Shader "Unlit/WaveGraph"
{
    Properties
    {
        P1ColorIn("Color1 In", Color) = (1.0, 0.5, 0.0, 1.0)
        P1ColorOut("Color1 Out", Color) = (1.0, 0.0, 0.0, 1.0)
        P2ColorIn("Color2 In", Color) = (0.0, 1.0, 0.5, 1.0)
        P2ColorOut("Color2 Out", Color) = (1.0, 1.0, 0.0, 1.0)
        P3ColorIn("Color3 In", Color) = (0.0, 0.5, 1.0, 1.0)
        P3ColorOut("Color3 Out", Color) = (0.0, 0.0, 1.0, 1.0)
        P4ColorIn("Color4 In", Color) = (0.5, 0.0, 5.0, 1.0)
        P4ColorOut("Color4 Out", Color) = (.5, 0.0, 0.0, 1.0)
        Amplitudes("Amplitudes", Vector) = (0.1, 0.2, 0.3, 0.4)
        Frequencies("Frequencies", Vector) = (40, 30, 20, 10)
        [Toggle(ENABLE_MULTIWAVE)] _MULTIWAVE ("Enable multiwave feature", Float) = 0

    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 100

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog
            #pragma multi_compile __ ENABLE_MULTIWAVE

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
            };

            half4 P1ColorIn;
            half4 P1ColorOut;
            half4 P2ColorIn;
            half4 P2ColorOut;
            half4 P3ColorIn;
            half4 P3ColorOut;
            half4 P4ColorIn;
            half4 P4ColorOut;
            half4 Amplitudes;
            half4 Frequencies;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }


            half3 CalcCurve(half2 uv, float amp, float freq, half3 c1, half3 c2)
            {
                float curve = amp * sin((freq * uv.x) + (2.0 * _Time.z));
                float lineAShape = smoothstep(1.0 - clamp(distance(curve + uv.y, 0.5), 0.0, 1.0), 1.0, 0.99);
                return (1.0 - lineAShape) * lerp(c1, c2, lineAShape);
            }

            half3 CalcComplexCurve(half2 uv, half4 amp, half4 freq, half3 c1, half3 c2)
            {
                float curve = amp.x * sin((freq.x * uv.x) + (2.0 * _Time.z));
                curve += amp.y * sin((freq.y * uv.x) + (2.0 * _Time.z));
                curve += amp.z * sin((freq.z * uv.x) + (2.0 * _Time.z));
                curve += amp.w * sin((freq.w * uv.x) + (2.0 * _Time.z));
                float lineAShape = smoothstep(1.0 - clamp(distance(curve + uv.y, 0.5), 0.0, 1.0), 1.0, 0.99);
                return (1.0 - lineAShape) * lerp(c1, c2, lineAShape);
            }


            half4 frag (v2f i) : SV_Target
            {
                // sample the texture
                half4 col = half4(0,0,0,1);// = tex2D(_MainTex, i.uv);
                /*
                float curve = 0.5 * sin((40 * i.uv.x) + (2.0 * _Time.z));

                float lineAShape = smoothstep(1.0 - clamp(distance(curve + i.uv.y, 0.5), 0.0, 1.0), 1.0, 0.99);
                half3  lineACol = (1.0 - lineAShape) * lerp(P1ColorIn, P1ColorOut, lineAShape);
                */
              #if ENABLE_MULTIWAVE
                col.rgb = CalcCurve(i.uv, Amplitudes.x, Frequencies.x, P1ColorIn, P1ColorOut);
                col.rgb += CalcCurve(i.uv, Amplitudes.y, Frequencies.y, P2ColorIn, P2ColorOut);
                col.rgb += CalcCurve(i.uv, Amplitudes.z, Frequencies.z, P3ColorIn, P3ColorOut);
                col.rgb += CalcCurve(i.uv, Amplitudes.w, Frequencies.w, P4ColorIn, P4ColorOut);
              #else
                col.rgb = CalcComplexCurve(i.uv, Amplitudes, Frequencies, P1ColorIn, P1ColorOut);
              #endif
                return col;
            }




            ENDCG
        }
    }
}