/**************************
* Includes
*
**************************/

using namespace std;
#define PI 3.1415265359
struct SVertex{	GLfloat x,y,z; 	GLfloat r,g,b;};
SVertex * Vertices;
int NumVertices;  //size of the vertex array
vector <GLuint> IndexVect;  //we first put the indices into this vector, then copy them to the array below
GLuint * Indices;
int NumIndices;   //size of the index array
GLfloat ChangeY = 0.025;//Indicates how much the y values of the highest and deepest vertex
float yRotated = 0.0;
bool PointsOnly = false;

void CreateSphere(int PointRows, int PointsPerRow)
{
NumVertices = (PointRows-2)*PointsPerRow + 2;
Vertices = new SVertex[NumVertices];
IndexVect.clear();  //to be sure it is empty
float x,y,z;
int i,j;
double r;
for (i = 1; i < (PointRows-1); i++){
for (j = 0; j < PointsPerRow; j++)
{
y = 1.0 - float(i) / float(PointRows-1)*2.0;
r = sin (acos(y));  //radius of the row
x = r * sin(float(j) / float(PointsPerRow)*PI*2.0);

z = r * cos(float(j) / float(PointsPerRow)*PI*2.0);
Vertices[(i-1)*PointsPerRow+j].x = x;
Vertices[(i-1)*PointsPerRow+j].y = y;
Vertices[(i-1)*PointsPerRow+j].z = z;
Vertices[(i-1)*PointsPerRow+j].r = (float)(i) / float(PointRows);
Vertices[(i-1)*PointsPerRow+j].g = 0.7;
Vertices[(i-1)*PointsPerRow+j].b = (float)(j) / float(PointsPerRow);
}
}

Vertices[(PointRows-2)*PointsPerRow].x = 0.0;
Vertices[(PointRows-2)*PointsPerRow].y = 1.0;
Vertices[(PointRows-2)*PointsPerRow].z = 0.0;
Vertices[(PointRows-2)*PointsPerRow].r = 1.0;
Vertices[(PointRows-2)*PointsPerRow].g = 0.7;
Vertices[(PointRows-2)*PointsPerRow].b = 1.0;
Vertices[(PointRows-2)*PointsPerRow+1].x = 0.0;
Vertices[(PointRows-2)*PointsPerRow+1].y = -1.0;
Vertices[(PointRows-2)*PointsPerRow+1].z = 0.0;
Vertices[(PointRows-2)*PointsPerRow+1].r = 1.0;
Vertices[(PointRows-2)*PointsPerRow+1].g = 0.7;
Vertices[(PointRows-2)*PointsPerRow+1].b = 1.0;

for (i = 1; i < (PointRows-2); i++)
{
for (j = 0; j < (PointsPerRow-1); j++)
{
IndexVect.push_back((i-1)*PointsPerRow+j);
IndexVect.push_back((i-1)*PointsPerRow+j+1);
IndexVect.push_back((i)*PointsPerRow+j);
IndexVect.push_back((i-1)*PointsPerRow+j+1);
IndexVect.push_back((i)*PointsPerRow+j+1);
IndexVect.push_back((i)*PointsPerRow+j);
}
IndexVect.push_back((i-1)*PointsPerRow+PointsPerRow-1);
IndexVect.push_back((i-1)*PointsPerRow);
IndexVect.push_back((i)*PointsPerRow+j);
IndexVect.push_back((i)*PointsPerRow);
IndexVect.push_back((i-1)*PointsPerRow);
IndexVect.push_back((i)*PointsPerRow+j);}		

	//The triangles to the highest and deepest vertices:
	for (j = 0; j< (PointsPerRow-1); j++)
	{
		IndexVect.push_back(j);
		IndexVect.push_back(j+1);
		IndexVect.push_back((PointRows-2)*PointsPerRow);
	}
	IndexVect.push_back(j);
	IndexVect.push_back(0);
	IndexVect.push_back((PointRows-2)*PointsPerRow);

	for (j = 0; j< (PointsPerRow-1); j++)
	{
		IndexVect.push_back((PointRows-3)*PointsPerRow+j);
		IndexVect.push_back((PointRows-3)*PointsPerRow+j+1);
		IndexVect.push_back((PointRows-2)*PointsPerRow+1);
	}
	IndexVect.push_back((PointRows-3)*PointsPerRow+j);
	IndexVect.push_back((PointRows-3)*PointsPerRow);
	IndexVect.push_back((PointRows-2)*PointsPerRow+1);
	Indices = new GLuint[IndexVect.size()];  //allocate the required memory
	for (i = 0; i < IndexVect.size(); i++)
	{
		Indices = IndexVect;
	}
	NumIndices = IndexVect.size();
	IndexVect.clear();  //no longer needed, takes only memory
}


void DrawSphere(void)
{
	if (!PointsOnly)
		glDrawElements(	GL_TRIANGLES, //mode
						NumIndices,  //count, ie. how many indices
						GL_UNSIGNED_INT, //type of the index array
						Indices);
	else 
		glDrawArrays(GL_POINTS,0,NumVertices);

}

void Display(void)
{
	glClear(GL_COLOR_BUFFER_BIT);
	glLoadIdentity();
	glTranslatef(0.0,0.0,-4.0);
	glRotatef(yRotated, 0.0, 1.0, 0.0);
	DrawSphere();
	glFlush();			//Finish rendering
	//glutSwapBuffers();
}

void Reshape(int x, int y)
{
	if (y == 0 || x == 0) return;  //Nothing is visible then, so return
	//Set a new projection matrix
	glMatrixMode(GL_PROJECTION);  
	glLoadIdentity();
	//Angle of view:40 degrees
	//Near clipping plane distance: 0.5
	//Far clipping plane distance: 20.0
//	gluPerspective(40.0,(GLdouble)x/(GLdouble)y,0.5,20.0);
	glViewport(0,0,x,y);  //Use the whole window for rendering
	glMatrixMode(GL_MODELVIEW);
	
}

void Idle(void)
{
	Vertices[NumVertices-2].y += ChangeY;
	Vertices[NumVertices-1].y -= ChangeY;

	if (Vertices[NumVertices-2].y> 1.5 || Vertices[NumVertices-2].y< 0.5)
		 ChangeY *= -1;
	yRotated += 0.3;
	Display();
}
void Keyboard(unsigned char key, int x, int y)
{
	switch(key)
	{
	case 'p': 
		PointsOnly = !PointsOnly;
		break;
	}
}


/**************************
 * Function Declarations
 *
 **************************/

LRESULT CALLBACK WndProc (HWND hWnd, UINT message,
WPARAM wParam, LPARAM lParam);
void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC);
void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC);


/**************************
 * WinMain
 *
 **************************/

int WINAPI WinMain (HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpCmdLine,
                    int iCmdShow)
{
    WNDCLASS wc;
    HWND hWnd;
    HDC hDC;
    HGLRC hRC;        
    MSG msg;
    BOOL bQuit = FALSE;
    float theta = 0.0f;

    /* register window class */
    wc.style = CS_OWNDC;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor (NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH) GetStockObject (BLACK_BRUSH);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = "GLSample";
    RegisterClass (&wc);

    /* create main window */
    hWnd = CreateWindow (
      "GLSample", "OpenGL Sample", 
      WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
      0, 0, 256, 256,
      NULL, NULL, hInstance, NULL);

    /* enable OpenGL for the window */
    EnableOpenGL (hWnd, &hDC, &hRC);
CreateSphere(160,160);
Reshape(100, 100);
DrawSphere();
glDrawElements(	GL_TRIANGLES, 	NumIndices, GL_UNSIGNED_INT, Indices);
glDrawArrays(GL_POINTS,0,NumVertices);


/* program main loop */
    while (!bQuit)
    {
        /* check for messages */
        if (PeekMessage (&msg, NULL, 0, 0, PM_REMOVE))
        {
            /* handle or dispatch messages */
            if (msg.message == WM_QUIT)
            {
                bQuit = TRUE;
            }
            else
            {
                TranslateMessage (&msg);
                DispatchMessage (&msg);
            }
        }
        else
        {
            /* OpenGL animation code goes here */
            glClearColor (1.0f, 1.0f, 1.0f, 0.0f);
            glClear (GL_COLOR_BUFFER_BIT);
            glPushMatrix ();
            glRotatef (theta, 0.0f, 0.0f, 1.0f);
            glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
            glEnableClientState(GL_VERTEX_ARRAY);/*321*/
            glEnableClientState(GL_COLOR_ARRAY);
            glVertexPointer(3, GL_FLOAT,sizeof(SVertex),Vertices);
            glColorPointer(3,GL_FLOAT,sizeof(SVertex),&Vertices[0].r);  //Pointer to the first color
            glPointSize(2.0);
            glClearColor(0.0,0.0,0.0,0.0);
            glPushMatrix ();
            glPopMatrix ();
            glBegin (GL_TRIANGLES);
            glColor3f (1.0f, 0.0f, 0.0f);   glVertex2f (0.0f, 1.0f);
            glColor3f (0.0f, 1.0f, 0.0f);   glVertex2f (0.87f, -0.5f);
            glColor3f (0.0f, 0.0f, 1.0f);   glVertex2f (-0.87f, -0.5f);
            glEnd ();
            glPopMatrix ();
            SwapBuffers (hDC);
            theta += 1.0f;
            Sleep (1);
        }
    }

    /* shutdown OpenGL */
    DisableOpenGL (hWnd, hDC, hRC);

    /* destroy the window explicitly */
    DestroyWindow (hWnd);

    return msg.wParam;
}


/********************
 * Window Procedure
 *
 ********************/

LRESULT CALLBACK WndProc (HWND hWnd, UINT message,WPARAM wParam, LPARAM lParam)
{switch (message)
{
case WM_CREATE:return 0;
case WM_CLOSE:PostQuitMessage (0);return 0;
case WM_DESTROY:return 0;
case WM_KEYDOWN:
switch (wParam){case VK_ESCAPE:PostQuitMessage(0);return 0;}return 0;

default:return DefWindowProc (hWnd, message, wParam, lParam);}
}


/*******************
 * Enable OpenGL
 *
 *******************/

void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC)
{
    PIXELFORMATDESCRIPTOR pfd;
    int iFormat;

    /* get the device context (DC) */
    *hDC = GetDC (hWnd);

    /* set the pixel format for the DC */
    ZeroMemory (&pfd, sizeof (pfd));
    pfd.nSize = sizeof (pfd);
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW | 
    PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 24;
    pfd.cDepthBits = 16;
    pfd.iLayerType = PFD_MAIN_PLANE;
    iFormat = ChoosePixelFormat (*hDC, &pfd);
    SetPixelFormat (*hDC, iFormat, &pfd);

    /* create and enable the render context (RC) */
    *hRC = wglCreateContext( *hDC );
    wglMakeCurrent( *hDC, *hRC );

}


/******************
 * Disable OpenGL
 *
 ******************/

void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC)
{
    wglMakeCurrent (NULL, NULL);
    wglDeleteContext (hRC);
    ReleaseDC (hWnd, hDC);
}