command an entity to move

entity.odin

@@ -1,15 +1,24 @@
 package main
 
+import "core:math"
 import rl "vendor:raylib"
 
 Entity :: distinct u32
 
 Entity_World :: struct {
-	count:       int,
-	active:      [MAX_ENTITIES]bool,
-	position:    [MAX_ENTITIES]Tile_Coord,
-	color:       [MAX_ENTITIES]rl.Color,
-	is_colonist: [MAX_ENTITIES]bool,
+	count:           int,
+	active:          [MAX_ENTITIES]bool,
+	position:        [MAX_ENTITIES]Tile_Coord,
+	color:           [MAX_ENTITIES]rl.Color,
+	is_colonist:     [MAX_ENTITIES]bool,
+	move_state:      [MAX_ENTITIES]Move_State,
+	move_target:     [MAX_ENTITIES]Tile_Coord,
+	visual_position: [MAX_ENTITIES]rl.Vector2,
+}
+
+Move_State :: enum {
+	Idle,
+	Moving,
 }
 
 entity_world_init :: proc() -> Entity_World {
@@ -24,6 +33,8 @@ entity_spawn_colonist :: proc(ew: ^Entity_World, pos: Tile_Coord) -> Entity {
 			ew.color[i] = {80, 140, 220, 225}
 			ew.is_colonist[i] = true
 			ew.count += 1
+			ew.visual_position[i] = tile_center_world(pos)
+			ew.move_state[i] = .Idle
 			return Entity(u32(i + 1))
 		}
 	}
@@ -41,10 +52,8 @@ entity_draw :: proc(ew: ^Entity_World, camera: ^Camera2D) {
 			continue
 		}
 
-		pos := ew.position[i]
-		wx := f32(pos.x * TILE_SIZE) + f32(TILE_SIZE) * 0.5
-		wy := f32(pos.y * TILE_SIZE) + f32(TILE_SIZE) * 0.5
-		sx, sy := world_to_screen(camera, wx, wy)
+		vp := ew.visual_position[i]
+		sx, sy := world_to_screen(camera, vp.x, vp.y)
 		radius := f32(TILE_SIZE) * 0.3 * camera.zoom
 
 		rl.DrawCircle(i32(sx), i32(sy), radius, ew.color[i])
@@ -52,3 +61,69 @@ entity_draw :: proc(ew: ^Entity_World, camera: ^Camera2D) {
 	}
 }
 
+tile_center_world :: proc(t: Tile_Coord) -> rl.Vector2 {
+	return rl.Vector2 {
+		f32(t.x * TILE_SIZE) + f32(TILE_SIZE) * 0.5,
+		f32(t.y * TILE_SIZE) + f32(TILE_SIZE) * 0.5,
+	}
+}
+
+entity_set_move_target :: proc(ew: ^Entity_World, e: Entity, target: Tile_Coord) -> bool {
+	i := entity_index(e)
+	if i < 0 || !ew.active[i] {return false}
+
+	if ew.position[i] == target {
+		ew.move_state[i] = .Idle
+		return true
+	}
+
+	ew.move_target[i] = target
+	ew.move_state[i] = .Moving
+	return true
+}
+
+entity_update_movement :: proc(ew: ^Entity_World, dt: f32) {
+	speed := f32(TILE_SIZE) * MOVE_SPEED
+
+	for i in 0 ..< MAX_ENTITIES {
+		if !ew.active[i] || ew.move_state[i] != .Moving {
+			continue
+		}
+
+		pos := ew.position[i]
+		target := ew.move_target[i]
+		if pos == target {
+			ew.move_state[i] = .Idle
+			continue
+		}
+
+		next := pos
+		if pos.x != target.x {
+			next.x += pos.x < target.x ? 1 : -1
+		} else if pos.y != target.y {
+			next.y += pos.y < target.y ? 1 : -1
+		}
+
+		goal := tile_center_world(next)
+		vp := ew.visual_position[i]
+
+		dx := goal.x - vp.x
+		dy := goal.y - vp.y
+		dist := math.sqrt(dx * dx + dy * dy)
+
+		if dist < 1.0 {
+			ew.position[i] = next
+			ew.visual_position[i] = goal
+		} else {
+			step := speed * dt
+			if step >= dist {
+				ew.visual_position[i] = goal
+				ew.position[i] = next
+			} else {
+				ew.visual_position[i].x += dx / dist * step
+				ew.visual_position[i].y += dy / dist * step
+			}
+		}
+	}
+}
+