func validPoint(ix, iy int16) bool {
x, y := int(ix), int(iy)
chart1 := image.Pt(x, y)
screen := util.ChartToScreen(chart1)
chart2 := util.ScreenToChart(screen)
// All points within tile rect should fall into chart.
tileOffset := image.Pt(rand.Intn(util.TileW), rand.Intn(util.TileH))
chart3 := util.ScreenToChart(screen.Add(tileOffset))
if chart1 != chart3 {
fmt.Println(tileOffset)
return false
}
return chart1 == chart2
}
// Beam generates a projectile beam effect in the game world.
func (f *Fx) Beam(origin space.Location, dir image.Point, length int, kind BeamKind) {
// Make a footprint for the beam shape.
shape := []image.Point{image.Pt(0, 0)}
for i := 0; i < length; i++ {
shape = append(shape, shape[len(shape)-1].Add(dir))
}
footprint := space.FootprintFromPoints(f.world.Manifold, origin, shape)
screenVec := util.ChartToScreen(shape[len(shape)-1])
// TODO: Different beam types.
f.anim.Add(
anim.Func(func(t int64, offset image.Point) {
gfx.Line(
sdl.Frame(),
offset.Add(util.HalfTile),
offset.Add(util.HalfTile).Add(screenVec),
gfx.LerpCol(gfx.Gold, gfx.Black, float64(t)/float64(.5e9)))
}), footprint, .2e9)
}
func (a *Anim) CollectSpritesAt(
sprites gfx.SpriteBatch,
loc space.Location,
offset image.Point,
layer int) gfx.SpriteBatch {
for _, oe := range a.index.At(loc) {
screenPos := util.ChartToScreen(oe.Offset.Mul(-1)).Add(offset)
animStore := oe.Entity.(animationStore)
// Delete ended animations as we encounter them.
if animStore.IsDead() {
a.index.Remove(oe.Entity)
continue
}
// Create sprites from the current frames of live animations.
sprites = append(
sprites,
gfx.Sprite{layer, screenPos, animStore.CurrentFrame()})
}
return sprites
}