Am having problem displaying the content of my rendering engine through OpenGL

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C++

OpenGL

I am trying to use OpenGL to display the result of my rendering engine but I get a blank screen with no display. Below is my main c++ file with OpenGL calls and the file with the rendering engine. Please what am I doing wrongly. The original raytracing by Jacco Bikker displays the result alright using Windows API (WinMain), the problem I have with that is that while trying to parallelize the code using cilk++ it will not work with WinMain() method. It only works with main() method in c++ that is why am using OpenGL to display.
Please anyone there who can help me out...I deeply appreciate it. Below is the main c++ file where the OpenGL calls are made:

#define _CRT_SECURE_NO_WARNINGS
 
#include <windows.h>
#include <GL/glew.h>
#include <GL/glut.h>
#include "common.h"
#include "raytracer.h"
#include "scene.h"
#include "surface.h"
#include "cilk.h"
#include "cilkview.h"
#include <cstdio>
#include <cassert>
#include <vector>

//#define SCRWIDTH 640
//#define SCRHEIGHT 480
#define SCRWIDTH 800
#define SCRHEIGHT 600
 
GLuint texture = 0;
Raytracer::Surface* surface = 0;
Pixel* buffer = 0;
Raytracer::Engine* tracer = 0;
 

void start(){
	// prepare output canvas
	surface = new Raytracer::Surface( SCRWIDTH, SCRHEIGHT );
	buffer = surface->GetBuffer();
	surface->Clear( 0 );
	surface->InitCharset();
	surface->Print( "timings:", 2, 2, 0xffffffff );
	// prepare renderer
	tracer = new Raytracer::Engine();
	tracer->GetScene()->InitScene();
	tracer->SetTarget( surface->GetBuffer(), SCRWIDTH, SCRHEIGHT );
int tpos = 60;
 
	
		 FILE *outFile;
 
		   outFile = fopen("RayTracing.out","a");
		   if (!outFile){
			   printf("Cannot open output file");
			   exit(1);
		   }
 
	//Displaying the Trace Depth to output file
	fprintf (outFile, "Tracing Depth : %d\n", TRACEDEPTH);
 
	// go
	while (1)
	{
		int fstart = GetTickCount();
		tracer->InitRender();
		while (!tracer->Render()) glutSwapBuffers();
		int ftime = GetTickCount() - fstart;
		char t[] = "00:00.000";
		t[6] = (ftime / 100) % 10 + '0';
		t[7] = (ftime / 10) % 10 + '0';
		t[8] = (ftime % 10) + '0';
		int secs = (ftime / 1000) % 60;
		int mins = (ftime / 60000) % 100;
		t[3] = ((secs / 10) % 10) + '0';
		t[4] = (secs % 10) + '0';
		t[1] = (mins % 10) + '0';
		t[0] = ((mins / 10) % 10) + '0';
 
		float par_time = ftime / 1000.f;	//Time accumulated is converted to seconds and stored in a variable
			
		fprintf (outFile, "%.3f\n", par_time);
		fflush (stdout);
		surface->Print( t, tpos, 2, 0xffffffff );
		tpos += 100;
	}
}
void render(void) {
	start();
	glClear(GL_COLOR_BUFFER_BIT);
	glRasterPos2i(0, 0);
	glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, texture);
	glDrawPixels(SCRWIDTH, SCRHEIGHT, GL_RGBA, GL_UNSIGNED_BYTE, 0);
	glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 
	glutSwapBuffers();
	glutPostRedisplay();
 
	
}
 
void reshape(int x, int y) {
	glViewport(0, 0, x, y);
 
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0); 
}
 

 
void appInit(int w, int h) {
	glGenBuffersARB(1, &texture);
	glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, texture);
	glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_ARB, w * h * sizeof(GLubyte) * 4, 0, GL_STREAM_DRAW_ARB);
	glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 
		
}
 

void idle() { glutPostRedisplay(); }
 

void cleanup(){
	glDeleteBuffersARB(1, &texture);
}
 
int main(int argc, char **argv) {
	
	atexit(cleanup);
	glutInit(&argc, argv);
 
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(SCRWIDTH, SCRHEIGHT);
	glutCreateWindow("Cilk Plus raytracer");
 
	glewInit();
	appInit(SCRWIDTH, SCRHEIGHT);
	glutDisplayFunc(render);
	glutIdleFunc(idle);
	glutReshapeFunc(reshape);
 
	glutMainLoop();
 
	return 0;
}

The raytracing engine is in the following file:

raytracer.cpp

// -----------------------------------------------------------
// raytracer.cpp
// 2004 - Jacco Bikker - jacco@bik5.com - www.bik5.com -   <><
// -----------------------------------------------------------

#include "raytracer.h"
#include "scene.h"
#include "common.h"
#include "windows.h"
#include "winbase.h"
#include "cilk.h"

 
namespace Raytracer {
 
Ray::Ray( vector3& a_Origin, vector3& a_Dir ) : 
	m_Origin( a_Origin ), 
	m_Direction( a_Dir )
{
}
 
Engine::Engine()
{
	m_Scene = new Scene();
}
 
Engine::~Engine()
{
	delete m_Scene;
}
 
// -----------------------------------------------------------
// Engine::SetTarget
// Sets the render target canvas
// -----------------------------------------------------------
void Engine::SetTarget( Pixel* a_Dest, int a_Width, int a_Height )
{
	// set pixel buffer address & size
	m_Dest = a_Dest;
	m_Width = a_Width;
	m_Height = a_Height;
}
 
// -----------------------------------------------------------
// Engine::Raytrace
// Naive ray tracing: Intersects the ray with every primitive
// in the scene to determine the closest intersection
// -----------------------------------------------------------
Primitive* Engine::Raytrace( Ray& a_Ray, Color& a_Acc, int a_Depth, float a_RIndex, float& a_Dist )
{
	if (a_Depth > TRACEDEPTH) return 0;
	// trace primary ray
	a_Dist = 1000000.0f;
	vector3 pi;
	Primitive* prim = 0;
	int result;
	// find the nearest intersection
	for ( int s = 0; s < m_Scene->GetNrPrimitives(); s++ )
	{
		Primitive* pr = m_Scene->GetPrimitive( s );
		int res;
		if (res = pr->Intersect( a_Ray, a_Dist )) 
		{
			prim = pr;
			result = res; // 0 = miss, 1 = hit, -1 = hit from inside primitive
		}
	}
	// no hit, terminate ray
	if (!prim) return 0;
		// ---- Handle intersection ----
	if (prim) {
		// Update statistics
		//m_statisticsDataStructCpp->rayIntersectionsCount[0]++;
		if (prim->IsLight())
		{
			// we hit a light, stop tracing
			a_Acc =Color( 1.0f, 1.0f, 1.0f );
		}
		else
		{
			// determine color at point of intersection
			pi = a_Ray.GetOrigin() + a_Ray.GetDirection() * a_Dist;
			// trace lights
			for ( int l = 0; l < m_Scene->GetNrPrimitives(); l++ )
			{
				Primitive* p = m_Scene->GetPrimitive( l );
 
				if (p->IsLight()) 
				{
					Primitive* light = p;
						// handle point light source
						float shade = 1.0f;
						if (light->GetType() == Primitive::SPHERE)
						{
							vector3 L = ((Sphere*)light)->GetCentre() - pi;
							float tdist = LENGTH( L );
							NORMALIZE(L);
							vector3 TempVector3(pi + L * EPSILON);
							Ray r = Ray( TempVector3, L );
							for ( int s = 0; s < m_Scene->GetNrPrimitives(); s++ )
							{
								Primitive* pr = m_Scene->GetPrimitive( s );						
								if ((pr != light) && (pr->Intersect( r, tdist )))
								{
									shade = 0;
									break;
								}
							}
						}
						if (shade > 0)
						{
							vector3 L = ((Sphere*)light)->GetCentre() - pi;
							NORMALIZE( L );
							vector3 N = prim->GetNormal( pi );
							// determine diffuse component
							if (prim->GetMaterial()->GetDiffuse() > 0)
							{
								float dot = DOT( L, N );
								if (dot > 0)
								{
									float diff = dot * prim->GetMaterial()->GetDiffuse() * shade;
									// add diffuse component to ray color
									Color ncol = diff * prim->GetMaterial()->GetColor();
									// Scale back the color, if necessary
									if (ncol.r > 1.0f || ncol.g > 1.0f || ncol.b > 1.0f)
									{
										float max = 1.0f;
										if (ncol.r > max) max = ncol.r;
										if (ncol.g > max) max = ncol.g;
										if (ncol.b > max) max = ncol.b;
										ncol *= 1.0f/max;
									}
									a_Acc += ncol;
								}
							}
							// determine specular component
							if (prim->GetMaterial()->GetSpecular() > 0)
							{
								// point light source: sample once for specular highlight
								vector3 V = a_Ray.GetDirection();
								vector3 R = L - 2.0f * DOT( L, N ) * N;
								float dot = DOT( V, R );
								if (dot > 0)
								{
									float spec = powf( dot, 20 ) * prim->GetMaterial()->GetSpecular() * shade;
									// add specular component to ray color
									Color ncol = spec * light->GetMaterial()->GetColor();
									// Adjust specular component to be within 0 <-> 1.0
									if (ncol.r > 1.0f) ncol.r = 1.0f; else if (ncol.r < 0.0f) ncol.r = 0.0f;
									if (ncol.g > 1.0f) ncol.g = 1.0f; else if (ncol.g < 0.0f) ncol.g = 0.0f;
									if (ncol.b > 1.0f) ncol.b = 1.0f; else if (ncol.b < 0.0f) ncol.b = 0.0f;
									a_Acc += ncol;								
								}
							}
						}
					}
				}
			// Scale back the local color contribution, if necessary
			if (a_Acc.r > 1.0f || a_Acc.g > 1.0f || a_Acc.b > 1.0f)
			{
				float max = 1.0f;
				if (a_Acc.r > max) max = a_Acc.r;
				if (a_Acc.g > max) max = a_Acc.g;
				if (a_Acc.b > max) max = a_Acc.b;
				a_Acc *= 1.0f/max;
			}
			// -- Calculate reflection --
			float refl = prim->GetMaterial()->GetReflection();
			if ((refl > 0.0f) && (a_Depth < TRACEDEPTH))
			{
				vector3 N = prim->GetNormal( pi );
				vector3 R = a_Ray.GetDirection() - 2.0f * DOT( a_Ray.GetDirection(), N ) * N;
				Color rcol( 0.0f, 0.0f, 0.0f );
				float dist;
				vector3 TempVector3(pi + R * EPSILON);
				Ray TempRay(TempVector3, R);
				Raytrace( TempRay, rcol, a_Depth + 1, a_RIndex, dist );
				a_Acc += refl * rcol;
			}
		}
	}
	else {
		// -- No intersection occured; stop tracing --
		// Update statistics
		//m_statisticsDataStructCpp->rayMissesCount[0]++;
		// Do nothing
	}
	
	// return pointer to primitive hit by primary ray
	return prim;
}
 
// -----------------------------------------------------------
// Engine::InitRender
// Initializes the renderer, by resetting the line / tile
// counters and precalculating some values
// -----------------------------------------------------------
void Engine::InitRender()
{
	// set firts line to draw to
	m_CurrLine = 20;
	// set pixel buffer address of first pixel
	m_PPos = 20 * m_Width;
	// screen plane in world space coordinates
	m_WX1 = -4, m_WX2 = 4, m_WY1 = m_SY = 3, m_WY2 = -3;
	// calculate deltas for interpolation
	m_DX = (m_WX2 - m_WX1) / m_Width;
	m_DY = (m_WY2 - m_WY1) / m_Height;
	m_SY += 20 * m_DY;
	// allocate space to store pointers to primitives for previous line
	m_LastRow = new Primitive*[m_Width];
	memset( m_LastRow, 0, m_Width * 4 );
	// statistics
	m_RayMissesCount = 0;
	m_RayIntersectionsCount = 0;
}
 
void Engine::PreRender() {
	// Prepare linearized data
	m_spheres.clear();
	m_planes.clear();
	Sphere* tempSphere;
	PlanePrim* tempPlane;
	int sphereCount;	
	int planesCount;
	Primitive* prim;
	for (int i = 0; i < m_Scene->GetNrPrimitives(); i++) {
		prim = m_Scene->GetPrimitive(i);
 
		tempSphere = dynamic_cast<Sphere*> (prim);
		if (dynamic_cast<Sphere*> (prim) != 0){
			m_spheres.push_back(tempSphere);
//			continue;
		}
		tempPlane = dynamic_cast<PlanePrim*> (prim);
		if (dynamic_cast<PlanePrim*> (prim) != 0)
			m_planes.push_back(tempPlane);
	}
	
	
	// Spheres
	m_sphereDataStructCpp = new SphereDataStructCpp(m_spheres.size());
	
	for (int i = 0; i < m_spheres.size(); i++)	{
		tempSphere = m_spheres[i];
		// Geometric Data
		m_sphereDataStructCpp->centerX[i] = tempSphere->GetCentre().x;
		m_sphereDataStructCpp->centerY[i] = tempSphere->GetCentre().y;
		m_sphereDataStructCpp->centerZ[i] = tempSphere->GetCentre().z;
		m_sphereDataStructCpp->recRadius[i] = tempSphere->GetRecRadius();
		m_sphereDataStructCpp->sqRadius[i] = tempSphere->GetSqRadius();
		// Material Data
		m_sphereDataStructCpp->diffuse[i] = tempSphere->GetMaterial()->GetDiffuse();
		m_sphereDataStructCpp->specular[i] = tempSphere->GetMaterial()->GetSpecular();
		m_sphereDataStructCpp->reflection[i] = tempSphere->GetMaterial()->GetReflection();
		m_sphereDataStructCpp->refraction[i] = tempSphere->GetMaterial()->GetRefraction();
		m_sphereDataStructCpp->refrIndex[i] = tempSphere->GetMaterial()->GetRefrIndex();
		// Color Data
		m_sphereDataStructCpp->red[i] = tempSphere->GetMaterial()->GetColor().r;
		m_sphereDataStructCpp->green[i] = tempSphere->GetMaterial()->GetColor().g;
		m_sphereDataStructCpp->blue[i] = tempSphere->GetMaterial()->GetColor().b;
		// Light?
		m_sphereDataStructCpp->isLight[i] = tempSphere->IsLight();
	}
	
	// Planes

	m_planeDataStructCpp = new PlaneDataStructCpp(m_planes.size());
	
	for (int i = 0; i < m_planes.size(); i++)	{
		tempPlane = m_planes[i];
		// Geometric data
		m_planeDataStructCpp->normalX[i] = tempPlane->GetNormal().x;
		m_planeDataStructCpp->normalY[i] = tempPlane->GetNormal().y;
		m_planeDataStructCpp->normalZ[i] = tempPlane->GetNormal().z;
		m_planeDataStructCpp->d[i] = tempPlane->GetD();
		// Material data
		m_planeDataStructCpp->diffuse[i] = tempPlane->GetMaterial()->GetDiffuse();
		m_planeDataStructCpp->specular[i] = tempPlane->GetMaterial()->GetSpecular();
		m_planeDataStructCpp->reflection[i] = tempPlane->GetMaterial()->GetReflection();
		m_planeDataStructCpp->refraction[i] = tempPlane->GetMaterial()->GetRefraction();
		m_planeDataStructCpp->refrIndex[i] = tempPlane->GetMaterial()->GetRefrIndex();
		// Color data
		m_planeDataStructCpp->red[i] = tempPlane->GetMaterial()->GetColor().r;
		m_planeDataStructCpp->green[i] = tempPlane->GetMaterial()->GetColor().g;
		m_planeDataStructCpp->blue[i] = tempPlane->GetMaterial()->GetColor().b;
		// Light data
		m_planeDataStructCpp->isLight[i] = tempPlane->IsLight();
	}
	
	// Statistics
	m_RayMissesCount = 0;
	m_RayIntersectionsCount = 0;
	
	m_statisticsDataStructCpp = new StatisticsDataStructCpp((size_t)m_CohortPSize);
	
		
}
 
// -----------------------------------------------------------
// Engine::Render
// Fires rays in the scene one scanline at a time, from left
// to right
// -----------------------------------------------------------
bool Engine::Render()
{
	// render scene
	vector3 o( 0, 0, -5 );
	// initialize timer
	int msecs = GetTickCount();
	// reset last found primitive pointer
	Primitive* lastprim = 0;
	// render remaining lines
	for ( int y = m_CurrLine; y < (m_Height - 20); y++ )
	{
		m_SX = m_WX1;
		// render pixels for current line
		for ( int x = 0; x < m_Width; x++ )
		{
			// fire primary ray
			Color acc( 0, 0, 0 );
			vector3 dir = vector3( m_SX, m_SY, 0 ) - o;
			NORMALIZE( dir );
			Ray r( o, dir );
			float dist;
			Primitive* prim = Raytrace( r, acc, 1, 1.0f, dist );
			int red = (int)(acc.r * 256);
			int green = (int)(acc.g * 256);
			int blue = (int)(acc.b * 256);
			if (red > 255) red = 255;
			if (green > 255) green = 255;
			if (blue > 255) blue = 255;
			m_Dest[m_PPos++] = (red << 16) + (green << 8) + blue;
			m_SX += m_DX;
		}
		
		m_SY += m_DY;
		// see if we've been working to long already
		if ((GetTickCount() - msecs) > 100) 
		{
			// return control to windows so the screen gets updated
			m_CurrLine = y + 1;
			return false;
		}
		
	}
	// all done
	return true;
}
 
}; // namespace Raytracer