package ox

import "surdeus.su/core/gg"
import "surdeus.su/core/gg/ax"

// The type implements animated sprites.
type AnimatedSprite struct {
	Sprite

	animations ax.AnimationSet
	animationId ax.AnimationId

	currentFrame int

	// This is time between animation frames, not
	// engine ones.
	timeBetweenFrames gg.Duration
	duration gg.Duration
}

func NewAnimatedSprite(
) *AnimatedSprite {
	ret := &AnimatedSprite{}
	return ret
}

// Change current animation to the specified one.
func (as *AnimatedSprite) Animate(id ax.AnimationId) bool {
	if as.AnimationId == id {
		return true
	}
	_, ok := as.Animations[id]
	if ok {
		as.duration = 0
		as.AnimationId = id
	}
	return ok
}

func (as *AnimatedSprite) Draw(c Context) []EVertex {
	as.duration += c.DrawDT()

	frames := as.Animations[as.AnimationId]
	fullTime := Duration(len(frames)) * as.TimeBetweenFrames
	if as.duration > fullTime {
		as.duration -= fullTime
	}

	as.Images[0] = frames[
		(as.duration/as.TimeBetweenFrames) %
			Duration(len(frames)),
	]

	return as.Sprite.Draw(c)
}