 );
std::size_t resultBufferSize( 4 * static_cast<size_t>( mNumOutputColumns ) );
cl::Buffer resultLineBuffer( ctx, CL_MEM_WRITE_ONLY,
resultBufferSize, nullptr, nullptr );
auto kernel = cl::Kernel( program, "rasterCalculator" );
for ( unsigned int i = 0; i < inputBuffers.size() ; i++ )
{
kernel.setArg( i, inputBuffers.at( i ) );
}
kernel.setArg( static_cast<unsigned int>( inputBuffers.size() ), resultLineBuffer );
QgsOpenClUtils::CPLAllocator<float> resultLine( static_cast<size_t>( mNumOutputColumns ) );
//open output dataset for writing
GDALDriverH outputDriver = openOutputDriver();
if ( !outputDriver )
{
mLastError = QObject::tr( "Could not obtain driver for %1" ).arg( mOutputFormat );
return CreateOutputError;
}
gdal::dataset_unique_ptr outputDataset( openOutputFile( outputDriver ) );
if ( !outputDataset )
{
mLastError = QObject::tr( "Could not create output %1" ).arg( mOutputFile );
return CreateOutputError;
}
GDALSetProjection( outputDataset.get(), mOutputCrs.toWkt().toLocal8Bit().data() );
GDALRasterBandH outputRasterBand = GDALGetRasterBand( outputDataset.get(), 1 );
if ( !outputRasterBand )
return BandError;
// Input block (buffer)
std::unique_ptr<QgsRasterBlock> block;
// Run kernel on all scanlines
auto rowHeight = mOutputRectangle.height() / mNumOutputRows;
for ( int line = 0; line < mNumOutputRows; line++ )
{
if ( feedback && feedback->isCanceled() )
{
break;
}
if ( feedback )
{
feedback->setProgress( 100.0 * static_cast< double >( line ) / mNumOutputRows );
}
// Read lines from rasters into the buffers
for ( const auto &ref : inputRefs )
{
// Read one row
QgsRectangle rect( mOutputRectangle );
rect.setYMaximum( rect.yMaximum() - rowHeight * line );
rect.setYMinimum( rect.yMaximum() - rowHeight );
// TODO: check if this is too slow
// if crs transform needed
if ( ref.layer->crs() != mOutputCrs )
{
QgsRasterProjector proj;
proj.setCrs( ref.layer->crs(), mOutputCrs );
proj.setInput( ref.layer->dataProvider() );
proj.setPrecision( QgsRasterProjector::Exact );
block.reset( proj.block( ref.band, rect, mNumOutputColumns, 1 ) );
}
else
{
block.reset( ref.layer->dataProvider()->block( ref.band, rect, mNumOutputColumns, 1 ) );
}
//for ( int i = 0; i < mNumOutputColumns; i++ )
// qDebug() << "Input: " << line << i << ref.varName << " = " << block->value( 0, i );
//qDebug() << "Writing buffer " << ref.index;
Q_ASSERT( ref.bufferSize == static_cast<size_t>( block->data().size( ) ) );
queue.enqueueWriteBuffer( inputBuffers[ref.index], CL_TRUE, 0,
ref.bufferSize, block->bits() );
}
// Run the kernel
queue.enqueueNDRangeKernel(
kernel,
0,
cl::NDRange( mNumOutputColumns )
);
// Write the result
queue.enqueueReadBuffer( resultLineBuffer, CL_TRUE, 0,
resultBufferSize, resultLine.get() );
//for ( int i = 0; i < mNumOutputColumns; i++ )
// qDebug() << "Output: " << line << i << " = " << resultLine[i];
if ( GDALRasterIO( outputRasterBand, GF_Write, 0, line, mNumOutputColumns, 1, resultLine.get(), mNumOutputColumns, 1, GDT_Float32, 0, 0 ) != CE_None )
{
return CreateOutputError;
}
}
if ( feedback && feedback->isCanceled() )
{
//delete the dataset without closing (because it is faster)
gdal::fast_delete_and_close( outputDataset, outputDriver, mOutputFile );
return Canceled;
}
inputBuffers.clear();
return Success;
}
#endif
GDALDriverH QgsRasterCalculator::openOutputDriver()
{
//open driver
GDALDriverH outputDriver = GDALGetDriverByName( mOutputFormat.toLocal8Bit().data() );
if ( !outputDriver )
{
return outputDriver; //return nullptr, driver does not exist
}
if ( !QgsGdalUtils::supportsRasterCreate( outputDriver ) )
{
return nullptr; //driver exist, but it does not support the create operation
}
return outputDriver;
}
gdal::dataset_unique_ptr QgsRasterCalculator::openOutputFile( GDALDriverH outputDriver )
{
//open output file
char **papszOptions = nullptr;
gdal::dataset_unique_ptr outputDataset( GDALCreate( outputDriver, mOutputFile.toUtf8().constData(), mNumOutputColumns, mNumOutputRows, 1, GDT_Float32, papszOptions ) );
if ( !outputDataset )
{
return nullptr;
}
//assign georef information
double geotransform[6];
outputGeoTransform( geotransform );
GDALSetGeoTransform( outputDataset.get(), geotransform );
return outputDataset;
}
void QgsRasterCalculator::outputGeoTransform( double *transform ) const
{
transform[0] = mOutputRectangle.xMinimum();
transform[1] = mOutputRectangle.width() / mNumOutputColumns;
transform[2] = 0;
transform[3] = mOutputRectangle.yMaximum();
transform[4] = 0;
transform[5] = -mOutputRectangle.height() / mNumOutputRows;
}
QString QgsRasterCalculator::lastError() const
{
return mLastError;
}
QVector<QgsRasterCalculatorEntry> QgsRasterCalculatorEntry::rasterEntries()
{
QVector<QgsRasterCalculatorEntry> availableEntries;
const QMap<QString, QgsMapLayer *> &layers = QgsProject::instance()->mapLayers();
auto uniqueRasterBandIdentifier = [ & ]( QgsRasterCalculatorEntry & entry ) -> bool
{
unsigned int i( 1 );
entry.ref = QStringLiteral( "%1@%2" ).arg( entry.raster->name() ).arg( entry.bandNumber );
while ( true )
{
bool unique( true );
for ( const auto &ref : qgis::as_const( availableEntries ) )
{
// Safety belt
if ( !( entry.raster && ref.raster ) )
continue;
// Check if a layer with the same data source was already added to the list
if ( ref.raster->publicSource() == entry.raster->publicSource() )
return false;
// If same name but different source
if ( ref.ref == entry.ref )
{
unique = false;
entry.ref = QStringLiteral( "%1_%2@%3" ).arg( entry.raster->name() ).arg( i++ ).arg( entry.bandNumber );
}
}
if ( unique )
return true;
}
};
QMap<QString, QgsMapLayer *>::const_iterator layerIt = layers.constBegin();
for ( ; layerIt != layers.constEnd(); ++layerIt )
{
QgsRasterLayer *rlayer = qobject_cast<QgsRasterLayer *>( layerIt.value() );
if ( rlayer && rlayer->dataProvider() && rlayer->dataProvider()->name() == QLatin1String( "gdal" ) )
{
//get number of bands
for ( int i = 0; i < rlayer->bandCount(); ++i )
{
QgsRasterCalculatorEntry entry;
entry.raster = rlayer;
entry.bandNumber = i + 1;
if ( ! uniqueRasterBandIdentifier( entry ) )
continue;
availableEntries.push_back( entry );
}
}
}
return availableEntries;
}