struct v2f_vertex_lit {
    vec2 uv;
    vec4 diff;
    vec4 spec;
};
struct v2f_img {
    vec4 pos;
    vec2 uv;
};
struct appdata_img {
    vec4 vertex;
    vec2 texcoord;
};
struct SurfaceOutput {
    vec3 Albedo;
    vec3 Normal;
    vec3 Emission;
    float Specular;
    float Gloss;
    float Alpha;
};
struct appdata_full {
    vec4 vertex;
    vec4 tangent;
    vec3 normal;
    vec4 texcoord;
    vec4 texcoord1;
    vec4 color;
};
struct LeafSurfaceOutput {
    vec3 Albedo;
    vec3 Normal;
    vec3 Emission;
    vec3 Translucency;
    float Specular;
    float Gloss;
    float Alpha;
};
struct v2f {
    vec4 pos;
    vec2 uv;
    vec3 color;
};
uniform vec4 _TerrainTreeLightColors[4];
uniform vec3 _TerrainTreeLightDirections[4];



void ExpandBillboard( in mat4 mat, inout vec4 pos, inout vec3 normal, inout vec4 tangent );
v2f vert( in appdata_full v );
void ExpandBillboard( in mat4 mat, inout vec4 pos, inout vec3 normal, inout vec4 tangent ) {
    float isBillboard;
    vec3 norb;
    vec3 tanb;
    isBillboard = (1.00000 - abs( tangent.w  ));
    norb = vec3( normalize( ( vec4( normal, 0.000000) * mat ) ));
    tanb = vec3( normalize( ( vec4( normal.z , 0.000000, ( -normal.x  ), 0.000000) * mat ) ));
    pos += (( tangent * mat ) * isBillboard);
    normal = mix( normal, norb, vec3( isBillboard));
    tangent = mix( tangent, vec4( tanb, -1.00000), vec4( isBillboard));
}
v2f vert( in appdata_full v ) {
    v2f o;
    vec3 lightColor;
    int i = 0;
    vec3 lightDir;
    float diff;
    ExpandBillboard( gl_ModelViewMatrixInverseTranspose, v.vertex, v.normal, v.tangent);
    o.pos = ( gl_ModelViewProjectionMatrix * v.vertex );
    o.uv = v.texcoord.xy ;
    lightColor = gl_LightModel.ambient.xyz ;
    for ( ; (i < 4); ( i++ )) {
        lightDir.xyz  = _TerrainTreeLightDirections[ i ];
        diff = max( 0.000000, ((dot( lightDir.xyz , v.normal) * 0.500000) + 0.500000));
        lightColor += vec3( (_TerrainTreeLightColors[ i ] * diff));
    }
    o.color = (lightColor * v.color.w );
    return o;
}
attribute vec4 TANGENT;
void main() {
    v2f xl_retval;
    appdata_full xlt_v;
    xlt_v.vertex = vec4( gl_Vertex);
    xlt_v.tangent = vec4( TANGENT);
    xlt_v.normal = vec3( gl_Normal);
    xlt_v.texcoord = vec4( gl_MultiTexCoord0);
    xlt_v.texcoord1 = vec4( gl_MultiTexCoord1);
    xlt_v.color = vec4( gl_Color);
    xl_retval = vert( xlt_v);
    gl_Position = vec4( xl_retval.pos);
    gl_TexCoord[0] = vec4( xl_retval.uv, 0.0, 0.0);
    gl_TexCoord[1] = vec4( xl_retval.color, 0.0);
}
