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gdal.input: use GDALDataset::RasterIO() to read RGB sources

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Enabled when the R,G,B channels are bands 1, 2 and 3
And also read the alpha channel at the same time, if it is band 4
This commit is contained in:
Even Rouault 2015-02-05 20:33:52 +01:00
parent 192f62ecbf
commit 073bad21c0
1 changed files with 35 additions and 8 deletions
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43
plugins/input/gdal/gdal_featureset.cpp
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@ -335,15 +335,42 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
}
}
}
raster_io_error = red->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 0,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
/* Use dataset RasterIO in priority in 99.9% of the cases */
if( red->GetBand() == 1 && green->GetBand() == 2 && blue->GetBand() == 3 )
{
int nBandsToRead = 3;
if( alpha != NULL && alpha->GetBand() == 4 && !raster_has_nodata )
{
nBandsToRead = 4;
alpha = NULL; // to avoid reading it again afterwards
}
raster_io_error = dataset_.RasterIO(GF_Read, x_off, y_off, width, height,
image.getBytes(),
image.width(), image.height(), GDT_Byte,
nBandsToRead, NULL,
4, 4 * image.width(), 1);
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
}
raster_io_error = green->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 1,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
else
{
raster_io_error = red->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 0,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
raster_io_error = green->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 1,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
raster_io_error = blue->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 2,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (raster_io_error == CE_Failure) {
throw datasource_exception(CPLGetLastErrorMsg());
}
}
raster_io_error = blue->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 2,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());