josh/ichigo
1
0
Fork 0
Code Issues Pull requests Projects Releases 1 Packages Wiki Activity Actions

comments

Browse source
This commit is contained in:
Josh Deprez 2021-09-01 12:12:25 +10:00
parent 2b5987a95e
commit 228f8b9b9a
1 changed files with 5 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
engine/parallax.go
View file

@ -17,16 +17,17 @@ func init() {
gob.Register(&Parallax{})
}
// Parallax is a container that changes its transform based on the position of a
// Parallax is a container that translates based on the position of a
// camera, intended to produce a "parallax" like effect.
type Parallax struct {
CameraID string
Factor float64 // how much to change in response to the camera
Factor float64 // how much to translate in response to the camera
Child interface{}
camera *Camera
}
// Prepare obtains a reference to the camera.
func (p *Parallax) Prepare(game *Game) error {
c, ok := game.Component(p.CameraID).(*Camera)
if !ok {
@ -36,8 +37,10 @@ func (p *Parallax) Prepare(game *Game) error {
return nil
}
// Scan returns the child component.
func (p *Parallax) Scan() []interface{} { return []interface{}{p.Child} }
// Transform returns a GeoM translation of Factor * camera.Centre.
func (p *Parallax) Transform() (opts ebiten.DrawImageOptions) {
x, y := float2(p.camera.Centre)
opts.GeoM.Translate(x*p.Factor, y*p.Factor)