From 273d07ae8501542fcaa19fd61610a6f9f76a8e4b Mon Sep 17 00:00:00 2001
From: Digvijaysinh Gohil <zdigv96@gmail.com>
Date: Sun, 10 Dec 2023 17:46:18 +0530
Subject: [PATCH] SwirlUV node added

---
 addons/ShaderLib/UV/SwirlUV.gd          | 75 +++++++++++++++++++++++++
 addons/ShaderLib/UV/SwirlUV.gdshaderinc |  8 +++
 2 files changed, 83 insertions(+)
 create mode 100644 addons/ShaderLib/UV/SwirlUV.gd
 create mode 100644 addons/ShaderLib/UV/SwirlUV.gdshaderinc

diff --git a/addons/ShaderLib/UV/SwirlUV.gd b/addons/ShaderLib/UV/SwirlUV.gd
new file mode 100644
index 0000000..11b170e
--- /dev/null
+++ b/addons/ShaderLib/UV/SwirlUV.gd
@@ -0,0 +1,75 @@
+@tool
+class_name VisualShaderNodeUVSwirl extends VisualShaderNodeCustom
+
+func _init() -> void:
+	_set_input_port_default_value(1, Vector2(0.5, 0.5))
+	_set_input_port_default_value(2, 10.0)
+	_set_input_port_default_value(3, Vector2(0.0, 0.0))
+
+	output_port_for_preview = 0
+
+func _get_name() -> String:
+	return "Swirl"
+
+func _get_category() -> String:
+	return "UV"
+
+func _get_description() -> String:
+	return "Applies a swirl warping effect similar to a black hole to the value of input UV."
+
+func _get_return_icon_type() -> VisualShaderNode.PortType:
+	return PORT_TYPE_VECTOR_2D
+
+func _get_input_port_count() -> int:
+	return 4
+
+func _get_input_port_name(port: int) -> String:
+	match port:
+		0:
+			return "uv"
+		1:
+			return "center"
+		2:
+			return "strength"
+		3:
+			return "offset"
+	return ""
+
+func _get_input_port_type(port: int) -> VisualShaderNode.PortType:
+	match port:
+		0, 1, 3:
+			return PORT_TYPE_VECTOR_2D
+		2:
+			return PORT_TYPE_SCALAR
+	return PORT_TYPE_SCALAR
+
+func _get_output_port_count() -> int:
+	return 1
+
+func _get_output_port_name(port: int) -> String:
+	return "uv"
+
+func _get_output_port_type(port: int) -> VisualShaderNode.PortType:
+	return PORT_TYPE_VECTOR_2D
+
+func _get_global_code(mode: Shader.Mode) -> String:
+	var code: String = preload("SwirlUV.gdshaderinc").code
+	return code
+
+func _get_code(input_vars: Array[String], output_vars: Array[String], mode: Shader.Mode, type: VisualShader.Type) -> String:
+	var uv: String
+
+	match mode:
+		0, 1:
+			uv = "UV"
+		_:
+			uv = "vec2(0.0)"
+
+	if input_vars[0]:
+		uv = input_vars[0]
+
+	var center: String = input_vars[1]
+	var strength: String = input_vars[2]
+	var offset: String = input_vars[3]
+
+	return output_vars[0] + " = swirl_uv(%s, %s, %s, %s);" % [uv, center, strength, offset]
diff --git a/addons/ShaderLib/UV/SwirlUV.gdshaderinc b/addons/ShaderLib/UV/SwirlUV.gdshaderinc
new file mode 100644
index 0000000..e277554
--- /dev/null
+++ b/addons/ShaderLib/UV/SwirlUV.gdshaderinc
@@ -0,0 +1,8 @@
+vec2 swirl_uv(vec2 uv, vec2 center, float strength, vec2 offset){
+	vec2 _delta = uv - center;
+	float _inverse_length = 1.0 - length(_delta);
+	float _angle = strength * _inverse_length;
+	float _x = cos(_angle) * _delta.x - sin(_angle) * _delta.y;
+	float _y = sin(_angle) * _delta.x + cos(_angle) * _delta.y;
+	return vec2(_x + center.x + offset.x, _y + center.y + offset.y);
+}
\ No newline at end of file