Add option to consider exact positions in RopeAnchor and RopeHandle

Author: mphe

demo/addons/ropesim/Rope.gd

@@ -167,7 +167,6 @@ func update_segments():
 
 # Access
 
-
 func get_num_points() -> int:
     return _points.size()
 
@@ -180,6 +179,16 @@ func get_point_perc(index: int) -> float:
     return index / float(_points.size() - 1) if _points.size() > 0 else 0.0
 
 
+func get_point_interpolate(position_perc: float) -> Vector2:
+    var idx := get_point_index(position_perc)
+    if idx == _points.size() - 1:
+        return _points[idx]
+    var next := idx + 1
+    var next_perc := get_point_perc(next)
+    var perc := get_point_perc(idx)
+    return lerp(_points[idx], _points[next], (position_perc - perc) / (next_perc - perc))
+
+
 func get_nearest_point_index(pos: Vector2) -> int:
     var min_dist = 1e10
     var idx = 0

demo/addons/ropesim/RopeAnchor.gd

@@ -10,6 +10,8 @@ export var enable: bool = true setget set_enable, get_enable  # Enable or disabl
 export(NodePath) var rope_path setget set_rope_path  # Target rope path.
 export(float, 0, 1) var rope_position = 1.0  # Position on the rope between 0 and 1.
 export var apply_angle := false  # Also apply rotation according to the rope curvature.
+## If false, only consider the nearest vertex on the rope. Otherwise, interpolate the position between two relevant points when applicable.
+export var precise: bool = false
 var _helper: RopeToolHelper
 
 
@@ -39,13 +41,18 @@ func set_enable(value: bool):
     enable = value
     _helper.enable = value
 
+
 func get_enable() -> bool:
     return _helper.enable
 
 
 func _update() -> void:
     var rope: Rope = _helper.target_rope
-    global_position = rope.get_point(rope.get_point_index(rope_position))
+
+    if precise:
+        global_position = rope.get_point_interpolate(rope_position)
+    else:
+        global_position = rope.get_point(rope.get_point_index(rope_position))
 
     if apply_angle:
         var a := rope.get_point(rope.get_point_index(rope_position - 0.1))

demo/addons/ropesim/RopeHandle.gd

@@ -10,6 +10,8 @@ export(NodePath) var rope_path setget set_rope_path  # Target rope path
 export(float, 0, 1) var rope_position = 1.0  # Position on the rope between 0 and 1.
 export var smoothing: bool = false  # Whether to smoothly snap to RopeHandle's position instead of instantly.
 export var smoothing_speed: float = 0.5  # Smoothing speed
+## If false, only affect the nearest vertex on the rope. Otherwise, affect both surrounding points when applicable.
+export var precise: bool = false
 var _helper: RopeToolHelper
 
 
@@ -28,12 +30,27 @@ func _on_pre_update() -> void:
     emit_signal("on_before_update")
     var rope: Rope = _helper.target_rope
     var point_index: int = rope.get_point_index(rope_position)
-    var new_pos: Vector2
-    if smoothing:
-        new_pos = rope.get_point(point_index).linear_interpolate(global_position, get_physics_process_delta_time() * smoothing_speed)
+
+    # Only use this method if this is not the last point.
+    if precise and point_index < rope.get_num_points() - 1:
+        # TODO: Consider creating a corresponding function in Rope.gd for universal access, e.g. set_point_interpolated().
+        var point_pos: Vector2 = rope.get_point_interpolate(rope_position)
+        var diff := global_position - point_pos
+        var pos_a: Vector2 = rope.get_point(point_index)
+        var pos_b: Vector2 = rope.get_point(point_index + 1)
+        var new_pos_a: Vector2 = pos_a + diff
+        var new_pos_b: Vector2 = pos_b + diff
+
+        _move_point(point_index, pos_a, new_pos_a)
+        _move_point(point_index + 1, pos_b, new_pos_b)
     else:
-        new_pos = global_position
-    rope.set_point(point_index, new_pos)
+        _move_point(point_index, rope.get_point(point_index), global_position)
+
+
+func _move_point(idx: int, from: Vector2, to: Vector2) -> void:
+    if smoothing:
+        to = from.linear_interpolate(to, get_physics_process_delta_time() * smoothing_speed)
+    _helper.target_rope.set_point(idx, to)
 
 
 func set_rope_path(value: NodePath):