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

#ifndef UNITY_CG_INCLUDED
#define UNITY_CG_INCLUDED

// -------------------------------------------------------------------
// Common functions

float saturate(float x)
{
    return max(0.0, min(1.0, x));
}


// -------------------------------------------------------------------
//  builtin values exposed from Unity

// Time values from Unity
uniform vec4 _Time;
uniform vec4 _SinTime;
uniform vec4 _CosTime;

// x = 1 or -1 (-1 if projection is flipped)
// y = near plane
// z = far plane
// w = 1/far plane
uniform vec4 _ProjectionParams;

// x = width
// y = height
// z = 1 + 1.0/width
// w = 1 + 1.0/height
uniform vec4 _ScreenParams;

uniform vec3 _WorldSpaceCameraPos;
uniform vec4 _WorldSpaceLightPos0;

uniform vec4 _LightPositionRange; // xyz = pos, w = 1/range

// -------------------------------------------------------------------
//  helper functions and macros used in many standard shaders

#if defined DIRECTIONAL || defined DIRECTIONAL_COOKIE
#define USING_DIRECTIONAL_LIGHT
#endif

#if defined DIRECTIONAL || defined DIRECTIONAL_COOKIE || defined POINT || defined SPOT || defined POINT_NOATT || defined POINT_COOKIE
#define USING_LIGHT_MULTI_COMPILE
#endif


#ifdef VERTEX

// Computes world space light direction
vec3 WorldSpaceLightDir( vec4 v )
{
    vec3 worldPos = (unity_ObjectToWorld * v).xyz;
    #ifndef USING_LIGHT_MULTI_COMPILE
        return _WorldSpaceLightPos0.xyz - worldPos * _WorldSpaceLightPos0.w;
    #else
        #ifndef USING_DIRECTIONAL_LIGHT
        return _WorldSpaceLightPos0.xyz - worldPos;
        #else
        return _WorldSpaceLightPos0.xyz;
        #endif
    #endif
}

// Computes object space light direction
vec3 ObjSpaceLightDir( vec4 v )
{
    vec3 objSpaceLightPos = (unity_WorldToObject * _WorldSpaceLightPos0).xyz;
    #ifndef USING_LIGHT_MULTI_COMPILE
        return objSpaceLightPos.xyz - v.xyz * _WorldSpaceLightPos0.w;
    #else
        #ifndef USING_DIRECTIONAL_LIGHT
        return objSpaceLightPos.xyz - v.xyz;
        #else
        return objSpaceLightPos.xyz;
        #endif
    #endif
}

// Computes world space view direction
vec3 WorldSpaceViewDir( vec4 v )
{
    return _WorldSpaceCameraPos.xyz - (unity_ObjectToWorld * v).xyz;
}

// Computes object space view direction
vec3 ObjSpaceViewDir( vec4 v )
{
    vec3 objSpaceCameraPos = (unity_WorldToObject * vec4(_WorldSpaceCameraPos.xyz, 1.0)).xyz;
    return objSpaceCameraPos - v.xyz;
}

// Declares 3x3 matrix 'rotation', filled with tangent space basis
// Do not use multiline define here, nVidia OpenGL drivers are buggy in parsing that.
#define TANGENT_SPACE_ROTATION vec3 binormal = cross( gl_Normal.xyz, Tangent.xyz ) * Tangent.w; mat3 rotation = mat3( Tangent.x, binormal.x, gl_Normal.x, Tangent.y, binormal.y, gl_Normal.y, Tangent.z, binormal.z, gl_Normal.z );


// Transforms float2 UV by scale/bias property (new method)
// GLSL ES does not support ## concat operator so we also provide macro that expects xxx_ST
#define TRANSFORM_TEX_ST(tex,namest) (tex.xy * namest.xy + namest.zw)
#ifndef GL_ES
    #define TRANSFORM_TEX(tex,name) TRANSFORM_TEX_ST(tex, name##_ST)
#endif

// Deprecated. Used to transform 4D UV by a fixed function texture matrix. Now just returns the passed UV.
#define TRANSFORM_UV(idx) (gl_TexCoord[0].xy)

#endif // VERTEX



// Calculates UV offset for parallax bump mapping
vec2 ParallaxOffset( float h, float height, vec3 viewDir )
{
    h = h * height - height/2.0;
    vec3 v = normalize(viewDir);
    v.z += 0.42;
    return h * (v.xy / v.z);
}


// Converts color to luminance (grayscale)
float Luminance( vec3 c )
{
    return dot( c, vec3(0.22, 0.707, 0.071) );
}


#endif