ebiten/example/game/sprites/sprites.go
2013-10-18 00:45:12 +09:00

132 lines
2.6 KiB
Go

package sprites
import (
"github.com/hajimehoshi/go-ebiten"
"github.com/hajimehoshi/go-ebiten/graphics"
"github.com/hajimehoshi/go-ebiten/graphics/matrix"
"image"
"math/rand"
"os"
"time"
)
const (
ebitenTextureWidth = 57
ebitenTextureHeight = 26
)
type Sprite struct {
width int
height int
ch chan bool
x int
y int
vx int
vy int
}
func newSprite(screenWidth, screenHeight, width, height int) *Sprite {
maxX := screenWidth - width
maxY := screenHeight - height
sprite := &Sprite{
width: width,
height: height,
ch: make(chan bool),
x: rand.Intn(maxX),
y: rand.Intn(maxY),
vx: rand.Intn(2)*2 - 1,
vy: rand.Intn(2)*2 - 1,
}
go sprite.update(screenWidth, screenHeight)
return sprite
}
func (sprite *Sprite) update(screenWidth, screenHeight int) {
maxX := screenWidth - sprite.width
maxY := screenHeight - sprite.height
for {
<-sprite.ch
sprite.x += sprite.vx
sprite.y += sprite.vy
if sprite.x < 0 || maxX <= sprite.x {
sprite.vx = -sprite.vx
}
if sprite.y < 0 || maxY <= sprite.y {
sprite.vy = -sprite.vy
}
sprite.ch <- true
}
}
func (sprite *Sprite) Update() {
sprite.ch <- true
<-sprite.ch
}
type Sprites struct {
ebitenTextureID graphics.TextureID
sprites []*Sprite
}
func New() *Sprites {
return &Sprites{}
}
func (game *Sprites) Init(tf graphics.TextureFactory) {
file, err := os.Open("images/ebiten.png")
if err != nil {
panic(err)
}
defer file.Close()
img, _, err := image.Decode(file)
if err != nil {
panic(err)
}
if game.ebitenTextureID, err = tf.NewTextureFromImage(img); err != nil {
panic(err)
}
}
func (game *Sprites) Update(context ebiten.GameContext) {
if game.sprites == nil {
game.sprites = []*Sprite{}
for i := 0; i < 100; i++ {
sprite := newSprite(
context.ScreenWidth(),
context.ScreenHeight(),
ebitenTextureWidth,
ebitenTextureHeight)
game.sprites = append(game.sprites, sprite)
}
}
for _, sprite := range game.sprites {
sprite.Update()
}
}
func (game *Sprites) Draw(g graphics.Context) {
g.Fill(128, 128, 255)
// Draw the sprites
locations := make([]graphics.TexturePart, 0, len(game.sprites))
for _, sprite := range game.sprites {
location := graphics.TexturePart{
LocationX: sprite.x,
LocationY: sprite.y,
Source: graphics.Rect{
0, 0, ebitenTextureWidth, ebitenTextureHeight,
},
}
locations = append(locations, location)
}
geometryMatrix := matrix.IdentityGeometry()
g.DrawTextureParts(game.ebitenTextureID, locations,
geometryMatrix, matrix.IdentityColor())
}
func init() {
rand.Seed(time.Now().UnixNano())
}