Extended HexGrid to allow getting hex center from offset coordinates.

addons/gdhexgrid/HexGrid.gd

@@ -207,6 +207,12 @@ func get_hex_center(hex):
 	hex = HexCell.new(hex)
 	return hex_transform * hex.axial_coords
 	
+func get_hex_center_from_offset(offset):
+	# Returns hex's centre position at the given offset coordinates
+	var hex = HexCell.new()
+	hex.offset_coords = offset
+	return hex_transform * hex.axial_coords
+	
 func get_hex_at(coords):
 	# Returns a HexCell at the given Vector2/3 on the projection plane
 	# If the given value is a Vector3, its x,z coords will be used

addons/gdhexgrid/HexShape.gd

@@ -0,0 +1,19 @@
+tool
+extends Polygon2D
+
+export(Color) var OutLine = Color(0,0,0) setget set_color
+export(float) var Width = 2.0 setget set_width
+
+func _draw():
+	var poly = get_polygon()
+	for i in range(1 , poly.size()):
+		draw_line(poly[i-1] , poly[i], OutLine , Width)
+	draw_line(poly[poly.size() - 1] , poly[0], OutLine , Width)
+
+func set_color(color):
+	OutLine = color
+	update()
+
+func set_width(new_width):
+	Width = new_width
+	update()

addons/gdhexgrid/HexShape.tscn

@@ -0,0 +1,51 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://HexShape.gd" type="Script" id=1]
+
+[node name="Highlight" type="Polygon2D"]
+color = Color( 1, 1, 1, 0 )
+polygon = PoolVector2Array( -12.5, 21.6506, 12.5, 21.6506, 25, 0, 12.5, -21.6506, -12.5, -21.6506, -25, 0 )
+script = ExtResource( 1 )
+OutLine = Color( 1, 1, 1, 0.133333 )
+
+[node name="Label" type="Label" parent="."]
+visible = false
+margin_left = 5.0
+margin_top = -39.0
+margin_right = 52.0
+margin_bottom = -25.0
+text = "SCREEN"
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="AreaCoords" type="Label" parent="."]
+visible = false
+margin_left = 55.0
+margin_top = -39.0
+margin_right = 105.0
+margin_bottom = -25.0
+text = "SCREEN"
+
+[node name="Label2" type="Label" parent="."]
+visible = false
+margin_left = 25.0
+margin_top = -19.0
+margin_right = 56.0
+margin_bottom = -5.0
+text = "HEX"
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="HexCoords" type="Label" parent="."]
+margin_left = -26.0
+margin_top = -8.0
+margin_right = 24.0
+margin_bottom = 6.0
+text = "HEX"
+align = 1
+valign = 1
+__meta__ = {
+"_edit_use_anchors_": false
+}

addons/gdhexgrid/demo_2d.gd

@@ -2,15 +2,55 @@
 extends Node2D
 
 var HexGrid = preload("./HexGrid.gd").new()
+var HexShape = preload("./HexShape.tscn")
 
 onready var highlight = get_node("Highlight")
 onready var area_coords = get_node("Highlight/AreaCoords")
 onready var hex_coords = get_node("Highlight/HexCoords")
 
+var rect_min = Vector2(-200, 50)
+var rect_max = Vector2(400, 200)
+
+var drag_start = null
 
 func _ready():
 	HexGrid.hex_scale = Vector2(50, 50)
 
+func _draw():
+	var hex_cell_bb_min = HexGrid.get_hex_at(rect_min).offset_coords
+	var hex_cell_bb_max = HexGrid.get_hex_at(rect_max).offset_coords
+	
+	var hex_cell_offset_min = Vector2(
+		min(hex_cell_bb_min.x, hex_cell_bb_max.x), 
+		min(hex_cell_bb_min.y, hex_cell_bb_max.y)
+		)
+		
+	var hex_cell_offset_max = Vector2(
+		max(hex_cell_bb_min.x, hex_cell_bb_max.x), 
+		max(hex_cell_bb_min.y, hex_cell_bb_max.y)
+		)		
+	
+	var rect_highlights = get_node ("rect_highlights")
+	if rect_highlights:
+		remove_child(rect_highlights)
+		rect_highlights.queue_free()
+	
+	rect_highlights = Node2D.new()
+	rect_highlights.name = "rect_highlights"
+	add_child(rect_highlights)
+	
+	for xi in range (hex_cell_offset_min.x, hex_cell_offset_max.x + 1):
+		for yi in range (hex_cell_offset_min.y, hex_cell_offset_max.y + 1):
+			var offset_coords = Vector2(xi, yi)
+			var hex_shape = HexShape.instance()
+			hex_shape.position = HexGrid.get_hex_center_from_offset(offset_coords)
+			var hex_shape_coords = hex_shape.get_node("HexCoords")
+			hex_shape_coords.text = str(offset_coords)
+			rect_highlights.add_child (hex_shape)
+		
+	var rect = Rect2(rect_min, rect_max - rect_min)
+	draw_rect (rect, Color("55FFFFFF"))
+
 
 func _unhandled_input(event):
 	if 'position' in event:
@@ -24,3 +64,15 @@ func _unhandled_input(event):
 		# Snap the highlight to the nearest grid cell
 		if highlight != null:
 			highlight.position = HexGrid.get_hex_center(HexGrid.get_hex_at(relative_pos))
+			
+		if event is InputEventMouseButton:
+			if event.button_index == BUTTON_LEFT:
+				if event.pressed:
+					drag_start = relative_pos
+				else:
+					drag_start = null
+
+		if drag_start != null:
+			rect_min = Vector2(min(drag_start.x, relative_pos.x), min(drag_start.y, relative_pos.y))
+			rect_max = Vector2(max(drag_start.x, relative_pos.x), max(drag_start.y, relative_pos.y))
+			update()