examples/airship: Refactoring

This commit is contained in:
Hajime Hoshi 2017-06-04 19:31:00 +09:00
parent 5cc7c68698
commit fadbf01826

View File

@ -171,9 +171,9 @@ func updateGroundImage(ground *ebiten.Image) {
ground.DrawImage(repeatedGophersImage, op)
}
func scaleForLine(h int, x int) float64 {
x = h - x
return 200*((-float64(x)+50)/(float64(x)+50)+1) - 200*((-float64(h)+50)/(float64(h)+50)+1)
func scaleForLine(x int) float64 {
// This is an very rough approximate calculation.
return math.Pow(float64(x), 1.2)
}
func drawGroundImage(screen *ebiten.Image, ground *ebiten.Image) {
@ -186,10 +186,9 @@ func drawGroundImage(screen *ebiten.Image, ground *ebiten.Image) {
op := &ebiten.DrawImageOptions{}
for i := 0; i < h; i++ {
op.GeoM.Reset()
r := scaleForLine(h, i)
j1 := scaleForLine(h, i)
j2 := scaleForLine(h, i+1)
dx0, dy0, dx1, dy1 := -int(r), int(j1), w+int(r), int(math.Ceil(j2))
x := scaleForLine(i)
j := scaleForLine(i)
dx0, dy0, dx1, dy1 := -x, j, float64(w)+x, j+4
sw := float64(dx1-dx0) / float64(w)
sh := float64(dy1 - dy0)
op.GeoM.Scale(sw, sh)