Bring in scroll damper

addons/SmoothScroll/plugin.cfg

@@ -4,5 +4,5 @@ name="SmoothScroll"
 description="""This plugin adds a new scroll container class
 with additional smooth scroll options."""
 author="Fabian Keßler (SpyrexDE)"
-version="1.2"
+version="1.3"
 script="plugin.gd"

addons/SmoothScroll/scroll_damper/cubic_scroll_damper.gd

@@ -0,0 +1,33 @@
+extends ScrollDamper
+class_name CubicScrollDamper
+
+
+## Friction, not physical. 
+## The higher the value, the more obvious the deceleration. 
+@export_range(0.001, 10000.0, 0.001, "or_greater", "hide_slider")
+var friction := 4.0:
+	set(val):
+		friction = max(val, 0.001)
+		_factor = pow(10.0, friction) - 1.0
+
+## Factor to use in formula
+var _factor := 10000.0:
+	set(val): _factor = max(val, 0.000000000001)
+
+
+func _calculate_velocity_by_time(time: float) -> float:
+	if time <= 0.0: return 0.0
+	return time*time*time * _factor
+
+
+func _calculate_time_by_velocity(velocity: float) -> float:
+	return pow(abs(velocity) / _factor, 1.0/3.0)
+
+
+func _calculate_offset_by_time(time: float) -> float:
+	time = max(time, 0.0)
+	return 1.0/4.0 * _factor * time*time*time*time
+
+
+func _calculate_time_by_offset(offset: float) -> float:
+	return pow(abs(offset) * 4.0 / _factor, 1.0/4.0)

addons/SmoothScroll/scroll_damper/expo_scroll_damper.gd

@@ -0,0 +1,47 @@
+extends ScrollDamper
+class_name ExpoScrollDamper
+
+
+## Friction, not physical. 
+## The higher the value, the more obvious the deceleration. 
+@export_range(0.001, 10000.0, 0.001, "or_greater", "hide_slider")
+var friction := 4.0:
+	set(val):
+		friction = max(val, 0.001)
+		_factor = pow(10.0, friction)
+
+## Factor to use in formula
+var _factor := 10000.0:
+	set(val): _factor = max(val, 1.000000000001)
+
+## Minumun velocity.
+@export_range(0.001, 100000.0, 0.001, "or_greater", "hide_slider")
+var minimum_velocity := 0.4:
+	set(val): minimum_velocity = max(val, 0.001)
+
+
+func _calculate_velocity_by_time(time: float) -> float:
+	var minimum_time = _calculate_time_by_velocity(minimum_velocity)
+	if time <= minimum_time: return 0.0
+	return pow(_factor, time)
+
+
+func _calculate_time_by_velocity(velocity: float) -> float:
+	return log(abs(velocity)) / log(_factor)
+
+
+func _calculate_offset_by_time(time: float) -> float:
+	return pow(_factor, time) / log(_factor)
+
+
+func _calculate_time_by_offset(offset: float) -> float:
+	return log(offset * log(_factor)) / log(_factor)
+
+
+func _calculate_velocity_to_dest(from: float, to: float) -> float:
+	var dist = to - from
+	var min_time = _calculate_time_by_velocity(minimum_velocity)
+	var min_offset = _calculate_offset_by_time(min_time)
+	var time = _calculate_time_by_offset(abs(dist) + min_offset)
+	var vel = _calculate_velocity_by_time(time) * sign(dist)
+	return vel

addons/SmoothScroll/scroll_damper/icon.svg.import

@@ -0,0 +1,37 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://4ok12qtgl7xq"
+path="res://.godot/imported/icon.svg-ab15342a73e61a79c8b3960fca89a8c3.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://addons/SmoothScroll/scroll_damper/icon.svg"
+dest_files=["res://.godot/imported/icon.svg-ab15342a73e61a79c8b3960fca89a8c3.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
+svg/scale=1.0
+editor/scale_with_editor_scale=false
+editor/convert_colors_with_editor_theme=false

addons/SmoothScroll/scroll_damper/linear_scroll_damper.gd

@@ -0,0 +1,33 @@
+extends ScrollDamper
+class_name LinearScrollDamper
+
+
+## Friction, not physical. 
+## The higher the value, the more obvious the deceleration. 
+@export_range(0.001, 10000.0, 0.001, "or_greater", "hide_slider")
+var friction := 4.0:
+	set(val):
+		friction = max(val, 0.001)
+		_factor = pow(10.0, friction) - 1.0
+
+## Factor to use in formula
+var _factor := 10000.0:
+	set(val): _factor = max(val, 0.000000000001)
+
+
+func _calculate_velocity_by_time(time: float) -> float:
+	if time <= 0.0: return 0.0
+	return time * _factor
+
+
+func _calculate_time_by_velocity(velocity: float) -> float:
+	return abs(velocity) / _factor
+
+
+func _calculate_offset_by_time(time: float) -> float:
+	time = max(time, 0.0)
+	return 1.0/2.0 * _factor * time*time
+
+
+func _calculate_time_by_offset(offset: float) -> float:
+	return sqrt(abs(offset) * 2.0 / _factor)

addons/SmoothScroll/scroll_damper/quad_scroll_damper.gd

@@ -0,0 +1,33 @@
+extends ScrollDamper
+class_name QuadScrollDamper
+
+
+## Friction, not physical. 
+## The higher the value, the more obvious the deceleration. 
+@export_range(0.001, 10000.0, 0.001, "or_greater", "hide_slider")
+var friction := 4.0:
+	set(val):
+		friction = max(val, 0.001)
+		_factor = pow(10.0, friction) - 1.0
+
+## Factor to use in formula
+var _factor := 10000.0:
+	set(val): _factor = max(val, 0.000000000001)
+
+
+func _calculate_velocity_by_time(time: float) -> float:
+	if time <= 0.0: return 0.0
+	return time*time * _factor
+
+
+func _calculate_time_by_velocity(velocity: float) -> float:
+	return sqrt(abs(velocity) / _factor)
+
+
+func _calculate_offset_by_time(time: float) -> float:
+	time = max(time, 0.0)
+	return 1.0/3.0 * _factor * time*time*time
+
+
+func _calculate_time_by_offset(offset: float) -> float:
+	return pow(abs(offset) * 3.0 / _factor, 1.0/3.0)

addons/SmoothScroll/scroll_damper/scroll_damper.gd

@@ -0,0 +1,74 @@
+@icon("icon.svg")
+extends Resource
+class_name ScrollDamper
+
+## Abstract class
+
+## Rebound strength. The higher the value, the faster it attracts. 
+@export_range(0.0, 1.0, 0.001, "or_greater", "hide_slider")
+var rebound_strength := 7.0:
+	set(val):
+		rebound_strength= max(val, 0.0)
+		_attract_factor = rebound_strength * rebound_strength * rebound_strength
+
+## Factor for attracting.
+var _attract_factor := 400.0:
+	set(val):
+		_attract_factor = max(val, 0.0)
+
+
+# Abstract method
+func _calculate_velocity_by_time(time: float) -> float:
+	return 0.0
+
+# Abstract method
+func _calculate_time_by_velocity(velocity: float) -> float:
+	return 0.0
+
+# Abstract method
+func _calculate_offset_by_time(time: float) -> float:
+	return 0.0
+
+# Abstract method
+func _calculate_time_by_offset(offset: float) -> float:
+	return 0.0
+
+
+func _calculate_velocity_to_dest(from: float, to: float) -> float:
+	var dist = to - from
+	var time = _calculate_time_by_offset(abs(dist))
+	var vel = _calculate_velocity_by_time(time) * sign(dist)
+	return vel
+
+
+func _calculate_next_velocity(present_time: float, delta_time: float) -> float:
+	return _calculate_velocity_by_time(present_time - delta_time)
+
+
+func _calculate_next_offset(present_time: float, delta_time: float) -> float:
+	return _calculate_offset_by_time(present_time) \
+		 - _calculate_offset_by_time(present_time - delta_time)
+
+
+## Return the result of next velocity and position according to delta time
+func slide(velocity: float, delta_time: float) -> Array:
+	var present_time = _calculate_time_by_velocity(velocity)
+	return [
+		_calculate_next_velocity(present_time, delta_time) * sign(velocity),
+		_calculate_next_offset(present_time, delta_time) * sign(velocity)
+	]
+
+
+## Emulate force that attracts something to destination.
+## Return the result of next velocity according to delta time
+func attract(from: float, to: float, velocity: float, delta_time: float) -> float:
+	var dist = to - from
+	var target_vel = _calculate_velocity_to_dest(from, to)
+	velocity += _attract_factor * dist * delta_time \
+		 + _calculate_velocity_by_time(delta_time) * sign(dist)
+	if (
+		(dist > 0 and velocity >= target_vel) \
+		or (dist < 0 and velocity <= target_vel) \
+	):
+		velocity = target_vel
+	return velocity

example.tscn

@@ -1,6 +1,7 @@
-[gd_scene load_steps=4 format=3 uid="uid://xqy4fhlaf2q3"]
+[gd_scene load_steps=7 format=3 uid="uid://xqy4fhlaf2q3"]
 
 [ext_resource type="Script" path="res://addons/SmoothScroll/SmoothScrollContainer.gd" id="1_su8ig"]
+[ext_resource type="Script" path="res://addons/SmoothScroll/scroll_damper/expo_scroll_damper.gd" id="2_ibjlc"]
 
 [sub_resource type="GDScript" id="GDScript_xo176"]
 script/source = "extends Control
@@ -15,6 +16,18 @@ func _on_h_slider_value_changed(value):
 	$Label.text = \"FPS: \" + str($HSlider.value)
 "
 
+[sub_resource type="Resource" id="Resource_lssh0"]
+script = ExtResource("2_ibjlc")
+friction = 4.0
+minimum_velocity = 0.4
+rebound_strength = 7.0
+
+[sub_resource type="Resource" id="Resource_nvbjt"]
+script = ExtResource("2_ibjlc")
+friction = 4.0
+minimum_velocity = 0.4
+rebound_strength = 7.0
+
 [sub_resource type="GDScript" id="GDScript_xu50n"]
 script/source = "extends RichTextLabel
 
@@ -63,6 +76,8 @@ offset_top = 147.0
 offset_right = 649.0
 offset_bottom = 393.0
 script = ExtResource("1_su8ig")
+wheel_scroll_damper = SubResource("Resource_lssh0")
+dragging_scroll_damper = SubResource("Resource_nvbjt")
 debug_mode = true
 
 [node name="Control" type="Control" parent="SmoothScrollContainer"]