source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/FrameBufferObject.cpp @ 2991

#include <iostream>
#include "FrameBufferObject.h"
#include "glInterface.h"

using namespace std;


namespace CHCDemoEngine
{


void PrintFBOStatus(GLenum status)
{
        switch(status)
        {
        case GL_FRAMEBUFFER_COMPLETE_EXT:
                //cout << "frame buffer object complete" << endl;
                break;
        case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:
                cerr << "incomplete attachment" << endl;
                break;
        case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
                cerr << "missing attachment" << endl;
                break;
        case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
                cerr << "incomplete dimensions" << endl;
                break;
        case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
                cerr << "incomplete formats" << endl;
                break;
        case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
                cerr << "incomplete draw buffer" << endl;
                break;
        case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
                cerr << "incomplete read buffer" << endl;
                break;
        case GL_FRAMEBUFFER_UNSUPPORTED_EXT:
                cerr << "framebuffer unsupported" << endl;
                break;
        default:
                cerr << "unknown status code " << status << endl;
        }
}


ColorBufferObject::ColorBufferObject(int w, int h, 
                                                                         int attachment_idx,
                                                                         FORMAT format, 
                                                                         WRAP_TYPE wrapType, 
                                                                         FILTER_TYPE filterType, 
                                                                         FILTER_TYPE filterTypeMipMap 
                                                                         )
{
        Init(w, h, attachment_idx, format, wrapType, filterType, true, filterTypeMipMap);
}


ColorBufferObject::ColorBufferObject(int w, int h, 
                                                                         int attachment_idx,
                                                                         FORMAT format, 
                                                                         WRAP_TYPE wrapType, 
                                                                         FILTER_TYPE filterType
                                                                         )
{
        Init(w, h, attachment_idx, format, wrapType, filterType, false, FILTER_NEAREST);
}


ColorBufferObject::~ColorBufferObject()
{
        glDeleteRenderbuffersEXT(1, &mId);
        glDeleteTextures(1, &mTexId);
}


void ColorBufferObject::Init(int w, int h, 
                                                         int attachment_idx,
                                                         FORMAT format, 
                                                         WRAP_TYPE wrapType, 
                                                         FILTER_TYPE filterType, 
                                                         bool useMipMap, 
                                                         FILTER_TYPE filterTypeMipMap
                                                         )
{
        mWidth = w;
        mHeight = h;

        switch (format)
        {
        case BUFFER_UBYTE:
                mGlFormat = GL_UNSIGNED_BYTE; mInternalFormat = GL_RGBA8; break;
        case BUFFER_FLOAT_16:
                mGlFormat = GL_FLOAT; mInternalFormat = GL_RGBA16F_ARB; break;
        case BUFFER_FLOAT_32: 
                mGlFormat = GL_FLOAT; mInternalFormat = GL_RGBA32F_ARB; break;
        default:
                mGlFormat = GL_UNSIGNED_BYTE; mInternalFormat = GL_RGBA8;
                cerr << "should not come here" << endl;
        }


        glGenRenderbuffersEXT(1, &mId);
        glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, mId);
        
        glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, mInternalFormat, w, h);
        glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, mrt[attachment_idx], GL_RENDERBUFFER_EXT, mId);


        glGenTextures(1, &mTexId);
        glBindTexture(GL_TEXTURE_2D, mTexId);
        glTexImage2D(GL_TEXTURE_2D, 0, mInternalFormat, w, h, 0, GL_RGBA, mGlFormat, NULL);

        glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, mrt[attachment_idx], GL_TEXTURE_2D, mTexId, 0);

        GLuint minfilterParam;
        GLuint magfilterParam;

        if (filterType == FILTER_NEAREST)
                magfilterParam = GL_NEAREST;
        else // FILTER_LINEAR
                magfilterParam = GL_LINEAR; 

        if (!useMipMap)
        {
                if (filterType == FILTER_NEAREST)
                        minfilterParam = GL_NEAREST;
                else // FILTER_LINEAR
                        minfilterParam = GL_LINEAR;
        }
        else
        {
                if (filterType == FILTER_NEAREST)
                {
                        if (filterTypeMipMap == FILTER_NEAREST)
                                minfilterParam = GL_NEAREST_MIPMAP_NEAREST;
                        else // FILTER_LINEAR
                                minfilterParam = GL_NEAREST_MIPMAP_LINEAR;
                }
                else // FILTER_LINEAR
                {
                        if (filterTypeMipMap == FILTER_NEAREST)
                                minfilterParam = GL_LINEAR_MIPMAP_NEAREST;
                        else // FILTER_LINEAR
                                minfilterParam = GL_LINEAR_MIPMAP_LINEAR;
                }
        }

        GLuint wrapParam;

        switch (wrapType)
        {
        case WRAP_REPEAT:
                wrapParam = GL_REPEAT; break;
        case WRAP_CLAMP_TO_EDGE:
                wrapParam = GL_CLAMP_TO_EDGE; break;
        }

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magfilterParam);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minfilterParam);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapParam);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapParam);

        if (useMipMap) 
        {
                glGenerateMipmapEXT(GL_TEXTURE_2D);
        }

        // print status
        PrintFBOStatus(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT));
}



void *ColorBufferObject::ReadTexture() const
{
        int bytes = 0;

        switch (mInternalFormat)
        {
        case GL_RGBA8:
                bytes = 8; break;
        case GL_RGBA16F_ARB:
                bytes = 16; break;
        case GL_RGBA32F_ARB: 
                bytes = 32; break;
        default:
                cerr << "should not come here" << endl;
        }

        
        glBindTexture(GL_TEXTURE_2D, mTexId);
        
        GLint width, height;
        glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &width);
        glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &height);

        //cout << "w: " << width << "h: " << height << endl;

        unsigned char *data = new unsigned char[bytes * 4 * width * height];

        glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_FLOAT, data);

        glBindTexture(GL_TEXTURE_2D, 0);
        glDisable(GL_TEXTURE_2D);

        float *d = (float *)data;

        return data;
}


/*****************************************************************/
/*                 FrameBufferObject implementation              */
/*****************************************************************/


FrameBufferObject::FrameBufferObject(int w, int h, DEPTH_FORMAT d, bool useDepthTex)
: mWidth(w), mHeight(h), mDepthTexId(0)
{
        glGenFramebuffersEXT(1, &mId);
        
        Bind();
        ///////////
        //-- create depth buffer

        if (d != DEPTH_NONE)
        {
                glGenRenderbuffersEXT(1, &mDepthId);    
                glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, mDepthId);

                GLuint depthFormat;

                switch (d)
                {
                case DEPTH_16:
                        depthFormat = GL_DEPTH_COMPONENT16; break;
                case DEPTH_24:
                        depthFormat = GL_DEPTH_COMPONENT24; break;
                case DEPTH_32: 
                        depthFormat = GL_DEPTH_COMPONENT32; break;
                default:        
                        cerr << "should not come here" << endl;
                }

                glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, depthFormat, w, h);
                

                glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, mDepthId);

                if (useDepthTex)
                {
                        glGenTextures(1, &mDepthTexId);
                        glBindTexture(GL_TEXTURE_2D, mDepthTexId);

                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
                        
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

                        glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

                        glTexImage2D(GL_TEXTURE_2D, 0, depthFormat, mWidth, mHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);

                        glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, mDepthTexId, 0);
                }
        }

        Release();
}


FrameBufferObject::~FrameBufferObject()
{
        glDeleteFramebuffersEXT(1, &mId);
        glDeleteRenderbuffersEXT(1, &mDepthId);

        if (mDepthTexId) glDeleteTextures(1, &mDepthTexId);

        CLEAR_CONTAINER(mColorBuffers);
}


int FrameBufferObject::AddColorBuffer(ColorBufferObject::FORMAT col, 
                                                                          ColorBufferObject::WRAP_TYPE wrapType, 
                                                                          ColorBufferObject::FILTER_TYPE filterType, 
                                                                          ColorBufferObject::FILTER_TYPE filterTypeMipMap)
{
        Bind();

        const int idx = (int)mColorBuffers.size();

        ColorBufferObject *colorBuf = 
                new ColorBufferObject(mWidth, mHeight, idx, col, wrapType, filterType, filterTypeMipMap);

        mColorBuffers.push_back(colorBuf);

        Release();

        return idx;
}



int FrameBufferObject::AddColorBuffer(ColorBufferObject::FORMAT col, 
                                                                          ColorBufferObject::WRAP_TYPE wrapType, 
                                                                          ColorBufferObject::FILTER_TYPE filterType)
{
        Bind();

        const int idx = (int)mColorBuffers.size();

        ColorBufferObject *colorBuf = 
                new ColorBufferObject(mWidth, mHeight, idx, col, wrapType, filterType);

        mColorBuffers.push_back(colorBuf);

        Release();

        return idx;
}


void FrameBufferObject::Bind() const
{
        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, mId);
}


void FrameBufferObject::Release()
{
        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}


} // namespace