gloscontext.cpp

来自「ncbi源码」· C++ 代码 · 共 133 行

/*
 * ===========================================================================
 * PRODUCTION $Log: gloscontext.cpp,v $
 * PRODUCTION Revision 1000.1  2004/06/01 20:53:05  gouriano
 * PRODUCTION PRODUCTION: UPGRADED [GCC34_MSVC7] Dev-tree R1.3
 * PRODUCTION
 * ===========================================================================
 */

/*  $Id: gloscontext.cpp,v 1000.1 2004/06/01 20:53:05 gouriano Exp $
 * ===========================================================================
 *
 *                            PUBLIC DOMAIN NOTICE
 *               National Center for Biotechnology Information
 *
 *  This software/database is a "United States Government Work" under the
 *  terms of the United States Copyright Act.  It was written as part of
 *  the author's official duties as a United States Government employee and
 *  thus cannot be copyrighted.  This software/database is freely available
 *  to the public for use. The National Library of Medicine and the U.S.
 *  Government have not placed any restriction on its use or reproduction.
 *
 *  Although all reasonable efforts have been taken to ensure the accuracy
 *  and reliability of the software and data, the NLM and the U.S.
 *  Government do not and cannot warrant the performance or results that
 *  may be obtained by using this software or data. The NLM and the U.S.
 *  Government disclaim all warranties, express or implied, including
 *  warranties of performance, merchantability or fitness for any particular
 *  purpose.
 *
 *  Please cite the author in any work or product based on this material.
 *
 * ===========================================================================
 *
 * Authors:  Mike DiCuccio
 *
 * File Description:
 *    CGlOsContext -- wrapper for Mesa3D's off-screen rendering extension
 */

#include <ncbi_pch.hpp>
#include <gui/opengl/mesa/gloscontext.hpp>

BEGIN_NCBI_SCOPE


//
// CGlOsContext ctor
// initialize our renderer with a virtual frame buffer of a given size.
// This frame buffer will always be initialized as an RGBA image.
CGlOsContext::CGlOsContext(size_t width, size_t height)
    : m_Image(new CImage(width, height, 4))
{
    // create our off-screen mesa rendering context
    // this context will use the screen image we've defined
#if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
    m_Ctx = OSMesaCreateContextExt( OSMESA_RGBA, 16, 0, 0, NULL );
#else
    m_Ctx = OSMesaCreateContext( OSMESA_RGBA, NULL );
#endif

    if ( !m_Ctx ) {
        LOG_POST(Error << "CGlOsContext(): "
                 "Failed to create off-screen rendering context");
    }
}


// destructor for cleaning up our OSMesa context
CGlOsContext::~CGlOsContext()
{
    if (m_Ctx) {
        OSMesaDestroyContext(m_Ctx);
    }
}


// make the current frame buffer the active buffer for rendering
bool CGlOsContext::MakeCurrent(void)
{
    if ( !m_Ctx ) {
        LOG_POST(Error << "CGlOsContext::MakeCurrent(): "
                 "Attempt to make an invalid context current");
        return false;
    }

    if ( !OSMesaMakeCurrent(m_Ctx, m_Image->SetData(), GL_UNSIGNED_BYTE,
                            m_Image->GetWidth(), m_Image->GetHeight()) ) {
        LOG_POST(Error << "CGlOsContext::MakeCurrent(): "
                 "Failed to make image surface current");
        return false;
    }

    return true;
}


// access the image we use for the virtual frame buffer
const CImage& CGlOsContext::GetBuffer(void) const
{
    return *m_Image;
}


// access the image we use for the virtual frame buffer
CImage& CGlOsContext::SetBuffer(void)
{
    return *m_Image;
}


END_NCBI_SCOPE


/*
 * ===========================================================================
 * $Log: gloscontext.cpp,v $
 * Revision 1000.1  2004/06/01 20:53:05  gouriano
 * PRODUCTION: UPGRADED [GCC34_MSVC7] Dev-tree R1.3
 *
 * Revision 1.3  2004/05/21 22:27:45  gorelenk
 * Added PCH ncbi_pch.hpp
 *
 * Revision 1.2  2003/06/12 19:46:21  dicuccio
 * Added non-const accessor for the image buffer
 *
 * Revision 1.1  2003/06/09 19:21:44  dicuccio
 * Initial revision
 *
 * ===========================================================================
 */