1
1
mirror of https://github.com/OpenDiablo2/OpenDiablo2 synced 2025-02-10 02:26:29 -05:00
OpenDiablo2/d2core/d2systems/movement.go
gravestench caafe7592c more work on ecs impl
* added command line arg for launching ecs impl
* removed render system tests, was causing gl context issues in tests
* fixed all lint errors in d2systems
2020-12-07 12:44:11 -08:00

82 lines
2.0 KiB
Go

package d2systems
import (
"time"
"github.com/OpenDiablo2/OpenDiablo2/d2common/d2util"
"github.com/gravestench/akara"
"github.com/OpenDiablo2/OpenDiablo2/d2core/d2components"
)
const (
logPrefixMovementSystem = "Movement System"
)
// NewMovementSystem creates a movement system
func NewMovementSystem() *MovementSystem {
cfg := akara.NewFilter().Require(d2components.Position, d2components.Velocity)
filter := cfg.Build()
sys := &MovementSystem{
BaseSubscriberSystem: akara.NewBaseSubscriberSystem(filter),
Logger: d2util.NewLogger(),
}
sys.SetPrefix(logPrefixMovementSystem)
return sys
}
// static check that MovementSystem implements the System interface
var _ akara.System = &MovementSystem{}
// MovementSystem handles entity movement based on velocity and position components
type MovementSystem struct {
*akara.BaseSubscriberSystem
*d2util.Logger
*d2components.PositionMap
*d2components.VelocityMap
}
// Init initializes the system with the given world
func (m *MovementSystem) Init(_ *akara.World) {
m.Info("initializing ...")
// try to inject the components we require, then cast the returned
// abstract ComponentMap back to the concrete implementation
m.PositionMap = m.InjectMap(d2components.Position).(*d2components.PositionMap)
m.VelocityMap = m.InjectMap(d2components.Velocity).(*d2components.VelocityMap)
}
// Update positions of all entities with their velocities
func (m *MovementSystem) Update() {
for subIdx := range m.Subscriptions {
entities := m.Subscriptions[subIdx].GetEntities()
m.Infof("Processing movement for %d entities ...", len(entities))
for entIdx := range entities {
m.ProcessEntity(entities[entIdx])
}
}
}
// ProcessEntity updates an individual entity in the movement system
func (m *MovementSystem) ProcessEntity(id akara.EID) {
position, found := m.GetPosition(id)
if !found {
return
}
velocity, found := m.GetVelocity(id)
if !found {
return
}
s := float64(m.World.TimeDelta) / float64(time.Second)
position.Vector = *position.Vector.Add(velocity.Vector.Clone().Scale(s))
}