feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
{
feature_ptr feature = feature_factory::create(ctx_,1);
GDALRasterBand * red = 0;
GDALRasterBand * green = 0;
GDALRasterBand * blue = 0;
GDALRasterBand * alpha = 0;
GDALRasterBand * grey = 0;
/*
#ifdef MAPNIK_LOG
double tr[6];
dataset_.GetGeoTransform(tr);
const double dx = tr[1];
const double dy = tr[5];
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: dx_=" << dx_ << " dx=" << dx << " dy_=" << dy_ << "dy=" << dy;
#endif
*/
CoordTransform t(raster_width_, raster_height_, raster_extent_, 0, 0);
box2d<double> intersect = raster_extent_.intersect(q.get_bbox());
box2d<double> box = t.forward(intersect);
//size of resized output pixel in source image domain
double margin_x = 1.0 / (fabs(dx_) * boost::get<0>(q.resolution()));
double margin_y = 1.0 / (fabs(dy_) * boost::get<1>(q.resolution()));
if (margin_x < 1)
{
margin_x = 1.0;
}
if (margin_y < 1)
{
margin_y = 1.0;
}
//select minimum raster containing whole box
int x_off = rint(box.minx() - margin_x);
int y_off = rint(box.miny() - margin_y);
int end_x = rint(box.maxx() + margin_x);
int end_y = rint(box.maxy() + margin_y);
//clip to available data
if (x_off < 0)
{
x_off = 0;
}
if (y_off < 0)
{
y_off = 0;
}
if (end_x > (int)raster_width_)
{
end_x = raster_width_;
}
if (end_y > (int)raster_height_)
{
end_y = raster_height_;
}
int width = end_x - x_off;
int height = end_y - y_off;
// don't process almost invisible data
if (box.width() < 0.5)
{
width = 0;
}
if (box.height() < 0.5)
{
height = 0;
}
//calculate actual box2d of returned raster
box2d<double> feature_raster_extent(x_off, y_off, x_off + width, y_off + height);
intersect = t.backward(feature_raster_extent);
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Raster extent=" << raster_extent_;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: View extent=" << intersect;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Query resolution=" << boost::get<0>(q.resolution()) << "," << boost::get<1>(q.resolution());
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: StartX=" << x_off << " StartY=" << y_off << " Width=" << width << " Height=" << height;
if (width > 0 && height > 0)
{
double width_res = boost::get<0>(q.resolution());
double height_res = boost::get<1>(q.resolution());
int im_width = int(width_res * intersect.width() + 0.5);
int im_height = int(height_res * intersect.height() + 0.5);
// if layer-level filter_factor is set, apply it
if (filter_factor_)
{
im_width *= filter_factor_;
im_height *= filter_factor_;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Applying layer filter_factor=" << filter_factor_;
}
// otherwise respect symbolizer level factor applied to query, default of 1.0
else
{
double sym_downsample_factor = q.get_filter_factor();
im_width *= sym_downsample_factor;
im_height *= sym_downsample_factor;
}
// case where we need to avoid upsampling so that the
// image can be later scaled within raster_symbolizer
if (im_width >= width || im_height >= height)
{
im_width = width;
im_height = height;
}
if (im_width > 0 && im_height > 0)
{
mapnik::raster_ptr raster = boost::make_shared<mapnik::raster>(intersect, im_width, im_height);
feature->set_raster(raster);
mapnik::image_data_32 & image = raster->data_;
image.set(0xffffffff);
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Image Size=(" << im_width << "," << im_height << ")";
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Reading band=" << band_;
if (band_ > 0) // we are querying a single band
{
if (band_ > nbands_)
{
throw datasource_exception((boost::format("GDAL Plugin: '%d' is an invalid band, dataset only has '%d' bands\n") % band_ % nbands_).str());
}
float* imageData = (float*)image.getBytes();
GDALRasterBand * band = dataset_.GetRasterBand(band_);
int hasNoData(0);
double nodata(0);
if (nodata_value_)
{
hasNoData = 1;
nodata = *nodata_value_;
}
else
{
nodata = band->GetNoDataValue(&hasNoData);
}
band->RasterIO(GF_Read, x_off, y_off, width, height,
imageData, image.width(), image.height(),
GDT_Float32, 0, 0);
if (hasNoData)
{
feature->put("NODATA",nodata);
}
}
else // working with all bands
{
for (int i = 0; i < nbands_; ++i)
{
GDALRasterBand * band = dataset_.GetRasterBand(i + 1);
#ifdef MAPNIK_LOG
get_overview_meta(band);
#endif
GDALColorInterp color_interp = band->GetColorInterpretation();
switch (color_interp)
{
case GCI_RedBand:
red = band;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Found red band";
break;
case GCI_GreenBand:
green = band;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Found green band";
break;
case GCI_BlueBand:
blue = band;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Found blue band";
break;
case GCI_AlphaBand:
alpha = band;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Found alpha band";
break;
case GCI_GrayIndex:
grey = band;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Found gray band";
break;
case GCI_PaletteIndex:
{
grey = band;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Found gray band, and colortable...";
GDALColorTable *color_table = band->GetColorTable();
if (color_table)
{
int count = color_table->GetColorEntryCount();
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Color Table count=" << count;
for (int j = 0; j < count; j++)
{
const GDALColorEntry *ce = color_table->GetColorEntry (j);
if (! ce) continue;
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Color entry RGB=" << ce->c1 << "," <<ce->c2 << "," << ce->c3;
}
}
break;
}
case GCI_Undefined:
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Found undefined band (assumming gray band)";
grey = band;
break;
default:
MAPNIK_LOG_WARN(gdal) << "gdal_featureset: Band type unknown!";
break;
}
}
if (red && green && blue)
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Processing rgb bands...";
int hasNoData = 0;
double nodata = 0.0;
if (nodata_value_)
{
hasNoData = 1;
nodata = *nodata_value_;
}
else
{
nodata = red->GetNoDataValue(&hasNoData);
}
if (hasNoData)
{
feature->put("NODATA",nodata);
}
GDALColorTable *color_table = red->GetColorTable();
if (! alpha && hasNoData && ! color_table)
{
// first read the data in and create an alpha channel from the nodata values
float* imageData = (float*)image.getBytes();
red->RasterIO(GF_Read, x_off, y_off, width, height,
imageData, image.width(), image.height(),
GDT_Float32, 0, 0);
int len = image.width() * image.height();
for (int i = 0; i < len; ++i)
{
if (nodata == imageData[i])
{
*reinterpret_cast<unsigned *>(&imageData[i]) = 0;
}
else
{
*reinterpret_cast<unsigned *>(&imageData[i]) = 0xFFFFFFFF;
}
}
}
red->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 0,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
green->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 1,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
blue->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 2,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
}
else if (grey)
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Processing gray band...";
int hasNoData(0);
double nodata(0);
if (nodata_value_)
{
hasNoData = 1;
nodata = *nodata_value_;
}
else
{
nodata = grey->GetNoDataValue(&hasNoData);
}
GDALColorTable* color_table = grey->GetColorTable();
if (hasNoData && ! color_table)
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: No data value for layer=" << nodata;
feature->put("NODATA",nodata);
// first read the data in and create an alpha channel from the nodata values
float* imageData = (float*)image.getBytes();
grey->RasterIO(GF_Read, x_off, y_off, width, height,
imageData, image.width(), image.height(),
GDT_Float32, 0, 0);
int len = image.width() * image.height();
for (int i = 0; i < len; ++i)
{
if (nodata == imageData[i])
{
*reinterpret_cast<unsigned *>(&imageData[i]) = 0;
}
else
{
*reinterpret_cast<unsigned *> (&imageData[i]) = 0xFFFFFFFF;
}
}
}
grey->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 0,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
grey->RasterIO(GF_Read,x_off, y_off, width, height, image.getBytes() + 1,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
grey->RasterIO(GF_Read,x_off, y_off, width, height, image.getBytes() + 2,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
if (color_table)
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Loading colour table...";
unsigned nodata_value = static_cast<unsigned>(nodata);
if (hasNoData)
{
feature->put("NODATA",static_cast<int>(nodata_value));
}
for (unsigned y = 0; y < image.height(); ++y)
{
unsigned int* row = image.getRow(y);
for (unsigned x = 0; x < image.width(); ++x)
{
unsigned value = row[x] & 0xff;
if (hasNoData && (value == nodata_value))
{
// make no data fully alpha
row[x] = 0;
}
else
{
const GDALColorEntry *ce = color_table->GetColorEntry(value);
if (ce)
{
// TODO - big endian support
row[x] = (ce->c4 << 24)| (ce->c3 << 16) | (ce->c2 << 8) | (ce->c1) ;
}
else
{
// make lacking color entry fully alpha
// note - gdal_translate makes black
row[x] = 0;
}
}
}
}
}
}
if (alpha)
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: processing alpha band...";
alpha->RasterIO(GF_Read, x_off, y_off, width, height, image.getBytes() + 3,
image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
}
}
return feature;
}
}
return feature_ptr();
}
