Polygon node for Godot Visual Shader

Polygon.gd

@tool
class_name VisualShaderNodePolygon
extends VisualShaderNodeCustom

func _get_name():
	return "Polygon"

func _get_category():
	return ""

func _get_description():
	return "Draws a polygon"

func _get_return_icon_type():
	return PORT_TYPE_SCALAR

func _get_input_port_count():
	return 4

func _get_input_port_name(port):
	if (port == 0): return "UV"
	if (port == 1): return "Sides"
	if (port == 2): return "Width"
	return "Height"

func _get_input_port_type(port):
	if (port == 0): return PORT_TYPE_VECTOR_2D
	return PORT_TYPE_SCALAR

func _get_output_port_count():
	return 1

func _get_output_port_name(port):
	return "Out"

func _get_output_port_type(port):
	return PORT_TYPE_SCALAR

func _get_global_code(mode):
	return "const float pi = 3.14159265359;"

func _get_code(input_vars, output_vars,
		mode, type):
	var UV = input_vars[0]
	var Sides = input_vars[1]
	var Width = input_vars[2]
	var Height = input_vars[3]
	var Out = output_vars[0]
	return "float aw = %s * cos(pi / %s);\n" % [Width, Sides] \
	+ "float ah = %s * cos(pi / %s);\n" % [Height, Sides] \
	+ "vec2 uv = (%s * 2.0 - 1.0) / vec2(aw, ah);\n" % UV \
	+ "uv.y *= -1.0;\n" \
	+ "float coord = atan(uv.x, uv.y);\n" \
	+ "float r = 2.0 * pi / %s;\n" % Sides \
	+ "float d = cos(floor(0.5 + coord / r) * r - coord) * length(uv);\n" \
	+ Out + " = clamp((1.0 - d) / fwidth(d), 0.0, 1.0);"