78 lines
1.8 KiB
Go
78 lines
1.8 KiB
Go
package engine
|
|
|
|
import (
|
|
"encoding/gob"
|
|
"fmt"
|
|
"image"
|
|
|
|
"drjosh.dev/gurgle/geom"
|
|
"github.com/hajimehoshi/ebiten/v2"
|
|
)
|
|
|
|
// Ensure Sprite satisfies interfaces.
|
|
var _ interface {
|
|
BoundingBoxer
|
|
Drawer
|
|
Scanner
|
|
Transformer
|
|
Updater
|
|
} = &Sprite{}
|
|
|
|
func init() {
|
|
gob.Register(&Sprite{})
|
|
}
|
|
|
|
// Sprite combines an Actor with the ability to Draw from a single spritesheet.
|
|
type Sprite struct {
|
|
Actor Actor
|
|
DrawOffset image.Point
|
|
Hides
|
|
Sheet Sheet
|
|
|
|
anim *Anim
|
|
}
|
|
|
|
// BoundingBox forwards the call to Actor.
|
|
func (s *Sprite) BoundingBox() geom.Box { return s.Actor.BoundingBox() }
|
|
|
|
// Draw draws the current cell to the screen.
|
|
func (s *Sprite) Draw(screen *ebiten.Image, opts *ebiten.DrawImageOptions) {
|
|
screen.DrawImage(s.Sheet.SubImage(s.anim.Cell()), opts)
|
|
}
|
|
|
|
// Scan returns the Actor and the Sheet.
|
|
func (s *Sprite) Scan() []interface{} {
|
|
return []interface{}{
|
|
&s.Actor,
|
|
&s.Sheet,
|
|
}
|
|
}
|
|
|
|
// SetAnim sets the Anim to use for the sprite. If it is not the same as the
|
|
// one currently set, it resets the new anim.
|
|
func (s *Sprite) SetAnim(a *Anim) {
|
|
if s.anim != a {
|
|
a.Reset()
|
|
}
|
|
s.anim = a
|
|
}
|
|
|
|
func (s *Sprite) String() string {
|
|
return fmt.Sprintf("Sprite@%v", s.Actor.Pos)
|
|
}
|
|
|
|
// Transform returns a translation by the DrawOffset and Actor.Pos projected
|
|
func (s *Sprite) Transform() (opts ebiten.DrawImageOptions) {
|
|
opts.GeoM.Translate(geom.CFloat(
|
|
// Reaching into Actor for a reference to Game so I don't have to
|
|
// implement Prepare in this file, but writing this long comment
|
|
// providing exposition...
|
|
geom.Project(s.Actor.game.Projection, s.Actor.Pos).
|
|
Add(s.DrawOffset),
|
|
))
|
|
return opts
|
|
}
|
|
|
|
// Update updates the Sprite's anim. anim can change a bit so we don't tell Game
|
|
// about it, but that means it must be updated manually.
|
|
func (s *Sprite) Update() error { return s.anim.Update() }
|