ebiten/examples/capture/main.go
2023-04-19 13:02:02 +09:00

133 lines
3.3 KiB
Go

// Copyright 2023 The Ebitengine 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 main
import (
"fmt"
"image/color"
"log"
"runtime"
"sync"
"github.com/hajimehoshi/ebiten/v2"
"github.com/hajimehoshi/ebiten/v2/ebitenutil"
"github.com/hajimehoshi/ebiten/v2/inpututil"
)
var pointerImage = ebiten.NewImage(8, 8)
func init() {
pointerImage.Fill(color.RGBA{0xff, 0, 0, 0xff})
}
const (
screenWidth = 640
screenHeight = 480
)
type Game struct {
initOnce sync.Once
mouseX int
mouseY int
x int
y int
}
func (g *Game) Update() error {
g.initOnce.Do(func() {
// initialize cursor position on first update
g.mouseX, g.mouseY = ebiten.CursorPosition()
})
if ebiten.CursorMode() == ebiten.CursorModeCaptured {
cursorX, cursorY := ebiten.CursorPosition()
deltaX, deltaY := cursorX-g.mouseX, cursorY-g.mouseY
g.mouseX, g.mouseY = cursorX, cursorY
if deltaX != 0 {
g.x += deltaX
}
if deltaY != 0 {
g.y += deltaY
}
// Constrain red dot within screen view.
if g.x < 0 {
g.x = 0
} else if g.x > screenWidth-pointerImage.Bounds().Dx() {
g.x = screenWidth - pointerImage.Bounds().Dx()
}
if g.y < 0 {
g.y = 0
} else if g.y > screenHeight-pointerImage.Bounds().Dy() {
g.y = screenHeight - pointerImage.Bounds().Dy()
}
}
if inpututil.IsKeyJustPressed(ebiten.KeySpace) {
if ebiten.CursorMode() == ebiten.CursorModeCaptured {
// Release mouse cursor capture.
ebiten.SetCursorMode(ebiten.CursorModeVisible)
} else {
// Recapture mouse cursor.
ebiten.SetCursorMode(ebiten.CursorModeCaptured)
// Reset mouse cursor position for its return.
g.mouseX, g.mouseY = ebiten.CursorPosition()
}
}
return nil
}
func (g *Game) Draw(screen *ebiten.Image) {
op := &ebiten.DrawImageOptions{}
op.GeoM.Translate(float64(g.x), float64(g.y))
screen.DrawImage(pointerImage, op)
var message string
if ebiten.CursorMode() == ebiten.CursorModeCaptured {
message = fmt.Sprintf("Move the red point with mouse captured\nPress Space to release mouse capture\n(%d, %d)", g.x, g.y)
} else {
message = fmt.Sprintf("The red point can only move when mouse captured\nPress Space to capture mouse\n(%d, %d)", g.x, g.y)
}
ebitenutil.DebugPrint(screen, message)
}
func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
return screenWidth, screenHeight
}
func main() {
ebiten.SetWindowTitle("Mouse Capture (Ebitengine Demo)")
ebiten.SetWindowSize(screenWidth, screenHeight)
// Web browsers allow cursor mode capture only with user interaction.
// Start without cursor captured with message indicating how to capture.
if runtime.GOOS != "js" {
ebiten.SetCursorMode(ebiten.CursorModeCaptured)
}
g := &Game{
x: screenWidth / 2,
y: screenHeight / 2,
}
if err := ebiten.RunGame(g); err != nil {
log.Fatal(err)
}
}