#include "qtofflinegl.h"
#include <traster.h>
#include <tconvert.h>

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

#ifdef _WIN32

void swapRedBlueChannels(
    void *buffer,
    int bufferSize)  // Flips The Red And Blue Bytes (WidthxHeight)
{
  void *b = buffer;  // Pointer To The Buffer

#ifdef x64
  int size   = bufferSize;
  UCHAR *pix = (UCHAR *)b;
  while (size > 0) {
    UCHAR r    = *pix;
    UCHAR b    = *(pix + 2);
    *pix       = b;
    *(pix + 2) = r;
    pix += 4;
    size--;
  }
#else
  __asm        // Assembler Code To Follow
  {
		mov ecx, bufferSize  // Counter Set To Dimensions Of Our Memory Block
			mov ebx, b  // Points ebx To Our Data (b)
			label:  // Label Used For Looping
			mov al,[ebx+0]  // Loads Value At ebx Into al
			mov ah,[ebx+2]  // Loads Value At ebx+2 Into ah
			mov [ebx+2],al  // Stores Value In al At ebx+2
			mov [ebx+0],ah  // Stores Value In ah At ebx

			add ebx,4  // Moves Through The Data By 4 Bytes
			dec ecx  // Decreases Our Loop Counter
			jnz label  // If Not Zero Jump Back To Label
  }
#endif
}

#endif

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

#if defined(MACOSX)
#if defined(powerpc)

void rightRotateBits(UCHAR *buf, int bufferSize) {
  UINT *buffer = (UINT *)buf;
  UINT app;
  for (int i = 0; i < bufferSize; i++, buffer++) {
    app     = *buffer;
    *buffer = app >> 8 | app << 24;
  }
}
#else
void rightRotateBits(UCHAR *buf, int bufferSize) {
  UINT *buffer = (UINT *)buf;
  UINT app;
  for (int i = 0; i < bufferSize; i++, buffer++) {
    app     = *buffer;
    *buffer = (app >> 16 & 0x000000ff) | (app << 16 & 0x00ff0000) |
              (app & 0xff00ff00);
  }
}
#endif
#endif

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

//=============================================================================
// QtOfflineGL : implem. offlineGL usando QT
//-----------------------------------------------------------------------------

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

QtOfflineGL::QtOfflineGL(TDimension rasterSize,
                         std::shared_ptr<TOfflineGL::Imp> shared)
    : TOfflineGL::Imp(rasterSize.lx, rasterSize.ly)
    , m_context(0)
    , m_oldContext(0) {
  createContext(rasterSize, std::move(shared));
  /*
makeCurrent();

glClearColor(0.0f,0.0f,0.0f,0.0f);
glClear(GL_COLOR_BUFFER_BIT);

doneCurrent();
*/
}

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

QtOfflineGL::~QtOfflineGL() {}

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

void QtOfflineGL::createContext(TDimension rasterSize,
                                std::shared_ptr<TOfflineGL::Imp> shared) {
  // Imposto il formato dei Pixel (pixelFormat)
  /*
   32,                    // 32-bit color depth
   0, 0, 0, 0, 0, 0,      // color bits ignored
   8,                     // no alpha buffer
   0,                     // shift bit ignored
   0,                     // no accumulation buffer
   0, 0, 0, 0,            // accum bits ignored
   32,                    // 32-bit z-buffer
   32,                    // max stencil buffer
   0,                     // no auxiliary buffer
   PFD_MAIN_PLANE,        // main layer
   0,                     // reserved
   0, 0, 0                // layer masks ignored

   ATTENZIONE !! SU MAC IL FORMATO E' DIVERSO (casomai possiamo mettere un
   ifdef)

   SPECIFICHE  MAC = depth_size 24, stencil_size 8, alpha_size 1

*/

  QGLFormat fmt;

#if defined(_WIN32)
  fmt.setAlphaBufferSize(8);
  fmt.setAlpha(true);
  fmt.setRgba(true);
  fmt.setDepthBufferSize(32);
  fmt.setDepth(true);
  fmt.setStencilBufferSize(32);
  fmt.setStencil(true);
  fmt.setAccum(false);
  fmt.setPlane(0);
#elif defined(MACOSX)
  fmt = QGLFormat::defaultFormat();
  // printf("GL Version: %s\n",glGetString(GL_VERSION));
  fmt.setVersion(2, 1); /* OSX10.8 では 3.2 だめかも */
#if 0
  fmt.setAlphaBufferSize(8);
  fmt.setAlpha(true);
  fmt.setRgba(true);
  fmt.setDepthBufferSize(32);
  fmt.setDepth(true);
  fmt.setStencilBufferSize(8);
  fmt.setStencil(true);
  fmt.setAccum(false);
  fmt.setPlane(0);
  fmt.setDirectRendering(false);
#endif
#elif defined(LINUX)
  fmt = QGLFormat::defaultFormat();
  // printf("GL Version: %s\n",glGetString(GL_VERSION));
  fmt.setVersion(2, 1); /* XXX? */
#endif

  QSurfaceFormat format;
  format.setProfile(QSurfaceFormat::CompatibilityProfile);

  m_surface = std::make_shared<QOffscreenSurface>();
  m_surface->setFormat(format);
  m_surface->create();

  m_context = std::make_shared<QOpenGLContext>();
  m_context->setFormat(format);
  m_context->create();
  m_context->makeCurrent(m_surface.get());

  QOpenGLFramebufferObjectFormat fbo_format;
  m_fbo = std::make_shared<QOpenGLFramebufferObject>(rasterSize.lx,
                                                     rasterSize.ly, fbo_format);
  m_fbo->bind();

  printf("create context:%p [thread:0x%x]\n", m_context.get(),
         QThread::currentThreadId());

  // Creo il contesto OpenGL - assicurandomi che sia effettivamente creato
  // NOTA: Se il contesto non viene creato, di solito basta ritentare qualche
  // volta.
}
//-----------------------------------------------------------------------------

void QtOfflineGL::makeCurrent() {
  if (m_context) {
    m_context->moveToThread(QThread::currentThread());
    m_context->makeCurrent(m_surface.get());
  }
  // else
  //  m_oldContext = 0;
}

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

void QtOfflineGL::doneCurrent() {
  if (m_context) {
    m_context->doneCurrent();
  }
}

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

void QtOfflineGL::saveCurrentContext() {
  //  m_oldContext = const_cast<QGLContext*>(QGLContext::currentContext());
}

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

void QtOfflineGL::restoreCurrentContext() {
  //  if(m_oldContext) m_oldContext->makeCurrent();
  //  m_oldContext = 0;
}

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

void QtOfflineGL::getRaster(TRaster32P raster) {
  makeCurrent();
  glFlush();

  int lx = raster->getLx();
  int ly = raster->getLy();

  raster->lock();
  raster->copy(TRaster32P(lx, ly, m_fbo->width(),
                          (TPixelRGBM32 *)m_fbo->toImage(false).bits(), false));
  raster->unlock();
}

// QGLPixelBuffer::hasOpenGLPbuffers() (statica) -> true se la scheda supporta i
// PBuffer

//=============================================================================
// QtOfflineGLPBuffer : implem. offlineGL usando QT e PBuffer
//-----------------------------------------------------------------------------

QtOfflineGLPBuffer::QtOfflineGLPBuffer(TDimension rasterSize)
    : TOfflineGL::Imp(rasterSize.lx, rasterSize.ly), m_context(0) {
  createContext(rasterSize);

  makeCurrent();

  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
  glClear(GL_COLOR_BUFFER_BIT);

  doneCurrent();
}

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

QtOfflineGLPBuffer::~QtOfflineGLPBuffer() {}

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

void QtOfflineGLPBuffer::createContext(TDimension rasterSize) {
  // Imposto il formato dei Pixel (pixelFormat)
  /*
32,                    // 32-bit color depth
0, 0, 0, 0, 0, 0,      // color bits ignored
8,                     // no alpha buffer
0,                     // shift bit ignored
0,                     // no accumulation buffer
0, 0, 0, 0,            // accum bits ignored
32,                    // 32-bit z-buffer
32,                    // max stencil buffer
0,                     // no auxiliary buffer
PFD_MAIN_PLANE,        // main layer
0,                     // reserved
0, 0, 0                // layer masks ignored

ATTENZIONE !! SU MAC IL FORMATO E' DIVERSO (casomai possiamo mettere un ifdef)

SPECIFICHE  MAC = depth_size 24, stencil_size 8, alpha_size 1

*/

  QGLFormat fmt;

#if defined(_WIN32)
  fmt.setAlphaBufferSize(8);
  fmt.setAlpha(false);
  fmt.setRgba(true);
  fmt.setDepthBufferSize(32);
  fmt.setDepth(true);
  fmt.setStencilBufferSize(32);
  fmt.setStencil(true);
  fmt.setAccum(false);
  fmt.setPlane(0);
#elif defined(MACOSX)
  fmt.setAlphaBufferSize(1);
  fmt.setAlpha(false);
  fmt.setRgba(true);
  fmt.setDepthBufferSize(24);
  fmt.setDepth(true);
  fmt.setStencilBufferSize(8);
  fmt.setStencil(true);
  fmt.setAccum(false);
  fmt.setPlane(0);
#elif defined(LINUX)
  fmt.setAlphaBufferSize(1);
  fmt.setAlpha(false);
  fmt.setRgba(true);
  fmt.setDepthBufferSize(24);
  fmt.setDepth(true);
  fmt.setStencilBufferSize(8);
  fmt.setStencil(true);
  fmt.setAccum(false);
  fmt.setPlane(0);
#endif

  // Il PixelBuffer deve essere con width ed height potenze di 2

  int sizeMax = std::max(rasterSize.lx, rasterSize.ly);

  // trovo la potenza di 2 che "contiene" sizeMax e la utilizzo per il PBuffer
  int pBufferSize = 2;
  while (pBufferSize < sizeMax) pBufferSize *= 2;

  m_context =
      std::make_shared<QGLPixelBuffer>(QSize(pBufferSize, pBufferSize), fmt);
}

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

void QtOfflineGLPBuffer::makeCurrent() {
  if (m_context) {
    m_context->makeCurrent();
  }
}

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

void QtOfflineGLPBuffer::doneCurrent() {
  if (m_context) m_context->doneCurrent();
}

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

void QtOfflineGLPBuffer::getRaster(TRaster32P raster) {
  makeCurrent();
  glFlush();

  // The image is stored using a 32-bit ARGB format (0xAARRGGBB).
  QImage image = m_context->toImage();

  int lx = raster->getLx(), ly = raster->getLy();

  static const TRaster32P emptyRaster;
  if (image.height() == 0 || image.width() == 0) return;

  // devo iniziare a leggere la Y da un certo offset
  // dato dalla differenza tra la y della image e la y del raster
  int yOffset = image.height() - ly;
  raster->lock();

  for (int y = 0; y < ly; y++) {
    QRgb *inpPix = (QRgb *)image.scanLine(yOffset + y);

    TPixel32 *pix    = raster->pixels(ly - 1 - y);
    TPixel32 *endPix = pix + lx;

    for (; pix < endPix; ++pix) {
      pix->m = 255;
      pix->r = qRed(*inpPix);
      pix->g = qGreen(*inpPix);
      pix->b = qBlue(*inpPix);
      inpPix++;
    }
  }
  raster->unlock();
}