vpGDIRenderer.cpp

/****************************************************************************
 *
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2019 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See http://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * GDI renderer for windows 32 display
 *
 * Authors:
 * Bruno Renier
 *
 *****************************************************************************/

#include <visp3/core/vpConfig.h>
#define GDI_ROBUST
#if (defined(VISP_HAVE_GDI))

#ifndef DOXYGEN_SHOULD_SKIP_THIS

#include <visp3/gui/vpGDIRenderer.h>

vpGDIRenderer::vpGDIRenderer() : m_bmp(NULL), m_bmp_width(0), m_bmp_height(0), timelost(0)
{
  // if the screen depth is not 32bpp, throw an exception
  int bpp = GetDeviceCaps(GetDC(NULL), BITSPIXEL);
  if (bpp != 32)
    throw vpDisplayException(vpDisplayException::depthNotSupportedError,
                             "vpGDIRenderer supports only 32bits depth: screen is %dbits depth!", bpp);

  InitializeCriticalSection(&m_criticalSection);

  // initialize GDI the palette
  vpColor pcolor; // Predefined colors

  pcolor = vpColor::black;
  m_colors[vpColor::id_black] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::lightBlue;
  m_colors[vpColor::id_lightBlue] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::blue;
  m_colors[vpColor::id_blue] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::darkBlue;
  m_colors[vpColor::id_darkBlue] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::cyan;
  m_colors[vpColor::id_cyan] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::lightGreen;
  m_colors[vpColor::id_lightGreen] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::green;
  m_colors[vpColor::id_green] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::darkGreen;
  m_colors[vpColor::id_darkGreen] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::lightRed;
  m_colors[vpColor::id_lightRed] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::red;
  m_colors[vpColor::id_red] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::darkRed;
  m_colors[vpColor::id_darkRed] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::white;
  m_colors[vpColor::id_white] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::lightGray;
  m_colors[vpColor::id_lightGray] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::gray;
  m_colors[vpColor::id_gray] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::darkGray;
  m_colors[vpColor::id_darkGray] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::yellow;
  m_colors[vpColor::id_yellow] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::orange;
  m_colors[vpColor::id_orange] = RGB(pcolor.R, pcolor.G, pcolor.B);
  pcolor = vpColor::purple;
  m_colors[vpColor::id_purple] = RGB(pcolor.R, pcolor.G, pcolor.B);

  m_rwidth = 0;
  m_rheight = 0;
}

vpGDIRenderer::~vpGDIRenderer()
{
  // Deletes the critical section object
  DeleteCriticalSection(&m_criticalSection);
  // Deletes the bitmap
  DeleteObject(m_bmp);
  // Deletes the font object
  DeleteObject(m_hFont);
}

bool vpGDIRenderer::init(HWND hWindow, unsigned int width, unsigned int height)
{
  timelost = 0.;
  m_hWnd = hWindow;

  m_rwidth = width;
  m_rheight = height;

  // creates the font
  m_hFont = CreateFont(18, 0, 0, 0, FW_NORMAL, false, false, false, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS,
                       CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY, DEFAULT_PITCH | FF_DONTCARE, NULL);
  return true;
}

void vpGDIRenderer::setImg(const vpImage<vpRGBa> &I)
{
  // converts the image into a HBITMAP
  convert(I, m_bmp);
}

void vpGDIRenderer::setImgROI(const vpImage<vpRGBa> &I, const vpImagePoint &iP, unsigned int width,
                              unsigned int height)
{
  // converts the image into a HBITMAP
  convertROI(I, iP, width, height);
}

void vpGDIRenderer::setImg(const vpImage<unsigned char> &I)
{
  // converts the image into a HBITMAP
  convert(I, m_bmp);
}

void vpGDIRenderer::setImgROI(const vpImage<unsigned char> &I, const vpImagePoint &iP, unsigned int width,
                              unsigned int height)
{
  // converts the image into a HBITMAP
  convertROI(I, iP, width, height);
}

bool vpGDIRenderer::render()
{
  // gets the window's DC
  PAINTSTRUCT ps;
  HDC hDCScreen = BeginPaint(m_hWnd, &ps);

  // create a memory DC
  HDC hDCMem = CreateCompatibleDC(hDCScreen);

  // selects this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);

  // blits it on the window's DC
  BitBlt(hDCScreen, 0, 0, static_cast<int>(m_rwidth), static_cast<int>(m_rheight), hDCMem, 0, 0, SRCCOPY);

  LeaveCriticalSection(&m_criticalSection);
  // DeleteDC(hDCMem);
  DeleteObject(hDCMem);

  EndPaint(m_hWnd, &ps);

  return true;
}

void vpGDIRenderer::convert(const vpImage<vpRGBa> &I, HBITMAP &hBmp)
{
  // allocate the buffer
  unsigned char *imBuffer = new unsigned char[m_rwidth * m_rheight * 4];

  if (m_rscale == 1) {
    for (unsigned int i = 0, k = 0; i < m_rwidth * m_rheight * 4; i += 4, k++) {
      imBuffer[i + 0] = I.bitmap[k].B;
      imBuffer[i + 1] = I.bitmap[k].G;
      imBuffer[i + 2] = I.bitmap[k].R;
      imBuffer[i + 3] = I.bitmap[k].A;
    }
  } else {
    for (unsigned int i = 0; i < m_rheight; i++) {
      unsigned int i_ = i * m_rscale;
      unsigned int ii_ = i * m_rwidth;
      for (unsigned int j = 0; j < m_rwidth; j++) {
        vpRGBa val = I[i_][j * m_rscale];
        unsigned int index_ = (ii_ + j) * 4;
        imBuffer[index_] = val.B;
        imBuffer[++index_] = val.G;
        imBuffer[++index_] = val.R;
        imBuffer[++index_] = val.A;
      }
    }
  }

  // updates the bitmap's pixel data
  updateBitmap(hBmp, imBuffer, m_rwidth, m_rheight);

  // we don't need this buffer anymore
  delete[] imBuffer;
}

void vpGDIRenderer::convertROI(const vpImage<vpRGBa> &I, const vpImagePoint &iP, unsigned int width,
                               unsigned int height)
{
  int i_min = (std::max)((int)ceil(iP.get_i() / m_rscale), 0);
  int j_min = (std::max)((int)ceil(iP.get_j() / m_rscale), 0);
  int i_max = (std::min)((int)ceil((iP.get_i() + height) / m_rscale), (int)m_rheight);
  int j_max = (std::min)((int)ceil((iP.get_j() + width) / m_rscale), (int)m_rwidth);

  int h = i_max - i_min;
  int w = j_max - j_min;

  // allocate the buffer
  unsigned char *imBuffer = new unsigned char[w * h * 4];

  if (m_rscale == 1) {
    vpRGBa *bitmap = I.bitmap;
    unsigned int iwidth = I.getWidth();
    bitmap = bitmap + (int)(i_min * iwidth + j_min);

    int k = 0;
    for (int i = 0; i < w * h * 4; i += 4) {
      imBuffer[i + 0] = (bitmap + k)->B;
      imBuffer[i + 1] = (bitmap + k)->G;
      imBuffer[i + 2] = (bitmap + k)->R;
      imBuffer[i + 3] = (bitmap + k)->A;
      // bitmap++;
      k++;
      if (k == w) {
        bitmap = bitmap + iwidth;
        k = 0;
      }
    }
  } else {
    for (int i = 0; i < h; i++) {
      unsigned int i_ = (i_min + i) * m_rscale;
      unsigned int ii_ = i * w;
      for (int j = 0; j < w; j++) {
        vpRGBa val = I[i_][(j_min + j) * m_rscale];
        unsigned int index_ = (ii_ + j) * 4;
        imBuffer[index_] = val.B;
        imBuffer[++index_] = val.G;
        imBuffer[++index_] = val.R;
        imBuffer[++index_] = val.A;
      }
    }
  }

  // updates the bitmap's pixel data
  updateBitmapROI(imBuffer, i_min, j_min, w, h);

  // we don't need this buffer anymore
  delete[] imBuffer;
}

void vpGDIRenderer::convert(const vpImage<unsigned char> &I, HBITMAP &hBmp)
{
  // allocate the buffer
  unsigned char *imBuffer = new unsigned char[m_rwidth * m_rheight * 4];

  if (m_rscale == 1) {
    for (unsigned int i = 0, k = 0; i < m_rwidth * m_rheight * 4; i += 4, k++) {
      imBuffer[i + 0] = I.bitmap[k];
      imBuffer[i + 1] = I.bitmap[k];
      imBuffer[i + 2] = I.bitmap[k];
      imBuffer[i + 3] = vpRGBa::alpha_default;
    }
  } else {
    for (unsigned int i = 0; i < m_rheight; i++) {
      unsigned int i_ = i * m_rscale;
      unsigned int ii_ = i * m_rwidth;
      for (unsigned int j = 0; j < m_rwidth; j++) {
        unsigned char val = I[i_][j * m_rscale];
        unsigned int index_ = (ii_ + j) * 4;
        imBuffer[index_] = val;
        imBuffer[++index_] = val;
        imBuffer[++index_] = val;
        imBuffer[++index_] = vpRGBa::alpha_default;
      }
    }
  }

  // updates the bitmap's pixel data
  updateBitmap(hBmp, imBuffer, m_rwidth, m_rheight);

  // we don't need this buffer anymore
  delete[] imBuffer;
}

void vpGDIRenderer::convertROI(const vpImage<unsigned char> &I, const vpImagePoint &iP, unsigned int width,
                               unsigned int height)
{
  int i_min = (std::max)((int)ceil(iP.get_i() / m_rscale), 0);
  int j_min = (std::max)((int)ceil(iP.get_j() / m_rscale), 0);
  int i_max = (std::min)((int)ceil((iP.get_i() + height) / m_rscale), (int)m_rheight);
  int j_max = (std::min)((int)ceil((iP.get_j() + width) / m_rscale), (int)m_rwidth);

  int h = i_max - i_min;
  int w = j_max - j_min;

  // allocate the buffer
  unsigned char *imBuffer = new unsigned char[w * h * 4];

  if (m_rscale == 1) {
    for (int i = 0; i < h; i++) {
      unsigned int i_ = i_min + i;
      unsigned int ii_ = i * w;
      for (int j = 0; j < w; j++) {
        unsigned char val = I[i_][j_min + j];
        unsigned int index_ = (ii_ + j) * 4;
        imBuffer[index_] = val;
        imBuffer[++index_] = val;
        imBuffer[++index_] = val;
        imBuffer[++index_] = vpRGBa::alpha_default;
      }
    }
  } else {
    for (int i = 0; i < h; i++) {
      unsigned int i_ = (i_min + i) * m_rscale;
      unsigned int ii_ = i * w;
      for (int j = 0; j < w; j++) {
        unsigned char val = I[i_][(j_min + j) * m_rscale];
        unsigned int index_ = (ii_ + j) * 4;
        imBuffer[index_] = val;
        imBuffer[++index_] = val;
        imBuffer[++index_] = val;
        imBuffer[++index_] = vpRGBa::alpha_default;
      }
    }
  }

  // updates the bitmap's pixel data
  updateBitmapROI(imBuffer, i_min, j_min, w, h);

  // we don't need this buffer anymore
  delete[] imBuffer;
}

bool vpGDIRenderer::updateBitmap(HBITMAP &hBmp, unsigned char *imBuffer, unsigned int w, unsigned int h)
{
  // the bitmap may only be accessed by one thread at the same time
  // that's why we enter critical section
  EnterCriticalSection(&m_criticalSection);

  // if the existing bitmap object is of the right size
  if ((m_bmp_width == w) && (m_bmp_height == h) && w != 0 && h != 0) {
    // just replace the content
    SetBitmapBits(hBmp, w * h * 4, imBuffer);
  } else {
    if (hBmp != NULL) {
      // delete the old BITMAP
      DeleteObject(hBmp);
    }
    // create a new BITMAP from this buffer
    if ((hBmp = CreateBitmap(static_cast<int>(w), static_cast<int>(h), 1, 32, (void *)imBuffer)) == NULL)
      return false;

    m_bmp_width = w;
    m_bmp_height = h;
  }

  LeaveCriticalSection(&m_criticalSection);
  return true;
}

bool vpGDIRenderer::updateBitmapROI(unsigned char *imBuffer, int i_min, int j_min, int w, int h)
{
  HBITMAP htmp = CreateBitmap(w, h, 1, 32, (void *)imBuffer);

  // get the window's DC
  HDC hDCScreen = GetDC(m_hWnd);
  HDC hDCMem = CreateCompatibleDC(hDCScreen);
  HDC hDCMem2 = CreateCompatibleDC(hDCScreen);

  // select this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);
  SelectObject(hDCMem2, htmp);

  BitBlt(hDCMem, j_min, i_min, w, h, hDCMem2, 0, 0, SRCCOPY);
  LeaveCriticalSection(&m_criticalSection);

  DeleteDC(hDCMem);
  ReleaseDC(m_hWnd, hDCScreen);
  DeleteObject(htmp);

  return true;
}

void vpGDIRenderer::setPixel(const vpImagePoint &iP, const vpColor &color)
{
  // get the window's DC
  HDC hDCScreen = GetDC(m_hWnd);
  HDC hDCMem = CreateCompatibleDC(hDCScreen);

  // select this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);

  if (color.id < vpColor::id_unknown)
    SetPixel(hDCMem, vpMath::round(iP.get_u() / m_rscale), vpMath::round(iP.get_v() / m_rscale), m_colors[color.id]);
  else {
    COLORREF gdicolor = RGB(color.R, color.G, color.B);
    SetPixel(hDCMem, vpMath::round(iP.get_u() / m_rscale), vpMath::round(iP.get_v() / m_rscale), gdicolor);
  }
  // display the result (flush)
  // BitBlt(hDCScreen, x, y, 1, 1, hDCMem, x, y, SRCCOPY);

  LeaveCriticalSection(&m_criticalSection);

  DeleteDC(hDCMem);
  ReleaseDC(m_hWnd, hDCScreen);
}

void vpGDIRenderer::drawLine(const vpImagePoint &ip1, const vpImagePoint &ip2, const vpColor &color,
                             unsigned int thickness, int style)
{
  HDC hDCScreen = NULL, hDCMem = NULL;
  HPEN hPen = NULL;
#ifdef GDI_ROBUST
  double start = vpTime::measureTimeMs();
  while (vpTime::measureTimeMs() - start < 1000) {
    hDCScreen = GetDC(m_hWnd);
    if (!hDCScreen)
      continue;
    hDCMem = CreateCompatibleDC(hDCScreen);
    if (!hDCMem) {
      ReleaseDC(m_hWnd, hDCScreen);
      continue;
    }

    // create the pen
    if (color.id < vpColor::id_unknown)
      hPen = CreatePen(style, static_cast<int>(thickness), m_colors[color.id]);
    else {
      COLORREF gdicolor = RGB(color.R, color.G, color.B);
      hPen = CreatePen(style, static_cast<int>(thickness), gdicolor);
    }
    if (!hPen) {
      DeleteDC(hDCMem);
      ReleaseDC(m_hWnd, hDCScreen);
      continue;
    }
    if (!SetBkMode(hDCMem, TRANSPARENT)) {
      DeleteObject(hPen);
      DeleteDC(hDCMem);
      ReleaseDC(m_hWnd, hDCScreen);
      continue;
    }

    // select this bmp in memory
    EnterCriticalSection(&m_criticalSection);

    if (!SelectObject(hDCMem, m_bmp)) {
      LeaveCriticalSection(&m_criticalSection);
      DeleteObject(hPen);
      DeleteDC(hDCMem);
      ReleaseDC(m_hWnd, hDCScreen);
      continue;
    }

    // select the pen
    if (!SelectObject(hDCMem, hPen)) {
      LeaveCriticalSection(&m_criticalSection);
      DeleteObject(hPen);
      DeleteDC(hDCMem);
      ReleaseDC(m_hWnd, hDCScreen);
      continue;
    }
    break;
  }
  timelost += (vpTime::measureTimeMs() - start);
#else
  // get the window's DC
  hDCScreen = GetDC(m_hWnd);
  hDCMem = CreateCompatibleDC(hDCScreen);
  // create the pen
  if (color.id < vpColor::id_unknown)
    hPen = CreatePen(style, static_cast<int>(thickness), m_colors[color.id]);
  else {
    COLORREF gdicolor = RGB(color.R, color.G, color.B);
    hPen = CreatePen(style, static_cast<int>(thickness), gdicolor);
  }
  SetBkMode(hDCMem, TRANSPARENT);

  // select this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);

  // select the pen
  SelectObject(hDCMem, hPen);
#endif
  // Warning: When thickness > 1 and pen style is PS_DASHDOT, the drawing
  // displays a solid line That's why in that case we implement the dashdot
  // line manually drawing multiple small lines
  if (thickness != 1 && style != PS_SOLID) {
    vpImagePoint ip1_ = ip1;
    vpImagePoint ip2_ = ip2;

    double size = 10. * m_rscale;
    double length = sqrt(vpMath::sqr(ip2_.get_i() - ip1_.get_i()) + vpMath::sqr(ip2_.get_j() - ip1_.get_j()));
    bool vertical_line = (int)ip2_.get_j() == (int)ip1_.get_j();
    if (vertical_line) {
      if (ip2_.get_i() < ip1_.get_i()) {
        std::swap(ip1_, ip2_);
      }
    } else if (ip2_.get_j() < ip1_.get_j()) {
      std::swap(ip1_, ip2_);
    }

    double diff_j = vertical_line ? 1 : ip2_.get_j() - ip1_.get_j();
    double deltaj = size / length * diff_j;
    double deltai = size / length * (ip2_.get_i() - ip1_.get_i());
    double slope = (ip2_.get_i() - ip1_.get_i()) / diff_j;
    double orig = ip1_.get_i() - slope * ip1_.get_j();

    if (vertical_line) {
      for (unsigned int i = (unsigned int)ip1_.get_i(); i < ip2_.get_i(); i += (unsigned int)(2 * deltai)) {
        double j = ip1_.get_j();

        // Move to the starting point
        MoveToEx(hDCMem, vpMath::round(j / m_rscale), vpMath::round(i / m_rscale), NULL);
        // Draw the line
        LineTo(hDCMem, vpMath::round(j / m_rscale), vpMath::round((i + deltai) / m_rscale));
      }
    } else {
      for (unsigned int j = (unsigned int)ip1_.get_j(); j < ip2_.get_j(); j += (unsigned int)(2 * deltaj)) {
        double i = slope * j + orig;
        // Move to the starting point
        MoveToEx(hDCMem, vpMath::round(j / m_rscale), vpMath::round(i / m_rscale), NULL);
        // Draw the line
        LineTo(hDCMem, vpMath::round((j + deltaj) / m_rscale), vpMath::round((i + deltai) / m_rscale));
      }
    }
  } else {
    // move to the starting point
    MoveToEx(hDCMem, vpMath::round(ip1.get_u() / m_rscale), vpMath::round(ip1.get_v() / m_rscale), NULL);
    // Draw the line
    LineTo(hDCMem, vpMath::round(ip2.get_u() / m_rscale), vpMath::round(ip2.get_v() / m_rscale));
  }

  LeaveCriticalSection(&m_criticalSection);

  DeleteObject(hPen);
  DeleteDC(hDCMem);
  ReleaseDC(m_hWnd, hDCScreen);
}

void vpGDIRenderer::drawRect(const vpImagePoint &topLeft, unsigned int width, unsigned int height, const vpColor &color,
                             bool fill, unsigned int thickness)
{
  if (thickness == 0)
    thickness = 1;
  // get the window's DC
  HDC hDCScreen = GetDC(m_hWnd);
  HDC hDCMem = CreateCompatibleDC(hDCScreen);

  // create the pen
  HPEN hPen;
  COLORREF gdicolor = RGB(0, 0, 0);

  if (color.id < vpColor::id_unknown)
    hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), m_colors[color.id]);
  else {
    gdicolor = RGB(color.R, color.G, color.B);
    hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), gdicolor);
  }

  // create an hollow or solid brush (depends on boolean fill)
  LOGBRUSH lBrush;
  if (fill) {
    lBrush.lbStyle = BS_SOLID;
    if (color.id < vpColor::id_unknown)
      lBrush.lbColor = m_colors[color.id];
    else {
      lBrush.lbColor = gdicolor;
    }
  } else
    lBrush.lbStyle = BS_HOLLOW;
  HBRUSH hbrush = CreateBrushIndirect(&lBrush);

  // select this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);

  // select the brush
  SelectObject(hDCMem, hbrush);
  // select the pen
  SelectObject(hDCMem, hPen);

  // draw the rectangle
  Rectangle(hDCMem, vpMath::round(topLeft.get_u() / m_rscale), vpMath::round(topLeft.get_v() / m_rscale),
            vpMath::round((topLeft.get_u() + width) / m_rscale), vpMath::round((topLeft.get_v() + height) / m_rscale));

  // display the result (flush)
  //  BitBlt(hDCScreen, j, i, width, height, hDCMem, j, i, SRCCOPY);

  LeaveCriticalSection(&m_criticalSection);

  DeleteObject(hbrush);
  DeleteObject(hPen);
  DeleteDC(hDCMem);
  ReleaseDC(m_hWnd, hDCScreen);
}

void vpGDIRenderer::clear(const vpColor &color)
{
  vpImagePoint ip;
  ip.set_i(0);
  ip.set_j(0);
  drawRect(ip, m_rwidth, m_rheight, color, true, 0);
}

void vpGDIRenderer::drawCircle(const vpImagePoint &center, unsigned int radius, const vpColor &color, bool fill,
                               unsigned int thickness)
{

  // get the window's DC
  HDC hDCScreen = GetDC(m_hWnd);
  HDC hDCMem = CreateCompatibleDC(hDCScreen);

  // create the pen
  HPEN hPen;
  if (color.id < vpColor::id_unknown)
    hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), m_colors[color.id]);
  else {
    COLORREF gdicolor = RGB(color.R, color.G, color.B);
    hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), gdicolor);
  }

  // create an hollow brush
  LOGBRUSH lBrush;
  lBrush.lbStyle = BS_HOLLOW;
  HBRUSH hbrush = CreateBrushIndirect(&lBrush);

  // computes bounding rectangle
  int radius_ = static_cast<int>(radius);
  int x1 = vpMath::round(center.get_u() / m_rscale) - radius_ / m_rscale;
  int y1 = vpMath::round(center.get_v() / m_rscale) - radius_ / m_rscale;
  int x2 = vpMath::round(center.get_u() / m_rscale) + radius_ / m_rscale;
  int y2 = vpMath::round(center.get_v() / m_rscale) + radius_ / m_rscale;

  // select this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);

  // select the brush
  SelectObject(hDCMem, hbrush);
  // select the pen
  SelectObject(hDCMem, hPen);

  // draw the circle
  if (fill == false)
    Ellipse(hDCMem, x1, y1, x2, y2);

  else {
    while (x2 - x1 > 0) {
      x1++;
      x2--;
      y1++;
      y2--;
      Ellipse(hDCMem, x1, y1, x2, y2);
    }
  }

  // display the result (flush)
  // BitBlt(hDCScreen, x1, y1, x2-x1, y2-y1, hDCMem, x1, y1, SRCCOPY);

  LeaveCriticalSection(&m_criticalSection);

  DeleteObject(hbrush);
  DeleteObject(hPen);
  DeleteDC(hDCMem);
  ReleaseDC(m_hWnd, hDCScreen);
}

void vpGDIRenderer::drawText(const vpImagePoint &ip, const char *text, const vpColor &color)
{
  // get the window's DC
  HDC hDCScreen = GetDC(m_hWnd);
  HDC hDCMem = CreateCompatibleDC(hDCScreen);

  // select this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);

  // Select the font
  SelectObject(hDCMem, m_hFont);

  // set the text color
  if (color.id < vpColor::id_unknown)
    SetTextColor(hDCMem, m_colors[color.id]);
  else {
    COLORREF gdicolor = RGB(color.R, color.G, color.B);
    SetTextColor(hDCMem, gdicolor);
  }

  // we don't use the bkColor
  SetBkMode(hDCMem, TRANSPARENT);

  SIZE size;
  int length = (int)strlen(text);

  // get the displayed string dimensions
  GetTextExtentPoint32(hDCMem, text, length, &size);

  // displays the string
  TextOut(hDCMem, vpMath::round(ip.get_u() / m_rscale), vpMath::round(ip.get_v() / m_rscale), text, length);

  // display the result (flush)
  // BitBlt(hDCScreen, j, i, size.cx, size.cy, hDCMem, j, i, SRCCOPY);

  LeaveCriticalSection(&m_criticalSection);

  DeleteDC(hDCMem);
  ReleaseDC(m_hWnd, hDCScreen);
}

void vpGDIRenderer::drawCross(const vpImagePoint &ip, unsigned int size, const vpColor &color, unsigned int thickness)
{
  /* unsigned */ int half_size = static_cast<int>(size / 2 / m_rscale);

  // if half_size is equal to zero, nothing is displayed with the code
  // just below. So, if half_size is equal to zero we just draw the
  // pixel.
  if (half_size) {
    // get the window's DC
    HDC hDCScreen = GetDC(m_hWnd);
    HDC hDCMem = CreateCompatibleDC(hDCScreen);

    // create the pen
    HPEN hPen;
    if (color.id < vpColor::id_unknown)
      hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), m_colors[color.id]);
    else {
      COLORREF gdicolor = RGB(color.R, color.G, color.B);
      hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), gdicolor);
    }

    // select this bmp in memory
    EnterCriticalSection(&m_criticalSection);
    SelectObject(hDCMem, m_bmp);

    // select the pen
    SelectObject(hDCMem, hPen);

    // move to the starting point
    MoveToEx(hDCMem, vpMath::round(ip.get_u() / m_rscale) - half_size, vpMath::round(ip.get_v() / m_rscale), NULL);
    // Draw the first line (horizontal)
    LineTo(hDCMem, vpMath::round(ip.get_u() / m_rscale) + half_size, vpMath::round(ip.get_v() / m_rscale));

    // move to the starting point
    MoveToEx(hDCMem, vpMath::round(ip.get_u() / m_rscale), vpMath::round(ip.get_v() / m_rscale) - half_size, NULL);
    // Draw the second line (vertical)
    LineTo(hDCMem, vpMath::round(ip.get_u() / m_rscale), vpMath::round(ip.get_v() / m_rscale) + half_size);

    // display the result (flush)
    //  BitBlt(hDCScreen, j-(size/2), i-(size/2), size, size,
    //     hDCMem, j-(size/2), i-(size/2), SRCCOPY);

    LeaveCriticalSection(&m_criticalSection);

    DeleteObject(hPen);
    DeleteDC(hDCMem);
    ReleaseDC(m_hWnd, hDCScreen);
  } else {
    setPixel(ip, color);
  }
}

void vpGDIRenderer::drawArrow(const vpImagePoint &ip1, const vpImagePoint &ip2, const vpColor &color, unsigned int w,
                              unsigned int h, unsigned int thickness)
{
  double a = ip2.get_i() / m_rscale - ip1.get_i() / m_rscale;
  double b = ip2.get_j() / m_rscale - ip1.get_j() / m_rscale;
  double lg = sqrt(vpMath::sqr(a) + vpMath::sqr(b));

  // computes the coordinates of the rectangle to blit later
  //   unsigned int x = (j2 >= j1) ? j1 : j2;
  //   unsigned int y = (i2 >= i1) ? i1 : i2;
  //   unsigned int w = (j2 >= j1) ? j2-j1 : j1-j2;
  //   unsigned int h = (i2 >= i1) ? i2-i1 : i1-i2;

  // get the window's DC
  HDC hDCScreen = GetDC(m_hWnd);
  HDC hDCMem = CreateCompatibleDC(hDCScreen);

  // create the pen
  HPEN hPen;
  if (color.id < vpColor::id_unknown)
    hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), m_colors[color.id]);
  else {
    COLORREF gdicolor = RGB(color.R, color.G, color.B);
    hPen = CreatePen(PS_SOLID, static_cast<int>(thickness), gdicolor);
  }

  // select this bmp in memory
  EnterCriticalSection(&m_criticalSection);
  SelectObject(hDCMem, m_bmp);

  // select the pen
  SelectObject(hDCMem, hPen);

  if ((a == 0) && (b == 0)) {
    // DisplayCrossLarge(i1,j1,3,col) ;
  } else {
    a /= lg;
    b /= lg;

    vpImagePoint ip3;
    ip3.set_i(ip2.get_i() / m_rscale - w * a);
    ip3.set_j(ip2.get_j() / m_rscale - w * b);

    vpImagePoint ip4;

    // double t = 0 ;
    // while (t<=_l)
    {
      ip4.set_i(ip3.get_i() - b * h);
      ip4.set_j(ip3.get_j() + a * h);

      if (lg > 2 * vpImagePoint::distance(ip2 / m_rscale, ip4)) {
        MoveToEx(hDCMem, vpMath::round(ip2.get_u() / m_rscale), vpMath::round(ip2.get_v() / m_rscale), NULL);
        LineTo(hDCMem, vpMath::round(ip4.get_u()), vpMath::round(ip4.get_v()));
      }
      // t+=0.1 ;
    }

    // t = 0 ;
    // while (t>= -_l)
    {
      ip4.set_i(ip3.get_i() + b * h);
      ip4.set_j(ip3.get_j() - a * h);

      if (lg > 2 * vpImagePoint::distance(ip2 / m_rscale, ip4)) {
        MoveToEx(hDCMem, vpMath::round(ip2.get_u() / m_rscale), vpMath::round(ip2.get_v() / m_rscale), NULL);
        LineTo(hDCMem, vpMath::round(ip4.get_u()), vpMath::round(ip4.get_v()));
      }

      // t-=0.1 ;
    }
    MoveToEx(hDCMem, vpMath::round(ip1.get_u() / m_rscale), vpMath::round(ip1.get_v() / m_rscale), NULL);
    LineTo(hDCMem, vpMath::round(ip2.get_u() / m_rscale), vpMath::round(ip2.get_v() / m_rscale));
  }

  // display the result (flush)
  //  BitBlt(hDCScreen, x, y, w, h, hDCMem, x, y, SRCCOPY);

  LeaveCriticalSection(&m_criticalSection);

  DeleteObject(hPen);
  DeleteDC(hDCMem);
  ReleaseDC(m_hWnd, hDCScreen);
}

void vpGDIRenderer::getImage(vpImage<vpRGBa> &I)
{
  // size of image buffer : m_rwidth*m_rheight*4
  unsigned int size = m_rwidth * m_rheight * 4;
  unsigned char *imBuffer = new unsigned char[size];

  // gets the hbitmap's bitmap
  GetBitmapBits(m_bmp, static_cast<LONG>(size), (void *)imBuffer);

  // resize the destination image as needed
  I.resize(m_rheight, m_rwidth);

  // copy the content
  for (unsigned int i = 0; i < size; i += 4) {
    I.bitmap[i >> 2].R = imBuffer[i + 2];
    I.bitmap[i >> 2].G = imBuffer[i + 1];
    I.bitmap[i >> 2].B = imBuffer[i + 0];
    I.bitmap[i >> 2].A = vpRGBa::alpha_default; // default opacity
  }

  delete[] imBuffer;
}
#endif
#elif !defined(VISP_BUILD_SHARED_LIBS)
// Work arround to avoid warning: libvisp_core.a(vpGDIRenderer.cpp.o) has no
// symbols
void dummy_vpGDIRenderer(){};
#endif