////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2011, Computer Graphics Group RWTH Aachen University         //
// All rights reserved.                                                       //
////////////////////////////////////////////////////////////////////////////////

#ifndef ACGL_RESOURCE_FRAMEBUFFER_HH
#define ACGL_RESOURCE_FRAMEBUFFER_HH

#include <ACGL/Resource/ResourceTypes.hh>
#include <ACGL/Resource/RenderBuffer.hh>
#include <ACGL/Resource/Texture.hh>
#include <ACGL/Utils/Log.hh>
#include <ACGL/Utils/StringOperations.hh>
#include <ACGL/GL.hh>

namespace ACGL{
namespace Resource{

class FrameBuffer
{
    // =================================================================================================== \/
    // ============================================================================================ STATIC \/
    // =================================================================================================== \/
private:
    static GLuint msBuffers[8];

    // ==================================================================================================== \/
    // ============================================================================================ STRUCTS \/
    // ==================================================================================================== \/
public:
    //! An attachment can be a texture or a render buffer
    struct Attachment
    {
        std::string name;
        SharedTexture texture;
        SharedRenderBuffer renderBuffer;
    };

    // ===================================================================================================== \/
    // ============================================================================================ TYPEDEFS \/
    // ===================================================================================================== \/
public:
    typedef std::vector< Attachment > AttachmentVec;

	// ========================================================================================================= \/
	// ============================================================================================ CONSTRUCTORS \/
	// ========================================================================================================= \/
public:
    FrameBuffer(GLsizei _width, GLsizei _height)
    :   mContext(0),
        mWidth(_width),
        mHeight(_height),
        mDrawBuffers(0),
        mColorAttachments(),
        mDepthAttachment()
    {
        glGenFramebuffers(1, &mContext);
        mDepthAttachment.name = "";
        mDepthAttachment.texture = SharedTexture();
        mDepthAttachment.renderBuffer = SharedRenderBuffer();
    }

    virtual ~FrameBuffer(void)
    {
        if(mContext != 0)
            glDeleteFramebuffers(1, &mContext);
    }

	// ==================================================================================================== \/
	// ============================================================================================ GETTERS \/
	// ==================================================================================================== \/
public:
    inline       GLuint         getContext          (void) const { return mContext;          }
    inline       GLsizei        getWidth            (void) const { return mWidth;            }
    inline       GLsizei        getHeight           (void) const { return mHeight;           }
    inline       GLsizei        getDrawBuffers      (void) const { return mDrawBuffers;      }
    inline const AttachmentVec& getColorAttachments (void) const { return mColorAttachments; }
    inline const Attachment&    getDepthAttachment  (void) const { return mDepthAttachment;  }

	// ===================================================================================================== \/
	// ============================================================================================ WRAPPERS \/
	// ===================================================================================================== \/
public:
    inline void bindAsRenderTarget(void) const
    {
        glBindFramebuffer(GL_FRAMEBUFFER, mContext);
        glDrawBuffers(mDrawBuffers, msBuffers);
    }

    inline void bind(void) const
    {
        glBindFramebuffer(GL_FRAMEBUFFER, mContext);
    }

    inline void setDrawBuffers(void) const
    {
        glDrawBuffers(mDrawBuffers, msBuffers);
    }

    inline void setViewport(void) const
    {
        glViewport(0, 0, mWidth, mHeight);
    }

    inline bool attachColorRenderBuffer(const SharedRenderBuffer& _renderBuffer)
    {
        if(_renderBuffer->getWidth() != mWidth && _renderBuffer->getHeight() != mHeight)
        {
            Utils::error() << "Attached render buffer for color has a wrong size!" << std::endl;
            return false;
        }
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + mDrawBuffers, GL_RENDERBUFFER, _renderBuffer->getContext());
        mDrawBuffers++;
        Attachment attachment = {"", SharedTexture(), _renderBuffer};
        mColorAttachments.push_back(attachment);
        return true;
    }

    inline bool attachColorTexture(const SharedTexture& _texture)
    {
        if(_texture->getWidth() != mWidth && _texture->getHeight() != mHeight)
        {
            Utils::error() << "Attached texture for color has a wrong size!" << std::endl;
            return false;
        }
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + mDrawBuffers, _texture->getTarget(), _texture->getContext(), 0);
        mDrawBuffers++;
        Attachment attachment = {"", _texture, SharedRenderBuffer()};
        mColorAttachments.push_back(attachment);
        return true;
    }

    inline bool setDepthRenderBuffer(const SharedRenderBuffer& _renderBuffer)
    {
        if(_renderBuffer->getWidth() != mWidth && _renderBuffer->getHeight() != mHeight)
        {
            Utils::error() << "Attached render buffer for depth has a wrong size!" << std::endl;
            return false;
        }
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _renderBuffer->getContext());
        #ifdef OPENGL_ES
            if( _renderBuffer->getInternalFormat() == GL_DEPTH24_STENCIL8_OES ||
                _renderBuffer->getInternalFormat() == GL_DEPTH_STENCIL_OES)
                glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, _renderBuffer->getContext());
        #else
            if( _renderBuffer->getInternalFormat() == GL_DEPTH24_STENCIL8 ||
                _renderBuffer->getInternalFormat() == GL_DEPTH_STENCIL)
                glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, _renderBuffer->getContext());
        #endif
        mDepthAttachment.renderBuffer = _renderBuffer;
        return true;
    }

    inline bool setDepthTexture(const SharedTexture& _texture)
    {
        if(_texture->getWidth() != mWidth && _texture->getHeight() != mHeight)
        {
            Utils::error() << "Attached texture for depth has a wrong size!" << std::endl;
            return false;
        }
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, _texture->getTarget(), _texture->getContext(), 0);
        #ifdef OPENGL_ES
            if( _texture->getInternalFormat() == GL_DEPTH24_STENCIL8_OES ||
                _texture->getInternalFormat() == GL_DEPTH_STENCIL_OES)
                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, _texture->getTarget(), _texture->getContext(), 0);
        #else
            if( _texture->getInternalFormat() == GL_DEPTH24_STENCIL8 ||
                _texture->getInternalFormat() == GL_DEPTH_STENCIL)
                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, _texture->getTarget(), _texture->getContext(), 0);
        #endif
        mDepthAttachment.texture = _texture;
        return true;
    }

    inline bool isFrameBufferComplete(void)
    {
        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
        {
            Utils::error() << "Failed to make complete FrameBuffer object: " << (glCheckFramebufferStatus(GL_FRAMEBUFFER)) << std::endl;
            return false;
        }
        return true;
    }

	// ==================================================================================================== \/
	// ============================================================================================ METHODS \/
	// ==================================================================================================== \/
protected:
    void clean(void);

	// =================================================================================================== \/
	// ============================================================================================ FIELDS \/
	// =================================================================================================== \/
protected:
    GLuint        mContext;
    GLsizei       mWidth;
    GLsizei       mHeight;
    GLsizei       mDrawBuffers;
    AttachmentVec mColorAttachments;
    Attachment    mDepthAttachment;
};

} // Resource
} // ACGL

#endif // ACGL_RESOURCE_FRAMEBUFFER_HH