Contrast node added

addons/ShaderLib/Artistic/Adjustment/ContrastNode.gd

@@ -0,0 +1,60 @@
+@tool
+class_name VisualShaderNodeAdjustmentContrastNode extends VisualShaderNodeCustom
+
+func _get_name() -> String:
+	return "ContrastNode"
+
+func _get_category() -> String:
+	return "Artistic/Adjustment"
+
+func _get_description() -> String:
+	return "Adjusts the contrast of input in by the amount of input contrast."
+
+func _get_return_icon_type() -> PortType:
+	return PORT_TYPE_VECTOR_3D
+
+func _get_input_port_count() -> int:
+	return 2
+
+func _get_input_port_name(port: int) -> String:
+	match port:
+		0:
+			return "in"
+		_:
+			return "contrast"
+
+func _get_input_port_type(port: int) -> PortType:
+	match port:
+		0:
+			return PORT_TYPE_VECTOR_3D
+		_:
+			return PORT_TYPE_SCALAR
+
+func _get_input_port_default_value(port: int) -> Variant:
+	match port:
+		1:
+			return 1.0
+		_:
+			return null
+
+func _get_output_port_count() -> int:
+	return 1
+
+func _get_output_port_name(port: int) -> String:
+	return "out"
+
+func _get_output_port_type(port: int) -> PortType:
+	return PORT_TYPE_VECTOR_3D
+
+func _get_global_code(mode: Shader.Mode) -> String:
+	var code: String = preload("ContrastNode.gdshaderinc").code
+	return code
+
+func _get_code(input_vars: Array[String], output_vars: Array[String], mode: Shader.Mode, type: VisualShader.Type) -> String:
+	var input: String = "vec3(1.0)"
+
+	if input_vars[0]:
+		input = input_vars[0]
+
+	var contrast: String = input_vars[1]
+	return output_vars[0] + " = contrast(%s, %s);" % [input, contrast]

addons/ShaderLib/Artistic/Adjustment/ContrastNode.gdshaderinc

@@ -0,0 +1,5 @@
+vec3 contrast(vec3 input, float contrast)
+{
+    float midpoint = pow(0.5, 2.2);
+    return (input - midpoint) * contrast + midpoint;
+}