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

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


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

// global declarations
LPDIRECT3D9 d3d;
LPDIRECT3DDEVICE9 d3ddev; 
LPD3DXMATRIXSTACK MatrixStack = NULL; //stog matrica
D3DXMATRIX matrica;

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

void valjak( float r, float h, int n, DWORD c1, DWORD c2);

float x = 0.0, y = 0.0, z = 0.0;
float kut = 0.0;

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;
		case VK_F1:
			d3ddev->SetRenderState(D3DRS_CULLMODE,D3DCULL_NONE);
			break;
		case VK_F2:
			d3ddev->SetRenderState(D3DRS_CULLMODE,D3DCULL_CCW|D3DCULL_CW);
			break;
		case VK_F3:
			d3ddev->SetRenderState(D3DRS_CULLMODE,D3DCULL_CW);
			break;
		case VK_F4:
			d3ddev->SetRenderState(D3DRS_SHADEMODE, D3DSHADE_FLAT);
			break;
		case VK_F5:
			d3ddev->SetRenderState(D3DRS_SHADEMODE, D3DSHADE_GOURAUD);
			break;
		case VK_F6:
			d3ddev->SetRenderState(D3DRS_ZENABLE, TRUE);
			break;
		case VK_F7:
			d3ddev->SetRenderState(D3DRS_ZENABLE, FALSE);
			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, D3DZB_TRUE);    // turn on the z-buffer
	d3ddev->SetRenderState(D3DRS_SHADEMODE, D3DSHADE_FLAT);
	d3ddev->SetRenderState(D3DRS_FILLMODE,D3DFILL_SOLID);
	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 (0.0f+x, 10.0f+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 

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

	D3DXMATRIX rotacija;
	D3DXMatrixRotationY(&rotacija, D3DXToRadian(kut));
	D3DXMatrixMultiply(&matrica, &matrica, &rotacija);
	d3ddev->SetTransform(D3DTS_WORLD, &matrica);
	valjak(2, 3.5, 30, 0xFFFFFF, 0XFF0000);

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

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

void valjak( float r, float h, int n, DWORD c1, DWORD c2){

	LPDIRECT3DVERTEXBUFFER9 buffer = NULL; 

	d3ddev->SetRenderState(D3DRS_CULLMODE, D3DCULL_CCW|D3DCULL_CW);

	CUSTOMVERTEX *vertices = new CUSTOMVERTEX[2*(n+1)];

	float korak = 2*M_PI/n;
	float t = 0.0;

	for( int i = 0; i <= n; i++ ){
		vertices[2*i].X = r*cos(t);
		vertices[2*i].Y = 0;
		vertices[2*i].Z = r*sin(t);

		vertices[2*i+1].X = r*cos(t);
		vertices[2*i+1].Y = h;
		vertices[2*i+1].Z = r*sin(t);

		if( i%2 == 0 ){
			vertices[2*i].COLOR = c2;
			vertices[2*i+1].COLOR = c2;
		}
		else{
			vertices[2*i].COLOR = c1;
			vertices[2*i+1].COLOR = c1;
		}
		t += korak;
	}

	d3ddev->CreateVertexBuffer(2*(n+1)*sizeof(CUSTOMVERTEX),
		0,
		CUSTOMFVF,
		D3DPOOL_MANAGED,
		&buffer,
		NULL);

	VOID* pVoid;

	buffer->Lock(0,0,(void**)&pVoid, 0 );
	memcpy(pVoid, vertices, 2*(n+1)*sizeof(CUSTOMVERTEX));
	buffer->Unlock();

	d3ddev->SetStreamSource(0, buffer, 0, sizeof(CUSTOMVERTEX));
	d3ddev->DrawPrimitive( D3DPT_TRIANGLESTRIP, 0, 2*n );

	d3ddev->SetRenderState(D3DRS_CULLMODE, D3DCULL_CCW);

	korak = 2*M_PI/n;
	t = 0.0;

	vertices[0].X = 0.0;
	vertices[0].Y = 0.0;
	vertices[0].Z = 0.0;
	vertices[0].COLOR = c2;

	for( int i = 1; i <= n+1; i++ ){
		vertices[i].X = r*cos(t);
		vertices[i].Y = 0;
		vertices[i].Z = r*sin(t);
		if( i%2 == 0 )
			vertices[i].COLOR = c1;
		else
			vertices[i].COLOR = c2;

		t += korak;
	}

	d3ddev->CreateVertexBuffer((n+2)*sizeof(CUSTOMVERTEX),
		0,
		CUSTOMFVF,
		D3DPOOL_MANAGED,
		&buffer,
		NULL);

	buffer->Lock(0,0,(void**)&pVoid, 0 );
	memcpy(pVoid, vertices, (n+2)*sizeof(CUSTOMVERTEX));
	buffer->Unlock();

	d3ddev->SetStreamSource(0, buffer, 0, sizeof(CUSTOMVERTEX));
	d3ddev->DrawPrimitive( D3DPT_TRIANGLEFAN, 0, n );

	d3ddev->SetRenderState(D3DRS_CULLMODE, D3DCULL_CW);
	D3DXMATRIX translacija;
	D3DXMatrixTranslation( &translacija, 0.0, h, 0.0 );
	MatrixStack->MultMatrixLocal(&translacija);
	d3ddev->SetTransform(D3DTS_WORLD, &(matrica*translacija));
	d3ddev->DrawPrimitive( D3DPT_TRIANGLEFAN, 0, n );
}

// this is the function that cleans up Direct3D and COM
void cleanD3D(void)
{
	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
		0.0f,   // the near view-plane
		100.0f);    // the far view-plane
	d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection); // set the projection
}