grid raycast algorithm

systems/grid.gd

@@ -120,16 +120,46 @@ func get_empty_stoppable(rule: Callable, unit: Unit, rays: int = 8) -> Array[int
 func raycast_unit(from: Vector2,direction: Vector2,distance: float = -1) -> Unit:
 	if not direction.is_normalized():
 		direction = direction.normalized()
-	var result = null
+	var result: Unit = null
 	
-	var to: Vector2 = from + direction * rows * columns
-	var dv: Vector2 = to.floor() - from.floor()
-	var step = abs(dv.x) + 1 if abs(dv.x) > abs(dv.y) else abs(dv.y) + 1
-	var check_pos = from
+	# Simple algorithm
+	var step: float = max(abs(direction.x),abs(direction.y))
+	var step_v: Vector2 = Vector2(direction.x/step,direction.y/step)
 	
-	while is_position_valid(check_pos) and distance != 0:
-		check_pos += dv/step
-		distance -= 1
+	var check_position: Vector2 = from + step_v * cell_size
+	while is_position_valid(check_position) and distance != 0:
+		var index: int = to_index(check_position)
+		if index == -1:
+			break
+		
+		if grid[index] != null:
+			result = grid[index]
+			break
+		
+		check_position += step_v * cell_size
+	
+	return result
+
+## Casts a ray along [code]direction[/code] from [code]from[/code] to find all units along the line. If distance is given, restricts lookup to [code]distance[/code] cells.
+func raycast_units(from: Vector2,direction: Vector2,distance: float = -1) -> Array[Unit]:
+	if not direction.is_normalized():
+		direction = direction.normalized()
+	var result: Array[Unit] = []
+	
+	# Simple algorithm
+	var step: float = max(abs(direction.x),abs(direction.y))
+	var step_v: Vector2 = Vector2(direction.x/step,direction.y/step)
+	
+	var check_position: Vector2 = from + step_v * cell_size
+	while is_position_valid(check_position) and distance != 0:
+		var index: int = to_index(check_position)
+		if index == -1:
+			break
+		
+		if grid[index] != null:
+			result.append(grid[index])
+		
+		check_position += step_v * cell_size
 	
 	return result
 
@@ -139,31 +169,19 @@ func raycast_empty(from: Vector2,direction: Vector2,distance: float = -1) -> Arr
 		direction = direction.normalized()
 	var result: Array[int] = []
 	
-	var dv: Vector2 = (Vector2.ONE/direction).round()
-	var steps_y: int = int(abs(dv.y))
-	var steps_x: int = int(abs(dv.x))
-	var check_pos = from.floor()
-	var change_y: bool = true if abs(dv.y) > abs(dv.x) else false
+	# Simple algorithm
+	var step: float = max(abs(direction.x),abs(direction.y))
+	var step_v: Vector2 = Vector2(direction.x/step,direction.y/step)
 	
-	while is_position_valid(check_pos) and distance != 0:
-		if steps_x == 0:
-			steps_x = int(abs(dv.x))
-			change_y = true
-		elif steps_y == 0:
-			steps_y = int(abs(dv.y))
-			change_y = false
-		
-		if change_y:
-			check_pos += Vector2(0,sign(dv.y)) * cell_size
-			steps_y-=1
-		else:
-			check_pos += Vector2(sign(dv.x),0) * cell_size
-			steps_x -= 1
-		
-		var index = to_index(check_pos)
+	var check_position: Vector2 = from + step_v * cell_size
+	while is_position_valid(check_position) and distance != 0:
+		var index: int = to_index(check_position)
 		if index == -1:
 			break
+		
 		if grid[index] == null:
 			result.append(index)
+		
+		check_position += step_v * cell_size
 	
 	return result