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alignment better

git-svn-id: http://svn.osgeo.org/qgis/trunk@15422 c8812cc2-4d05-0410-92ff-de0c093fc19c
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rblazek
rblazek committed Mar 10, 2011
1 parent 8990dc5 commit 51a07a640eabbcd2780ff78dd3e6b1a35d7b3767
Showing with 71 additions and 11 deletions.
  1. +71 −11 src/providers/gdal/qgsgdalprovider.cpp
@@ -532,6 +532,11 @@ void QgsGdalProvider::readBlock( int theBandNo, QgsRectangle const & theExtent,
QgsDebugMsg( "thePixelHeight = " + QString::number( thePixelHeight ) );
QgsDebugMsg( "theExtent: " + theExtent.toString() );

for ( int i = 0 ; i < 6; i++ )
{
QgsDebugMsg( QString( "transform : %1" ).arg( mGeoTransform[i] ) );
}

// TODO: fill block with no data values

QgsRectangle myRasterExtent = theExtent.intersect( &mExtent );
@@ -589,46 +594,57 @@ void QgsGdalProvider::readBlock( int theBandNo, QgsRectangle const & theExtent,
double center, centerRaster;
int rasterTop, rasterBottom, rasterLeft, rasterRight;

// We have to extend destination grid for GDALRasterIO to keep resolution:
double topSpace, bottomSpace, leftSpace, rightSpace;

// top
center = myRasterExtent.yMaximum() - yRes/2;
// center in raster space
// GDAL states that mGeoTransform[3] is top, but probably it can be also bottom
// if mGeoTransform[5] is negative
if ( mGeoTransform[5] > 0 )
// if mGeoTransform[5] is negative ??? No, mGeoTransform[5] is negative normaly
// - vice versa?
//if ( mGeoTransform[5] > 0 )
if ( mGeoTransform[5] < 0 )
{
centerRaster = ( mGeoTransform[3] - center ) / mGeoTransform[5];
centerRaster = -1. * ( mGeoTransform[3] - center ) / mGeoTransform[5];
}
else
{
centerRaster = ( center - mGeoTransform[3] ) / mGeoTransform[5];
}
rasterTop = static_cast<int> ( floor ( centerRaster ) );
topSpace = (mGeoTransform[3] + rasterTop*mGeoTransform[5])- myRasterExtent.yMaximum();

// bottom
center = myRasterExtent.yMinimum() + yRes/2;
if ( mGeoTransform[5] > 0 )
//if ( mGeoTransform[5] > 0 )
if ( mGeoTransform[5] < 0 )
{
centerRaster = ( mGeoTransform[3] - center ) / mGeoTransform[5];
centerRaster = -1. * ( mGeoTransform[3] - center ) / mGeoTransform[5];
}
else
{
centerRaster = ( center - mGeoTransform[3] ) / mGeoTransform[5];
}
rasterBottom = static_cast<int> ( floor ( centerRaster ) );
bottomSpace = myRasterExtent.yMinimum() - ( mGeoTransform[3] + (rasterBottom+1)*mGeoTransform[5] );

// left
center = myRasterExtent.xMinimum() + xRes/2;
centerRaster = ( center - mGeoTransform[0] ) / mGeoTransform[1];
rasterLeft = static_cast<int> ( floor ( centerRaster ) );
leftSpace = myRasterExtent.xMinimum() - (mGeoTransform[0] + rasterLeft * mGeoTransform[1] );

// right
center = myRasterExtent.xMaximum() - xRes/2;
centerRaster = ( center - mGeoTransform[0] ) / mGeoTransform[1];
rasterRight = static_cast<int> ( floor ( centerRaster ) );
rightSpace = (mGeoTransform[0] + (rasterRight+1)*mGeoTransform[1]) - myRasterExtent.xMaximum();

QgsDebugMsg( QString("rasterTop = %1 rasterBottom = %2 rasterLeft = %3 rasterRight = %4").arg(rasterTop).arg(rasterBottom).arg(rasterLeft).arg(rasterRight) );

// Allocate temporary block
QgsDebugMsg( QString("topSpace = %1 bottomSpace = %2 leftSpace = %3 rightSpace = %4").arg(topSpace).arg(bottomSpace).arg(leftSpace).arg(rightSpace) );

int width = right - left + 1;
int height = bottom - top + 1;

@@ -637,6 +653,29 @@ void QgsGdalProvider::readBlock( int theBandNo, QgsRectangle const & theExtent,

QgsDebugMsg( QString("width = %1 height = %2 rasterWidth = %3 rasterHeight = %4").arg(width).arg(height).arg(rasterWidth).arg(rasterHeight) );


double rasterXRes = extent().width() / xSize();
double rasterYRes = extent().height() / ySize();

// TODO: what is better floor/ceil, can be negative?
// should be similar
//double xAdd = rasterWidth*rasterXRes - width*xRes;
double xAdd = leftSpace + rightSpace;
int xAddPixels = static_cast<int> ( round( xAdd / xRes ) );
int leftAddPixels = static_cast<int> ( round( leftSpace / xRes ) );

//double leftAdd = rasterWidth*rasterXRes - width*xRes;
double yAdd = topSpace + bottomSpace;
int yAddPixels = static_cast<int> ( round( yAdd / yRes ) );
int topAddPixels = static_cast<int> ( round( topSpace / yRes ) );

QgsDebugMsg( QString("xAddPixels = %1 yAddPixels = %2 leftAddPixels = %3 topAddPixels = %4").arg(xAddPixels).arg(yAddPixels).arg(leftAddPixels).arg(topAddPixels) );

int totalWidth = width + xAddPixels;
int totalHeight = height + yAddPixels;

QgsDebugMsg( QString("totalWidth = %1 totalHeight = %2").arg(totalWidth).arg(totalHeight) );

int size = dataTypeSize(theBandNo) / 8;

// fill with null values
@@ -650,7 +689,11 @@ void QgsGdalProvider::readBlock( int theBandNo, QgsRectangle const & theExtent,
}

GDALRasterBandH gdalBand = GDALGetRasterBand( mGdalDataset, theBandNo );
GDALDataType type = ( GDALDataType )mGdalDataType[theBandNo-1];
CPLErrorReset();

// This can be probably used if xAddPixels and yAddPixels are 0 to avoid memcpy
#if 0
// Calc beginnig of data if raster does not start at top
block = (char *) theBlock;
if ( top != 0 )
@@ -663,23 +706,40 @@ void QgsGdalProvider::readBlock( int theBandNo, QgsRectangle const & theExtent,
if ( left != 0 ) {
block += size * left;
}

GDALDataType type = ( GDALDataType )mGdalDataType[theBandNo-1];

CPLErrorReset();
CPLErr err = GDALRasterIO( gdalBand, GF_Read,
rasterLeft, rasterTop, rasterWidth, rasterHeight,
(void *)block,
width, height, type,
0, nLineSpace );
#endif

// Allocate temporary block
void *tmpBlock = malloc( size * totalWidth * totalHeight );

CPLErrorReset();
CPLErr err = GDALRasterIO( gdalBand, GF_Read,
rasterLeft, rasterTop, rasterWidth, rasterHeight,
(void *)tmpBlock,
totalWidth, totalHeight, type,
0, 0 );

if ( err != CPLE_None )
{
QgsLogger::warning( "RasterIO error: " + QString::fromUtf8( CPLGetLastErrorMsg() ) );
QgsDebugMsg ( "RasterIO error: " + QString::fromUtf8( CPLGetLastErrorMsg() ) );
free ( tmpBlock );
return;
}

for ( int i = 0; i < height; i++ ) {
int r = i + topAddPixels;
char *src = (char *)tmpBlock + size*r*totalWidth + size*leftAddPixels;
char *dst = (char *)theBlock + size*(top+i)*thePixelWidth + size*(left);
memcpy ( dst, src, size*width );
}


free ( tmpBlock );
return;
}

// this is old version which was using GDALWarpOperation, unfortunately

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