91 lines
2.3 KiB
Go
91 lines
2.3 KiB
Go
package system
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import (
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"math"
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"time"
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"code.rocketnine.space/tslocum/monovania/entity"
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"code.rocketnine.space/tslocum/gohan"
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"code.rocketnine.space/tslocum/monovania/component"
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"github.com/hajimehoshi/ebiten/v2"
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)
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func angle(x1, y1, x2, y2 float64) float64 {
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return math.Atan2(y1-y2, x1-x2)
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}
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type fireWeaponSystem struct {
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player gohan.Entity
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}
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func NewFireWeaponSystem(player gohan.Entity) *fireWeaponSystem {
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return &fireWeaponSystem{
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player: player,
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}
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}
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func (_ *fireWeaponSystem) Matches(e gohan.Entity) bool {
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weapon := component.Weapon(e)
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return weapon != nil
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}
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func (s *fireWeaponSystem) fire(weapon *component.WeaponComponent, position *component.PositionComponent, fireAngle float64) {
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if time.Since(weapon.LastFire) < weapon.FireRate {
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return
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}
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weapon.Ammo--
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weapon.LastFire = time.Now()
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speedX := math.Cos(fireAngle) * -weapon.BulletSpeed
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speedY := math.Sin(fireAngle) * -weapon.BulletSpeed
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bullet := entity.NewBullet(position.X, position.Y, speedX, speedY)
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_ = bullet
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}
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func (s *fireWeaponSystem) Update(_ gohan.Entity) error {
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return nil // TODO
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weapon := component.Weapon(s.player)
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if weapon.Ammo <= 0 {
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return nil
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}
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position := component.Position(s.player)
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if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
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cursorX, cursorY := ebiten.CursorPosition()
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fireAngle := angle(position.X, position.Y, float64(cursorX), float64(cursorY))
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s.fire(weapon, position, fireAngle)
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}
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switch {
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case ebiten.IsKeyPressed(ebiten.KeyLeft) && ebiten.IsKeyPressed(ebiten.KeyUp):
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s.fire(weapon, position, math.Pi/4)
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case ebiten.IsKeyPressed(ebiten.KeyLeft) && ebiten.IsKeyPressed(ebiten.KeyDown):
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s.fire(weapon, position, -math.Pi/4)
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case ebiten.IsKeyPressed(ebiten.KeyRight) && ebiten.IsKeyPressed(ebiten.KeyUp):
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s.fire(weapon, position, math.Pi*.75)
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case ebiten.IsKeyPressed(ebiten.KeyRight) && ebiten.IsKeyPressed(ebiten.KeyDown):
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s.fire(weapon, position, -math.Pi*.75)
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case ebiten.IsKeyPressed(ebiten.KeyLeft):
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s.fire(weapon, position, 0)
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case ebiten.IsKeyPressed(ebiten.KeyRight):
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s.fire(weapon, position, math.Pi)
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case ebiten.IsKeyPressed(ebiten.KeyUp):
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s.fire(weapon, position, math.Pi/2)
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case ebiten.IsKeyPressed(ebiten.KeyDown):
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s.fire(weapon, position, -math.Pi/2)
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}
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return nil
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}
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func (_ *fireWeaponSystem) Draw(_ gohan.Entity, _ *ebiten.Image) error {
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return gohan.ErrSystemWithoutDraw
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}
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