tins2021/animatedtexture.go

package tins2021

import (
	"opslag.de/schobers/geom"
	"opslag.de/schobers/zntg/ui"
)

type AnimatedTexture struct {
	texture   NamedTexture
	animation ui.Texture
	frames    []geom.RectangleF32
}

func newAnimatedTexture(texture NamedTexture, animation ui.Texture, n int) AnimatedTexture {
	frames := make([]geom.RectangleF32, 0, n)
	height := float32(animation.Height())
	width := float32(animation.Width())
	for i := 0; i < n; i++ {
		left := width * float32(i) / float32(n)
		right := width * float32(i+1) / float32(n)
		frames = append(frames, geom.RectF32(left, 0, right, height))
	}
	return AnimatedTexture{texture: texture, animation: animation, frames: frames}
}

func NewAnimatedTexture(texture NamedTexture, n int) AnimatedTexture {
	return newAnimatedTexture(texture, texture.Texture(), n)
}

func FitAnimatedTexture(texture NamedTexture, scale float32, n int) AnimatedTexture {
	height := float32(texture.Texture().Height())
	scale = ScaleRound(height, scale)
	return newAnimatedTexture(texture, texture.Scaled(scale), n)
}

func (t AnimatedTexture) Draw(renderer ui.Renderer, pos geom.PointF32, frame int) {
	renderer.DrawTexturePointOptions(t.animation, pos, ui.DrawOptions{Source: &t.frames[frame]})
}

func (t AnimatedTexture) FrameSize(i int) geom.PointF32 { return t.frames[i].Size() }

func (t AnimatedTexture) Frames() int { return len(t.frames) }

func (t AnimatedTexture) Scale(scale float32) AnimatedTexture {
	return FitAnimatedTexture(t.texture, scale, t.Frames())
}

func FindScaleRound(length, desired float32) float32 {
	return ScaleRound(length, desired/length)
}

func ScaleRound(length, scale float32) float32 {
	return geom.Round32(length*scale) / length
}