add spline to linechart

addons/easy_charts/control_charts/LineChart/line_chart.gd

@@ -10,10 +10,81 @@ func _draw_line(from: Point, to: Point, function_index: int) -> void:
 		true
 		)
 
+#func u(t) -> float:
+#	return pow(1.0 - t, 2) / (pow(t, 2) + pow(1.0 - t, 2))
+#
+#func ratio(t: float) -> float:
+#	return abs((pow(t, 2) + pow(1.0 - t, 2) - 1.0) / (pow(t, 2) + pow(1.0 - t, 2)))
+#
+#func find_a(B: Vector2, C: Vector2, t: float) -> Vector2:
+#	return B + ((B - C) / ratio(t))
+#
+#func find_c(P0: Vector2, P2: Vector2, t: float) -> Vector2:
+#	return (u(t) * P0) + ((1.0 - u(t)) * P2)
+#
+#func _bezier(P0: Vector2, P1: Vector2, P2: Vector2, w: float) -> Vector2:
+#	return (pow(1.0 - w, 2) * P0) + (2.0 * w * (1.0 - w) * P1) + (pow(w, 2) * P2)
+#
+#func find_t(P0: Vector2, P1: Vector2, P2: Vector2) -> float:
+#	return abs(P0.distance_to(P1)) / (abs(P0.distance_to(P1)) + abs(P2.distance_to(P1)))
+#
+#func _draw_spline(p1: Point, p2: Point, p3: Point) -> void:
+#	var t: float = find_t(p1.position, p2.position, p3.position)
+#	var c: Vector2 = find_c(p1.position, p3.position, t)
+#	var a: Vector2 = find_a(p2.position, c, t)
+#	for j in 101:
+#		var bezier1: Vector2 = _bezier(p1.position, a, p3.position, (j / 100.0) - 0.01)
+#		var bezier2: Vector2 = _bezier(p1.position, a, p3.position, j / 100.0)
+#		draw_line(bezier1, bezier2, Color.black, 1, true)
+
+# Draw a B-Spline using the Catmull-Rom method
+# Also, add a fake starting and ending point to complete the beginning and the end of the spline
+# @points = a list of at least 4 coordinates
+# @tension = some value greater than 0, defaulting to 1
+func _draw_spline(points: Array, function: int, density: float = 10.0, tension: float = 1) -> void:
+	var spline_points: Array = []
+	
+	var augmented: Array = points.duplicate(true)
+	var pi: Point = Point.new(points.front().position - Vector2(10, -10), Pair.new())
+	var pf: Point = Point.new(points.back().position + Vector2(10, 10), Pair.new())
+	
+	augmented.insert(0, pi)
+	augmented.append(pf)
+	
+	for p in range(1, augmented.size() - 2, 1) : #(inclusive)
+		var p0: Vector2 = augmented[p - 1].position
+#	  v1 = p1 = augmented[p]
+		var p1: Vector2 = augmented[p].position
+		var v1: Vector2 = p1
+#	  v2 = p2 = augmented[p+1]
+		var p2: Vector2 = augmented[p + 1].position
+		var v2: Vector2 = p2
+		var p3: Vector2 = augmented[p + 2].position
+		
+		var s: int = 2.0 * tension
+		var dv1: Vector2 = (p2 - p0) / s
+		var dv2: Vector2 = (p3 - p1) / s
+		
+		for f in range(0, density + 1, 1):
+			var t: float = f / density
+			var c0: float = (2.0 * pow(t, 3)) - (3.0 * pow(t,2)) + 1.0
+			var c1: float = pow(t, 3) - (2.0 * pow(t, 2)) + t
+			var c2: float = (-2.0 * pow(t, 3)) + (3.0 * pow(t, 2))
+			var c3: float = pow(t, 3) - pow(t, 2)
+			var crp: Vector2 = (c0 * v1 + c1 * dv1 + c2 * v2 + c3 * dv2)
+#			draw_circle(crp, 4, Color.magenta)
+			spline_points.append(crp)
+	
+	for i in range(1, spline_points.size()):
+		draw_line(spline_points[i-1], spline_points[i], chart_properties.get_function_color(function), chart_properties.line_width, true)
+
 func _draw_lines() -> void:
 	for function in function_points.size():
-		for i in range(1, function_points[function].size()):
-			_draw_line(function_points[function][i], function_points[function][i - 1], function)
+		if chart_properties.use_splines:
+			_draw_spline(function_points[function], function)
+		else:
+			for i in range(1, function_points[function].size()):
+				_draw_line(function_points[function][i - 1], function_points[function][i], function)
 
 func _draw() -> void:
 	if chart_properties.lines:

addons/easy_charts/examples/line_chart/Control.gd

@@ -7,9 +7,9 @@ func _ready():
 	# NOTE: `x.size() == y.size()` or `x.size() == y[n].size()`
 	var y: Array = [
 		ArrayOperations.multiply_float(ArrayOperations.cos(x), 1.0),
-		ArrayOperations.add_float(ArrayOperations.multiply_int(ArrayOperations.sin(x), 1), 0)
+		ArrayOperations.multiply_float(ArrayOperations.sin(x), 1.0)
 	]
-	print(y)
+	
 	# Add some labels for the x axis, we don't want to use our x values array
 	# they will be printed on the chart ticks instead of the value of the x axis.
 	var x_labels: Array = ArrayOperations.suffix(x, "s")
@@ -24,8 +24,10 @@ func _ready():
 	cp.x_scale = 10
 	cp.y_label = ("Sensor values")
 	cp.y_scale = 10
-	cp.points = false
+	cp.points = true
 	cp.line_width = 2.0
+	cp.point_radius = 2.5
+	cp.use_splines = true
 	cp.interactive = false # false by default, it allows the chart to create a tooltip to show point values
 	# and interecept clicks on the plot
 	
@@ -43,8 +45,8 @@ func _process(delta: float):
 	# and updaptes the plot
 	var new_val: float = $LineChart.x.back() + 1
 	$LineChart.x.append(new_val)
-	$LineChart.y[0].append(cos(new_val) * 20)
-	$LineChart.y[1].append(20 + sin(new_val) * 20)
+	$LineChart.y[0].append(cos(new_val))
+	$LineChart.y[1].append(2 + sin(new_val))
 	$LineChart.x_labels.append(str(new_val) + "s")
 	$LineChart.update()
 

addons/easy_charts/utilities/classes/plotting/chart_properties.gd

@@ -23,6 +23,8 @@ var points: bool = true
 var lines: bool = true
 var interactive: bool = false
 
+var use_splines: bool = false
+
 var colors: Dictionary = {
 	bounding_box = Color.black,
 	grid = Color.gray,