Curve tool implementation (#1019)

* curve tool

* formatting

* formatting

* saving my progress

* update to kirita mode

* Formatting

* fixes for mirror mode

* added way to remove point, added tool shortcut

* Add translation strings

* Use Curve2D instead of a control_points array

---------

Co-authored-by: Emmanouil Papadeas <35376950+OverloadedOrama@users.noreply.github.com>

Translations/Translations.pot

@@ -1275,6 +1275,16 @@ msgid "Line Tool\n\n"
 "Hold %s to displace the shape's origin"
 msgstr ""
 
+msgid "Curve Tool\n\n"
+"%s for left mouse button\n"
+"%s for right mouse button\n\n"
+"Draws bezier curves\n"
+"Press and drag to control the curvature\n"
+"Press and drag to curve them\n"
+"Press %s to remove the last added point"
+msgstr ""
+
+
 msgid "Rectangle Tool\n\n"
 "%s for left mouse button\n"
 "%s for right mouse button\n\n"
@@ -2342,6 +2352,9 @@ msgstr ""
 msgid "Line Tool"
 msgstr ""
 
+msgid "Curve Tool"
+msgstr ""
+
 msgid "Rectangle Tool"
 msgstr ""
 

assets/graphics/tools/cursors/curvetool.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://deuy67ughoib3"
+path="res://.godot/imported/curvetool.png-035b507342a996edf5b660cc7e5f8671.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://assets/graphics/tools/cursors/curvetool.png"
+dest_files=["res://.godot/imported/curvetool.png-035b507342a996edf5b660cc7e5f8671.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

assets/graphics/tools/curvetool.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://br0lilqrvdvdc"
+path="res://.godot/imported/curvetool.png-15311b84332d233b1a0c1817d9a6bd5d.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://assets/graphics/tools/curvetool.png"
+dest_files=["res://.godot/imported/curvetool.png-15311b84332d233b1a0c1817d9a6bd5d.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

project.godot

@@ -865,6 +865,16 @@ go_to_next_layer={
 "events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"command_or_control_autoremap":true,"alt_pressed":false,"shift_pressed":false,"pressed":false,"keycode":0,"physical_keycode":4194320,"key_label":0,"unicode":0,"echo":false,"script":null)
 ]
 }
+left_curvetool_tool={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":74,"physical_keycode":0,"key_label":0,"unicode":106,"echo":false,"script":null)
+]
+}
+right_curvetool_tool={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":true,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":74,"physical_keycode":0,"key_label":0,"unicode":106,"echo":false,"script":null)
+]
+}
 
 [input_devices]
 

src/Autoload/Tools.gd

@@ -151,6 +151,22 @@ Hold %s to displace the shape's origin""",
 			["shape_perfect", "shape_center", "shape_displace"]
 		)
 	),
+	"CurveTool":
+	(
+		Tool
+		. new(
+			"CurveTool",
+			"Curve Tool",
+			"curvetool",
+			"res://src/Tools/DesignTools/CurveTool.tscn",
+			[Global.LayerTypes.PIXEL],
+			"""Draws bezier curves
+Press %s/%s to add new points
+Press and drag to control the curvature
+Press %s to remove the last added point""",
+			["activate_left_tool", "activate_right_tool", "change_tool_mode"]
+		)
+	),
 	"RectangleTool":
 	(
 		Tool

src/Tools/DesignTools/CurveTool.gd

@@ -0,0 +1,234 @@
+extends "res://src/Tools/BaseDraw.gd"
+
+var _curve := Curve2D.new()  ## The [Curve2D] responsible for the shape of the curve being drawn.
+var _drawing := false  ## Set to true when a curve is being drawn.
+var _editing_bezier := false  ## Needed to determine when to show the control points preview line.
+var _thickness := 1  ## The thickness of the curve.
+
+
+func _init() -> void:
+	Global.project_about_to_switch.connect(_draw_shape)  # To prevent tool from remaining active
+	_drawer.color_op = Drawer.ColorOp.new()
+	update_indicator()
+
+
+func update_brush() -> void:
+	pass
+
+
+func _on_Thickness_value_changed(value: int) -> void:
+	_thickness = value
+	update_indicator()
+	update_config()
+	save_config()
+
+
+func update_indicator() -> void:
+	var bitmap := BitMap.new()
+	bitmap.create(Vector2i.ONE * _thickness)
+	bitmap.set_bit_rect(Rect2i(Vector2i.ZERO, Vector2i.ONE * _thickness), true)
+	_indicator = bitmap
+	_polylines = _create_polylines(_indicator)
+
+
+func get_config() -> Dictionary:
+	var config := super.get_config()
+	config["thickness"] = _thickness
+	return config
+
+
+func set_config(config: Dictionary) -> void:
+	super.set_config(config)
+	_thickness = config.get("thickness", _thickness)
+
+
+func update_config() -> void:
+	super.update_config()
+	$ThicknessSlider.value = _thickness
+
+
+func _input(event: InputEvent) -> void:
+	if _drawing:
+		if event is InputEventMouseButton:
+			if event.double_click and event.button_index == tool_slot.button:
+				$DoubleClickTimer.start()
+				_draw_shape()
+		else:
+			if event.is_action_pressed("change_tool_mode"):  # Control removes the last added point
+				if _curve.point_count > 1:
+					_curve.remove_point(_curve.point_count - 1)
+
+
+func draw_start(pos: Vector2i) -> void:
+	if !$DoubleClickTimer.is_stopped():
+		return
+	pos = snap_position(pos)
+	super.draw_start(pos)
+	if Input.is_action_pressed("shape_displace"):
+		_picking_color = true
+		_pick_color(pos)
+		return
+	Global.canvas.selection.transform_content_confirm()
+	update_mask()
+	if !_drawing:
+		_drawing = true
+	_curve.add_point(pos)
+
+
+func draw_move(pos: Vector2i) -> void:
+	pos = snap_position(pos)
+	super.draw_move(pos)
+	if _picking_color:  # Still return even if we released Alt
+		if Input.is_action_pressed("shape_displace"):
+			_pick_color(pos)
+		return
+	if _drawing:
+		_editing_bezier = true
+		var current_position := _curve.get_point_position(_curve.point_count - 1) - Vector2(pos)
+		_curve.set_point_in(_curve.point_count - 1, current_position)
+		_curve.set_point_out(_curve.point_count - 1, -current_position)
+
+
+func draw_end(pos: Vector2i) -> void:
+	_editing_bezier = false
+	super.draw_end(pos)
+
+
+func draw_preview() -> void:
+	if not _drawing:
+		return
+	var canvas: Node2D = Global.canvas.previews
+	var pos := canvas.position
+	var canvas_scale := canvas.scale
+	if Global.mirror_view:  # This fixes previewing in mirror mode
+		pos.x = pos.x + Global.current_project.size.x
+		canvas_scale.x = -1
+
+	var points := _bezier()
+	canvas.draw_set_transform(pos, canvas.rotation, canvas_scale)
+	var indicator := _fill_bitmap_with_points(points, Global.current_project.size)
+
+	for line in _create_polylines(indicator):
+		canvas.draw_polyline(PackedVector2Array(line), Color.BLACK)
+
+	canvas.draw_set_transform(canvas.position, canvas.rotation, canvas.scale)
+
+	if _editing_bezier:
+		var start := _curve.get_point_position(0)
+		if _curve.point_count > 1:
+			start = (
+				_curve.get_point_position(_curve.point_count - 1)
+				+ _curve.get_point_in(_curve.point_count - 1)
+			)
+		var end := (
+			_curve.get_point_position(_curve.point_count - 1)
+			+ _curve.get_point_out(_curve.point_count - 1)
+		)
+		if Global.mirror_view:  # This fixes previewing in mirror mode
+			start.x = Global.current_project.size.x - start.x - 1
+			end.x = Global.current_project.size.x - end.x - 1
+
+		canvas.draw_line(start, end, Color.BLACK)
+		var circle_radius := Vector2.ONE * (5.0 / Global.camera.zoom.x)
+		draw_empty_circle(canvas, start, circle_radius, Color.BLACK)
+		draw_empty_circle(canvas, end, circle_radius, Color.BLACK)
+
+
+func _draw_shape() -> void:
+	var points := _bezier()
+	prepare_undo("Draw Shape")
+	for point in points:
+		# Reset drawer every time because pixel perfect sometimes breaks the tool
+		_drawer.reset()
+		# Draw each point offsetted based on the shape's thickness
+		draw_tool(point)
+	_curve.clear_points()
+	_drawing = false
+	commit_undo()
+
+
+## Get the [member _curve]'s baked points, and draw lines between them using [method _fill_gap].
+func _bezier() -> Array[Vector2i]:
+	var last_pixel := Global.canvas.current_pixel
+	if Global.mirror_view:
+		# Mirror the last point of the curve
+		last_pixel.x = (Global.current_project.size.x - 1) - last_pixel.x
+	_curve.add_point(last_pixel)
+	var points := _curve.get_baked_points()
+	_curve.remove_point(_curve.point_count - 1)
+	var final_points: Array[Vector2i] = []
+	for i in points.size() - 1:
+		var point1 := points[i]
+		var point2 := points[i + 1]
+		final_points.append_array(_fill_gap(point1, point2))
+	return final_points
+
+
+## Fills the gap between [param point_a] and [param point_b] using Bresenham's line algorithm.
+## Takes the [member _thickness] into account.
+func _fill_gap(point_a: Vector2i, point_b: Vector2i) -> Array[Vector2i]:
+	var array: Array[Vector2i] = []
+	var dx := absi(point_b.x - point_a.x)
+	var dy := -absi(point_b.y - point_a.y)
+	var err := dx + dy
+	var e2 := err << 1
+	var sx := 1 if point_a.x < point_b.x else -1
+	var sy := 1 if point_a.y < point_b.y else -1
+	var x := point_a.x
+	var y := point_a.y
+
+	var start := point_a - Vector2i.ONE * (_thickness >> 1)
+	var end := start + Vector2i.ONE * _thickness
+	for yy in range(start.y, end.y):
+		for xx in range(start.x, end.x):
+			array.append(Vector2i(xx, yy))
+
+	while !(x == point_b.x && y == point_b.y):
+		e2 = err << 1
+		if e2 >= dy:
+			err += dy
+			x += sx
+		if e2 <= dx:
+			err += dx
+			y += sy
+
+		var pos := Vector2i(x, y)
+		start = pos - Vector2i.ONE * (_thickness >> 1)
+		end = start + Vector2i.ONE * _thickness
+		for yy in range(start.y, end.y):
+			for xx in range(start.x, end.x):
+				array.append(Vector2i(xx, yy))
+
+	return array
+
+
+func _fill_bitmap_with_points(points: Array[Vector2i], bitmap_size: Vector2i) -> BitMap:
+	var bitmap := BitMap.new()
+	bitmap.create(bitmap_size)
+
+	for point in points:
+		if point.x < 0 or point.y < 0 or point.x >= bitmap_size.x or point.y >= bitmap_size.y:
+			continue
+		bitmap.set_bitv(point, 1)
+
+	return bitmap
+
+
+# Thanks to
+# https://www.reddit.com/r/godot/comments/3ktq39/drawing_empty_circles_and_curves/cv0f4eo/
+func draw_empty_circle(
+	canvas: CanvasItem, circle_center: Vector2, circle_radius: Vector2, color: Color
+) -> void:
+	var draw_counter := 1
+	var line_origin := Vector2()
+	var line_end := Vector2()
+	line_origin = circle_radius + circle_center
+
+	while draw_counter <= 360:
+		line_end = circle_radius.rotated(deg_to_rad(draw_counter)) + circle_center
+		canvas.draw_line(line_origin, line_end, color)
+		draw_counter += 1
+		line_origin = line_end
+
+	line_end = circle_radius.rotated(TAU) + circle_center
+	canvas.draw_line(line_origin, line_end, color)