GeometryShader.h

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/*********************************************************\
 *  File: GeometryShader.h                               *
 *
 *  Copyright (C) 2002-2012 The PixelLight Team (http://www.pixellight.org/)
 *
 *  This file is part of PixelLight.
 *
 *  PixelLight is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  PixelLight is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with PixelLight. If not, see <http://www.gnu.org/licenses/>.
\*********************************************************/


#ifndef __PLRENDERER_GEOMETRYSHADER_H__
#define __PLRENDERER_GEOMETRYSHADER_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLRenderer/Renderer/Shader.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLRenderer {


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Abstract renderer geometry shader resource
*/
class GeometryShader : public Shader {


    //[-------------------------------------------------------]
    //[ Public definitions                                    ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Input primitive type
        */
        enum EInputPrimitiveType {
            InputPoints             =  0,   /**< List of point primitives */
            InputLines              =  1,   /**< List of line or line strip primitives */
            InputLinesAdjacency     =  2,   /**< List of line with adjacency or line strip with adjacency primitives */
            InputTriangles          =  3,   /**< List of triangle or triangle strip primitives */
            InputTrianglesAdjacency =  4    /**< List of triangle with adjacency or triangle strip with adjacency primitives */
        };

        /**
        *  @brief
        *    Output primitive type
        */
        enum EOutputPrimitiveType {
            OutputPoints    =  0,   /**< A list of of point primitives */
            OutputLines     =  1,   /**< A list of line primitives */
            OutputTriangles =  2    /**< A list of triangle primitives */
        };


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Destructor
        */
        PLRENDERER_API virtual ~GeometryShader();


    //[-------------------------------------------------------]
    //[ Public virtual GeometryShader functions               ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Returns the input primitive type
        *
        *  @return
        *    The input primitive type
        */
        virtual EInputPrimitiveType GetInputPrimitiveType() const = 0;

        /**
        *  @brief
        *    Returns the output primitive type
        *
        *  @return
        *    The output primitive type
        */
        virtual EOutputPrimitiveType GetOutputPrimitiveType() const = 0;

        /**
        *  @brief
        *    Returns the number of output vertices
        *
        *  @return
        *    The number of output vertices, 0 if the maximum possible number of output vertices should be used
        */
        virtual PLCore::uint32 GetNumOfOutputVertices() const = 0;

        /**
        *  @brief
        *    Sets the geometry shader source code
        *
        *  @param[in] sSourceCode
        *    Geometry shader source code, usually blank ASCII code
        *  @param[in] nInputPrimitiveType
        *    Input primitive type, for "Shader::SetSourceCode()" "InputTriangles" is used as default
        *  @param[in] nOutputPrimitiveType
        *    Output primitive type, for "Shader::SetSourceCode()" "OutputTriangles" is used as default
        *  @param[in] nNumOfOutputVertices
        *    Number of output vertices, 0 if the maximum possible number of output vertices should be used, for "Shader::SetSourceCode()" "0" is used as default
        *  @param[in] sProfile
        *    Geometry shader profile to use, if empty string, a default profile will be used which usually
        *    tries to use the best available profile that runs on most hardware
        *  @param[in] sArguments
        *    Optional shader compiler arguments, e.g. "version=150" when using Cg and a "glslg" profile
        *  @param[in] sEntry
        *    Entry point, if empty string, "main" is used as default
        *
        *  @return
        *    'true' if all went fine, else 'false'
        *
        *  @remarks
        *    Extended version of "Shader::SetSourceCode()" for geometry shaders allowing also to specify
        *    the input/output primitives and the number of generated vertices. Please note that not each
        *    internal implementation may actually need this information, but it's highly recommended to
        *    provide this information anyway to be able to switch the internal implementation (e.g. using
        *    OpenGL instead of DirectX and/or Cg instead of HLSL/GLSL).
        *
        *  @see
        *   - "Shader::SetSourceCode()" for additional information
        */
        virtual bool SetSourceCode(const PLCore::String &sSourceCode, EInputPrimitiveType nInputPrimitiveType, EOutputPrimitiveType nOutputPrimitiveType, PLCore::uint32 nNumOfOutputVertices, const PLCore::String &sProfile = "", const PLCore::String &sArguments = "", const PLCore::String &sEntry = "") = 0;


    //[-------------------------------------------------------]
    //[ Protected functions                                   ]
    //[-------------------------------------------------------]
    protected:
        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] cRenderer
        *    Owner renderer
        */
        PLRENDERER_API GeometryShader(Renderer &cRenderer);


    //[-------------------------------------------------------]
    //[ Private functions                                     ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Copy constructor
        *
        *  @param[in] cSource
        *    Source to copy from
        */
        GeometryShader(const GeometryShader &cSource);

        /**
        *  @brief
        *    Copy operator
        *
        *  @param[in] cSource
        *    Source to copy from
        *
        *  @return
        *    Reference to this instance
        */
        GeometryShader &operator =(const GeometryShader &cSource);


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLRenderer


#endif // __PLRENDERER_GEOMETRYSHADER_H__