Added Wave Form Nodes (#1547)

* small sampling of wave form nodes
* updates to waveform calcs
* fixed noise wave function
* updates noise wave and changelog
* update name of node directory folder
* updated maths and noise sine wave node name + changelog
* updated filename for noise sine wave node
* updated float to precision in noise sine wave
* updated changelog

com.unity.shadergraph/CHANGELOG.md

 
 This adds gradient functionality via two new nodes. The Sample Gradient node samples a gradient given a Time parameter. You can define this gradient on the Gradient slot control view. The Gradient Asset node defines a gradient that can be sampled by multiple Sample Gradient nodes using different Time parameters.
 
+### Waveform nodes
+
+![](.data/wave_form_nodes.png)
+
+Math nodes now have a Waves category. The category has four different nodes: Triangle wave, Sawtooth wave, Square wave, and Noise Sine wave.
+The Triangle, Sawtooth, and Square wave nodes output a waveform with a range of -1 to 1 over a period of 1.
+The Noise Sine wave outputs a standard Sine wave with a range of -1 to 1 over a period of 2 * pi. For variance, random noise is added to the amplitude of the Sine wave, within a determined range.
+
 ## Normal Derive Nodes
 
 ![](.data/normal_derive_nodes.png)

com.unity.shadergraph/Editor/Data/Nodes/Math/Wave.meta

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com.unity.shadergraph/Editor/Data/Nodes/Math/Wave/NoiseSineWaveNode.cs

+using UnityEngine;
+using System.Reflection;
+
+namespace UnityEditor.ShaderGraph
+{
+    [Title("Math", "Wave", "Noise Sine Wave")]
+    class NoiseSineWaveNode : CodeFunctionNode
+    {
+        public NoiseSineWaveNode()
+        {
+            name = "Noise Sine Wave";
+        }
+
+        public override string documentationURL
+        {
+            get { return "https://github.com/Unity-Technologies/ShaderGraph/wiki/Noise-Sine-Wave-Node"; }
+        }
+
+        protected override MethodInfo GetFunctionToConvert()
+        {
+            return GetType().GetMethod("NoiseSineWave", BindingFlags.Static | BindingFlags.NonPublic);
+        }
+
+        static string NoiseSineWave(
+            [Slot(0, Binding.None)] DynamicDimensionVector In,
+            [Slot(1, Binding.None, -0.5f, 0.5f, 1, 1)] Vector2 MinMax,
+            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+        {
+            return
+                @"
+{
+    {precision} sinIn = sin(In);
+    {precision} sinInOffset = sin(In + 1.0);
+    {precision} randomno =  frac(sin((sinIn - sinInOffset) * (12.9898 + 78.233))*43758.5453);
+    {precision} noise = lerp(MinMax.x, MinMax.y, randomno);
+    Out = sinIn + noise;
+}
+";
+        }
+    }
+}

com.unity.shadergraph/Editor/Data/Nodes/Math/Wave/NoiseSineWaveNode.cs.meta

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com.unity.shadergraph/Editor/Data/Nodes/Math/Wave/SawtoothWaveNode.cs

+using System.Reflection;
+
+namespace UnityEditor.ShaderGraph
+{
+    [Title("Math", "Wave", "Sawtooth Wave")]
+    class SawtoothWaveNode : CodeFunctionNode
+    {
+        public SawtoothWaveNode()
+        {
+            name = "Sawtooth Wave";
+        }
+
+        public override string documentationURL
+        {
+            get { return "https://github.com/Unity-Technologies/ShaderGraph/wiki/Sawtooth-Wave-Node"; }
+        }
+
+        protected override MethodInfo GetFunctionToConvert()
+        {
+            return GetType().GetMethod("SawtoothWave", BindingFlags.Static | BindingFlags.NonPublic);
+        }
+
+        static string SawtoothWave(
+            [Slot(0, Binding.None)] DynamicDimensionVector In,
+            [Slot(1, Binding.None)] out DynamicDimensionVector Out)
+        {
+            return
+                @"
+{
+    Out = 2 * (In - floor(0.5 + In));
+}
+";
+        }
+    }
+}

com.unity.shadergraph/Editor/Data/Nodes/Math/Wave/SawtoothWaveNode.cs.meta

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com.unity.shadergraph/Editor/Data/Nodes/Math/Wave/SquareWaveNode.cs

+using System.Reflection;
+
+namespace UnityEditor.ShaderGraph
+{
+    [Title("Math", "Wave", "Square Wave")]
+    class SquareWaveNode : CodeFunctionNode
+    {
+        public SquareWaveNode()
+        {
+            name = "Square Wave";
+        }
+
+        public override string documentationURL
+        {
+            get { return "https://github.com/Unity-Technologies/ShaderGraph/wiki/Square-Wave-Node"; }
+        }
+
+        protected override MethodInfo GetFunctionToConvert()
+        {
+            return GetType().GetMethod("SquareWave", BindingFlags.Static | BindingFlags.NonPublic);
+        }
+
+        static string SquareWave(
+            [Slot(0, Binding.None)] DynamicDimensionVector In,
+            [Slot(1, Binding.None)] out DynamicDimensionVector Out)
+        {
+            return
+                @"
+{
+    Out = 1.0 - 2.0 * round(frac(In));
+}
+";
+        }
+    }
+}

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com.unity.shadergraph/Editor/Data/Nodes/Math/Wave/TriangleWaveNode.cs

+using System.Reflection;
+
+namespace UnityEditor.ShaderGraph
+{
+    [Title("Math", "Wave", "Triangle Wave")]
+    class TriangleWaveNode : CodeFunctionNode
+    {
+        public TriangleWaveNode()
+        {
+            name = "Triangle Wave";
+        }
+
+        public override string documentationURL
+        {
+            get { return "https://github.com/Unity-Technologies/ShaderGraph/wiki/Triangle-Wave-Node"; }
+        }
+
+        protected override MethodInfo GetFunctionToConvert()
+        {
+            return GetType().GetMethod("TriangleWave", BindingFlags.Static | BindingFlags.NonPublic);
+        }
+
+        static string TriangleWave(
+            [Slot(0, Binding.None)] DynamicDimensionVector In,
+            [Slot(1, Binding.None)] out DynamicDimensionVector Out)
+        {
+            return
+                @"
+{
+    Out = 2.0 * abs( 2 * (In - floor(0.5 + In)) ) - 1.0;
+}
+";
+        }
+    }
+}

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