static QByteArray _readDtmData( QgsRasterDataProvider *provider, const QgsRectangle &extent, int res )
{
QElapsedTimer t;
t.start();
// TODO: use feedback object? (but GDAL currently does not support cancelation anyway)
QgsRasterBlock *block = provider->block( 1, extent, res, res );
QByteArray data;
if ( block )
{
block->convert( Qgis::Float32 ); // currently we expect just floats
data = block->data();
data.detach(); // this should make a deep copy
delete block;
}
return data;
}
float QgsDemHeightMapGenerator::heightAt( double x, double y )
{
// TODO: this is quite a primitive implementation: better to use heightmaps currently in use
int res = 1024;
QgsRectangle rect = mDtm->extent();
if ( mDtmCoarseData.isEmpty() )
{
QgsRasterBlock *block = mDtm->dataProvider()->block( 1, rect, res, res );
block->convert( Qgis::Float32 );
mDtmCoarseData = block->data();
mDtmCoarseData.detach(); // make a deep copy
delete block;
}
int cellX = ( int )( ( x - rect.xMinimum() ) / rect.width() * res + .5f );
int cellY = ( int )( ( rect.yMaximum() - y ) / rect.height() * res + .5f );
cellX = qBound( 0, cellX, res - 1 );
cellY = qBound( 0, cellY, res - 1 );
const float *data = ( const float * ) mDtmCoarseData.constData();
return data[cellX + cellY * res];
}
QByteArray QgsDemHeightMapGenerator::renderSynchronously( int x, int y, int z )
{
// extend the rect by half-pixel on each side? to get the values in "corners"
QgsRectangle extent = mTilingScheme.tileToExtent( x, y, z );
float mapUnitsPerPixel = extent.width() / mResolution;
extent.grow( mapUnitsPerPixel / 2 );
// but make sure not to go beyond the full extent (returns invalid values)
QgsRectangle fullExtent = mTilingScheme.tileToExtent( 0, 0, 0 );
extent = extent.intersect( &fullExtent );
QgsRasterBlock *block = mDtm->dataProvider()->block( 1, extent, mResolution, mResolution );
QByteArray data;
if ( block )
{
block->convert( Qgis::Float32 ); // currently we expect just floats
data = block->data();
data.detach(); // this should make a deep copy
delete block;
}
return data;
}
QgsRasterBlock * QgsRasterDataProvider::block( int theBandNo, QgsRectangle const & theExtent, int theWidth, int theHeight )
{
QgsDebugMsg( QString( "theBandNo = %1 theWidth = %2 theHeight = %3" ).arg( theBandNo ).arg( theWidth ).arg( theHeight ) );
QgsDebugMsg( QString( "theExtent = %1" ).arg( theExtent.toString() ) );
QgsRasterBlock *block = new QgsRasterBlock( dataType( theBandNo ), theWidth, theHeight, noDataValue( theBandNo ) );
if ( block->isEmpty() )
{
QgsDebugMsg( "Couldn't create raster block" );
return block;
}
// Read necessary extent only
QgsRectangle tmpExtent = extent().intersect( &theExtent );
if ( tmpExtent.isEmpty() )
{
QgsDebugMsg( "Extent outside provider extent" );
block->setIsNoData();
return block;
}
double xRes = theExtent.width() / theWidth;
double yRes = theExtent.height() / theHeight;
double tmpXRes, tmpYRes;
double providerXRes = 0;
double providerYRes = 0;
if ( capabilities() & ExactResolution )
{
providerXRes = extent().width() / xSize();
providerYRes = extent().height() / ySize();
tmpXRes = qMax( providerXRes, xRes );
tmpYRes = qMax( providerYRes, yRes );
if ( doubleNear( tmpXRes, xRes ) ) tmpXRes = xRes;
if ( doubleNear( tmpYRes, yRes ) ) tmpYRes = yRes;
}
else
{
tmpXRes = xRes;
tmpYRes = yRes;
}
if ( tmpExtent != theExtent ||
tmpXRes > xRes || tmpYRes > yRes )
{
// Read smaller extent or lower resolution
// Calculate row/col limits (before tmpExtent is aligned)
int fromRow = qRound(( theExtent.yMaximum() - tmpExtent.yMaximum() ) / yRes );
int toRow = qRound(( theExtent.yMaximum() - tmpExtent.yMinimum() ) / yRes ) - 1;
int fromCol = qRound(( tmpExtent.xMinimum() - theExtent.xMinimum() ) / xRes ) ;
int toCol = qRound(( tmpExtent.xMaximum() - theExtent.xMinimum() ) / xRes ) - 1;
QgsDebugMsg( QString( "fromRow = %1 toRow = %2 fromCol = %3 toCol = %4" ).arg( fromRow ).arg( toRow ).arg( fromCol ).arg( toCol ) );
if ( fromRow < 0 || fromRow >= theHeight || toRow < 0 || toRow >= theHeight ||
fromCol < 0 || fromCol >= theWidth || toCol < 0 || toCol >= theWidth )
{
// Should not happen
QgsDebugMsg( "Row or column limits out of range" );
return block;
}
// If lower source resolution is used, the extent must beS aligned to original
// resolution to avoid possible shift due to resampling
if ( tmpXRes > xRes )
{
int col = floor(( tmpExtent.xMinimum() - extent().xMinimum() ) / providerXRes );
tmpExtent.setXMinimum( extent().xMinimum() + col * providerXRes );
col = ceil(( tmpExtent.xMaximum() - extent().xMinimum() ) / providerXRes );
tmpExtent.setXMaximum( extent().xMinimum() + col * providerXRes );
}
if ( tmpYRes > yRes )
{
int row = floor(( extent().yMaximum() - tmpExtent.yMaximum() ) / providerYRes );
tmpExtent.setYMaximum( extent().yMaximum() - row * providerYRes );
row = ceil(( extent().yMaximum() - tmpExtent.yMinimum() ) / providerYRes );
tmpExtent.setYMinimum( extent().yMaximum() - row * providerYRes );
}
int tmpWidth = qRound( tmpExtent.width() / tmpXRes );
int tmpHeight = qRound( tmpExtent.height() / tmpYRes );
tmpXRes = tmpExtent.width() / tmpWidth;
tmpYRes = tmpExtent.height() / tmpHeight;
QgsDebugMsg( QString( "Reading smaller block tmpWidth = %1 theHeight = %2" ).arg( tmpWidth ).arg( tmpHeight ) );
QgsDebugMsg( QString( "tmpExtent = %1" ).arg( tmpExtent.toString() ) );
block->setIsNoData();
QgsRasterBlock *tmpBlock = new QgsRasterBlock( dataType( theBandNo ), tmpWidth, tmpHeight, noDataValue( theBandNo ) );
readBlock( theBandNo, tmpExtent, tmpWidth, tmpHeight, tmpBlock->data() );
int pixelSize = dataTypeSize( theBandNo );
double xMin = theExtent.xMinimum();
double yMax = theExtent.yMaximum();
double tmpXMin = tmpExtent.xMinimum();
double tmpYMax = tmpExtent.yMaximum();
for ( int row = fromRow; row <= toRow; row++ )
{
double y = yMax - ( row + 0.5 ) * yRes;
int tmpRow = floor(( tmpYMax - y ) / tmpYRes );
for ( int col = fromCol; col <= toCol; col++ )
{
double x = xMin + ( col + 0.5 ) * xRes;
int tmpCol = floor(( x - tmpXMin ) / tmpXRes );
if ( tmpRow < 0 || tmpRow >= tmpHeight || tmpCol < 0 || tmpCol >= tmpWidth )
{
QgsDebugMsg( "Source row or column limits out of range" );
block->setIsNoData(); // so that the problem becomes obvious and fixed
delete tmpBlock;
return block;
}
size_t tmpIndex = tmpRow * tmpWidth + tmpCol;
size_t index = row * theWidth + col;
char *tmpBits = tmpBlock->bits( tmpIndex );
char *bits = block->bits( index );
if ( !tmpBits )
{
QgsDebugMsg( QString( "Cannot get input block data tmpRow = %1 tmpCol = %2 tmpIndex = %3." ).arg( tmpRow ).arg( tmpCol ).arg( tmpIndex ) );
continue;
}
if ( !bits )
{
QgsDebugMsg( "Cannot set output block data." );
continue;
}
memcpy( bits, tmpBits, pixelSize );
}
}
delete tmpBlock;
}
else
{
readBlock( theBandNo, theExtent, theWidth, theHeight, block->data() );
}
// apply user no data values
// TODO: there are other readBlock methods where no data are not applied
block->applyNodataValues( userNoDataValue( theBandNo ) );
return block;
}