/*
HelperPlace puts an entity on to the map at a particular position
*/
func HelperPlace(db *engine.EntityDB, eid engine.Entity, r engine.Entity, x, y, z int64) {
if !db.Has(r, "map") {
return
}
db.Get(r, "map").(*EntityMap).Set(x, y, z, eid)
pos := db.Create(eid, "position").(*Position)
pos.R, pos.X, pos.Y, pos.Z = r, x, y, z
}
/*
CreateMap creates a new map region entity and returns it
*/
func CreateMap(db *engine.EntityDB) engine.Entity {
retval := db.New("map")
// Register a chunk generator on the map
emap := db.Get(retval, "map").(*base.EntityMap)
emap.RegisterChunkGenerator(NewStoneFieldGenerator(db, .05))
return retval
}
/*
HelperMove validates an entity's attempt to move and sets the entity's
movement component appropriately. Returns true if the entity could move
*/
func HelperMove(db *engine.EntityDB, eid engine.Entity, dx, dy, dz int64) bool {
if !db.Has(eid, "movement", "position") {
return false
}
pos := db.Get(eid, "position").(*Position)
emap := db.Get(pos.R, "map").(*EntityMap)
mov := db.Get(eid, "movement").(*Movement)
// TODO: fix layer system and make it real.
// Check the entities in the layer beneath the move target
// to see if the entity is a wall (with art symbol '#')
target := emap.Get(pos.X+dx, pos.Y+dy, pos.Z+dz-1)
if db.Has(target, "art") && db.Get(target, "art").(*Art).Symbol == '#' {
mov.Dx = 0
mov.Dy = 0
mov.Dz = 0
return false
}
// Move can be done!
mov.Dx = dx
mov.Dy = dy
mov.Dz = dz
return true
}
func (ai *FollowAI) Act(db *engine.EntityDB, eid engine.Entity) {
epos := db.Get(eid, "position").(*base.Position)
tpos := db.Get(ai.Target, "position").(*base.Position)
dx, dy := int64(0), int64(0)
if epos.X > tpos.X+1 || epos.X < tpos.X-1 {
dx = int64(math.Copysign(1, float64(tpos.X-epos.X)))
}
if epos.Y > tpos.Y+1 || epos.Y < tpos.Y-1 {
dy = int64(math.Copysign(1, float64(tpos.Y-epos.Y)))
}
// Since the bat is situated at z-level 2, it will never find
// a wall with art symbol '#' at one level below, so this move
// function still allows the bat to fly over stones! ^_^
// Hence the "+1" for the z; so the bat stays one level above
// the player.
base.HelperMove(db, eid, dx, dy, tpos.Z-epos.Z+1)
}
/*
SystemMove applies makes every entity with movement try to move in the map
*/
func SystemMove(db *engine.EntityDB) {
for _, eid := range db.Search("movement", "position") {
pos := db.Get(eid, "position").(*Position)
mov := db.Get(eid, "movement").(*Movement)
emap := db.Get(pos.R, "map").(*EntityMap)
// Prevent entities from moving on top of each other, temporarily
if emap.Get(pos.X+mov.Dx, pos.Y+mov.Dy, pos.Z+mov.Dz) != 0 {
continue
}
// Move and update the map
emap.Set(pos.X, pos.Y, pos.Z, 0)
pos.X += mov.Dx
pos.Y += mov.Dy
pos.Z += mov.Dz
emap.Set(pos.X, pos.Y, pos.Z, eid)
}
}
/*
RenderMapAt draws a portion of the map centered at the given entity
*/
func RenderMapAt(db *engine.EntityDB, eid engine.Entity) {
width, height := termbox.Size()
pos := db.Get(eid, "position").(*base.Position)
emap := db.Get(pos.R, "map").(*base.EntityMap)
for y := 0; y < height; y++ {
py := pos.Y + int64(y-height/2)
for x := 0; x < width; x++ {
px := pos.X + int64(x-width/2)
// Search for the highest entity on the map in the same general layer
// as the passed entity that can be drawn. This will need to be more
// formal in the future (not hardcoded knowing the player is on z level
// 1, tiles are on z level 0, and the bat at z level 2)
topArt := &base.Art{}
for i := int64(1); i >= -1; i-- {
entity := emap.Get(px, py, pos.Z+i)
if db.Has(entity, "art") {
topArt = db.Get(entity, "art").(*base.Art)
break
}
}
// And draw the found art, which will be an empty black square
// if nothing was found
Draw(x, height-1-y, topArt.Symbol, topArt.Fg, topArt.Bg)
}
}
termbox.Flush()
}
/*
SystemAct allows each entity with an AI to attempt to act
*/
func SystemAct(db *engine.EntityDB) {
for _, eid := range db.Search("ai", "position") {
ai := db.Get(eid, "ai").(*AI)
ai.Controller.Act(db, eid)
}
}