//-
// ==========================================================================
// Copyright (C) 2005 ATI Technologies Inc. All rights reserved.
//
// Copyright (C) 1995 - 2005 Alias Systems Corp. and/or its licensors.  All 
// rights reserved. 
// 
// The coded instructions, statements, computer programs, and/or related 
// material (collectively the "Data") in these files are provided by Alias 
// Systems Corp. ("Alias") and/or its licensors for the exclusive use of the 
// Customer (as defined in the Alias Software License Agreement that 
// accompanies this Alias software). Such Customer has the right to use, 
// modify, and incorporate the Data into other products and to distribute such 
// products for use by end-users.
//  
// THE DATA IS PROVIDED "AS IS".  ALIAS HEREBY DISCLAIMS ALL WARRANTIES 
// RELATING TO THE DATA, INCLUDING, WITHOUT LIMITATION, ANY AND ALL EXPRESS OR 
// IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND/OR FITNESS FOR A 
// PARTICULAR PURPOSE. IN NO EVENT SHALL ALIAS BE LIABLE FOR ANY DAMAGES 
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// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, OR IN EQUITY, 
// ARISING OUT OF ACCESS TO, USE OF, OR RELIANCE UPON THE DATA.
// ==========================================================================
//+

//
//
// Shader.h
//
//  This file defines the abstract interface for different shader types to be used with .fx
// files in the Maya renderer. The goal is to have a default shader, a GLSL fx shader, and an
// HLSL fx shader 
//
//
////////////////////////////////////////////////////////////////////////////////////////////////////

#ifndef SHADER_H
#define SHADER_H

#include <string>

class shader {
  public:

    enum DataType {
      dtFloat,
      dtVec2,
      dtVec3,
      dtVec4,
      dtInt,
      dtIVec2,
      dtIVec3,
      dtIVec4,
      dtBool,
      dtBVec2,
      dtBVec3,
      dtBVec4,
      dtMat2,
      dtMat3,
      dtMat4,
      dtUnknown
    };

    enum Semantic {
      /* no semantic, standard parameter */
      smNone,
      /* standard matrices */
      smWorld,
      smView,
      smProjection,
      smWorldView,
      smViewProjection,
      smWorldViewProjection,
      /* inverse matrices */
      smWorldI,
      smViewI,
      smProjectionI,
      smWorldViewI,
      smViewProjectionI,
      smWorldViewProjectionI,
      /* transpose matrices */
      smWorldT,
      smViewT,
      smProjectionT,
      smWorldViewT,
      smViewProjectionT,
      smWorldViewProjectionT,
      /* inverse tranpose matrices */
      smWorldIT,
      smViewIT,
      smProjectionIT,
      smWorldViewIT,
      smViewProjectionIT,
      smWorldViewProjectionIT,
      /* semantic is unknown */
      smUnknown
    };

    enum SamplerType {
      st1D,
      st2D,
      st3D,
      stCube,
      st1DShadow,
      st2DShadow,
      stUnknown
    };

    virtual ~shader() {};

    virtual bool valid() = 0;
    virtual int passCount() = 0;
    virtual int techniqueCount() = 0;
    virtual const char* techniqueName( int n) = 0;
    virtual bool build() = 0;
    virtual void bind() = 0;
    virtual void unbind() = 0;
    virtual void setTechnique( int t) = 0;
    virtual void setPass( int p) = 0;
    virtual const char* getVertexShader( int pass) = 0;
    virtual const char* getPixelShader( int pass) = 0;

    //need to have queries for attribs and uniforms
    virtual int uniformCount() = 0;
    virtual int samplerCount() = 0;
    virtual int attributeCount() = 0;
    virtual const char* uniformName(int i) = 0;
    virtual DataType uniformType(int i) = 0;
    virtual Semantic uniformSemantic(int i) = 0;
    virtual float* uniformDefault(int i) { return 0;};
    virtual const char* samplerName(int i) = 0;
    virtual SamplerType samplerType(int i) = 0;
    virtual const char* attributeName(int i) = 0;
    virtual DataType attributeType(int i) = 0;
    virtual int attributeHandle(int i) = 0;

    //need set functions for current values
    virtual void updateUniformBool( int i, bool val) = 0;
    virtual void updateUniformInt( int i, int val) = 0;
    virtual void updateUniformFloat( int i, float val) = 0;
    virtual void updateUniformBVec( int i, const bool* val) = 0;
    virtual void updateUniformIVec( int i, const int* val) = 0;
    virtual void updateUniformVec( int i, const float* val) = 0;
    virtual void updateUniformMat( int i, const float* val) = 0;
    virtual void updateUniformMat( int i, const double* val) = 0;
    virtual void updateSampler( int i, unsigned int val) = 0;

    //predefined attributes
    virtual bool usesColor() = 0;
    virtual bool usesNormal() = 0;
    virtual bool usesTexCoord( int set) = 0;
    virtual bool usesTangent() = 0;
    virtual bool usesBinormal() = 0;
    virtual int tangentSlot() = 0;
    virtual int binormalSlot() = 0;

    //error reporting
    virtual const char* errorString() = 0;

    static int size(DataType dt);
    static bool isBound(Semantic sm);

    //how do we handle error reporting?
    static shader* create( const char *filename);
    static std::string sError;
};

inline int shader::size(DataType dt) {

  switch (dt) {
    case dtFloat:
    case dtInt:
    case dtBool:
      return 1;
    case dtVec2:
    case dtIVec2:
    case dtBVec2:
      return 2;
    case dtVec3:
    case dtIVec3:
    case dtBVec3:
      return 3;
    case dtVec4:
    case dtIVec4:
    case dtBVec4:
      return 4;
    case dtMat2:
      return 4;
    case dtMat3:
      return 9;
    case dtMat4:
      return 16;
	default:
	  break;
  };

  return 0;
}

inline bool shader::isBound(Semantic sm) {
  if ( (sm >= smWorld) && (sm <= smWorldViewProjectionIT))
    return true;

  return false;
}

#endif //SHADER_H