// Glew include

#include <gl glew.h=""></gl>

// TnzCore includes

#include "tgl.h"

// Qt includes

#include <qcoreapplication></qcoreapplication>

#include <qthread></qthread>

#include <qdatetime></qdatetime>

#include <qopenglframebufferobject></qopenglframebufferobject>

#include <qopenglshaderprogram></qopenglshaderprogram>

#include <qopenglcontext></qopenglcontext>

#include <qoffscreensurface></qoffscreensurface>

#include <qopenglwidget></qopenglwidget>

// STD includes

#include <map></map>

#include <memory></memory>

#include "stdfx/shadingcontext.h"

//*****************************************************************

//    Local Namespace stuff

//*****************************************************************

namespace {

typedef std::unique_ptr<qopenglcontext> QOpenGLContextP;</qopenglcontext>

typedef std::unique_ptr<qopenglframebufferobject> QOpenGLFramebufferObjectP;</qopenglframebufferobject>

typedef std::unique_ptr<qopenglshaderprogram> QOpenGLShaderProgramP;</qopenglshaderprogram>

struct CompiledShader {

  QOpenGLShaderProgramP m_program;

  QDateTime m_lastModified;

public:

  CompiledShader() {}

  CompiledShader(const CompiledShader &) { assert(!m_program.get()); }

};

}  // namespace

TQOpenGLWidget::TQOpenGLWidget() {}

void TQOpenGLWidget::initializeGL() {

  QOffscreenSurface *surface = new QOffscreenSurface();

  // context()->create();

  // context()->makeCurrent(surface);

}

//*****************************************************************

//    ShadingContext::Imp  definition

//*****************************************************************

struct ShadingContext::Imp {

  QOpenGLContextP m_context;        //!< OpenGL context.

  QOpenGLFramebufferObjectP m_fbo;  //!< Output buffer.

  QOffscreenSurface *m_surface;

  std::map

           CompiledShader>

      m_shaderPrograms;  //!< Shader Programs stored in the context.

                         //!  \warning   Values have \p unique_ptr members.

public:

  Imp();

  static QSurfaceFormat format();

  void initMatrix(int lx, int ly);

private:

  // Not copyable

  Imp(const Imp &);

  Imp &operator=(const Imp &);

};

//--------------------------------------------------------

ShadingContext::Imp::Imp() : m_context(new QOpenGLContext()), m_surface() {}

//--------------------------------------------------------

QSurfaceFormat ShadingContext::Imp::format() {

  QSurfaceFormat fmt;

#ifdef MACOSX

  fmt.setVersion(3, 2);

  fmt.setProfile(QSurfaceFormat::CompatibilityProfile);

#endif

  return fmt;

}

//--------------------------------------------------------

void ShadingContext::Imp::initMatrix(int lx, int ly) {

  glViewport(0, 0, lx, ly);

  glMatrixMode(GL_PROJECTION);

  glLoadIdentity();

  gluOrtho2D(0, lx, 0, ly);

  glMatrixMode(GL_MODELVIEW);

  glLoadIdentity();

}

//*****************************************************************

//    ShadingContext  implementation

//*****************************************************************

ShadingContext::ShadingContext(QOffscreenSurface *surface) : m_imp(new Imp) {

  m_imp->m_surface = surface;

  m_imp->m_surface->create();

  QSurfaceFormat format;

  m_imp->m_context->setFormat(format);

  m_imp->m_context->create();

  m_imp->m_context->makeCurrent(m_imp->m_surface);

  // m_imp->m_pixelBuffer->context()->create();

  // m_imp->m_fbo(new QOpenGLFramebufferObject(1, 1));

  makeCurrent();

   if( GLEW_VERSION_3_2 ) {

       glewExperimental = GL_TRUE;

   }

  glewInit();

  doneCurrent();

}

//--------------------------------------------------------

ShadingContext::~ShadingContext() {

  // Destructor of QGLPixelBuffer calls QOpenGLContext::makeCurrent()

  // internally,

  // so the current thread must be the owner of QGLPixelBuffer context,

  // when the destructor of m_imp->m_context is called.

  m_imp->m_context->moveToThread(QThread::currentThread());

}

//--------------------------------------------------------

ShadingContext::Support ShadingContext::support() {

  // return !QGLPixelBuffer::hasOpenGLPbuffers()

  //           ? NO_PIXEL_BUFFER

  //           : !QOpenGLShaderProgram::hasOpenGLShaderPrograms() ? NO_SHADERS :

  //           OK;

  return !QOpenGLShaderProgram::hasOpenGLShaderPrograms() ? NO_SHADERS : OK;

}

//--------------------------------------------------------

bool ShadingContext::isValid() const { return m_imp->m_context->isValid(); }

//--------------------------------------------------------

/*

QGLFormat ShadingContext::defaultFormat(int channelsSize)

{

  QGL::FormatOptions opts =

    QGL::SingleBuffer     |

    QGL::NoAccumBuffer    |

    QGL::NoDepthBuffer    |                           // I guess it could be

necessary to let at least

    QGL::NoOverlay        |                           // the depth buffer

enabled... Fragment shaders could

    QGL::NoSampleBuffers  |                           // use it...

    QGL::NoStencilBuffer  |

    QGL::NoStereoBuffers;

  QGLFormat fmt(opts);

  fmt.setDirectRendering(true);                       // Just to be explicit -

USE HARDWARE ACCELERATION

  fmt.setRedBufferSize(channelsSize);

  fmt.setGreenBufferSize(channelsSize);

  fmt.setBlueBufferSize(channelsSize);

  fmt.setAlphaBufferSize(channelsSize);

  // TODO: 64-bit mode should be settable here

  return fmt;

}

*/

//--------------------------------------------------------

void ShadingContext::makeCurrent() {

  m_imp->m_context->moveToThread(QThread::currentThread());

  m_imp->m_context.reset(new QOpenGLContext());

  QSurfaceFormat format;

  m_imp->m_context->setFormat(format);

  m_imp->m_context->create();

  m_imp->m_context->makeCurrent(m_imp->m_surface);

}

//--------------------------------------------------------

void ShadingContext::doneCurrent() {

  m_imp->m_context->moveToThread(0);

  m_imp->m_context->doneCurrent();

}

//--------------------------------------------------------

void ShadingContext::resize(int lx, int ly,

                            const QOpenGLFramebufferObjectFormat &fmt) {

  if (m_imp->m_fbo.get() && m_imp->m_fbo->width() == lx &&

      m_imp->m_fbo->height() == ly && m_imp->m_fbo->format() == fmt)

    return;

  if (lx == 0 || ly == 0) {

    m_imp->m_fbo.reset(0);

  } else {

    bool get                         = m_imp->m_fbo.get();

    QOpenGLContext *currContext      = m_imp->m_context->currentContext();

    bool yes                         = false;

    if (currContext) bool yes        = true;

    while (!currContext) currContext = m_imp->m_context->currentContext();

    m_imp->m_fbo.reset(new QOpenGLFramebufferObject(lx, ly, fmt));

    assert(m_imp->m_fbo->isValid());

    m_imp->m_fbo->bind();

  }

}

//--------------------------------------------------------

QOpenGLFramebufferObjectFormat ShadingContext::format() const {

  QOpenGLFramebufferObject *fbo = m_imp->m_fbo.get();

  return fbo ? m_imp->m_fbo->format() : QOpenGLFramebufferObjectFormat();

}

//--------------------------------------------------------

TDimension ShadingContext::size() const {

  QOpenGLFramebufferObject *fbo = m_imp->m_fbo.get();

  return fbo ? TDimension(fbo->width(), fbo->height()) : TDimension();

}

//--------------------------------------------------------

void ShadingContext::addShaderProgram(const QString &shaderName,

                                      QOpenGLShaderProgram *program) {

  std::map<qstring, compiledshader="">::iterator st =</qstring,>

      m_imp->m_shaderPrograms

          .insert(std::make_pair(shaderName, CompiledShader()))

          .first;

  st->second.m_program.reset(program);

}

//--------------------------------------------------------

void ShadingContext::addShaderProgram(const QString &shaderName,

                                      QOpenGLShaderProgram *program,

                                      const QDateTime &lastModified) {

  std::map<qstring, compiledshader="">::iterator st =</qstring,>

      m_imp->m_shaderPrograms

          .insert(std::make_pair(shaderName, CompiledShader()))

          .first;

  st->second.m_program.reset(program);

  st->second.m_lastModified = lastModified;

}

//--------------------------------------------------------

bool ShadingContext::removeShaderProgram(const QString &shaderName) {

  return (m_imp->m_shaderPrograms.erase(shaderName) > 0);

}

//--------------------------------------------------------

QOpenGLShaderProgram *ShadingContext::shaderProgram(

    const QString &shaderName) const {

  std::map<qstring, compiledshader="">::iterator st =</qstring,>

      m_imp->m_shaderPrograms.find(shaderName);

  return (st != m_imp->m_shaderPrograms.end()) ? st->second.m_program.get() : 0;

}

//--------------------------------------------------------

QDateTime ShadingContext::lastModified(const QString &shaderName) const {

  std::map<qstring, compiledshader="">::iterator st =</qstring,>

      m_imp->m_shaderPrograms.find(shaderName);

  return (st != m_imp->m_shaderPrograms.end()) ? st->second.m_lastModified

                                               : QDateTime();

}

//--------------------------------------------------------

std::pair<qopenglshaderprogram *,="" qdatetime=""> ShadingContext::shaderData(</qopenglshaderprogram>

    const QString &shaderName) const {

  std::map<qstring, compiledshader="">::iterator st =</qstring,>

      m_imp->m_shaderPrograms.find(shaderName);

  return (st != m_imp->m_shaderPrograms.end())

             ? std::make_pair(st->second.m_program.get(),

                              st->second.m_lastModified)

             : std::make_pair((QOpenGLShaderProgram *)0, QDateTime());

}

//--------------------------------------------------------

GLuint ShadingContext::loadTexture(const TRasterP &src, GLuint texUnit) {

  glActiveTexture(GL_TEXTURE0 + texUnit);

  GLuint texId;

  glGenTextures(1, &texId);

  glBindTexture(GL_TEXTURE_2D, texId);

  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,

                  GL_CLAMP);  // These must be used on a bound texture,

  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,

                  GL_CLAMP);  // and are remembered in the OpenGL context.

  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,

                  GL_NEAREST);  // They can be set here, no need for

  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,

                  GL_NEAREST);  // the user to do it.

  glPixelStorei(GL_UNPACK_ROW_LENGTH, src->getWrap());

  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

  GLenum chanType = TRaster32P(src) ? GL_UNSIGNED_BYTE : GL_UNSIGNED_SHORT;

  glTexImage2D(GL_TEXTURE_2D,

               0,             // one level only

               GL_RGBA,       // pixel channels count

               src->getLx(),  // width

               src->getLy(),  // height

               0,             // border size

               TGL_FMT,       // pixel format

               chanType,      // channel data type

               (GLvoid *)src->getRawData());

  assert(glGetError() == GL_NO_ERROR);

  return texId;

}

//----------------------------------------------------------------------

void ShadingContext::unloadTexture(GLuint texId) {

  glDeleteTextures(1, &texId);

}

//--------------------------------------------------------

void ShadingContext::draw(const TRasterP &dst) {

  assert("ShadingContext::resize() must be invoked at least once before this" &&

         m_imp->m_fbo.get());

  int lx = dst->getLx(),

      ly = dst->getLy();  // NOTE: We're not using m_imp->m_fbo's size, since

                          // it could be possibly greater than the required

                          // destination surface.

  m_imp->initMatrix(lx, ly);  // This call sets the OpenGL viewport to this

                              // size - and matches (1, 1) to dst's (lx, ly)

  {

    glBegin(GL_QUADS);

    glVertex2f(0.0, 0.0);

    glVertex2f(lx, 0.0);

    glVertex2f(lx, ly);

    glVertex2f(0.0, ly);

    glEnd();

  }

  glPixelStorei(GL_PACK_ROW_LENGTH, dst->getWrap());

  // Read the fbo to dst

  if (TRaster32P ras32 = dst)

    glReadPixels(0, 0, lx, ly, GL_BGRA_EXT, GL_UNSIGNED_BYTE,

                 dst->getRawData());

  else {

    assert(TRaster64P(dst));

    glReadPixels(0, 0, lx, ly, GL_BGRA_EXT, GL_UNSIGNED_SHORT,

                 dst->getRawData());

  }

  assert(glGetError() == GL_NO_ERROR);

}

//--------------------------------------------------------

void ShadingContext::transformFeedback(int varyingsCount,

                                       const GLsizeiptr *varyingSizes,

                                       GLvoid **bufs) {

  // Generate buffer objects

  std::vector<gluint> bufferObjectNames(varyingsCount, 0);</gluint>

  glGenBuffers(varyingsCount, &bufferObjectNames[0]);

  for (int v = 0; v != varyingsCount; ++v) {

    glBindBuffer(GL_ARRAY_BUFFER, bufferObjectNames[v]);

    glBufferData(GL_ARRAY_BUFFER, varyingSizes[v], bufs[v], GL_STATIC_READ);

    glBindBuffer(GL_ARRAY_BUFFER, 0);

    glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, v, bufferObjectNames[v]);

  }

  // Draw

  GLuint Query = 0;

  glGenQueries(1, &Query);

  {

    // Disable rasterization, vertices processing only!

    glEnable(GL_RASTERIZER_DISCARD);

    glBeginQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN, Query);

    glBeginTransformFeedback(GL_POINTS);

    glBegin(GL_POINTS);

    glVertex2f(0.0f, 0.0f);

    glEnd();

    glEndTransformFeedback();

    glEndQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN);

    glDisable(GL_RASTERIZER_DISCARD);

  }

  GLint count = 0;

  glGetQueryObjectiv(Query, GL_QUERY_RESULT, &count);

  glDeleteQueries(1, &Query);

  // Retrieve transformed data

  for (int v = 0; v != varyingsCount; ++v) {

    glBindBuffer(GL_ARRAY_BUFFER, bufferObjectNames[v]);

    glGetBufferSubData(GL_ARRAY_BUFFER, 0, varyingSizes[v], bufs[v]);

  }

  glBindBuffer(GL_ARRAY_BUFFER, 0);

  // Delete buffer objects

  glDeleteBuffers(varyingsCount, &bufferObjectNames[0]);

}