ebiten/examples/vector/main.go

168 lines
3.0 KiB
Go

// 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.
// +build example jsgo
package main
import (
"image/color"
"log"
"math"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/vector"
)
const (
screenWidth = 640
screenHeight = 480
)
func drawEbitenText(screen *ebiten.Image) {
var path vector.Path
// E
path.MoveTo(60, 20)
path.LineTo(20, 20)
path.LineTo(20, 60)
path.LineTo(60, 60)
path.MoveTo(20, 40)
path.LineTo(60, 40)
// B
path.MoveTo(110, 20)
path.LineTo(80, 20)
path.LineTo(80, 60)
path.LineTo(110, 60)
path.LineTo(120, 50)
path.LineTo(110, 40)
path.LineTo(120, 30)
path.LineTo(110, 20)
path.LineTo(80, 20)
path.MoveTo(80, 40)
path.LineTo(110, 40)
// I
path.MoveTo(140, 20)
path.LineTo(140, 60)
// T
path.MoveTo(160, 20)
path.LineTo(200, 20)
path.MoveTo(180, 20)
path.LineTo(180, 60)
// E
path.MoveTo(260, 20)
path.LineTo(220, 20)
path.LineTo(220, 60)
path.LineTo(260, 60)
path.MoveTo(220, 40)
path.LineTo(260, 40)
// N
path.MoveTo(280, 60)
path.LineTo(280, 20)
path.LineTo(320, 60)
path.LineTo(320, 20)
op := &vector.DrawPathOptions{}
op.LineWidth = 8
op.StrokeColor = color.RGBA{0xdb, 0x56, 0x20, 0xff}
path.Draw(screen, op)
}
type roundingPoint struct {
cx float32
cy float32
r float32
degree int
}
func (r *roundingPoint) Update() {
r.degree++
r.degree %= 360
}
func (r *roundingPoint) Position() (float32, float32) {
s, c := math.Sincos(float64(r.degree) / 360 * 2 * math.Pi)
return r.cx + r.r*float32(c), r.cy + r.r*float32(s)
}
func drawLinesByRoundingPoints(screen *ebiten.Image, points []*roundingPoint) {
if len(points) == 0 {
return
}
var path vector.Path
path.MoveTo(points[0].Position())
for i := 1; i < len(points); i++ {
path.LineTo(points[i].Position())
}
op := &vector.DrawPathOptions{}
op.LineWidth = 4
op.StrokeColor = color.White
path.Draw(screen, op)
}
var points = []*roundingPoint{
{
cx: 100,
cy: 120,
r: 10,
degree: 0,
},
{
cx: 120,
cy: 120,
r: 10,
degree: 90,
},
{
cx: 100,
cy: 140,
r: 10,
degree: 180,
},
{
cx: 120,
cy: 140,
r: 10,
degree: 270,
},
}
func update(screen *ebiten.Image) error {
for _, p := range points {
p.Update()
}
if ebiten.IsDrawingSkipped() {
return nil
}
drawEbitenText(screen)
drawLinesByRoundingPoints(screen, points)
return nil
}
func main() {
if err := ebiten.Run(update, screenWidth, screenHeight, 1, "Vector (Ebiten Demo)"); err != nil {
log.Fatal(err)
}
}