// This shader draws a texture on the mesh.
Shader "custom/tunnel"
{
    // The _BaseMap variable is visible in the Material's Inspector, as a field
    // called Base Map.
    Properties
    { 
        _BackgroundColor("Background Color", Color) = (0,0,0,0)
        [HDR] _NebulaColor1("Nebula Color 1", Color) = (1,1,1,1)
        [HDR] _NebulaColor2("Nebula Color 2", Color) = (1,1,1,1)
        [HDR] _FractalColor("Fractal Color", Color) = (1,1,1,1)
        [HDR] _GroundColor("Ground Color", Color) = (1,1,1,1)
        [HDR] _CoreColor("Core Color", Color) = (1,1,1,1)
        [HDR] _BarsColor("Bars Color", Color) = (1,1,1,1)
        
        _SkyWeight("Sky Weight", Float) = 1.0
        _FractalWeight("Fractal Weight", Range(0.0,1.0)) = 1.0
        _NebulaWeight("Nebula Weight", Range(0.0,1.0)) = 1.0
        _BarsWeight("Bars Weight", Float) = 1.0
        _StarsWeight("Stars Weight", Range(0.0,1.0)) = 1.0
        _GroundWeight("Ground Weight", Float) = 1.0
        _GroundMaskAngle("Ground Mask Angle", Float) = 1.0
        
        _FractalScale("Fractal Scale", Float) = 6.0
        _FractalRotateSpeed("Fractal Rotate Speed", Float) = 20.0
        _FractalPower("Fractal Power", Float) = 1.0
        _FractalInner("Fractal Inner", Float) = 0.2
        _FractalFadeHeight("Fractal Fade Height", Float) = 0.25
        
        _Nebula1Power("Nebula 1 Power", Float) = 1.0
        _Nebula2Power("Nebula 2 Power", Float) = 1.0
        
        _CoreRadius("Core Radius", Range(0, 1.0)) = 1.0
        _CoreThiccness("Core Thiccness", Range(0,1.0)) = 1.0
        
        _OuterCircleRadius("Outer Circle Radius", Range(0,10)) = 0.5
        _OuterCircleThickness("Outer Circle Thickness", Range(0,1.0)) = 0.1
        
        _NebulaMap("Nebula Map", 2D) = "black"
        _StarMap("Star Map", 2D) = "black"
        _FractalMap("Fractal Map", 2D) = "black"
        
//        _ShakeStrength("Shake Strength", Float) = 0.01
        
        _Intensity("Intensity", Float) = 1.0
    }

    SubShader
    {
        Tags { "RenderType" = "Opaque" "RenderPipeline" = "UniversalRenderPipeline" }

        Pass
        {
            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"            

            struct Attributes
            {
                float4 positionOS   : POSITION;
                // The uv variable contains the UV coordinate on the texture for the
                // given vertex.
                float2 uv           : TEXCOORD0;
            };

            struct Varyings
            {
                float4 positionHCS  : SV_POSITION;
                // The uv variable contains the UV coordinate on the texture for the
                // given vertex.
                float2 uv           : TEXCOORD0;
            };
            
            float4 _BackgroundColor;
            float4 _NebulaColor1;
            float4 _NebulaColor2;
            float4 _FractalColor;
            float4 _GroundColor;
            float4 _CoreColor;
            float4 _BarsColor;
            
            float _FractalScale = 6.0;
            float _FractalRotateSpeed = 20.0;
            float _FractalPower = 1.0;
            float _FractalInner = 0.2;
            float _FractalWeight = 1.0;
            float _FractalFadeHeight = 0.25;

            float _Nebula1Power = 1.0;
            float _Nebula2Power = 1.0;
            float _NebulaWeight = 1.0;

            float _SkyWeight;
            float _BarsWeight;
            float _StarsWeight;
            float _GroundWeight;
            float _GroundMaskAngle;

            // circles
            float _CoreRadius;
            float _CoreThiccness;
            float _OuterCircleRadius;
            float _OuterCircleThickness;
            
            float _Intensity;
            float _CameraShake = 0.0;

            float _DistanceToNextBeat;
            float _DistanceSinceLastBeat;
            
            float _PlayerXPos;
            float _PlayerXMove;
            float _TrackWidth = 20;
            
            TEXTURE2D(_NebulaMap);
            SAMPLER(sampler_NebulaMap);
            TEXTURE2D(_StarMap);
            SAMPLER(sampler_StarMap);
            TEXTURE2D(_FractalMap);
            SAMPLER(sampler_FractalMap);

            CBUFFER_START(UnityPerMaterial)
                // The following line declares the _BaseMap_ST variable, so that you
                // can use the _BaseMap variable in the fragment shader. The _ST 
                // suffix is necessary for the tiling and offset function to work.
                float4 _NebulaMap_ST;
                float4 _StarMap_ST;
                float4 _FractalMap_ST;
            CBUFFER_END

            Varyings vert(Attributes IN)
            {
                Varyings OUT;
                OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);
                OUT.uv = IN.uv;
                return OUT;
            }


            float2 rotateUV(float2 uv, float rotation)
            {
                float mid = 0.5;
                return float2(
                    cos(rotation) * (uv.x - mid) + sin(rotation) * (uv.y - mid) + mid,
                    cos(rotation) * (uv.y - mid) - sin(rotation) * (uv.x - mid) + mid
                );
            }            
            
            float4 nebula(float r, float a)
            {
                // sample nebula 1
                float n1_stretch = 1.0/50.0;
                float n1_speed = 20.0;
                float n1_spin = 10.0;
                // float n1_power = 2.0;
                float n1_cutoff = 0.5;
                
                float2 nuv1;
                nuv1.x = n1_stretch/(r*r) + _Time * n1_speed;
                nuv1.y = a/PI + _Time * n1_spin;
                half4 nebula1 = SAMPLE_TEXTURE2D(_NebulaMap, sampler_NebulaMap, nuv1);
                nebula1 *= _NebulaColor1;
                nebula1 *= max(0,_Nebula1Power*r-n1_cutoff);
                
                // sample nebula 2 - same as nebula 1 but in another direction
                float n2_stretch = 1.0/100.0;
                float n2_speed = 30.0;
                float n2_spin = -5.0;
                // float n2_power = 4.0;
                float n2_cutoff = 0.5;

                float2 nuv2;
                nuv2.x = n2_stretch/(r*r) + _Time * n2_speed;
                nuv2.y = a/PI + _Time * n2_spin;
                half4 nebula2 = SAMPLE_TEXTURE2D(_NebulaMap, sampler_NebulaMap, nuv2.yx);
                nebula2 *= _NebulaColor2;
                nebula2 *= max(0,_Nebula2Power*r - n2_cutoff);

                return (nebula1 + nebula2) * _Intensity * _NebulaWeight;
            }

            float4 stars(float r, float a)
            {
                // sample stars
                float starStretch = 1.0/100.0;
                float starSpeed = 10.0 * _Intensity;
                float starWrap = 3.5f;
                
                // star uv
                float2 suv;
                // use the root to make them into radial lines instead of a tunnel
                suv.x = starStretch/sqrt(r) + _Time * starSpeed;
                suv.y = (float)starWrap*a/PI;
                half4 star = SAMPLE_TEXTURE2D(_StarMap, sampler_StarMap, suv);
                star *= r * r * 2.0;

                return star * _Intensity * _StarsWeight;
            }
            
            // same as fractals but calling it from a function turns them into bars?? 
            float4 bars(float r, float p)
            {
                // fractal uv
                float2 fuv1 = p / _FractalScale + float2(0.5,0.5);
                fuv1 = rotateUV(fuv1,_Time*_FractalRotateSpeed);
                half4 fractal1 = SAMPLE_TEXTURE2D(_FractalMap, sampler_FractalMap, fuv1);
                fractal1 *= _FractalColor;
                fractal1 *= _FractalPower;

                // fractal 2
                float2 fuv2 = p / _FractalScale + float2(0.5,0.5);
                fuv2 = rotateUV(fuv2,-_Time*_FractalRotateSpeed*3.561);
                fuv2.x=1.0-fuv2.x;
                half4 fractal2 = SAMPLE_TEXTURE2D(_FractalMap, sampler_FractalMap, fuv2);
                fractal2 *= _FractalColor * sin(_Time*3);
                fractal2 *= _FractalPower;

                half4 fractal = max(fractal1,fractal2) * _Intensity;
                
                return fractal * _Intensity * _BarsWeight;
            }

            float4 ground(float2 p, float r, float a)
            {
                float4 nothing = float4(0,0,0,0);
                float angle = PI;

                float t = (abs(a/PI)*PI) * -min(p.y, 0);
                t = min(r, t);
                // t *= -abs(p.y);
                // t += ;
                // t *= (1.0-r*0.5);

                // float y = -p.y;
                
                return lerp(nothing, _GroundColor, t) * _GroundWeight;
            }

            float4 blurry_circle(float2 p, float radius, float thickness)
            {
                float r_p = length(p);
                // outer circle is white/circle color
                // inner circle is black and a bit smaller

                float d =abs(radius-r_p)*1.0/thickness;
                d*=d;
                float4 color = max(d, 0);
                color.a = 1.0;

                // color -= max((_CircleRadius-_CircleThickness)-r, 0);

                color = 1.0-color;

                float b = _DistanceToNextBeat;
                b*=b;
                
                color *= 1.0+b;
                
                return max(color, 0);
            }

            float4 filled_circle(float2 p, float r)
            {
                float inside = step(length(p),r);
                return lerp(float4(0,0,0,0),float4(1,1,1,1),inside);
            }
            
            float4 frag(Varyings IN) : SV_Target
            {
                float2 res = _ScreenParams;
                float2 p = -1.0+2.0*IN.positionHCS.xy/res.xy;
                p.x *= res.x/res.y;

                float2 cameraShake;
                float shake = _Time*50;
                cameraShake.x = cos(shake*12.3341)+sin(shake*19.231057);
                cameraShake.y = cos(shake*17.12311)+sin(shake*14.2315165);
                cameraShake*=_CameraShake;
                p += cameraShake;

                // shared tunnel vars
                float r = length(p);
                float a = atan(p.y/p.x);

                // for some reason trying to sample the fractal in a function turns it into bars
                // looks cool but no idea why it happens so these fractals are inline
                float2 fuv1 = p / _FractalScale + float2(0.5,0.5);
                fuv1 = rotateUV(fuv1,_Time*_FractalRotateSpeed);
                half4 fractal1 = SAMPLE_TEXTURE2D(_FractalMap, sampler_FractalMap, fuv1);
                fractal1 *= _FractalColor;
                // fractal1 *= max(0, r-_CoreRadius);
                fractal1 *= _FractalWeight;
                fractal1 *= _Intensity;
                
                float2 fuv2 = p / _FractalScale + float2(0.5,0.5);
                fuv2 = rotateUV(fuv2,PI*-(_PlayerXPos/20.0));
                // fuv2.x=1.0-fuv2.x;
                half4 fractal2 = SAMPLE_TEXTURE2D(_FractalMap, sampler_FractalMap, fuv2);
                fractal2 *= _FractalColor * sin(_Time*3);
                // fractal2 *= max(0, r-_CoreRadius);
                fractal2 *= _FractalWeight;
                fractal2 *= _Intensity;
                
                float4 color = _BackgroundColor;

                // precalc some stuff
                float f = fractal1 + fractal2;
                // float f = fractal2;
                float g = ground(p, r, a);
                // float g_mask = step(_GroundMaskAngle,g);
                float n = nebula(r, a);
                float s = stars(r, a);
                float b = bars(r, p);

                // fractal
                // color += fractal_both;

                // nebula
                // float4 normal_bars = normalize(bars(r,p));
                // color += normal_bars;
                // float4 nebula_bars = bars(r, p) * _DistanceSinceLastBeat * 5;
                // color += stars(r, a);
                // color += circle(p, r);
                // float4 neb = nebula(r, a);
                // color += neb;
                
                // sky
                float4 sky = _BackgroundColor;
                sky += f * _FractalColor;            // fractal
                sky += s;            // stars
                float4 clouds = n;
                clouds *= (1.0-g);    // mask out ground
                sky += clouds;
                sky *= (1.0-g);  // mask out ground
                
                // sky = max(f,s);
                // stars masked by ground
                // color += max(0,s,g_mask);

                
                // ground
                float4 ground_color = float4(0,0,0,0);
                // hazy ground base
                ground_color += g;
                // speedy boye
                float4 ground_fast = n * g;
                ground_color += ground_fast;
                ground_color *= _GroundColor;
                color = max(color, ground_color);

                // bars
                float4 bars_color = b;
                bars_color = lerp(bars_color,ground_color,g);
                bars_color *= _BarsColor;
                bars_color *= lerp(0, bars_color, _DistanceToNextBeat);
                bars_color = lerp(bars_color, ground_color, g);
                
                sky += bars_color * _BarsWeight;
                sky *= _SkyWeight;
                color += sky;

                // core
                float4 core_color = blurry_circle(p, _CoreRadius, _CoreThiccness);
                core_color *= _CoreColor;
                color += core_color;
                // color = lerp(color, core_color, step(0.001,core_color));
                
                // rays
                float4 rays_colour;
                
                // spee
                // color += lerp(sky, n, g);
                
                
                // float4 outer_circle = blurry_circle(p,_OuterCircleRadius,_OuterCircleThickness);
                // color += lerp(0,outer_circle,ground(p,r,a));
                
                // float4 core = filled_circle(p,_CoreRadius);
                // color += core;

                // color = float4(1,1,1,1)*outer_circle;
                // bars, nebula, fractal, 
                // average across all fx
                
                return color;
            }
            ENDHLSL
        }
    }
}