65 lines
1.4 KiB
Go
65 lines
1.4 KiB
Go
package systems
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import (
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. "openquell/components"
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"github.com/hajimehoshi/ebiten/v2"
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"github.com/mlange-42/arche/ecs"
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"github.com/mlange-42/arche/generic"
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)
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type ParticleSystem struct {
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World *ecs.World
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Selector *generic.Filter2[Position, Particle]
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Cellsize int
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}
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func NewParticleSystem(world *ecs.World, cellsize int) *ParticleSystem {
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system := &ParticleSystem{
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Selector: generic.NewFilter2[Position, Particle](),
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World: world,
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Cellsize: cellsize,
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}
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return system
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}
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func (system *ParticleSystem) Update() {
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// display debris after collecting
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EntitiesToRemove := []ecs.Entity{}
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query := system.Selector.Query(system.World)
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for query.Next() {
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// we loop, but it's only one anyway
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_, particle := query.Get()
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switch {
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// particle shows from earlier tick, animate
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case particle.Index > -1 && particle.Index < len(particle.Particles)-1:
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particle.Index++
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default:
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// last sprite reached, remove it
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EntitiesToRemove = append(EntitiesToRemove, query.Entity())
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}
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}
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for _, entity := range EntitiesToRemove {
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system.World.RemoveEntity(entity)
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}
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}
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func (system *ParticleSystem) Draw(screen *ebiten.Image) {
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// write particles (these are no tiles!)
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op := &ebiten.DrawImageOptions{}
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query := system.Selector.Query(system.World)
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for query.Next() {
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pos, particle := query.Get()
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op.GeoM.Reset()
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op.GeoM.Translate(float64(pos.X), float64(pos.Y))
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screen.DrawImage(particle.Particles[particle.Index], op)
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}
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}
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