本文整理汇总了C++中mapnik::rint方法的典型用法代码示例。如果您正苦于以下问题：C++ mapnik::rint方法的具体用法？C++ mapnik::rint怎么用？C++ mapnik::rint使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类mapnik的用法示例。
在下文中一共展示了mapnik::rint方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: get_feature
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
{
//.........这里部分代码省略.........