james-willis commented on code in PR #1073: URL: https://github.com/apache/sedona-db/pull/1073#discussion_r3643066338
########## rust/sedona-raster-functions/src/footprint.rs: ########## @@ -0,0 +1,58 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Raster footprint helpers shared by the raster spatial-predicate kernels and +//! the optimized raster spatial join. +//! +//! A raster's footprint is the convex hull of its four corners in world +//! coordinates. Because the affine geotransform may include skew/rotation, each +//! corner is computed individually rather than assumed axis-aligned. + +use datafusion_common::{DataFusionError, Result}; +use sedona_geometry::wkb_factory::write_wkb_polygon; +use sedona_raster::affine_transformation::to_world_coordinate; +use sedona_raster::traits::RasterRef; + +/// The four corners of a raster's footprint in world coordinates. +/// +/// Returned in ring order: upper-left `(0, 0)`, upper-right `(width, 0)`, +/// lower-right `(width, height)`, lower-left `(0, height)`. +pub fn raster_footprint_corners(raster: &dyn RasterRef) -> [(f64, f64); 4] { + let width = raster.metadata().width(); + let height = raster.metadata().height(); + + [ + to_world_coordinate(raster, 0, 0), + to_world_coordinate(raster, width, 0), + to_world_coordinate(raster, width, height), + to_world_coordinate(raster, 0, height), + ] +} + +/// Write WKB for the convex-hull polygon of the raster footprint. +/// +/// The ring is the four [`raster_footprint_corners`] closed back to the +/// upper-left corner. This can be used to build Binary arrays, as the arrow-rs +/// `BinaryBuilder` implements [`std::io::Write`]. +pub fn write_convexhull_wkb(raster: &dyn RasterRef, out: &mut impl std::io::Write) -> Result<()> { Review Comment: https://github.com/apache/sedona/issues/3154 https://github.com/apache/sedona-db/issues/1076 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
