// Game Engine.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
//#include "Game Engine.h"

// 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 and keyboard macros
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEY_UP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1)

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

// global declarations
LPDIRECT3D9 d3d;    // the pointer to our Direct3D interface
LPDIRECT3DDEVICE9 d3ddev;    // the pointer to the device class
//LPDIRECT3DVERTEXBUFFER9 t_buffer = NULL;    // the pointer to the vertex buffer
//LPDIRECT3DVERTEXBUFFER9 t2_buffer = NULL;    // the pointer to the vertex buffer
//LPDIRECT3DVERTEXBUFFER9 t3_buffer = NULL;    // the pointer to the vertex buffer
LPDIRECT3DSURFACE9 z_buffer = NULL;    // the pointer to the z-buffer


// global variables
LPD3DXMESH meshSpaceship;
DWORD numMaterials;

D3DMATERIAL9* material;    // define the material object

// function prototypes
void initD3D(HWND hWnd);    // sets up and initializes Direct3D
void render_frame(void);    // renders a single frame
void cleanD3D(void);    // closes Direct3D and releases memory
void init_graphics(void);    // 3D declarations
void init_light(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 = (WNDPROC)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_EX_TOPMOST | WS_POPUP, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,
                          NULL, NULL, hInstance, NULL);

    // set up and initialize Direct3D
    initD3D(hWnd);

    // enter the main loop:

    MSG msg;

    while(TRUE)
    {
        DWORD starting_point = GetTickCount();

        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            if (msg.message == WM_QUIT)
                break;

            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }

        render_frame();

        // check the 'escape' key
        if(KEY_DOWN(VK_ESCAPE))
		{        
			PostMessage(hWnd, WM_DESTROY, 0, 0);
			break;
		}

        while ((GetTickCount() - starting_point) < 25);
    }

    // clean up DirectX and COM
    cleanD3D();

    return (INT)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;
    }

    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 = FALSE;
    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;

    // create a device class using this information and the info from the d3dpp stuct
    d3d->CreateDevice(D3DADAPTER_DEFAULT,
                      D3DDEVTYPE_HAL,
                      hWnd,
                      D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                      &d3dpp,
                      &d3ddev);

    init_graphics();    // call the function to initialize the Hypercraft
	init_light();

    d3ddev->SetRenderState(D3DRS_LIGHTING, TRUE);    // turn off the 3D lighting
    d3ddev->SetRenderState(D3DRS_ZENABLE, TRUE);    // turn on the z-buffer
    d3ddev->SetRenderState(D3DRS_AMBIENT, D3DCOLOR_XRGB(50, 50, 50));    // ambient light

    return;
}


// this is the function used to render a single frame
void render_frame(void)
{
    d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(255, 255, 255), 1.0f, 0);
    d3ddev->Clear(0, NULL, D3DCLEAR_ZBUFFER, D3DCOLOR_XRGB(255, 255, 255), 1.0f, 0);

    d3ddev->BeginScene();

    // select which vertex format we are using
    d3ddev->SetFVF(CUSTOMFVF);

	static float index = 0.0f; index+=0.03f; // an ever-increasing float value
    
	// set the view transform
    D3DXMATRIX matView;    // the view transform matrix
    D3DXMatrixLookAtLH(&matView,
    &D3DXVECTOR3 (0.0f, 3.0f, 6.0f),    // 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 

    // set the projection transform
    D3DXMATRIX matProjection;    // the projection transform matrix
    D3DXMatrixPerspectiveFovLH(&matProjection,
                               D3DXToRadian(45),    // the horizontal field of view
                               (FLOAT)SCREEN_WIDTH / (FLOAT)SCREEN_HEIGHT, // aspect ratio
                               1.0f,   // the near view-plane
                               1000.0f);    // the far view-plane
    d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection); // set the projection

    // set the world transform
    D3DXMATRIX mat;    // a matrix to store the rotation for each triangle
    D3DXMatrixRotationX(&mat, index);    // the rotation matrix
    d3ddev->SetTransform(D3DTS_WORLD, &(mat));    // set the world transform

	meshSpaceship->DrawSubset(0);

    d3ddev->EndScene(); 

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

    return;
}


// this is the function that cleans up Direct3D and COM
void cleanD3D(void)
{
	meshSpaceship->Release();    // close and release the spaceship mesh
    t_buffer->Release();    // close and release the vertex buffer
    d3ddev->Release();    // close and release the 3D device
    d3d->Release();    // close and release Direct3D

    return;
}


// this is the function that puts the 3D models into video RAM
void init_graphics(void)
{

D3DXCreateTeapot(d3ddev, &meshSpaceship, NULL);    // create the teapot
	// local variable (in the init_graphics() function)

    return;
}

// this is the function that sets up the lights and materials
void init_light(void)
{
    D3DLIGHT9 light;    // create the light struct
    D3DMATERIAL9 material;    // create the material struct

    ZeroMemory(&light, sizeof(light));    // clear out the struct for use
    light.Type = D3DLIGHT_DIRECTIONAL;    // make the light type 'directional light'
    light.Diffuse.r = 0.5f;    // .5 red
    light.Diffuse.g = 0.5f;    // .5 green
    light.Diffuse.b = 0.5f;    // .5 blue
    light.Diffuse.a = 1.0f;    // full alpha (we'll get to that soon)

    D3DVECTOR vecDirection = {-1.0f, -0.3f, -1.0f};    // the direction of the light
    light.Direction = vecDirection;    // set the direction

    d3ddev->SetLight(0, &light);    // send the light struct properties to light #0
    d3ddev->LightEnable(0, TRUE);    // turn on light #0

    ZeroMemory(&material, sizeof(D3DMATERIAL9));    // clear out the struct for use
    material.Diffuse.r = material.Ambient.r = 1.0f;    // set the material to full red
    material.Diffuse.g = material.Ambient.g = 1.0f;    // set the material to full green
    material.Diffuse.b = material.Ambient.b = 1.0f;    // set the material to full blue
    material.Diffuse.a = material.Ambient.a = 1.0f;    // set the material to full alpha

    d3ddev->SetMaterial(&material);    // set the globably-used material to &material

    return;
}