Make circle brushes scale properly, with support for even-numebered diameters

Also reverts commit 488cf0cc93

src/Autoload/DrawingAlgos.gd

@@ -42,7 +42,6 @@ func get_ellipse_points(pos: Vector2, size: Vector2) -> Array:
 		array.append(v4)
 
 		e2 = 2 * err
-
 		if e2 <= dy:
 			y0 += 1
 			y1 -= 1
@@ -70,6 +69,37 @@ func get_ellipse_points(pos: Vector2, size: Vector2) -> Array:
 	return array
 
 
+func get_ellipse_points_filled(pos: Vector2, size: Vector2, thickness := 1) -> PoolVector2Array:
+	var offsetted_size := size + Vector2.ONE * (thickness - 1)
+	var border := get_ellipse_points(pos, offsetted_size)
+	var filling := []
+
+	for x in range(1, ceil(offsetted_size.x / 2)):
+		var fill := false
+		var prev_is_true := false
+		for y in range(0, ceil(offsetted_size.y / 2)):
+			var top_l_p := Vector2(x, y)
+			var bit := border.has(pos + top_l_p)
+
+			if bit and not fill:
+				prev_is_true = true
+				continue
+
+			if not bit and (fill or prev_is_true):
+				filling.append(pos + top_l_p)
+				filling.append(pos + Vector2(x, offsetted_size.y - y - 1))
+				filling.append(pos + Vector2(offsetted_size.x - x - 1, y))
+				filling.append(pos + Vector2(offsetted_size.x - x - 1, offsetted_size.y - y - 1))
+
+				if prev_is_true:
+					fill = true
+					prev_is_true = false
+			elif bit and fill:
+				break
+
+	return PoolVector2Array(border + filling)
+
+
 func scale_3x(sprite: Image, tol: float = 50) -> Image:
 	var scaled := Image.new()
 	scaled.create(sprite.get_width() * 3, sprite.get_height() * 3, false, Image.FORMAT_RGBA8)

src/Tools/Draw.gd

@@ -214,9 +214,7 @@ func _prepare_tool() -> void:
 	var strength := _strength
 	if Global.pressure_sensitivity_mode == Global.PressureSensitivity.ALPHA:
 		strength *= Tools.pen_pressure
-	_drawer.pixel_perfect = false
-	if _brush_size == 1 and _brush.type == Brushes.PIXEL:
-		_drawer.pixel_perfect = Tools.pixel_perfect
+	_drawer.pixel_perfect = Tools.pixel_perfect if _brush_size == 1 else false
 	_drawer.horizontal_mirror = Tools.horizontal_mirror
 	_drawer.vertical_mirror = Tools.vertical_mirror
 	_drawer.color_op.strength = strength
@@ -300,36 +298,18 @@ func _compute_draw_tool_pixel(position: Vector2) -> PoolVector2Array:
 	return result
 
 
-# Algorithm based on http://members.chello.at/easyfilter/bresenham.html
 # Compute the array of coordinates that should be drawn
 func _compute_draw_tool_circle(position: Vector2, fill := false) -> PoolVector2Array:
+	var size := Vector2(_brush_size, _brush_size)
+	var pos = position - (size / 2).floor()
 	if _circle_tool_shortcut:
 		return _draw_tool_circle_from_map(position)
 
 	var result := PoolVector2Array()
-	var r := _brush_size
-	var x := -r
-	var y := 0
-	var err := 2 - r * 2
-	var draw := true
 	if fill:
-		result.append(position)
-	while x < 0:
-		if draw:
-			for i in range(1 if fill else -x, -x + 1):
-				result.append(position + Vector2(-i, y))
-				result.append(position + Vector2(-y, -i))
-				result.append(position + Vector2(i, -y))
-				result.append(position + Vector2(y, i))
-		draw = not fill
-		r = err
-		if r <= y:
-			y += 1
-			err += y * 2 + 1
-			draw = true
-		if r > x || err > y:
-			x += 1
-			err += x * 2 + 1
+		result = DrawingAlgos.get_ellipse_points_filled(pos, size)
+	else:
+		result = DrawingAlgos.get_ellipse_points(pos, size)
 	return result
 
 

src/Tools/EllipseTool.gd

@@ -2,35 +2,7 @@ extends "res://src/Tools/ShapeDrawer.gd"
 
 
 func _get_shape_points_filled(size: Vector2) -> PoolVector2Array:
-	var offsetted_size := size + Vector2.ONE * (_thickness - 1)
-	var border := DrawingAlgos.get_ellipse_points(Vector2.ZERO, offsetted_size)
-	var filling := []
-	var bitmap := _fill_bitmap_with_points(border, offsetted_size)
-
-	for x in range(1, ceil(offsetted_size.x / 2)):
-		var fill := false
-		var prev_is_true := false
-		for y in range(0, ceil(offsetted_size.y / 2)):
-			var top_l_p := Vector2(x, y)
-			var bit := bitmap.get_bit(top_l_p)
-
-			if bit and not fill:
-				prev_is_true = true
-				continue
-
-			if not bit and (fill or prev_is_true):
-				filling.append(top_l_p)
-				filling.append(Vector2(x, offsetted_size.y - y - 1))
-				filling.append(Vector2(offsetted_size.x - x - 1, y))
-				filling.append(Vector2(offsetted_size.x - x - 1, offsetted_size.y - y - 1))
-
-				if prev_is_true:
-					fill = true
-					prev_is_true = false
-			elif bit and fill:
-				break
-
-	return PoolVector2Array(border + filling)
+	return DrawingAlgos.get_ellipse_points_filled(Vector2.ZERO, size, _thickness)
 
 
 func _get_shape_points(size: Vector2) -> PoolVector2Array: