// This files includes definition of common uniform variables in OCCT GLSL programs

#define THE_MAX_LIGHTS      8
#define THE_MAX_CLIP_PLANES 8

// Vertex attributes
// Note: At the moment, we just 'rename' the default OpenGL
// vertex attributes from compatibility profile. In the next
// release old functionality will be removed from shader API.
#ifdef VERTEX_SHADER
  #define occColor    gl_Color          //!< Vertex color
  #define occNormal   gl_Normal         //!< Normal  coordinates
  #define occVertex   gl_Vertex         //!< Vertex  coordinates
  #define occTexCoord gl_MultiTexCoord0 //!< Texture coordinates
#endif

// Matrix state
uniform mat4 occWorldViewMatrix;  //!< World-view  matrix
uniform mat4 occProjectionMatrix; //!< Projection  matrix
uniform mat4 occModelWorldMatrix; //!< Model-world matrix

uniform mat4 occWorldViewMatrixInverse;    //!< Inverse of the world-view  matrix
uniform mat4 occProjectionMatrixInverse;   //!< Inverse of the projection  matrix
uniform mat4 occModelWorldMatrixInverse;   //!< Inverse of the model-world matrix

uniform mat4 occWorldViewMatrixTranspose;  //!< Transpose of the world-view  matrix
uniform mat4 occProjectionMatrixTranspose; //!< Transpose of the projection  matrix
uniform mat4 occModelWorldMatrixTranspose; //!< Transpose of the model-world matrix

uniform mat4 occWorldViewMatrixInverseTranspose;  //!< Transpose of the inverse of the world-view  matrix
uniform mat4 occProjectionMatrixInverseTranspose; //!< Transpose of the inverse of the projection  matrix
uniform mat4 occModelWorldMatrixInverseTranspose; //!< Transpose of the inverse of the model-world matrix

// light type enumeration
const int OccLightType_Direct = 1; //!< directional     light source
const int OccLightType_Point  = 2; //!< isotropic point light source
const int OccLightType_Spot   = 3; //!< spot            light source

// Light sources
uniform vec4 occLightAmbient;                    //!< Cumulative ambient color
uniform int  occLightSourcesCount;               //!< Total number of light sources
int   occLight_Type              (in int theId); //!< Type of light source
int   occLight_IsHeadlight       (in int theId); //!< Is light a headlight?
vec4  occLight_Diffuse           (in int theId); //!< Diffuse intensity for specified light source
vec4  occLight_Specular          (in int theId); //!< Specular intensity (currently - equals to diffuse intencity)
vec4  occLight_Position          (in int theId); //!< Position of specified light source
vec4  occLight_SpotDirection     (in int theId); //!< Direction of specified spot light source
float occLight_ConstAttenuation  (in int theId); //!< Const attenuation factor of positional light source
float occLight_LinearAttenuation (in int theId); //!< Linear attenuation factor of positional light source
float occLight_SpotCutOff        (in int theId); //!< Maximum spread angle of the spot light (in radians)
float occLight_SpotExponent      (in int theId); //!< Attenuation of the spot light intensity (from 0 to 1)

// Front material properties accessors
vec4  occFrontMaterial_Emission(void);     //!< Emission color
vec4  occFrontMaterial_Ambient(void);      //!< Ambient  reflection
vec4  occFrontMaterial_Diffuse(void);      //!< Diffuse  reflection
vec4  occFrontMaterial_Specular(void);     //!< Specular reflection
float occFrontMaterial_Shininess(void);    //!< Specular exponent
float occFrontMaterial_Transparency(void); //!< Transparency coefficient

// Front material properties accessors
vec4  occBackMaterial_Emission(void);      //!< Emission color
vec4  occBackMaterial_Ambient(void);       //!< Ambient  reflection
vec4  occBackMaterial_Diffuse(void);       //!< Diffuse  reflection
vec4  occBackMaterial_Specular(void);      //!< Specular reflection
float occBackMaterial_Shininess(void);     //!< Specular exponent
float occBackMaterial_Transparency(void);  //!< Transparency coefficient

uniform int       occDistinguishingMode;   //!< Are front and back faces distinguished?
uniform int       occTextureEnable;        //!< Is texture enabled?
uniform sampler2D occActiveSampler;        //!< Current active sampler

// clipping planes state
const int OccEquationCoords_View  = 0; //!< view-space  clipping plane
const int OccEquationCoords_World = 1; //!< world-space clipping plane

//! Parameters of clipping planes
uniform vec4 occClipPlaneEquations[THE_MAX_CLIP_PLANES];
uniform int  occClipPlaneSpaces   [THE_MAX_CLIP_PLANES];