// Version:    <1.0>

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// Copyright ( C ) 2008 Apple Inc. All Rights Reserved.

//

////////////////////////////////////////////////////////////////////////////////////////////////////

#include "fbo.h"

#include <OpenGL/gl.h>

#include <OpenGL/glu.h>

FrameBufferObject::FrameBufferObject() :

    m_bIsEnabled(false),

    m_uiWidth(0),

    m_uiHeight(0),

    m_uiFramebufferId(0),

    m_uiRenderbufferId(0)

{

    memset(m_abAttached, false, 64 * sizeof(bool));

}

FrameBufferObject::~FrameBufferObject()

{

    destroy();

}

void

FrameBufferObject::destroy()

{

    disable();

    if(m_uiRenderbufferId)

    {

        glDeleteRenderbuffersEXT(1, &m_uiRenderbufferId);

        m_uiRenderbufferId = 0;

    }   

    if(m_uiFramebufferId)

    {

        glDeleteFramebuffersEXT(1, &m_uiFramebufferId);

        m_uiFramebufferId = 0;

    }   

    memset(m_abAttached, false, 64 * sizeof(bool));

}

bool

FrameBufferObject::setup(

    uint uiWidth, uint uiHeight, bool bUseRenderbuffer)

{

    destroy();

    m_uiWidth = uiWidth;

    m_uiHeight = uiHeight;

    if(bUseRenderbuffer)

    {

        m_uiRenderbufferId = createRenderbuffer(uiWidth, uiHeight);

        if(m_uiRenderbufferId == 0)

            return false;

    }

    m_uiFramebufferId = createFramebuffer();   

    if(m_uiFramebufferId == 0)

        return false;

    return true;

}

void

FrameBufferObject::enable(bool bClear)

{

    if(m_bIsEnabled)

        return;

    if(m_uiFramebufferId == 0)

        return;

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_uiFramebufferId);

//    checkFramebufferStatus("Binding framebuffer");

    if(m_uiRenderbufferId != 0)

    {

        glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, 

                                     GL_DEPTH_ATTACHMENT_EXT, 

                                     GL_RENDERBUFFER_EXT, 

                                     m_uiRenderbufferId);

        checkFramebufferStatus("Binding render buffer");

    }

    if(bClear)

    {

        glViewport(0, 0, m_uiWidth, m_uiHeight);

        GLbitfield bfBuffers = 0;

        if(isColorUsed())

            bfBuffers |= GL_COLOR_BUFFER_BIT;

        if(isDepthUsed())

            bfBuffers |= GL_DEPTH_BUFFER_BIT;

        if(isStencilUsed())

            bfBuffers |= GL_STENCIL_BUFFER_BIT;

        if(bfBuffers)

            glClear(bfBuffers);

        checkFramebufferStatus("Clearing framebuffer");

    }

    m_bIsEnabled = true;

}

void

FrameBufferObject::disable()

{

    if(!m_bIsEnabled)

        return;

//    checkFramebufferStatus("Disabling framebuffer");

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);    

    m_bIsEnabled = false;

}

void

FrameBufferObject::attach(

    GLenum eAttachment, 

    GLenum eTarget, 

    uint uiTextureId)

{

    printf("FrameBufferObject: Attaching Framebuffer [%d] Texture [%d] %d \n", 

        m_uiFramebufferId, uiTextureId, (int)eTarget);

    enable();

    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, 

                              eAttachment, eTarget, 

                              uiTextureId, 0);

    uint uiIndex = (uint)eAttachment - (uint)GL_COLOR_ATTACHMENT0_EXT;

    m_abAttached[uiIndex] = true;

    if(isDepthUsed() && !isColorUsed())

    {

        glReadBuffer(GL_NONE);

        glDrawBuffer(GL_NONE);

        printf("FrameBufferObject: Disabling read and draw buffers\n");

    }

    checkFramebufferStatus("Attaching texture");

    disable();

}

void

FrameBufferObject::detach(

    GLenum eAttachment,

    GLenum eTarget)

{

    printf("FrameBufferObject: Detaching Framebuffer [%d] Texture [x] %d\n", 

        m_uiFramebufferId, (int)eTarget);

    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, 

                              eAttachment, 

                              eTarget, 

                              0, 0);

    uint uiIndex = (uint)eAttachment - (uint)GL_COLOR_ATTACHMENT0_EXT;

    m_abAttached[uiIndex] = false;

}

bool

FrameBufferObject::isAttached(

    GLenum eAttachment)

{

    uint uiIndex = (uint)eAttachment - (uint)GL_COLOR_ATTACHMENT0_EXT;

    if(uiIndex >= GL_COLOR_ATTACHMENT0_EXT && uiIndex < 64)

        return m_abAttached[uiIndex];

    return false;

}

bool

FrameBufferObject::isColorUsed()

{

    for(uint i = (uint)GL_COLOR_ATTACHMENT0_EXT; i <= (uint)GL_COLOR_ATTACHMENT15_EXT; i++)

    {

        uint uiIndex = i - (uint)GL_COLOR_ATTACHMENT0_EXT;

        if(m_abAttached[uiIndex])

            return true;

    }

    return false;

}

bool

FrameBufferObject::isDepthUsed()

{

    if(m_uiRenderbufferId)

        return true;

    uint uiIndex = (uint)GL_DEPTH_ATTACHMENT_EXT - (uint)GL_COLOR_ATTACHMENT0_EXT;

    if(m_abAttached[uiIndex])

        return true;

    return false;

}

bool

FrameBufferObject::isStencilUsed()

{

    uint uiIndex = (uint)GL_STENCIL_ATTACHMENT_EXT - (uint)GL_COLOR_ATTACHMENT0_EXT;

    if(m_abAttached[uiIndex])

        return true;

    return false;

}

uint 

FrameBufferObject::createFramebuffer()

{

    uint uiFboId = 0;

    glGenFramebuffersEXT(1, &uiFboId);

    printf("FrameBufferObject: Created Framebuffer %d\n", uiFboId);

    return uiFboId;

}

uint 

FrameBufferObject::createRenderbuffer(

    uint uiWidth, uint uiHeight)

{

    uint uiRboId = 0;

    GLint iDepthBits = 0;

    GLenum eDepthType = GL_DEPTH_COMPONENT24_ARB;

    glGetIntegerv(GL_DEPTH_BITS, &iDepthBits);

    if (iDepthBits == 16)

        eDepthType = GL_DEPTH_COMPONENT16_ARB;

    else if(iDepthBits == 24)

        eDepthType = GL_DEPTH_COMPONENT24_ARB;

    else if(iDepthBits == 32)

        eDepthType = GL_DEPTH_COMPONENT32_ARB;

    glGenRenderbuffersEXT(1, &uiRboId);

    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, uiRboId);

    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, eDepthType, uiWidth, uiHeight);

    printf("FrameBufferObject: Created Renderbuffer %d\n", uiRboId);

    return uiRboId;

}

void

FrameBufferObject::checkFramebufferStatus(const char *acMessage)

{

    GLenum eStatus = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);

    if(eStatus == GL_FRAMEBUFFER_COMPLETE_EXT)

        return;

    if(acMessage)

        printf("FrameBufferObject: FBO Error: %s\n", acMessage);

    switch(eStatus) 

    {                                          

    case GL_FRAMEBUFFER_COMPLETE_EXT: 

        break;                                                

    case GL_FRAMEBUFFER_UNSUPPORTED_EXT:                   

        printf("FrameBufferObject: FBO Error: Format Unsupported!\n");

        break;       

    case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:

        printf("FrameBufferObject: FBO Error: Incomplete Attachment!\n");

        break;                                      

    case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:

        printf("FrameBufferObject: FBO Error: Incomplete Missing Attachment!\n");

        break;                              

    case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:

        printf("FrameBufferObject: FBO Error: Incomplete Dimensions!\n");

        break;                              

    case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:

        printf("FrameBufferObject: FBO Error: Incomplete Formats!\n");

        break;                              

    case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:

        printf("FrameBufferObject: FBO Error: Incomplete Draw Buffer!\n");

        break;                                  

    case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:

        printf("FrameBufferObject: FBO Error: Incomplete Read Buffer!\n");

        break;                                  

    default:

        printf("FrameBufferObject: Unknown FBO Status Error '%d'\n", (int)eStatus);

        break;

    }

    GLenum eError = glGetError();

    switch(eError)

    {

    case(0):

        break;

    case(GL_INVALID_FRAMEBUFFER_OPERATION_EXT):

        printf("FrameBufferObject: OpenGL Error: Invalid Framebuffer Operation!\n");

        break;

    case(GL_INVALID_ENUM):

        printf("FrameBufferObject: OpenGL Error: Invalid Enumerate!\n");

        break;

    case(GL_INVALID_VALUE):

        printf("FrameBufferObject: OpenGL Error: Invalid Value!\n");

        break;

    case(GL_INVALID_OPERATION):

        printf("FrameBufferObject: OpenGL Error: Invalid Operation!\n");

        break;

    case(GL_STACK_OVERFLOW):

        printf("FrameBufferObject: OpenGL Error: Stack Overflow!\n");

        break;

    case(GL_STACK_UNDERFLOW):

        printf("FrameBufferObject: OpenGL Error: Stack Underflow!\n");

        break;

    case(GL_OUT_OF_MEMORY):

        printf("FrameBufferObject: OpenGL Error: Out of Memory!\n");

        break;

    default:

        printf("FrameBufferObject: Unknown OpenGL Error '%d'\n", (int)eError);

        break;

    }

}