render_3d_raytrace.cpp

Go to the documentation of this file.

/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2015-2020 Mario Luzeiro <[email protected]>
 * Copyright (C) 2015-2021 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include <gal/opengl/kiglew.h> // Must be included first

#include <algorithm>
#include <atomic>
#include <chrono>
#include <climits>
#include <thread>

#include "render_3d_raytrace.h"
#include "mortoncodes.h"
#include "../color_rgb.h"
#include "3d_fastmath.h"
#include "3d_math.h"
#include "../common_ogl/ogl_utils.h"
#include <profile.h> // To use GetRunningMicroSecs or another profiling utility
#include <wx/log.h>


RENDER_3D_RAYTRACE::RENDER_3D_RAYTRACE( EDA_3D_CANVAS* aCanvas, BOARD_ADAPTER& aAdapter, CAMERA& aCamera ) :
 RENDER_3D_BASE( aCanvas, aAdapter, aCamera ),
 m_postShaderSsao( aCamera )
{
 wxLogTrace( m_logTrace, wxT( "RENDER_3D_RAYTRACE::RENDER_3D_RAYTRACE" ) );

 m_openglSupportsVertexBufferObjects = false;
 m_pboId = GL_NONE;
 m_pboDataSize = 0;
 m_accelerator = nullptr;
 m_convertedDummyBlockCount = 0;
 m_converted2dRoundSegmentCount = 0;
 m_oldWindowsSize.x = 0;
 m_oldWindowsSize.y = 0;
 m_outlineBoard2dObjects = nullptr;
 m_antioutlineBoard2dObjects = nullptr;
 m_firstHitinfo = nullptr;
 m_shaderBuffer = nullptr;
 m_cameraLight = nullptr;

 m_xoffset = 0;
 m_yoffset = 0;

 m_isPreview = false;
 m_renderState = RT_RENDER_STATE_MAX; // Set to an initial invalid state
 m_renderStartTime = 0;
 m_blockRenderProgressCount = 0;
}


RENDER_3D_RAYTRACE::~RENDER_3D_RAYTRACE()
{
 wxLogTrace( m_logTrace, wxT( "RENDER_3D_RAYTRACE::~RENDER_3D_RAYTRACE" ) );

 delete m_accelerator;
 m_accelerator = nullptr;

 delete m_outlineBoard2dObjects;
 m_outlineBoard2dObjects = nullptr;

 delete m_antioutlineBoard2dObjects;
 m_antioutlineBoard2dObjects = nullptr;

 delete[] m_shaderBuffer;
 m_shaderBuffer = nullptr;

 deletePbo();
}


int RENDER_3D_RAYTRACE::GetWaitForEditingTimeOut()
{
 return 1000; // ms
}


void RENDER_3D_RAYTRACE::deletePbo()
{
 // Delete PBO if it was created
 if( m_openglSupportsVertexBufferObjects )
 {
 if( glIsBufferARB( m_pboId ) )
 glDeleteBuffers( 1, &m_pboId );

 m_pboId = GL_NONE;
 }
}


void RENDER_3D_RAYTRACE::SetCurWindowSize( const wxSize& aSize )
{
 if( m_windowSize != aSize )
 {
 m_windowSize = aSize;
 glViewport( 0, 0, m_windowSize.x, m_windowSize.y );

 initializeNewWindowSize();
 }
}


void RENDER_3D_RAYTRACE::restartRenderState()
{
 m_renderStartTime = GetRunningMicroSecs();

 m_renderState = RT_RENDER_STATE_TRACING;
 m_blockRenderProgressCount = 0;

 m_postShaderSsao.InitFrame();

 m_blockPositionsWasProcessed.resize( m_blockPositions.size() );

 // Mark the blocks not processed yet
 std::fill( m_blockPositionsWasProcessed.begin(), m_blockPositionsWasProcessed.end(), 0 );
}


static inline void SetPixel( GLubyte* p, const COLOR_RGB& v )
{
 p[0] = v.c[0];
 p[1] = v.c[1];
 p[2] = v.c[2];
 p[3] = 255;
}


bool RENDER_3D_RAYTRACE::Redraw( bool aIsMoving, REPORTER* aStatusReporter,
 REPORTER* aWarningReporter )
{
 bool requestRedraw = false;

 // Initialize openGL if need
 if( !m_is_opengl_initialized )
 {
 if( !initializeOpenGL() )
 return false;

 //aIsMoving = true;
 requestRedraw = true;

 // It will assign the first time the windows size, so it will now
 // revert to preview mode the first time the Redraw is called
 m_oldWindowsSize = m_windowSize;
 initializeBlockPositions();
 }

 std::unique_ptr<BUSY_INDICATOR> busy = CreateBusyIndicator();

 // Reload board if it was requested
 if( m_reloadRequested )
 {
 if( aStatusReporter )
 aStatusReporter->Report( _( "Loading..." ) );

 //aIsMoving = true;
 requestRedraw = true;
 Reload( aStatusReporter, aWarningReporter, false );
 }


 // Recalculate constants if windows size was changed
 if( m_windowSize != m_oldWindowsSize )
 {
 m_oldWindowsSize = m_windowSize;
 aIsMoving = true;
 requestRedraw = true;

 initializeBlockPositions();
 }


 // Clear buffers
 glClearColor( 0.0f, 0.0f, 0.0f, 1.0f );
 glClearDepth( 1.0f );
 glClearStencil( 0x00 );
 glClear( GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );

 // 4-byte pixel alignment
 glPixelStorei( GL_UNPACK_ALIGNMENT, 4 );

 glDisable( GL_STENCIL_TEST );
 glDisable( GL_LIGHTING );
 glDisable( GL_COLOR_MATERIAL );
 glDisable( GL_DEPTH_TEST );
 glDisable( GL_TEXTURE_2D );
 glDisable( GL_BLEND );
 glDisable( GL_MULTISAMPLE );

 const bool was_camera_changed = m_camera.ParametersChanged();

 if( requestRedraw || aIsMoving || was_camera_changed )
 m_renderState = RT_RENDER_STATE_MAX; // Set to an invalid state,
 // so it will restart again latter

 // This will only render if need, otherwise it will redraw the PBO on the screen again
 if( aIsMoving || was_camera_changed )
 {
 // Set head light (camera view light) with the opposite direction of the camera
 if( m_cameraLight )
 m_cameraLight->SetDirection( -m_camera.GetDir() );

 OglDrawBackground( SFVEC3F( m_boardAdapter.m_BgColorTop),
 SFVEC3F( m_boardAdapter.m_BgColorBot) );

 // Bind PBO
 glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, m_pboId );

 // Get the PBO pixel pointer to write the data
 GLubyte* ptrPBO = (GLubyte *)glMapBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB,
 GL_WRITE_ONLY_ARB );

 if( ptrPBO )
 {
 renderPreview( ptrPBO );

 // release pointer to mapping buffer, this initialize the coping to PBO
 glUnmapBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB );
 }

 glWindowPos2i( m_xoffset, m_yoffset );
 }
 else
 {
 // Bind PBO
 glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, m_pboId );

 if( m_renderState != RT_RENDER_STATE_FINISH )
 {
 // Get the PBO pixel pointer to write the data
 GLubyte* ptrPBO = (GLubyte *)glMapBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB,
 GL_WRITE_ONLY_ARB );

 if( ptrPBO )
 {
 render( ptrPBO, aStatusReporter );

 if( m_renderState != RT_RENDER_STATE_FINISH )
 requestRedraw = true;

 // release pointer to mapping buffer, this initialize the coping to PBO
 glUnmapBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB );
 }
 }

 if( m_renderState == RT_RENDER_STATE_FINISH )
 {
 glClear( GL_COLOR_BUFFER_BIT );
 }

 glWindowPos2i( m_xoffset, m_yoffset );
 }

 // This way it will blend the progress rendering with the last buffer. eg:
 // if it was called after a openGL.
 glEnable( GL_BLEND );
 glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 glEnable( GL_ALPHA_TEST );
 glDrawPixels( m_realBufferSize.x, m_realBufferSize.y, GL_RGBA, GL_UNSIGNED_BYTE, 0 );
 glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, 0 );

 return requestRedraw;
}


void RENDER_3D_RAYTRACE::render( GLubyte* ptrPBO, REPORTER* aStatusReporter )
{
 if( ( m_renderState == RT_RENDER_STATE_FINISH ) || ( m_renderState >= RT_RENDER_STATE_MAX ) )
 {
 restartRenderState();

 if( m_cameraLight )
 m_cameraLight->SetDirection( -m_camera.GetDir() );

 if( m_boardAdapter.GetRenderEngine() == RENDER_ENGINE::OPENGL )
 {
 // Set all pixels of PBO transparent (Alpha to 0)
 // This way it will draw the full buffer but only shows the updated (
 // already calculated) squares
 unsigned int nPixels = m_realBufferSize.x * m_realBufferSize.y;
 GLubyte* tmp_ptrPBO = ptrPBO + 3; // PBO is RGBA

 for( unsigned int i = 0; i < nPixels; ++i )
 {
 *tmp_ptrPBO = 0;
 tmp_ptrPBO += 4; // PBO is RGBA
 }
 }

 m_backgroundColorTop = ConvertSRGBToLinear( (SFVEC3F)m_boardAdapter.m_BgColorTop );
 m_backgroundColorBottom = ConvertSRGBToLinear( (SFVEC3F)m_boardAdapter.m_BgColorBot );
 }

 switch( m_renderState )
 {
 case RT_RENDER_STATE_TRACING:
 renderTracing( ptrPBO, aStatusReporter );
 break;

 case RT_RENDER_STATE_POST_PROCESS_SHADE:
 postProcessShading( ptrPBO, aStatusReporter );
 break;

 case RT_RENDER_STATE_POST_PROCESS_BLUR_AND_FINISH:
 postProcessBlurFinish( ptrPBO, aStatusReporter );
 break;

 default:
 wxASSERT_MSG( false, wxT( "Invalid state on m_renderState" ) );
 restartRenderState();
 break;
 }

 if( aStatusReporter && ( m_renderState == RT_RENDER_STATE_FINISH ) )
 {
 // Calculation time in seconds
 const double elapsed_time = (double)( GetRunningMicroSecs() - m_renderStartTime ) / 1e6;

 aStatusReporter->Report( wxString::Format( _( "Rendering time %.3f s" ), elapsed_time ) );
 }
}


void RENDER_3D_RAYTRACE::renderTracing( GLubyte* ptrPBO, REPORTER* aStatusReporter )
{
 m_isPreview = false;

 auto startTime = std::chrono::steady_clock::now();
 bool breakLoop = false;

 std::atomic<size_t> numBlocksRendered( 0 );
 std::atomic<size_t> currentBlock( 0 );
 std::atomic<size_t> threadsFinished( 0 );

 size_t parallelThreadCount = std::min<size_t>(
 std::max<size_t>( std::thread::hardware_concurrency(), 2 ),
 m_blockPositions.size() );

 for( size_t ii = 0; ii < parallelThreadCount; ++ii )
 {
 std::thread t = std::thread( [&]()
 {
 for( size_t iBlock = currentBlock.fetch_add( 1 );
 iBlock < m_blockPositions.size() && !breakLoop;
 iBlock = currentBlock.fetch_add( 1 ) )
 {
 if( !m_blockPositionsWasProcessed[iBlock] )
 {
 renderBlockTracing( ptrPBO, iBlock );
 numBlocksRendered++;
 m_blockPositionsWasProcessed[iBlock] = 1;

 // Check if it spend already some time render and request to exit
 // to display the progress
 if( std::chrono::duration_cast<std::chrono::milliseconds>(
 std::chrono::steady_clock::now() - startTime ).count() > 150 )
 breakLoop = true;
 }
 }

 threadsFinished++;
 } );

 t.detach();
 }

 while( threadsFinished < parallelThreadCount )
 std::this_thread::sleep_for( std::chrono::milliseconds( 10 ) );

 m_blockRenderProgressCount += numBlocksRendered;

 if( aStatusReporter )
 aStatusReporter->Report( wxString::Format( _( "Rendering: %.0f %%" ),
 (float) ( m_blockRenderProgressCount * 100 )
 / (float) m_blockPositions.size() ) );

 // Check if it finish the rendering and if should continue to a post processing
 // or mark it as finished
 if( m_blockRenderProgressCount >= m_blockPositions.size() )
 {
 if( m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_POST_PROCESSING ) )
 m_renderState = RT_RENDER_STATE_POST_PROCESS_SHADE;
 else
 m_renderState = RT_RENDER_STATE_FINISH;
 }
}


#ifdef USE_SRGB_SPACE

#define SRGB_GAMA 2.4f


// This function implements the conversion from linear RGB to sRGB
// https://github.com/g-truc/glm/blob/master/glm/gtc/color_space.inl#L12
static SFVEC3F convertLinearToSRGB( const SFVEC3F& aRGBcolor )
{
 const float gammaCorrection = 1.0f / SRGB_GAMA;
 const SFVEC3F clampedColor = glm::clamp( aRGBcolor, SFVEC3F( 0.0f ), SFVEC3F( 1.0f ) );

 return glm::mix( glm::pow( clampedColor, SFVEC3F(gammaCorrection) ) * 1.055f - 0.055f,
 clampedColor * 12.92f,
 glm::lessThan( clampedColor, SFVEC3F(0.0031308f) ) );
}


// This function implements the conversion from sRGB to linear RGB
// https://github.com/g-truc/glm/blob/master/glm/gtc/color_space.inl#L35
SFVEC3F ConvertSRGBToLinear( const SFVEC3F& aSRGBcolor )
{
 const float gammaCorrection = SRGB_GAMA;

 return glm::mix( glm::pow( ( aSRGBcolor + SFVEC3F( 0.055f ) )
 * SFVEC3F( 0.94786729857819905213270142180095f ),
 SFVEC3F( gammaCorrection ) ),
 aSRGBcolor * SFVEC3F( 0.07739938080495356037151702786378f ),
 glm::lessThanEqual( aSRGBcolor, SFVEC3F( 0.04045f ) ) );
}

#endif


void RENDER_3D_RAYTRACE::renderFinalColor( GLubyte* ptrPBO, const SFVEC3F& rgbColor,
 bool applyColorSpaceConversion )
{
 SFVEC3F color = rgbColor;

#ifdef USE_SRGB_SPACE
 // if( applyColorSpaceConversion )
 // rgbColor = glm::convertLinearToSRGB( rgbColor );

 if( applyColorSpaceConversion )
 color = convertLinearToSRGB( rgbColor );
#endif

 ptrPBO[0] = (unsigned int) glm::clamp( (int) ( color.r * 255 ), 0, 255 );
 ptrPBO[1] = (unsigned int) glm::clamp( (int) ( color.g * 255 ), 0, 255 );
 ptrPBO[2] = (unsigned int) glm::clamp( (int) ( color.b * 255 ), 0, 255 );
 ptrPBO[3] = 255;
}


static void HITINFO_PACKET_init( HITINFO_PACKET* aHitPacket )
{
 // Initialize hitPacket with a "not hit" information
 for( unsigned int i = 0; i < RAYPACKET_RAYS_PER_PACKET; ++i )
 {
 aHitPacket[i].m_HitInfo.m_tHit = std::numeric_limits<float>::infinity();
 aHitPacket[i].m_HitInfo.m_acc_node_info = 0;
 aHitPacket[i].m_hitresult = false;
 aHitPacket[i].m_HitInfo.m_HitNormal = SFVEC3F( 0.0f );
 aHitPacket[i].m_HitInfo.m_ShadowFactor = 1.0f;
 }
}


void RENDER_3D_RAYTRACE::renderRayPackets( const SFVEC3F* bgColorY, const RAY* aRayPkt,
 HITINFO_PACKET* aHitPacket, bool is_testShadow,
 SFVEC3F* aOutHitColor )
{
 for( unsigned int y = 0, i = 0; y < RAYPACKET_DIM; ++y )
 {
 for( unsigned int x = 0; x < RAYPACKET_DIM; ++x, ++i )
 {
 if( aHitPacket[i].m_hitresult == true )
 {
 aOutHitColor[i] = shadeHit( bgColorY[y], aRayPkt[i], aHitPacket[i].m_HitInfo,
 false, 0, is_testShadow );
 }
 else
 {
 aOutHitColor[i] = bgColorY[y];
 }
 }
 }
}


void RENDER_3D_RAYTRACE::renderAntiAliasPackets( const SFVEC3F* aBgColorY,
 const HITINFO_PACKET* aHitPck_X0Y0,
 const HITINFO_PACKET* aHitPck_AA_X1Y1,
 const RAY* aRayPck, SFVEC3F* aOutHitColor )
{
 const bool is_testShadow = m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_SHADOWS );

 for( unsigned int y = 0, i = 0; y < RAYPACKET_DIM; ++y )
 {
 for( unsigned int x = 0; x < RAYPACKET_DIM; ++x, ++i )
 {
 const RAY& rayAA = aRayPck[i];

 HITINFO hitAA;
 hitAA.m_tHit = std::numeric_limits<float>::infinity();
 hitAA.m_acc_node_info = 0;

 bool hitted = false;

 const unsigned int idx0y1 = ( x + 0 ) + RAYPACKET_DIM * ( y + 1 );
 const unsigned int idx1y1 = ( x + 1 ) + RAYPACKET_DIM * ( y + 1 );

 // Gets the node info from the hit.
 const unsigned int nodex0y0 = aHitPck_X0Y0[ i ].m_HitInfo.m_acc_node_info;
 const unsigned int node_AA_x0y0 = aHitPck_AA_X1Y1[ i ].m_HitInfo.m_acc_node_info;

 unsigned int nodex1y0 = 0;

 if( x < (RAYPACKET_DIM - 1) )
 nodex1y0 = aHitPck_X0Y0[ i + 1 ].m_HitInfo.m_acc_node_info;

 unsigned int nodex0y1 = 0;

 if( y < ( RAYPACKET_DIM - 1 ) && idx0y1 < RAYPACKET_RAYS_PER_PACKET )
 nodex0y1 = aHitPck_X0Y0[idx0y1].m_HitInfo.m_acc_node_info;

 unsigned int nodex1y1 = 0;

 if( ( x < ( RAYPACKET_DIM - 1 ) ) && ( y < ( RAYPACKET_DIM - 1 ) )
 && idx1y1 < RAYPACKET_RAYS_PER_PACKET )
 nodex1y1 = aHitPck_X0Y0[idx1y1].m_HitInfo.m_acc_node_info;

 // If all notes are equal we assume there was no change on the object hits.
 if( ( ( nodex0y0 == nodex1y0 ) || ( nodex1y0 == 0 ) )
 && ( ( nodex0y0 == nodex0y1 ) || ( nodex0y1 == 0 ) )
 && ( ( nodex0y0 == nodex1y1 ) || ( nodex1y1 == 0 ) )
 && ( nodex0y0 == node_AA_x0y0 ) )
 {
 // Option 1
 // This option will give a very good quality on reflections (slow)
 /*
 if( m_accelerator->Intersect( rayAA, hitAA, nodex0y0 ) )
 {
 aOutHitColor[i] += shadeHit( aBgColorY[y], rayAA, hitAA, false, 0 );
 }
 else
 {
 if( m_accelerator->Intersect( rayAA, hitAA ) )
 aOutHitColor[i] += shadeHit( aBgColorY[y], rayAA, hitAA, false, 0 );
 else
 aOutHitColor[i] += hitColor[i];
 }
 */

 // Option 2
 // Trace again with the same node,
 // then if miss just give the same color as before
 //if( m_accelerator->Intersect( rayAA, hitAA, nodex0y0 ) )
 // aOutHitColor[i] += shadeHit( aBgColorY[y], rayAA, hitAA, false, 0 );

 // Option 3
 // Use same color
 }
 else
 {
 // Try to intersect the different nodes
 // It tests the possible combination of hitted or not hitted points
 // This will try to get the best hit for this ray

 if( nodex0y0 != 0 )
 hitted |= m_accelerator->Intersect( rayAA, hitAA, nodex0y0 );

 if( ( nodex1y0 != 0 ) && ( nodex0y0 != nodex1y0 ) )
 hitted |= m_accelerator->Intersect( rayAA, hitAA, nodex1y0 );

 if( ( nodex0y1 != 0 ) && ( nodex0y0 != nodex0y1 ) && ( nodex1y0 != nodex0y1 ) )
 hitted |= m_accelerator->Intersect( rayAA, hitAA, nodex0y1 );

 if( ( nodex1y1 != 0 ) && ( nodex0y0 != nodex1y1 ) && ( nodex0y1 != nodex1y1 ) &&
 ( nodex1y0 != nodex1y1 ) )
 hitted |= m_accelerator->Intersect( rayAA, hitAA, nodex1y1 );

 if( (node_AA_x0y0 != 0 ) && ( nodex0y0 != node_AA_x0y0 ) &&
 ( nodex0y1 != node_AA_x0y0 ) && ( nodex1y0 != node_AA_x0y0 ) &&
 ( nodex1y1 != node_AA_x0y0 ) )
 hitted |= m_accelerator->Intersect( rayAA, hitAA, node_AA_x0y0 );

 if( hitted )
 {
 // If we got any result, shade it
 aOutHitColor[i] = shadeHit( aBgColorY[y], rayAA, hitAA, false, 0,
 is_testShadow );
 }
 else
 {
 // Note: There are very few cases that will end on this situation
 // so it is not so expensive to trace a single ray from the beginning

 // It was missed the 'last nodes' so, trace a ray from the beginning
 if( m_accelerator->Intersect( rayAA, hitAA ) )
 aOutHitColor[i] = shadeHit( aBgColorY[y], rayAA, hitAA, false, 0,
 is_testShadow );
 }
 }
 }
 }
}


#define DISP_FACTOR 0.075f


void RENDER_3D_RAYTRACE::renderBlockTracing( GLubyte* ptrPBO, signed int iBlock )
{
 // Initialize ray packets
 const SFVEC2UI& blockPos = m_blockPositions[iBlock];
 const SFVEC2I blockPosI = SFVEC2I( blockPos.x + m_xoffset, blockPos.y + m_yoffset );

 RAYPACKET blockPacket( m_camera, (SFVEC2F) blockPosI + SFVEC2F( DISP_FACTOR, DISP_FACTOR ),
 SFVEC2F( DISP_FACTOR, DISP_FACTOR ) /* Displacement random factor */ );


 HITINFO_PACKET hitPacket_X0Y0[RAYPACKET_RAYS_PER_PACKET];

 HITINFO_PACKET_init( hitPacket_X0Y0 );

 // Calculate background gradient color
 SFVEC3F bgColor[RAYPACKET_DIM];// Store a vertical gradient color

 for( unsigned int y = 0; y < RAYPACKET_DIM; ++y )
 {
 const float posYfactor = (float) ( blockPosI.y + y ) / (float) m_windowSize.y;

 bgColor[y] = m_backgroundColorTop * SFVEC3F(posYfactor) +
 m_backgroundColorBottom * ( SFVEC3F(1.0f) - SFVEC3F(posYfactor) );
 }

 // Intersect ray packets (calculate the intersection with rays and objects)
 if( !m_accelerator->Intersect( blockPacket, hitPacket_X0Y0 ) )
 {
 // If block is empty then set shades and continue
 if( m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_POST_PROCESSING ) )
 {
 for( unsigned int y = 0; y < RAYPACKET_DIM; ++y )
 {
 const SFVEC3F& outColor = bgColor[y];

 const unsigned int yBlockPos = blockPos.y + y;

 for( unsigned int x = 0; x < RAYPACKET_DIM; ++x )
 {
 m_postShaderSsao.SetPixelData( blockPos.x + x, yBlockPos,
 SFVEC3F( 0.0f ), outColor,
 SFVEC3F( 0.0f ), 0, 1.0f );
 }
 }
 }

 // This will set the output color to be displayed
 // If post processing is enabled, it will not reflect the final result
 // (as the final color will be computed on post processing)
 // but it is used for report progress
 const bool isFinalColor = !m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_POST_PROCESSING );

 for( unsigned int y = 0; y < RAYPACKET_DIM; ++y )
 {
 const SFVEC3F& outColor = bgColor[y];

 const unsigned int yConst = blockPos.x + ( ( y + blockPos.y ) * m_realBufferSize.x );

 for( unsigned int x = 0; x < RAYPACKET_DIM; ++x )
 {
 GLubyte* ptr = &ptrPBO[( yConst + x ) * 4];

 renderFinalColor( ptr, outColor, isFinalColor );
 }
 }

 // There is nothing more here to do.. there are no hits ..
 // just background so continue
 return;
 }

 SFVEC3F hitColor_X0Y0[RAYPACKET_RAYS_PER_PACKET];

 // Shade original (0, 0) hits ("paint" the intersected objects)
 renderRayPackets( bgColor, blockPacket.m_ray, hitPacket_X0Y0,
 m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_SHADOWS ), hitColor_X0Y0 );

 if( m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_ANTI_ALIASING ) )
 {
 SFVEC3F hitColor_AA_X1Y1[RAYPACKET_RAYS_PER_PACKET];

 // Intersect one blockPosI + (0.5, 0.5) used for anti aliasing calculation
 HITINFO_PACKET hitPacket_AA_X1Y1[RAYPACKET_RAYS_PER_PACKET];
 HITINFO_PACKET_init( hitPacket_AA_X1Y1 );

 RAYPACKET blockPacket_AA_X1Y1( m_camera, (SFVEC2F) blockPosI + SFVEC2F( 0.5f, 0.5f ),
 SFVEC2F( DISP_FACTOR, DISP_FACTOR ) );

 if( !m_accelerator->Intersect( blockPacket_AA_X1Y1, hitPacket_AA_X1Y1 ) )
 {
 // Missed all the package
 for( unsigned int y = 0, i = 0; y < RAYPACKET_DIM; ++y )
 {
 const SFVEC3F& outColor = bgColor[y];

 for( unsigned int x = 0; x < RAYPACKET_DIM; ++x, ++i )
 {
 hitColor_AA_X1Y1[i] = outColor;
 }
 }
 }
 else
 {
 renderRayPackets( bgColor, blockPacket_AA_X1Y1.m_ray, hitPacket_AA_X1Y1,
 m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_SHADOWS ),
 hitColor_AA_X1Y1 );
 }

 SFVEC3F hitColor_AA_X1Y0[RAYPACKET_RAYS_PER_PACKET];
 SFVEC3F hitColor_AA_X0Y1[RAYPACKET_RAYS_PER_PACKET];
 SFVEC3F hitColor_AA_X0Y1_half[RAYPACKET_RAYS_PER_PACKET];

 for( unsigned int i = 0; i < RAYPACKET_RAYS_PER_PACKET; ++i )
 {
 const SFVEC3F color_average = ( hitColor_X0Y0[i] +
 hitColor_AA_X1Y1[i] ) * SFVEC3F( 0.5f );

 hitColor_AA_X1Y0[i] = color_average;
 hitColor_AA_X0Y1[i] = color_average;
 hitColor_AA_X0Y1_half[i] = color_average;
 }

 RAY blockRayPck_AA_X1Y0[RAYPACKET_RAYS_PER_PACKET];
 RAY blockRayPck_AA_X0Y1[RAYPACKET_RAYS_PER_PACKET];
 RAY blockRayPck_AA_X1Y1_half[RAYPACKET_RAYS_PER_PACKET];

 RAYPACKET_InitRays_with2DDisplacement(
 m_camera, (SFVEC2F) blockPosI + SFVEC2F( 0.5f - DISP_FACTOR, DISP_FACTOR ),
 SFVEC2F( DISP_FACTOR, DISP_FACTOR ), blockRayPck_AA_X1Y0 );

 RAYPACKET_InitRays_with2DDisplacement(
 m_camera, (SFVEC2F) blockPosI + SFVEC2F( DISP_FACTOR, 0.5f - DISP_FACTOR ),
 SFVEC2F( DISP_FACTOR, DISP_FACTOR ), blockRayPck_AA_X0Y1 );

 RAYPACKET_InitRays_with2DDisplacement(
 m_camera, (SFVEC2F) blockPosI + SFVEC2F( 0.25f - DISP_FACTOR, 0.25f - DISP_FACTOR ),
 SFVEC2F( DISP_FACTOR, DISP_FACTOR ), blockRayPck_AA_X1Y1_half );

 renderAntiAliasPackets( bgColor, hitPacket_X0Y0, hitPacket_AA_X1Y1, blockRayPck_AA_X1Y0,
 hitColor_AA_X1Y0 );

 renderAntiAliasPackets( bgColor, hitPacket_X0Y0, hitPacket_AA_X1Y1, blockRayPck_AA_X0Y1,
 hitColor_AA_X0Y1 );

 renderAntiAliasPackets( bgColor, hitPacket_X0Y0, hitPacket_AA_X1Y1,
 blockRayPck_AA_X1Y1_half, hitColor_AA_X0Y1_half );

 // Average the result
 for( unsigned int i = 0; i < RAYPACKET_RAYS_PER_PACKET; ++i )
 {
 hitColor_X0Y0[i] = ( hitColor_X0Y0[i] + hitColor_AA_X1Y1[i] + hitColor_AA_X1Y0[i] +
 hitColor_AA_X0Y1[i] + hitColor_AA_X0Y1_half[i] ) *
 SFVEC3F( 1.0f / 5.0f );
 }
 }

 // Copy results to the next stage
 GLubyte* ptr = &ptrPBO[( blockPos.x + ( blockPos.y * m_realBufferSize.x ) ) * 4];

 const uint32_t ptrInc = ( m_realBufferSize.x - RAYPACKET_DIM ) * 4;

 if( m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_POST_PROCESSING ) )
 {
 SFVEC2I bPos;
 bPos.y = blockPos.y;

 for( unsigned int y = 0, i = 0; y < RAYPACKET_DIM; ++y )
 {
 bPos.x = blockPos.x;

 for( unsigned int x = 0; x < RAYPACKET_DIM; ++x, ++i )
 {
 const SFVEC3F& hColor = hitColor_X0Y0[i];

 if( hitPacket_X0Y0[i].m_hitresult == true )
 m_postShaderSsao.SetPixelData( bPos.x, bPos.y,
 hitPacket_X0Y0[i].m_HitInfo.m_HitNormal,
 hColor,
 blockPacket.m_ray[i].at(
 hitPacket_X0Y0[i].m_HitInfo.m_tHit ),
 hitPacket_X0Y0[i].m_HitInfo.m_tHit,
 hitPacket_X0Y0[i].m_HitInfo.m_ShadowFactor );
 else
 m_postShaderSsao.SetPixelData( bPos.x, bPos.y, SFVEC3F( 0.0f ), hColor,
 SFVEC3F( 0.0f ), 0, 1.0f );

 renderFinalColor( ptr, hColor, false );

 bPos.x++;
 ptr += 4;
 }

 ptr += ptrInc;
 bPos.y++;
 }
 }
 else
 {
 for( unsigned int y = 0, i = 0; y < RAYPACKET_DIM; ++y )
 {
 for( unsigned int x = 0; x < RAYPACKET_DIM; ++x, ++i )
 {
 renderFinalColor( ptr, hitColor_X0Y0[i], true );
 ptr += 4;
 }

 ptr += ptrInc;
 }
 }
}


void RENDER_3D_RAYTRACE::postProcessShading( GLubyte* /* ptrPBO */, REPORTER* aStatusReporter )
{
 if( m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_POST_PROCESSING ) )
 {
 if( aStatusReporter )
 aStatusReporter->Report( _( "Rendering: Post processing shader" ) );

 m_postShaderSsao.SetShadowsEnabled(
 m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_SHADOWS ) );

 std::atomic<size_t> nextBlock( 0 );
 std::atomic<size_t> threadsFinished( 0 );

 size_t parallelThreadCount = std::max<size_t>( std::thread::hardware_concurrency(), 2 );

 for( size_t ii = 0; ii < parallelThreadCount; ++ii )
 {
 std::thread t = std::thread( [&]()
 {
 for( size_t y = nextBlock.fetch_add( 1 ); y < m_realBufferSize.y;
 y = nextBlock.fetch_add( 1 ) )
 {
 SFVEC3F* ptr = &m_shaderBuffer[ y * m_realBufferSize.x ];

 for( signed int x = 0; x < (int)m_realBufferSize.x; ++x )
 {
 *ptr = m_postShaderSsao.Shade( SFVEC2I( x, y ) );
 ptr++;
 }
 }

 threadsFinished++;
 } );

 t.detach();
 }

 while( threadsFinished < parallelThreadCount )
 std::this_thread::sleep_for( std::chrono::milliseconds( 10 ) );

 m_postShaderSsao.SetShadedBuffer( m_shaderBuffer );

 // Set next state
 m_renderState = RT_RENDER_STATE_POST_PROCESS_BLUR_AND_FINISH;
 }
 else
 {
 // As this was an invalid state, set to finish
 m_renderState = RT_RENDER_STATE_FINISH;
 }
}


void RENDER_3D_RAYTRACE::postProcessBlurFinish( GLubyte* ptrPBO, REPORTER* /* aStatusReporter */ )
{
 if( m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_POST_PROCESSING ) )
 {
 // Now blurs the shader result and compute the final color
 std::atomic<size_t> nextBlock( 0 );
 std::atomic<size_t> threadsFinished( 0 );

 size_t parallelThreadCount = std::max<size_t>( std::thread::hardware_concurrency(), 2 );

 for( size_t ii = 0; ii < parallelThreadCount; ++ii )
 {
 std::thread t = std::thread( [&]()
 {
 for( size_t y = nextBlock.fetch_add( 1 ); y < m_realBufferSize.y;
 y = nextBlock.fetch_add( 1 ) )
 {
 GLubyte* ptr = &ptrPBO[ y * m_realBufferSize.x * 4 ];

 for( signed int x = 0; x < (int)m_realBufferSize.x; ++x )
  {
 const SFVEC3F bluredShadeColor = m_postShaderSsao.Blur( SFVEC2I( x, y ) );

#ifdef USE_SRGB_SPACE
 const SFVEC3F originColor = convertLinearToSRGB(
 m_postShaderSsao.GetColorAtNotProtected( SFVEC2I( x, y ) ) );
#else
 const SFVEC3F originColor =
 m_postShaderSsao.GetColorAtNotProtected( SFVEC2I( x, y ) );
#endif
 const SFVEC3F shadedColor = m_postShaderSsao.ApplyShadeColor(
 SFVEC2I( x, y ), originColor, bluredShadeColor );

 renderFinalColor( ptr, shadedColor, false );

 ptr += 4;
 }
 }

 threadsFinished++;
 } );

 t.detach();
 }

 while( threadsFinished < parallelThreadCount )
 std::this_thread::sleep_for( std::chrono::milliseconds( 10 ) );

 // Debug code
 //m_postShaderSsao.DebugBuffersOutputAsImages();
 }

 // End rendering
 m_renderState = RT_RENDER_STATE_FINISH;
}


void RENDER_3D_RAYTRACE::renderPreview( GLubyte* ptrPBO )
{
 m_isPreview = true;

 std::atomic<size_t> nextBlock( 0 );
 std::atomic<size_t> threadsFinished( 0 );

 size_t parallelThreadCount = std::min<size_t>(
 std::max<size_t>( std::thread::hardware_concurrency(), 2 ),
 m_blockPositions.size() );

 for( size_t ii = 0; ii < parallelThreadCount; ++ii )
 {
 std::thread t = std::thread( [&]()
 {
 for( size_t iBlock = nextBlock.fetch_add( 1 ); iBlock < m_blockPositionsFast.size();
 iBlock = nextBlock.fetch_add( 1 ) )
 {
 const SFVEC2UI& windowPosUI = m_blockPositionsFast[ iBlock ];
 const SFVEC2I windowsPos = SFVEC2I( windowPosUI.x + m_xoffset,
 windowPosUI.y + m_yoffset );

 RAYPACKET blockPacket( m_camera, windowsPos, 4 );

 HITINFO_PACKET hitPacket[RAYPACKET_RAYS_PER_PACKET];

 // Initialize hitPacket with a "not hit" information
 for( HITINFO_PACKET& packet : hitPacket )
 {
 packet.m_HitInfo.m_tHit = std::numeric_limits<float>::infinity();
 packet.m_HitInfo.m_acc_node_info = 0;
 packet.m_hitresult = false;
 }

 // Intersect packet block
 m_accelerator->Intersect( blockPacket, hitPacket );

 // Calculate background gradient color
 SFVEC3F bgColor[RAYPACKET_DIM];

 for( unsigned int y = 0; y < RAYPACKET_DIM; ++y )
 {
 const float posYfactor =
 (float) ( windowsPos.y + y * 4.0f ) / (float) m_windowSize.y;

 bgColor[y] = (SFVEC3F) m_boardAdapter.m_BgColorTop * SFVEC3F( posYfactor )
 + (SFVEC3F) m_boardAdapter.m_BgColorBot
 * ( SFVEC3F( 1.0f ) - SFVEC3F( posYfactor ) );
 }

 COLOR_RGB hitColorShading[RAYPACKET_RAYS_PER_PACKET];

 for( unsigned int i = 0; i < RAYPACKET_RAYS_PER_PACKET; ++i )
 {
 const SFVEC3F bhColorY = bgColor[i / RAYPACKET_DIM];

 if( hitPacket[i].m_hitresult == true )
 {
 const SFVEC3F hitColor = shadeHit( bhColorY, blockPacket.m_ray[i],
 hitPacket[i].m_HitInfo, false,
 0, false );

 hitColorShading[i] = COLOR_RGB( hitColor );
 }
 else
 hitColorShading[i] = bhColorY;
 }

 COLOR_RGB cLRB_old[(RAYPACKET_DIM - 1)];

 for( unsigned int y = 0; y < (RAYPACKET_DIM - 1); ++y )
 {
 const SFVEC3F bgColorY = bgColor[y];
 const COLOR_RGB bgColorYRGB = COLOR_RGB( bgColorY );

 // This stores cRTB from the last block to be reused next time in a cLTB pixel
 COLOR_RGB cRTB_old;

 //RAY cRTB_ray;
 //HITINFO cRTB_hitInfo;

 for( unsigned int x = 0; x < ( RAYPACKET_DIM - 1 ); ++x )
 {
 // pxl 0 pxl 1 pxl 2 pxl 3 pxl 4
 // x0 x1 ...
 // .---------------------------.
 // y0 | cLT | cxxx | cLRT | cxxx | cRT |
 // | cxxx | cLTC | cxxx | cRTC | cxxx |
 // | cLTB | cxxx | cC | cxxx | cRTB |
 // | cxxx | cLBC | cxxx | cRBC | cxxx |
 // '---------------------------'
 // y1 | cLB | cxxx | cLRB | cxxx | cRB |

 const unsigned int iLT = ( ( x + 0 ) + RAYPACKET_DIM * ( y + 0 ) );
 const unsigned int iRT = ( ( x + 1 ) + RAYPACKET_DIM * ( y + 0 ) );
 const unsigned int iLB = ( ( x + 0 ) + RAYPACKET_DIM * ( y + 1 ) );
 const unsigned int iRB = ( ( x + 1 ) + RAYPACKET_DIM * ( y + 1 ) );

 // !TODO: skip when there are no hits
 const COLOR_RGB& cLT = hitColorShading[ iLT ];
 const COLOR_RGB& cRT = hitColorShading[ iRT ];
 const COLOR_RGB& cLB = hitColorShading[ iLB ];
 const COLOR_RGB& cRB = hitColorShading[ iRB ];

 // Trace and shade cC
 COLOR_RGB cC = bgColorYRGB;

 const SFVEC3F& oriLT = blockPacket.m_ray[ iLT ].m_Origin;
 const SFVEC3F& oriRB = blockPacket.m_ray[ iRB ].m_Origin;

 const SFVEC3F& dirLT = blockPacket.m_ray[ iLT ].m_Dir;
 const SFVEC3F& dirRB = blockPacket.m_ray[ iRB ].m_Dir;

 SFVEC3F oriC;
 SFVEC3F dirC;

 HITINFO centerHitInfo;
 centerHitInfo.m_tHit = std::numeric_limits<float>::infinity();

 bool hittedC = false;

 if( ( hitPacket[iLT].m_hitresult == true )
 || ( hitPacket[iRT].m_hitresult == true )
 || ( hitPacket[iLB].m_hitresult == true )
 || ( hitPacket[iRB].m_hitresult == true ) )
  {
 oriC = ( oriLT + oriRB ) * 0.5f;
 dirC = glm::normalize( ( dirLT + dirRB ) * 0.5f );

 // Trace the center ray
 RAY centerRay;
 centerRay.Init( oriC, dirC );

 const unsigned int nodeLT = hitPacket[ iLT ].m_HitInfo.m_acc_node_info;
 const unsigned int nodeRT = hitPacket[ iRT ].m_HitInfo.m_acc_node_info;
 const unsigned int nodeLB = hitPacket[ iLB ].m_HitInfo.m_acc_node_info;
 const unsigned int nodeRB = hitPacket[ iRB ].m_HitInfo.m_acc_node_info;

 if( nodeLT != 0 )
 hittedC |= m_accelerator->Intersect( centerRay, centerHitInfo,
 nodeLT );

 if( ( nodeRT != 0 ) && ( nodeRT != nodeLT ) )
 hittedC |= m_accelerator->Intersect( centerRay, centerHitInfo,
 nodeRT );

 if( ( nodeLB != 0 ) && ( nodeLB != nodeLT ) && ( nodeLB != nodeRT ) )
 hittedC |= m_accelerator->Intersect( centerRay, centerHitInfo,
 nodeLB );

 if( ( nodeRB != 0 ) && ( nodeRB != nodeLB ) && ( nodeRB != nodeLT )
 && ( nodeRB != nodeRT ) )
 hittedC |= m_accelerator->Intersect( centerRay, centerHitInfo,
 nodeRB );

 if( hittedC )
 {
 cC = COLOR_RGB( shadeHit( bgColorY, centerRay, centerHitInfo,
 false, 0, false ) );
 }
 else
 {
 centerHitInfo.m_tHit = std::numeric_limits<float>::infinity();
 hittedC = m_accelerator->Intersect( centerRay, centerHitInfo );

 if( hittedC )
 cC = COLOR_RGB( shadeHit( bgColorY, centerRay, centerHitInfo,
 false, 0, false ) );
 }
 }

 // Trace and shade cLRT
 COLOR_RGB cLRT = bgColorYRGB;

 const SFVEC3F& oriRT = blockPacket.m_ray[ iRT ].m_Origin;
 const SFVEC3F& dirRT = blockPacket.m_ray[ iRT ].m_Dir;

 if( y == 0 )
 {
 // Trace the center ray
 RAY rayLRT;
 rayLRT.Init( ( oriLT + oriRT ) * 0.5f,
 glm::normalize( ( dirLT + dirRT ) * 0.5f ) );

 HITINFO hitInfoLRT;
 hitInfoLRT.m_tHit = std::numeric_limits<float>::infinity();

 if( hitPacket[iLT].m_hitresult && hitPacket[iRT].m_hitresult
 && ( hitPacket[iLT].m_HitInfo.pHitObject
 == hitPacket[iRT].m_HitInfo.pHitObject ) )
 {
 hitInfoLRT.pHitObject = hitPacket[ iLT ].m_HitInfo.pHitObject;
 hitInfoLRT.m_tHit = ( hitPacket[ iLT ].m_HitInfo.m_tHit +
 hitPacket[ iRT ].m_HitInfo.m_tHit ) * 0.5f;
 hitInfoLRT.m_HitNormal =
 glm::normalize( ( hitPacket[ iLT ].m_HitInfo.m_HitNormal +
 hitPacket[ iRT ].m_HitInfo.m_HitNormal ) * 0.5f );

 cLRT = COLOR_RGB( shadeHit( bgColorY, rayLRT, hitInfoLRT, false,
 0, false ) );
 cLRT = BlendColor( cLRT, BlendColor( cLT, cRT ) );
 }
 else
 {
 // If any hits
 if( hitPacket[ iLT ].m_hitresult || hitPacket[ iRT ].m_hitresult )
 {
 const unsigned int nodeLT =
 hitPacket[ iLT ].m_HitInfo.m_acc_node_info;
 const unsigned int nodeRT =
 hitPacket[ iRT ].m_HitInfo.m_acc_node_info;

 bool hittedLRT = false;

 if( nodeLT != 0 )
 hittedLRT |= m_accelerator->Intersect( rayLRT, hitInfoLRT,
 nodeLT );

 if( ( nodeRT != 0 ) && ( nodeRT != nodeLT ) )
 hittedLRT |= m_accelerator->Intersect( rayLRT, hitInfoLRT,
 nodeRT );

 if( hittedLRT )
 cLRT = COLOR_RGB( shadeHit( bgColorY, rayLRT, hitInfoLRT,
 false, 0, false ) );
 else
 {
 hitInfoLRT.m_tHit = std::numeric_limits<float>::infinity();

 if( m_accelerator->Intersect( rayLRT,hitInfoLRT ) )
 cLRT = COLOR_RGB( shadeHit( bgColorY, rayLRT,
 hitInfoLRT, false,
 0, false ) );
 }
 }
 }
 }
 else
 {
 cLRT = cLRB_old[x];
 }

 // Trace and shade cLTB
 COLOR_RGB cLTB = bgColorYRGB;

 if( x == 0 )
 {
 const SFVEC3F &oriLB = blockPacket.m_ray[ iLB ].m_Origin;
 const SFVEC3F& dirLB = blockPacket.m_ray[ iLB ].m_Dir;

 // Trace the center ray
 RAY rayLTB;
 rayLTB.Init( ( oriLT + oriLB ) * 0.5f,
 glm::normalize( ( dirLT + dirLB ) * 0.5f ) );

 HITINFO hitInfoLTB;
 hitInfoLTB.m_tHit = std::numeric_limits<float>::infinity();

 if( hitPacket[ iLT ].m_hitresult && hitPacket[ iLB ].m_hitresult
 && ( hitPacket[ iLT ].m_HitInfo.pHitObject ==
 hitPacket[ iLB ].m_HitInfo.pHitObject ) )
 {
 hitInfoLTB.pHitObject = hitPacket[ iLT ].m_HitInfo.pHitObject;
 hitInfoLTB.m_tHit = ( hitPacket[ iLT ].m_HitInfo.m_tHit +
 hitPacket[ iLB ].m_HitInfo.m_tHit ) * 0.5f;
 hitInfoLTB.m_HitNormal =
 glm::normalize( ( hitPacket[ iLT ].m_HitInfo.m_HitNormal +
 hitPacket[ iLB ].m_HitInfo.m_HitNormal ) * 0.5f );
 cLTB = COLOR_RGB( shadeHit( bgColorY, rayLTB, hitInfoLTB, false,
 0, false ) );
 cLTB = BlendColor( cLTB, BlendColor( cLT, cLB) );
 }
 else
 {
 // If any hits
 if( hitPacket[ iLT ].m_hitresult || hitPacket[ iLB ].m_hitresult )
 {
 const unsigned int nodeLT =
 hitPacket[ iLT ].m_HitInfo.m_acc_node_info;
 const unsigned int nodeLB =
 hitPacket[ iLB ].m_HitInfo.m_acc_node_info;

 bool hittedLTB = false;

 if( nodeLT != 0 )
 hittedLTB |= m_accelerator->Intersect( rayLTB, hitInfoLTB,
 nodeLT );

 if( ( nodeLB != 0 ) && ( nodeLB != nodeLT ) )
 hittedLTB |= m_accelerator->Intersect( rayLTB, hitInfoLTB,
 nodeLB );

 if( hittedLTB )
 cLTB = COLOR_RGB( shadeHit( bgColorY, rayLTB, hitInfoLTB,
 false, 0, false ) );
 else
 {
 hitInfoLTB.m_tHit = std::numeric_limits<float>::infinity();

 if( m_accelerator->Intersect( rayLTB, hitInfoLTB ) )
 cLTB = COLOR_RGB( shadeHit( bgColorY, rayLTB,
 hitInfoLTB, false,
 0, false ) );
 }
 }
 }
 }
 else
 {
 cLTB = cRTB_old;
 }

 // Trace and shade cRTB
 COLOR_RGB cRTB = bgColorYRGB;

 // Trace the center ray
 RAY rayRTB;
 rayRTB.Init( ( oriRT + oriRB ) * 0.5f,
 glm::normalize( ( dirRT + dirRB ) * 0.5f ) );

 HITINFO hitInfoRTB;
 hitInfoRTB.m_tHit = std::numeric_limits<float>::infinity();

 if( hitPacket[ iRT ].m_hitresult && hitPacket[ iRB ].m_hitresult
 && ( hitPacket[ iRT ].m_HitInfo.pHitObject ==
 hitPacket[ iRB ].m_HitInfo.pHitObject ) )
 {
 hitInfoRTB.pHitObject = hitPacket[ iRT ].m_HitInfo.pHitObject;

 hitInfoRTB.m_tHit = ( hitPacket[ iRT ].m_HitInfo.m_tHit +
 hitPacket[ iRB ].m_HitInfo.m_tHit ) * 0.5f;

 hitInfoRTB.m_HitNormal =
 glm::normalize( ( hitPacket[ iRT ].m_HitInfo.m_HitNormal +
 hitPacket[ iRB ].m_HitInfo.m_HitNormal ) * 0.5f );

 cRTB = COLOR_RGB( shadeHit( bgColorY, rayRTB, hitInfoRTB, false, 0,
 false ) );
 cRTB = BlendColor( cRTB, BlendColor( cRT, cRB ) );
 }
 else
 {
 // If any hits
 if( hitPacket[ iRT ].m_hitresult || hitPacket[ iRB ].m_hitresult )
 {
 const unsigned int nodeRT =
 hitPacket[ iRT ].m_HitInfo.m_acc_node_info;
 const unsigned int nodeRB =
 hitPacket[ iRB ].m_HitInfo.m_acc_node_info;

 bool hittedRTB = false;

 if( nodeRT != 0 )
 hittedRTB |= m_accelerator->Intersect( rayRTB, hitInfoRTB,
 nodeRT );

 if( ( nodeRB != 0 ) && ( nodeRB != nodeRT ) )
 hittedRTB |= m_accelerator->Intersect( rayRTB, hitInfoRTB,
 nodeRB );

 if( hittedRTB )
 {
 cRTB = COLOR_RGB( shadeHit( bgColorY, rayRTB, hitInfoRTB,
 false, 0, false) );
 }
 else
 {
 hitInfoRTB.m_tHit = std::numeric_limits<float>::infinity();

 if( m_accelerator->Intersect( rayRTB, hitInfoRTB ) )
 cRTB = COLOR_RGB( shadeHit( bgColorY, rayRTB, hitInfoRTB,
 false, 0, false ) );
 }
 }
 }

 cRTB_old = cRTB;

 // Trace and shade cLRB
 COLOR_RGB cLRB = bgColorYRGB;

 const SFVEC3F& oriLB = blockPacket.m_ray[ iLB ].m_Origin;
 const SFVEC3F& dirLB = blockPacket.m_ray[ iLB ].m_Dir;

 // Trace the center ray
 RAY rayLRB;
 rayLRB.Init( ( oriLB + oriRB ) * 0.5f,
 glm::normalize( ( dirLB + dirRB ) * 0.5f ) );

 HITINFO hitInfoLRB;
 hitInfoLRB.m_tHit = std::numeric_limits<float>::infinity();

 if( hitPacket[iLB].m_hitresult && hitPacket[iRB].m_hitresult
 && ( hitPacket[iLB].m_HitInfo.pHitObject ==
  hitPacket[iRB].m_HitInfo.pHitObject ) )
 {
 hitInfoLRB.pHitObject = hitPacket[ iLB ].m_HitInfo.pHitObject;

 hitInfoLRB.m_tHit = ( hitPacket[ iLB ].m_HitInfo.m_tHit +
 hitPacket[ iRB ].m_HitInfo.m_tHit ) * 0.5f;

 hitInfoLRB.m_HitNormal =
 glm::normalize( ( hitPacket[ iLB ].m_HitInfo.m_HitNormal +
 hitPacket[ iRB ].m_HitInfo.m_HitNormal ) * 0.5f );

 cLRB = COLOR_RGB( shadeHit( bgColorY, rayLRB, hitInfoLRB, false, 0,
 false ) );
 cLRB = BlendColor( cLRB, BlendColor( cLB, cRB ) );
 }
 else
 {
 // If any hits
 if( hitPacket[ iLB ].m_hitresult || hitPacket[ iRB ].m_hitresult )
 {
 const unsigned int nodeLB =
 hitPacket[ iLB ].m_HitInfo.m_acc_node_info;
 const unsigned int nodeRB =
 hitPacket[ iRB ].m_HitInfo.m_acc_node_info;

 bool hittedLRB = false;

 if( nodeLB != 0 )
 hittedLRB |= m_accelerator->Intersect( rayLRB, hitInfoLRB,
 nodeLB );

 if( ( nodeRB != 0 ) && ( nodeRB != nodeLB ) )
 hittedLRB |= m_accelerator->Intersect( rayLRB, hitInfoLRB,
 nodeRB );

 if( hittedLRB )
 {
 cLRB = COLOR_RGB( shadeHit( bgColorY, rayLRB, hitInfoLRB,
 false, 0, false ) );
 }
 else
 {
 hitInfoLRB.m_tHit = std::numeric_limits<float>::infinity();

 if( m_accelerator->Intersect( rayLRB, hitInfoLRB ) )
  cLRB = COLOR_RGB( shadeHit( bgColorY, rayLRB, hitInfoLRB,
 false, 0, false ) );
 }
 }
 }

 cLRB_old[x] = cLRB;

 // Trace and shade cLTC
 COLOR_RGB cLTC = BlendColor( cLT , cC );

 if( hitPacket[ iLT ].m_hitresult || hittedC )
 {
 // Trace the center ray
 RAY rayLTC;
 rayLTC.Init( ( oriLT + oriC ) * 0.5f,
 glm::normalize( ( dirLT + dirC ) * 0.5f ) );

 HITINFO hitInfoLTC;
 hitInfoLTC.m_tHit = std::numeric_limits<float>::infinity();

 bool hitted = false;

 if( hittedC )
 hitted = centerHitInfo.pHitObject->Intersect( rayLTC, hitInfoLTC );
 else if( hitPacket[ iLT ].m_hitresult )
 hitted = hitPacket[ iLT ].m_HitInfo.pHitObject->Intersect(
 rayLTC,
 hitInfoLTC );

 if( hitted )
 cLTC = COLOR_RGB( shadeHit( bgColorY, rayLTC, hitInfoLTC, false,
 0, false ) );
 }

 // Trace and shade cRTC
 COLOR_RGB cRTC = BlendColor( cRT , cC );

 if( hitPacket[ iRT ].m_hitresult || hittedC )
 {
 // Trace the center ray
 RAY rayRTC;
 rayRTC.Init( ( oriRT + oriC ) * 0.5f,
 glm::normalize( ( dirRT + dirC ) * 0.5f ) );

 HITINFO hitInfoRTC;
 hitInfoRTC.m_tHit = std::numeric_limits<float>::infinity();

 bool hitted = false;

 if( hittedC )
 hitted = centerHitInfo.pHitObject->Intersect( rayRTC, hitInfoRTC );
 else if( hitPacket[ iRT ].m_hitresult )
 hitted = hitPacket[ iRT ].m_HitInfo.pHitObject->Intersect( rayRTC,
 hitInfoRTC );

 if( hitted )
 cRTC = COLOR_RGB( shadeHit( bgColorY, rayRTC, hitInfoRTC, false,
 0, false ) );
 }

 // Trace and shade cLBC
 COLOR_RGB cLBC = BlendColor( cLB , cC );

 if( hitPacket[ iLB ].m_hitresult || hittedC )
 {
 // Trace the center ray
 RAY rayLBC;
 rayLBC.Init( ( oriLB + oriC ) * 0.5f,
 glm::normalize( ( dirLB + dirC ) * 0.5f ) );

 HITINFO hitInfoLBC;
 hitInfoLBC.m_tHit = std::numeric_limits<float>::infinity();

 bool hitted = false;

 if( hittedC )
 hitted = centerHitInfo.pHitObject->Intersect( rayLBC, hitInfoLBC );
 else if( hitPacket[ iLB ].m_hitresult )
 hitted = hitPacket[ iLB ].m_HitInfo.pHitObject->Intersect( rayLBC,
 hitInfoLBC );

 if( hitted )
 cLBC = COLOR_RGB( shadeHit( bgColorY, rayLBC, hitInfoLBC, false,
 0, false ) );
 }

 // Trace and shade cRBC
 COLOR_RGB cRBC = BlendColor( cRB , cC );

 if( hitPacket[ iRB ].m_hitresult || hittedC )
 {
 // Trace the center ray
 RAY rayRBC;
 rayRBC.Init( ( oriRB + oriC ) * 0.5f,
 glm::normalize( ( dirRB + dirC ) * 0.5f ) );

 HITINFO hitInfoRBC;
 hitInfoRBC.m_tHit = std::numeric_limits<float>::infinity();

 bool hitted = false;

 if( hittedC )
 hitted = centerHitInfo.pHitObject->Intersect( rayRBC, hitInfoRBC );
 else if( hitPacket[ iRB ].m_hitresult )
 hitted = hitPacket[ iRB ].m_HitInfo.pHitObject->Intersect( rayRBC,
 hitInfoRBC );

 if( hitted )
 cRBC = COLOR_RGB( shadeHit( bgColorY, rayRBC, hitInfoRBC, false,
 0, false ) );
 }

 // Set pixel colors
 GLubyte* ptr =
 &ptrPBO[( 4 * x + m_blockPositionsFast[iBlock].x
 + m_realBufferSize.x
 * ( m_blockPositionsFast[iBlock].y + 4 * y ) ) * 4];
 SetPixel( ptr + 0, cLT );
  SetPixel( ptr + 4, BlendColor( cLT, cLRT, cLTC ) );
 SetPixel( ptr + 8, cLRT );
 SetPixel( ptr + 12, BlendColor( cLRT, cRT, cRTC ) );

 ptr += m_realBufferSize.x * 4;
 SetPixel( ptr + 0, BlendColor( cLT , cLTB, cLTC ) );
 SetPixel( ptr + 4, BlendColor( cLTC, BlendColor( cLT , cC ) ) );
 SetPixel( ptr + 8, BlendColor( cC, BlendColor( cLRT, cLTC, cRTC ) ) );
 SetPixel( ptr + 12, BlendColor( cRTC, BlendColor( cRT , cC ) ) );

 ptr += m_realBufferSize.x * 4;
 SetPixel( ptr + 0, cLTB );
 SetPixel( ptr + 4, BlendColor( cC, BlendColor( cLTB, cLTC, cLBC ) ) );
 SetPixel( ptr + 8, cC );
 SetPixel( ptr + 12, BlendColor( cC, BlendColor( cRTB, cRTC, cRBC ) ) );

 ptr += m_realBufferSize.x * 4;
 SetPixel( ptr + 0, BlendColor( cLB , cLTB, cLBC ) );
 SetPixel( ptr + 4, BlendColor( cLBC, BlendColor( cLB , cC ) ) );
 SetPixel( ptr + 8, BlendColor( cC, BlendColor( cLRB, cLBC, cRBC ) ) );
 SetPixel( ptr + 12, BlendColor( cRBC, BlendColor( cRB , cC ) ) );
 }
 }
 }

 threadsFinished++;
 } );

 t.detach();
 }

 while( threadsFinished < parallelThreadCount )
 std::this_thread::sleep_for( std::chrono::milliseconds( 10 ) );
}


#define USE_EXPERIMENTAL_SOFT_SHADOWS 1

SFVEC3F RENDER_3D_RAYTRACE::shadeHit( const SFVEC3F& aBgColor, const RAY& aRay, HITINFO& aHitInfo,
 bool aIsInsideObject, unsigned int aRecursiveLevel,
 bool is_testShadow ) const
{
 const MATERIAL* objMaterial = aHitInfo.pHitObject->GetMaterial();
 wxASSERT( objMaterial != nullptr );

 SFVEC3F outColor = objMaterial->GetEmissiveColor() + objMaterial->GetAmbientColor();

 if( aRecursiveLevel > 7 )
 return outColor;

 SFVEC3F hitPoint = aHitInfo.m_HitPoint;

 hitPoint += aHitInfo.m_HitNormal * m_boardAdapter.GetNonCopperLayerThickness() * 0.6f;

 const SFVEC3F diffuseColorObj = aHitInfo.pHitObject->GetDiffuseColor( aHitInfo );

#if USE_EXPERIMENTAL_SOFT_SHADOWS
 const bool is_aa_enabled = m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_ANTI_ALIASING ) &&
 (!m_isPreview);
#endif

 float shadow_att_factor_sum = 0.0f;

 unsigned int nr_lights_that_can_cast_shadows = 0;

 for( const LIGHT* light : m_lights )
 {
 SFVEC3F vectorToLight;
 SFVEC3F colorOfLight;
 float distToLight;

 light->GetLightParameters( hitPoint, vectorToLight, colorOfLight, distToLight );

 if( m_isPreview )
 colorOfLight = SFVEC3F( 1.0f );

 const float NdotL = glm::dot( aHitInfo.m_HitNormal, vectorToLight );

 // Only calc shade if the normal is facing the direction of light,
 // otherwise it is in the shadow
 if( NdotL >= FLT_EPSILON )
 {
 float shadow_att_factor_light = 1.0f;

 if( is_testShadow && light->GetCastShadows() )
 {
 nr_lights_that_can_cast_shadows++;
#if USE_EXPERIMENTAL_SOFT_SHADOWS
 // For rays that are recursive, just calculate one hit shadow
 if( aRecursiveLevel > 0 )
 {
#endif
 RAY rayToLight;
 rayToLight.Init( hitPoint, vectorToLight );

 // Test if point is not in the shadow.
 // Test for any hit from the point in the direction of light
 if( m_accelerator->IntersectP( rayToLight, distToLight ) )
 shadow_att_factor_light = 0.0f;

#if USE_EXPERIMENTAL_SOFT_SHADOWS
 }
 else // Experimental softshadow calculation
 {

 const unsigned int shadow_number_of_samples =
 m_boardAdapter.m_RtShadowSampleCount;
 const float shadow_inc_factor = 1.0f / (float) ( shadow_number_of_samples );

 for( unsigned int i = 0; i < shadow_number_of_samples; ++i )
 {
 RAY rayToLight;

 if( i == 0 )
 {
 rayToLight.Init( hitPoint, vectorToLight );
 }
 else
 {
 const SFVEC3F unifVector = UniformRandomHemisphereDirection();
 const SFVEC3F disturbed_vector_to_light =
 glm::normalize( vectorToLight + unifVector *
 m_boardAdapter.m_RtSpreadShadows );

 rayToLight.Init( hitPoint, disturbed_vector_to_light );
 }

 // !TODO: there are multiple ways that this tests can be
  // optimized. Eg: by packing rays or to test against the
 // latest hit object.
 if( m_accelerator->IntersectP( rayToLight, distToLight ) )
 {
 shadow_att_factor_light -= shadow_inc_factor;
 }
 }
 }
#endif
 shadow_att_factor_sum += shadow_att_factor_light;
 }

 outColor += objMaterial->Shade( aRay, aHitInfo, NdotL, diffuseColorObj, vectorToLight,
 colorOfLight, shadow_att_factor_light );
 }

 // Only use the headlight for preview
 if( m_isPreview )
 break;
 }

 // Improvement: this is not taking in account the lightcolor
 if( nr_lights_that_can_cast_shadows > 0 )
 {
 aHitInfo.m_ShadowFactor = glm::max(
 shadow_att_factor_sum / (float) ( nr_lights_that_can_cast_shadows * 1.0f ), 0.0f );
 }
 else
 {
 aHitInfo.m_ShadowFactor = 1.0f;
 }

 // Clamp color to not be brighter than 1.0f
 outColor = glm::min( outColor, SFVEC3F( 1.0f ) );

 if( !m_isPreview )
 {
 // Reflections
 if( ( objMaterial->GetReflection() > 0.0f )
 && m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_REFLECTIONS )
 && ( aRecursiveLevel < objMaterial->GetReflectionRecursionCount() ) )
 {
 const unsigned int reflection_number_of_samples =
 objMaterial->GetReflectionRayCount();

 SFVEC3F sum_color = SFVEC3F( 0.0f );

 const SFVEC3F reflectVector = aRay.m_Dir - 2.0f *
 glm::dot( aRay.m_Dir, aHitInfo.m_HitNormal ) * aHitInfo.m_HitNormal;

 for( unsigned int i = 0; i < reflection_number_of_samples; ++i )
 {
 RAY reflectedRay;

 if( i == 0 )
 {
 reflectedRay.Init( hitPoint, reflectVector );
 }
 else
 {
 // Apply some randomize to the reflected vector
 const SFVEC3F random_reflectVector =
 glm::normalize( reflectVector +
 UniformRandomHemisphereDirection() *
 m_boardAdapter.m_RtSpreadReflections );

 reflectedRay.Init( hitPoint, random_reflectVector );
 }

 HITINFO reflectedHit;
 reflectedHit.m_tHit = std::numeric_limits<float>::infinity();

 if( m_accelerator->Intersect( reflectedRay, reflectedHit ) )
 {
 sum_color += ( diffuseColorObj + objMaterial->GetSpecularColor() ) *
 shadeHit( aBgColor, reflectedRay, reflectedHit, false,
 aRecursiveLevel + 1, is_testShadow ) *
 SFVEC3F( objMaterial->GetReflection() *
 // Falloff factor
 (1.0f / ( 1.0f + 0.75f * reflectedHit.m_tHit *
 reflectedHit.m_tHit) ) );
 }
 }

 outColor += (sum_color / SFVEC3F( (float)reflection_number_of_samples) );
 }

 // Refraction
 const float objTransparency = aHitInfo.pHitObject->GetModelTransparency();

 if( ( objTransparency > 0.0f ) && m_boardAdapter.GetFlag( FL_RENDER_RAYTRACING_REFRACTIONS )
 && ( aRecursiveLevel < objMaterial->GetRefractionRecursionCount() ) )
 {
 const float airIndex = 1.000293f;
 const float glassIndex = 1.49f;
 const float air_over_glass = airIndex / glassIndex;
 const float glass_over_air = glassIndex / airIndex;

 const float refractionRatio = aIsInsideObject?glass_over_air:air_over_glass;

 SFVEC3F refractedVector;

 if( Refract( aRay.m_Dir, aHitInfo.m_HitNormal, refractionRatio, refractedVector ) )
 {
 // This increase the start point by a "fixed" factor so it will work the
 // same for all distances
 const SFVEC3F startPoint =
 aRay.at( aHitInfo.m_tHit + m_boardAdapter.GetNonCopperLayerThickness() *
 0.25f );

 const unsigned int refractions_number_of_samples =
 objMaterial->GetRefractionRayCount();

 SFVEC3F sum_color = SFVEC3F(0.0f);

 for( unsigned int i = 0; i < refractions_number_of_samples; ++i )
 {
 RAY refractedRay;

 if( i == 0 )
 {
 refractedRay.Init( startPoint, refractedVector );
 }
 else
 {
 // apply some randomize to the refracted vector
 const SFVEC3F randomizeRefractedVector =
 glm::normalize( refractedVector +
 UniformRandomHemisphereDirection() *
 m_boardAdapter.m_RtSpreadRefractions );

 refractedRay.Init( startPoint, randomizeRefractedVector );
 }

 HITINFO refractedHit;
 refractedHit.m_tHit = std::numeric_limits<float>::infinity();

 SFVEC3F refractedColor = aBgColor;

 if( m_accelerator->Intersect( refractedRay, refractedHit ) )
 {
 refractedColor = shadeHit( aBgColor, refractedRay, refractedHit,
 !aIsInsideObject, aRecursiveLevel + 1, false );

 const SFVEC3F absorbance = ( SFVEC3F(1.0f) - diffuseColorObj ) *
 (1.0f - objTransparency ) *
 objMaterial->GetAbsorvance() *
 refractedHit.m_tHit;

 const SFVEC3F transparency = 1.0f / ( absorbance + 1.0f );

 sum_color += refractedColor * transparency;
 }
 else
 {
 sum_color += refractedColor;
 }
 }

 outColor = outColor * ( 1.0f - objTransparency ) + objTransparency * sum_color
 / SFVEC3F( (float) refractions_number_of_samples );
 }
 else
 {
 outColor = outColor * ( 1.0f - objTransparency ) + objTransparency * aBgColor;
 }
 }
 }

 return outColor;
}


void RENDER_3D_RAYTRACE::initializeNewWindowSize()
{
 initPbo();
}


void RENDER_3D_RAYTRACE::initPbo()
{
 if( GLEW_ARB_pixel_buffer_object )
 {
 m_openglSupportsVertexBufferObjects = true;

 // Try to delete vbo if it was already initialized
 deletePbo();

 // Learn about Pixel buffer objects at:
 // http://www.songho.ca/opengl/gl_pbo.html
 // http://web.eecs.umich.edu/~sugih/courses/eecs487/lectures/25-PBO+Mipmapping.pdf
 // "create 2 pixel buffer objects, you need to delete them when program exits.
 // glBufferDataARB with NULL pointer reserves only memory space."

 // This sets the number of RGBA pixels
 m_pboDataSize = m_realBufferSize.x * m_realBufferSize.y * 4;

 glGenBuffersARB( 1, &m_pboId );
 glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, m_pboId );
 glBufferDataARB( GL_PIXEL_UNPACK_BUFFER_ARB, m_pboDataSize, 0, GL_STREAM_DRAW_ARB );
 glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, 0 );

 wxLogTrace( m_logTrace,
 wxT( "RENDER_3D_RAYTRACE:: GLEW_ARB_pixel_buffer_object is supported" ) );
 }
}


bool RENDER_3D_RAYTRACE::initializeOpenGL()
{
 m_is_opengl_initialized = true;

 return true;
}


static float distance( const SFVEC2UI& a, const SFVEC2UI& b )
{
 const float dx = (float) a.x - (float) b.x;
 const float dy = (float) a.y - (float) b.y;
 return hypotf( dx, dy );
}


void RENDER_3D_RAYTRACE::initializeBlockPositions()
{
 m_realBufferSize = SFVEC2UI( 0 );

 // Calc block positions for fast preview mode
 m_blockPositionsFast.clear();

 unsigned int i = 0;

 while(1)
 {
 const unsigned int mX = DecodeMorton2X(i);
 const unsigned int mY = DecodeMorton2Y(i);

 i++;

 const SFVEC2UI blockPos( mX * 4 * RAYPACKET_DIM - mX * 4,
 mY * 4 * RAYPACKET_DIM - mY * 4 );

 if( ( blockPos.x >= ( (unsigned int)m_windowSize.x - ( 4 * RAYPACKET_DIM + 4 ) ) ) &&
 ( blockPos.y >= ( (unsigned int)m_windowSize.y - ( 4 * RAYPACKET_DIM + 4 ) ) ) )
 break;

 if( ( blockPos.x < ( (unsigned int)m_windowSize.x - ( 4 * RAYPACKET_DIM + 4 ) ) ) &&
 ( blockPos.y < ( (unsigned int)m_windowSize.y - ( 4 * RAYPACKET_DIM + 4 ) ) ) )
 {
 m_blockPositionsFast.push_back( blockPos );

 if( blockPos.x > m_realBufferSize.x )
 m_realBufferSize.x = blockPos.x;

 if( blockPos.y > m_realBufferSize.y )
 m_realBufferSize.y = blockPos.y;
 }
 }

 m_fastPreviewModeSize = m_realBufferSize;

 m_realBufferSize.x = ( ( m_realBufferSize.x + RAYPACKET_DIM * 4 ) & RAYPACKET_INVMASK );
 m_realBufferSize.y = ( ( m_realBufferSize.y + RAYPACKET_DIM * 4 ) & RAYPACKET_INVMASK );

 m_xoffset = ( m_windowSize.x - m_realBufferSize.x ) / 2;
 m_yoffset = ( m_windowSize.y - m_realBufferSize.y ) / 2;

 m_postShaderSsao.UpdateSize( m_realBufferSize );

 // Calc block positions for regular rendering. Choose an 'inside out' style of rendering.
 m_blockPositions.clear();
 const int blocks_x = m_realBufferSize.x / RAYPACKET_DIM;
 const int blocks_y = m_realBufferSize.y / RAYPACKET_DIM;
 m_blockPositions.reserve( blocks_x * blocks_y );

 for( int x = 0; x < blocks_x; ++x )
 {
 for( int y = 0; y < blocks_y; ++y )
 m_blockPositions.emplace_back( x * RAYPACKET_DIM, y * RAYPACKET_DIM );
 }

 const SFVEC2UI center( m_realBufferSize.x / 2, m_realBufferSize.y / 2 );
 std::sort( m_blockPositions.begin(), m_blockPositions.end(),
 [&]( const SFVEC2UI& a, const SFVEC2UI& b ) {
 // Sort order: inside out.
 return distance( a, center ) < distance( b, center );
 } );

 // Create m_shader buffer
 delete[] m_shaderBuffer;
 m_shaderBuffer = new SFVEC3F[m_realBufferSize.x * m_realBufferSize.y];

 initPbo();
}


BOARD_ITEM* RENDER_3D_RAYTRACE::IntersectBoardItem( const RAY& aRay )
{
 HITINFO hitInfo;
 hitInfo.m_tHit = std::numeric_limits<float>::infinity();

 if( m_accelerator )
 {
 if( m_accelerator->Intersect( aRay, hitInfo ) )
 {
 if( hitInfo.pHitObject )
 return hitInfo.pHitObject->GetBoardItem();
 }
 }

 return nullptr;
}