Bullet hell video game
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

169 lines
4.6 KiB

package system
import (
"image"
"image/color"
"code.rocketnine.space/tslocum/brownboxbatman/component"
. "code.rocketnine.space/tslocum/brownboxbatman/ecs"
"code.rocketnine.space/tslocum/brownboxbatman/world"
"code.rocketnine.space/tslocum/gohan"
"github.com/hajimehoshi/ebiten/v2"
)
const rewindThreshold = 1
type MovementSystem struct {
ScreenW, ScreenH float64
}
func NewMovementSystem() *MovementSystem {
s := &MovementSystem{
ScreenW: 640,
ScreenH: 480,
}
return s
}
func drawDebugRect(r image.Rectangle, c color.Color, overrideColorScale bool) gohan.Entity {
rectEntity := ECS.NewEntity()
rectImg := ebiten.NewImage(r.Dx(), r.Dy())
rectImg.Fill(c)
ECS.AddComponent(rectEntity, &component.PositionComponent{
X: float64(r.Min.X),
Y: float64(r.Min.Y),
})
ECS.AddComponent(rectEntity, &component.SpriteComponent{
Image: rectImg,
OverrideColorScale: overrideColorScale,
})
return rectEntity
}
func (_ *MovementSystem) Needs() []gohan.ComponentID {
return []gohan.ComponentID{
component.PositionComponentID,
component.VelocityComponentID,
}
}
func (_ *MovementSystem) Uses() []gohan.ComponentID {
return []gohan.ComponentID{
component.WeaponComponentID,
}
}
func (s *MovementSystem) Update(ctx *gohan.Context) error {
if world.World.MessageVisible {
return nil
}
if world.World.GameOver && ctx.Entity == world.World.Player {
return nil
}
position := component.Position(ctx)
velocity := component.Velocity(ctx)
vx, vy := velocity.X, velocity.Y
if ctx.Entity == world.World.Player && (world.World.NoClip || world.World.Debug != 0) && ebiten.IsKeyPressed(ebiten.KeyShift) {
vx, vy = vx*2, vy*2
}
position.X, position.Y = position.X+vx, position.Y+vy
// Force player to remain within the screen bounds.
if ctx.Entity == world.World.Player {
screenX, screenY := s.levelCoordinatesToScreen(position.X, position.Y)
if screenX < 0 {
diff := screenX / world.World.CamScale
position.X -= diff
} else if screenX > float64(world.World.ScreenW)-world.World.PlayerWidth {
diff := (float64(world.World.ScreenW) - world.World.PlayerWidth - screenX) / world.World.CamScale
position.X += diff
}
if screenY < 0 {
diff := screenY / world.World.CamScale
position.Y -= diff
} else if screenY > float64(world.World.ScreenH)-world.World.PlayerHeight {
diff := (float64(world.World.ScreenH) - world.World.PlayerHeight - screenY) / world.World.CamScale
position.Y += diff
}
world.World.PlayerX, world.World.PlayerY = position.X, position.Y
playerRect := image.Rect(int(position.X), int(position.Y), int(position.X+world.World.PlayerWidth), int(position.Y+world.World.PlayerHeight))
for _, r := range world.World.HazardRects {
if playerRect.Overlaps(r) {
world.World.SetGameOver(0, 0)
return nil
}
}
} else if ctx.Entity == world.World.BrokenPieceA || ctx.Entity == world.World.BrokenPieceB {
sprite := ECS.Component(ctx.Entity, component.SpriteComponentID).(*component.SpriteComponent)
if ctx.Entity == world.World.BrokenPieceA {
sprite.Angle -= 0.05
} else {
sprite.Angle += 0.05
}
}
// Check creepBullet collision.
if world.World.NoClip {
return nil
}
bulletSize := 8.0
bulletRect := image.Rect(int(position.X), int(position.Y), int(position.X+bulletSize), int(position.Y+bulletSize))
creepBullet := ECS.Component(ctx.Entity, component.CreepBulletComponentID)
playerBullet := ECS.Component(ctx.Entity, component.PlayerBulletComponentID)
// Check hazard collisions.
if creepBullet != nil || playerBullet != nil {
for _, hazardRect := range world.World.HazardRects {
if bulletRect.Overlaps(hazardRect) {
ctx.RemoveEntity()
return nil
}
}
}
if creepBullet != nil {
playerRect := image.Rect(int(world.World.PlayerX), int(world.World.PlayerY), int(world.World.PlayerX+world.World.PlayerWidth), int(world.World.PlayerY+world.World.PlayerHeight))
if bulletRect.Overlaps(playerRect) {
world.World.SetGameOver(velocity.X, velocity.Y)
return nil
}
return nil
}
if playerBullet != nil {
for i, creepRect := range world.World.CreepRects {
if bulletRect.Overlaps(creepRect) {
creep := ECS.Component(world.World.CreepEntities[i], component.CreepComponentID).(*component.CreepComponent)
if creep.Active {
creep.Health--
creep.DamageTicks = 144 / 2
ctx.RemoveEntity()
return nil
}
}
}
}
return nil
}
func (s *MovementSystem) levelCoordinatesToScreen(x, y float64) (float64, float64) {
return (x - world.World.CamX) * world.World.CamScale, (y - world.World.CamY) * world.World.CamScale
}
func (_ *MovementSystem) Draw(_ *gohan.Context, screen *ebiten.Image) error {
return gohan.ErrSystemWithoutDraw
}