Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
57 lines (48 sloc) 1.46 KB
// Copyright 2019 The Ebiten Authors
//
// 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 math
import (
"math"
)
type Point struct {
X float32
Y float32
}
type Vec2 struct {
X float32
Y float32
}
func (p Vec2) Cross(other Vec2) float32 {
return p.X*other.Y - p.Y*other.X
}
type Segment struct {
P0 Point
P1 Point
}
func (s Segment) Translate(offset float32) Segment {
a := math.Atan2(float64(s.P1.Y-s.P0.Y), float64(s.P1.X-s.P0.X))
si, co := math.Sincos(a + math.Pi/2)
dx, dy := float32(co)*offset, float32(si)*offset
return Segment{
P0: Point{s.P0.X + dx, s.P0.Y + dy},
P1: Point{s.P1.X + dx, s.P1.Y + dy},
}
}
func (s Segment) IntersectionAsLines(other Segment) Point {
v1 := Vec2{other.P1.X - other.P0.X, other.P1.Y - other.P0.Y}
d0 := v1.Cross(Vec2{s.P0.X - other.P0.X, s.P0.Y - other.P0.Y})
d1 := -v1.Cross(Vec2{s.P1.X - other.P1.X, s.P1.Y - other.P1.Y})
t := d0 / (d0 + d1)
return Point{s.P0.X + (s.P1.X-s.P0.X)*t, s.P0.Y + (s.P1.Y-s.P0.Y)*t}
}
You can’t perform that action at this time.