// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

Shader "Azure[Sky] Dynamic Skybox/Particles Additive"
{
    Properties
    {
        _TintColor("Tint Color", Color) = (0.5,0.5,0.5,0.5)
        _MainTex("Particle Texture", 2D) = "white" {}
        _InvFade("Soft Particles Factor", Range(0.01,3.0)) = 1.0
    }

    Category
    {

        Tags { "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" "PreviewType" = "Plane" }
        Blend SrcAlpha One
        ColorMask RGB
        Cull Off Lighting Off ZWrite Off

        SubShader
        {
            Pass
            {

                CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
                #pragma target 2.0
                #pragma multi_compile_particles
                #pragma multi_compile_fog

                #include "UnityCG.cginc"

                sampler2D _MainTex;
                fixed4 _TintColor;

                struct appdata_t
                {
                    float4 vertex : POSITION;
                    fixed4 color : COLOR;
                    float2 texcoord : TEXCOORD0;
                    UNITY_VERTEX_INPUT_INSTANCE_ID
                };

                struct v2f
                {
                    float4 vertex : SV_POSITION;
                    fixed4 color : COLOR;
                    float2 texcoord : TEXCOORD0;
                    UNITY_FOG_COORDS(1)
                    #ifdef SOFTPARTICLES_ON
                    float4 projPos : TEXCOORD2;
                    #endif
                    UNITY_VERTEX_OUTPUT_STEREO
                };

                float4 _MainTex_ST;

                v2f vert(appdata_t v)
                {
                    v2f o;
                    UNITY_SETUP_INSTANCE_ID(v);
                    UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
                    o.vertex = UnityObjectToClipPos(v.vertex);
                    #ifdef SOFTPARTICLES_ON
                    o.projPos = ComputeScreenPos(o.vertex);
                    COMPUTE_EYEDEPTH(o.projPos.z);
                    #endif
                    o.color = v.color;
                    o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
                    UNITY_TRANSFER_FOG(o,o.vertex);
                    return o;
                }

                UNITY_DECLARE_DEPTH_TEXTURE(_CameraDepthTexture);
                float _InvFade;

                fixed4 frag(v2f i) : SV_Target
                {
                    UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(i);

                    #ifdef SOFTPARTICLES_ON
                    float sceneZ = LinearEyeDepth(SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos)));
                    float partZ = i.projPos.z;
                    float fade = saturate(_InvFade * (sceneZ - partZ));
                    i.color.a *= fade;
                    #endif

                    fixed4 col = 2.0f * i.color * _TintColor * tex2D(_MainTex, i.texcoord);
                    col.a = saturate(col.a); // alpha should not have double-brightness applied to it, but we can't fix that legacy behavior without breaking everyone's effects, so instead clamp the output to get sensible HDR behavior (case 967476)

                    UNITY_APPLY_FOG_COLOR(i.fogCoord, col, fixed4(0.0f, 0.0f, 0.0f, 0.0f)); // fog towards black due to our blend mode

                    // Color correction
                    #ifdef UNITY_COLORSPACE_GAMMA
                    col = pow(col, 2.0f);
                    #endif

                    return col;
                }
                ENDCG
            }
        }
    }
}