surrealpatch/util/geof/inside.go
2021-12-14 08:13:19 +00:00

31 lines
908 B
Go

// Copyright © 2016 SurrealDB Ltd.
//
// Licensed 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.
package geof
import (
"github.com/surrealdb/surrealdb/sql"
)
func Inside(a *sql.Point, b *sql.Polygon) bool {
beg := len(b.PS) - 1
end := 0
contains := raycast(a, b.PS[beg], b.PS[end])
for i := 1; i < len(b.PS); i++ {
if raycast(a, b.PS[i-1], b.PS[i]) {
contains = !contains
}
}
return contains
}