//##################################################################################################
//
//   Custom Visualization Core library
//   Copyright (C) 2011-2013 Ceetron AS
//
//   This library may be used under the terms of either the GNU General Public License or
//   the GNU Lesser General Public License as follows:
//
//   GNU General Public License Usage
//   This library is free software: you can redistribute it and/or modify
//   it under the terms of the GNU General Public License as published by
//   the Free Software Foundation, either version 3 of the License, or
//   (at your option) any later version.
//
//   This library 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 General Public License at <<http://www.gnu.org/licenses/gpl.html>>
//   for more details.
//
//   GNU Lesser General Public License Usage
//   This library 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 2.1 of the License, or
//   (at your option) any later version.
//
//   This library 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 at <<http://www.gnu.org/licenses/lgpl-2.1.html>>
//   for more details.
//
//##################################################################################################


#pragma once

#include "cvfRenderState.h"
#include "cvfString.h"

namespace cvf {

class Sampler;
class Texture;
class ShaderProgram;


//==================================================================================================
//
// Binds a texture and a sampler to a texture unit
//
//==================================================================================================
class RenderStateTextureBindings : public RenderState
{
public:
    RenderStateTextureBindings();
    RenderStateTextureBindings(Texture* texture, Sampler* sampler, const char* samplerUniformName);
    ~RenderStateTextureBindings();

    void            addBinding(Texture* texture, Sampler* sampler, const char* samplerUniformName);
    int             bindingCount() const;

    Texture*        texture(int bindingIdx);
    const Texture*  texture(int bindingIdx) const;
    Sampler*        sampler(int bindingIdx);
    const Sampler*  sampler(int bindingIdx) const;
    String          samplerUniformName(int bindingIdx) const;
    
    virtual void    applyOpenGL(OpenGLContext* oglContext) const;
    void            setupTextures(OpenGLContext* oglContext);
    void            applySamplerTextureUnitUniforms(OpenGLContext* oglContext, ShaderProgram* shaderProgram) const;

public:
    static const int MAX_TEXTURE_UNITS = 16;

private:
    struct BindingEntry
    {
        ref<Texture>    texture;     
        ref<Sampler>    sampler;  
        String          samplerUniformName; 
    };

    BindingEntry    m_bindings[MAX_TEXTURE_UNITS];
    int             m_bindingCount;
};


}  // namespace cvf