// include the basic windows header files and the Direct3D header file
#include <windows.h>
#include <windowsx.h>
#include <d3d9.h>
#include <d3dx9.h>

// define the screen resolution
#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600

float width = 800.0;
float height = 600.0;

float a = 1.0;
float kut = 0.0;
float y = 0.0;
float x = 0.0;
float z = 0.0;

// include the Direct3D Library files
#pragma comment (lib, "d3d9.lib")
#pragma comment (lib, "d3dx9.lib")

// global declarations
LPDIRECT3D9 d3d;
LPDIRECT3DDEVICE9 d3ddev;
LPDIRECT3DVERTEXBUFFER9 v_buffer = NULL;    // the pointer to the vertex buffer
LPDIRECT3DVERTEXBUFFER9 t_buffer = NULL;
LPD3DXMATRIXSTACK MatrixStack = NULL; //stog matrica

// function prototypes
void initD3D(HWND hWnd);
void render_frame(void);
void cleanD3D(void);
void resizeD3DScene(int width, int height);

void kocka( float a, DWORD boja );
void trava(float d, int n, DWORD boja);

void crtaj_kocku(void);

struct CUSTOMVERTEX {FLOAT X, Y, Z; DWORD COLOR;};
#define CUSTOMFVF (D3DFVF_XYZ | D3DFVF_DIFFUSE)

// the WindowProc function prototype
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);


// the entry point for any Windows program
int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow)
{
    HWND hWnd;
    WNDCLASSEX wc;

    ZeroMemory(&wc, sizeof(WNDCLASSEX));

    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.lpszClassName = L"WindowClass";

    RegisterClassEx(&wc);

    hWnd = CreateWindowEx(NULL, L"WindowClass", L"Our Direct3D Program",
                          WS_OVERLAPPEDWINDOW, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,
                          NULL, NULL, hInstance, NULL);

    ShowWindow(hWnd, nCmdShow);

    initD3D(hWnd);
	resizeD3DScene(SCREEN_WIDTH, SCREEN_HEIGHT);

    MSG msg;

    while(TRUE)
    {
        while(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }

        if(msg.message == WM_QUIT)
            break;

        render_frame();
    }

    cleanD3D();

    return msg.wParam;
}


// this is the main message handler for the program
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch(message)
    {
	case WM_DESTROY:
		{
			PostQuitMessage(0);
			return 0;
		} break;
	case WM_SIZE:		// Resize The Direct3D Window
		{
			// LoWord=Width, HiWord=Height
			resizeD3DScene(LOWORD(lParam), HIWORD(lParam));
			return 0;			// Jump Back
		}
		break;
	case WM_KEYDOWN:
			switch(wParam){
				case VK_UP:
					y++;
					break;
				case VK_DOWN:
					y--;
					break;
				case VK_LEFT:
					x--;
					break;
				case VK_RIGHT:
					x++;
					break;
				case VK_PRIOR:
					z++;
					break;
				case VK_NEXT:
					z--;
					break;
			}
		break;
    }

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


// this function initializes and prepares Direct3D for use
void initD3D(HWND hWnd)
{
    d3d = Direct3DCreate9(D3D_SDK_VERSION);

    D3DPRESENT_PARAMETERS d3dpp;

    ZeroMemory(&d3dpp, sizeof(d3dpp));
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.hDeviceWindow = hWnd;
    d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;
    d3dpp.BackBufferWidth = SCREEN_WIDTH;
    d3dpp.BackBufferHeight = SCREEN_HEIGHT;
    d3dpp.EnableAutoDepthStencil = TRUE;
    d3dpp.AutoDepthStencilFormat = D3DFMT_D16;

    d3d->CreateDevice(D3DADAPTER_DEFAULT,
                      D3DDEVTYPE_HAL,
                      hWnd,
                      D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                      &d3dpp,
                      &d3ddev);


    d3ddev->SetRenderState(D3DRS_LIGHTING, FALSE);    // turn off the 3D lighting
    d3ddev->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);    // turn off culling
    d3ddev->SetRenderState(D3DRS_ZENABLE, TRUE);    // turn on the z-buffer

	D3DXCreateMatrixStack( 0, &MatrixStack );

}


// this is the function used to render a single frame
void render_frame(void)
{
    d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
    d3ddev->Clear(0, NULL, D3DCLEAR_ZBUFFER, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);

    d3ddev->BeginScene();

    d3ddev->SetFVF(CUSTOMFVF);

    // set the view transform
    D3DXMATRIX matView;    // the view transform matrix
    D3DXMatrixLookAtLH(&matView,
    &D3DXVECTOR3 (3.0f+x, 3.0f+y, -20.0f+z),    // the camera position
    &D3DXVECTOR3 (0.0f, 0.0f, 0.0f),      // the look-at position
    &D3DXVECTOR3 (0.0f, 1.0f, 0.0f));    // the up direction
    d3ddev->SetTransform(D3DTS_VIEW, &matView);    // set the view transform to matView 

	D3DXMATRIX matrica;
	D3DXMatrixIdentity(&matrica);
	d3ddev->SetTransform(D3DTS_WORLD, &matrica );

	MatrixStack->Push();
	trava(20.0, 40, 0x00FF00);
	D3DXMATRIX translacija_trave;
	D3DXMatrixTranslation(&translacija_trave, -10.0, 0.0, -10.0 );
	MatrixStack->MultMatrixLocal(&translacija_trave);
	d3ddev->SetStreamSource(0, t_buffer, 0, sizeof(CUSTOMVERTEX));
	d3ddev->SetTransform(D3DTS_WORLD,MatrixStack->GetTop());
	d3ddev->DrawPrimitive( D3DPT_LINELIST, 0, 80 );
	MatrixStack->Pop();

	d3ddev->SetTransform(D3DTS_WORLD,MatrixStack->GetTop());
	crtaj_kocku();

	D3DXMATRIX m;
	D3DXMatrixTranslation(&m,0.0, a, 0.0 );
	d3ddev->SetTransform( D3DTS_WORLD, &m );
	crtaj_kocku();

	D3DXMatrixTranslation(&m,0.0, 2*a, 0.0 );
	d3ddev->SetTransform( D3DTS_WORLD, &(m) );
	crtaj_kocku();

	D3DXMatrixTranslation(&m,0.0, 3*a, 0.0 );
	d3ddev->SetTransform( D3DTS_WORLD, &(m) );
	crtaj_kocku();

	D3DXMatrixTranslation(&m,0.0, 4*a, 0.0 );
	d3ddev->SetTransform( D3DTS_WORLD, &(m) );
	crtaj_kocku();

	D3DXMATRIX rotacijaX;
	D3DXMatrixRotationX(&rotacijaX, D3DXToRadian(kut));

	MatrixStack->Push();
	D3DXMATRIX rotacija1;
	D3DXMatrixRotationY(&rotacija1, D3DXToRadian(2*kut));
	D3DXMatrixTranslation(&m,a, 2*a, 0.0 );

	MatrixStack->MultMatrixLocal( &rotacija1 );
	d3ddev->SetTransform( D3DTS_WORLD, &(m*rotacija1) );
	crtaj_kocku();

	MatrixStack->Push();
	D3DXMatrixTranslation(&m,2*a, 2*a, 0.0 );
	d3ddev->SetTransform( D3DTS_WORLD, &(rotacijaX*m*rotacija1) );
	crtaj_kocku();
	MatrixStack->Pop();

	MatrixStack->Pop();

	MatrixStack->Push();

	D3DXMATRIX rotacija2;
	D3DXMatrixRotationY(&rotacija2, D3DXToRadian(-kut));

	D3DXMatrixTranslation(&m,a, 4*a, 0.0 );
	d3ddev->SetTransform( D3DTS_WORLD, &(m*rotacija2) );
	crtaj_kocku();

	MatrixStack->Push();
	D3DXMatrixTranslation(&m,2*a, 4*a, 0.0 );
	d3ddev->SetTransform( D3DTS_WORLD, &(rotacijaX*m*rotacija2) );
	crtaj_kocku();
	MatrixStack->Pop();
	MatrixStack->Pop();

    d3ddev->EndScene(); 

    d3ddev->Present(NULL, NULL, NULL, NULL);

	kut++;
	if( kut == 360.0 ){
		kut = 0.0;
	}
}

void crtaj_kocku(void){
	kocka(a, 0xFFFF00);
	d3ddev->SetStreamSource(0, v_buffer, 0, sizeof(CUSTOMVERTEX));
	d3ddev->DrawPrimitive( D3DPT_LINESTRIP, 0, 5 );
	d3ddev->DrawPrimitive( D3DPT_LINESTRIP, 5, 5 );
	d3ddev->DrawPrimitive( D3DPT_LINELIST, 10, 4 );
}

void kocka( float a, DWORD boja ){
	float d = a/2;
	CUSTOMVERTEX vertices[] =
	{
		{-d,-d,-d,boja},
		{d,-d,-d,boja},
		{d,-d,d,boja},
		{-d,-d,d,boja},
		{-d,-d,-d,boja},
		{-d,d,-d,boja},
		{d,d,-d,boja},
		{d,d,d,boja},
		{-d,d,d,boja},
		{-d,d,-d,boja},
		{-d,-d,-d,boja},
		{-d,d,-d,boja},
		{d,-d,-d,boja},
		{d,d,-d,boja},
		{-d,-d,d,boja},
		{-d,d,d,boja},
		{d,-d,d,boja},
		{d,d,d,boja}
	};

	d3ddev->CreateVertexBuffer(18*sizeof(CUSTOMVERTEX),
		0,
		CUSTOMFVF,
		D3DPOOL_MANAGED,
		&v_buffer,
		NULL);

	VOID* pVoid;

	v_buffer->Lock(0,0,(void**)&pVoid, 0 );
	memcpy(pVoid, vertices, sizeof(vertices));
	v_buffer->Unlock();
}

void trava( float d, int n, DWORD boja ){
	float s = d/n;

	CUSTOMVERTEX *vertices = new CUSTOMVERTEX[4*n];

	for( int i = 0; i < n; i++ ){
		vertices[4*i].X = i*s;
		vertices[4*i].Y = 0.0;
		vertices[4*i].Z = 0.0;
		vertices[4*i].COLOR = boja;

		vertices[4*i+1].X = i*s;
		vertices[4*i+1].Y = 0.0;
		vertices[4*i+1].Z = d;
		vertices[4*i+1].COLOR = boja;

		vertices[4*i+2].X = 0.0;
		vertices[4*i+2].Y = 0.0;
		vertices[4*i+2].Z = i*s;
		vertices[4*i+2].COLOR = boja;

		vertices[4*i+3].X = d;
		vertices[4*i+3].Y = 0.0;
		vertices[4*i+3].Z = i*s;
		vertices[4*i+3].COLOR = boja;
	}

	d3ddev->CreateVertexBuffer(4*n*sizeof(CUSTOMVERTEX),
		0,
		CUSTOMFVF,
		D3DPOOL_MANAGED,
		&t_buffer,
		NULL);

	VOID* pVoid;

	t_buffer->Lock(0,0,(void**)&pVoid, 0 );
	memcpy(pVoid, vertices, 4*n*sizeof(CUSTOMVERTEX));
	t_buffer->Unlock();
}

// this is the function that cleans up Direct3D and COM
void cleanD3D(void)
{
    //v_buffer->Release();
    d3ddev->Release();
    d3d->Release();
}

void resizeD3DScene(int width, int height)
{
 // set the projection transform
    D3DXMATRIX matProjection;    // the projection transform matrix
    D3DXMatrixPerspectiveFovLH(&matProjection,
                               D3DXToRadian(45),    // the horizontal field of view
                               (FLOAT)width / (FLOAT)height, // aspect ratio
                               1.0f,   // the near view-plane
                               100.0f);    // the far view-plane
    d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection); // set the projection
}