// include the basic windows header files and the Direct3D header file
#include <windows.h>
#include <windowsx.h>
#include <d3d9.h>
#include <d3dx9.h>
#include <dinput.h>
#include <Cg/cg.h>
#include <Cg/cgGL.h>
#include <Cg/cgD3D9.h>

// define the screen resolution and keyboard macros
#define SCREEN_WIDTH 1680
#define SCREEN_HEIGHT 1050
#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")
#pragma comment (lib, "dinput.lib")
#pragma comment (lib, "dinput8.lib")
#pragma comment (lib, "dxguid.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
LPDIRECT3DSURFACE9 z_buffer = NULL;    // the pointer to the z-buffer
LPDIRECTINPUT8 din;    // the pointer to our DirectInput interface
LPDIRECTINPUTDEVICE8 dinkeyboard;    // the pointer to the keyboard device
float XAngle, YAngle, ZAngle, XPos, YPos, ZPos = 0.0f;
static const char *myProgramFileName = "testshader.cg";

// mesh declarations
LPD3DXMESH meshGround, meshBox;    // define the mesh pointer
D3DMATERIAL9* materialGround;	// define the material of the ground
D3DMATERIAL9* materialBox;		// define the material of the box
DWORD numGroundMaterials, numBoxMaterials;    // stores the number of materials in the mesh

// 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);    // sets up the light and the material
void initDInput(HINSTANCE hInstance, HWND hWnd);    // sets up and initializes DirectInput
void detect_keys(void);    // gets the current keys being pressed

// 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"WindowClass1";

    RegisterClassEx(&wc);

    hWnd = CreateWindowEx(NULL,
                          L"WindowClass1",
                          L"Our Direct3D Program",
                          WS_EX_TOPMOST | WS_POPUP,
                          0, 0,
                          SCREEN_WIDTH, SCREEN_HEIGHT,
                          NULL,
                          NULL,
                          hInstance,
                          NULL);

    ShowWindow(hWnd, nCmdShow);

    // set up and initialize Direct3D
    initD3D(hWnd);
	initDInput(hInstance, hWnd);

	// CG
	static CGprofile myCgVertexProfile;
	const char **profileOpts;
	myCgVertexProfile = cgD3D9GetLatestVertexProfile();

	profileOpts = cgD3D9GetOptimalOptions(myCgVertexProfile);

	CGcontext myCgContext = cgCreateContext();
	CGprogram myCgVertexProgram =
    cgCreateProgramFromFile(
		  myCgContext,              /* Cg runtime context */
		  CG_SOURCE,                /* Program in human-readable form */
		  myProgramFileName,  /* Name of file containing program */
		  myCgVertexProfile,        /* Profile: OpenGL ARB vertex program */
		  "main",      /* Entry function name */
		  profileOpts);             /* Pass optimal compiler options */

	//CGprogram MyCGProgram = cgCreateProgram(context, CG_SOURCE, myProgramFileName, CG_PROFILE_ARBVP1, "main", NULL);

    // 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);

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

    // clean up DirectX, COM and DirectX Input
    cleanD3D();

    return msg.wParam;
}

// this is the function that initializes DirectInput
void initDInput(HINSTANCE hInstance, HWND hWnd)
{
    // create the DirectInput interface
    DirectInput8Create(hInstance,    // the handle to the application
                       DIRECTINPUT_VERSION,    // the compatible version
                       IID_IDirectInput8,    // the DirectInput interface version
                       (void**)&din,    // the pointer to the interface
                       NULL);    // COM stuff, so we'll set it to NULL

    // create the keyboard device
    din->CreateDevice(GUID_SysKeyboard,    // the default keyboard ID being used
                      &dinkeyboard,    // the pointer to the device interface
                      NULL);    // COM stuff, so we'll set it to NULL

    dinkeyboard->SetDataFormat(&c_dfDIKeyboard); // set the data format to keyboard format

    // set the control you will have over the keyboard
    dinkeyboard->SetCooperativeLevel(hWnd,
                                     DISCL_NONEXCLUSIVE | DISCL_BACKGROUND);

	return;    // return to WinMain()
}

// this is the function that detects keystrokes and displays them in a message box
void detect_keys(void)
{
    static BYTE keystate[256];    // create a static storage for the key-states

    dinkeyboard->Acquire();    // get access if we don't have it already

    dinkeyboard->GetDeviceState(256, (LPVOID)keystate);    // fill keystate with values

	if(keystate[DIK_LEFT] & 0x80)
		XAngle += 0.03f;

	if(keystate[DIK_RIGHT] & 0x80)
		XAngle -= 0.03f;

	if(keystate[DIK_UP] & 0x80)
		YAngle += 0.03f;

	if(keystate[DIK_DOWN] & 0x80)
		YAngle -= 0.03f;

    return;
}

// 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;    // automatically run the z-buffer for us
    d3dpp.AutoDepthStencilFormat = D3DFMT_D16;    // 16-bit pixel format for the z-buffer

    // 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 triangle
    init_light();    // call the function to initialize the light and material

    d3ddev->SetRenderState(D3DRS_LIGHTING, TRUE);    // turn on 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(0, 0, 0), 1.0f, 0);
    d3ddev->Clear(0, NULL, D3DCLEAR_ZBUFFER, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);

    d3ddev->BeginScene();

    // SET UP THE TRANSFORMS

	// Declaring all the variables needed for the transform

	D3DXMATRIX matView, matRotX, matRotY, matRotZ, matTrans, matWorld;
	//static float XAngle, YAngle, ZAngle, XPos, YPos, ZPos = 0.0f;

    D3DXMatrixLookAtLH(&matView,
    &D3DXVECTOR3 (0.0f, 4.0f, 8.0f),    // 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 
	
    D3DXMATRIX matProjection;    // the projection transform matrix
    D3DXMatrixPerspectiveFovLH(&matProjection,
                               D3DXToRadian(70),    // the horizontal field of view
                               SCREEN_WIDTH / SCREEN_HEIGHT,    // the aspect ratio
                               1.0f,    // the near view-plane
                               100.0f);    // the far view-plane
    d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection);    // set the projection

	detect_keys();

	D3DXMatrixRotationX(&matRotX, XAngle);
	D3DXMatrixRotationY(&matRotY, YAngle);
	D3DXMatrixRotationZ(&matRotZ, ZAngle);
	D3DXMatrixTranslation(&matTrans, ZAngle, XAngle, YAngle);
	D3DXMatrixIdentity(&matWorld);

	D3DXMatrixMultiply(&matWorld, &matWorld, &matTrans);
	D3DXMatrixMultiply(&matWorld, &matWorld, &matRotZ);
	D3DXMatrixMultiply(&matWorld, &matWorld, &matRotY);
	D3DXMatrixMultiply(&matWorld, &matWorld, &matRotX);

	d3ddev->SetTransform(D3DTS_WORLD, &(matWorld));

    // draw the spaceship
    for(DWORD i = 0; i < numBoxMaterials; i++)    // loop through each subset
    {
        d3ddev->SetMaterial(&materialBox);    // set the material for the subset
        meshBox->DrawSubset(i);    // draw the subset
    }

	// draw the spaceship
    for(DWORD i = 0; i < numGroundMaterials; i++)    // loop through each subset
    {
        d3ddev->SetMaterial(&materialGround);    // set the material for the subset
        meshGround->DrawSubset(i);    // draw the subset
    }

    d3ddev->EndScene(); 

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

    return;
}

// this is the function that puts the 3D models into video RAM
void init_graphics(void)
{
    LPD3DXBUFFER bufGroundMaterial, bufBoxMaterial;

    D3DXLoadMeshFromX(L"ground.x",    // load this file
                      D3DXMESH_SYSTEMMEM,    // load the mesh into system memory
                      d3ddev,    // the Direct3D Device
                      NULL,    // we aren't using adjacency
                      &bufGroundMaterial,    // put the materials here
                      NULL,    // we aren't using effect instances
                      &numGroundMaterials,    // the number of materials in this model
                      &meshGround);    // put the mesh here

	D3DXLoadMeshFromX(L"box.x",    // load this file
                      D3DXMESH_SYSTEMMEM,    // load the mesh into system memory
                      d3ddev,    // the Direct3D Device
                      NULL,    // we aren't using adjacency
                      &bufBoxMaterial,    // put the materials here
                      NULL,    // we aren't using effect instances
                      &numBoxMaterials,    // the number of materials in this model
                      &meshBox);    // put the mesh here

    // retrieve the pointer to the buffer containing the material information
    D3DXMATERIAL* tempGroundMaterials = (D3DXMATERIAL*)bufGroundMaterial->GetBufferPointer();
	D3DXMATERIAL* tempBoxMaterials = (D3DXMATERIAL*)bufBoxMaterial->GetBufferPointer();

    // create a new material buffer for each material in the mesh
    materialGround = new D3DMATERIAL9[numGroundMaterials];

    for(DWORD i = 0; i < numGroundMaterials; i++)    // for each material...
    {
        materialGround = tempGroundMaterials.MatD3D;    // get the material info
        materialGround.Ambient = materialGround.Diffuse;    // make ambient the same as diffuse
    }
	
	materialBox = new D3DMATERIAL9[numBoxMaterials];
	
	for(DWORD i = 0; i < numBoxMaterials; i++)    // for each material...
    {
        materialBox = tempBoxMaterials.MatD3D;    // get the material info
        materialBox.Ambient = materialBox.Diffuse;    // make ambient the same as diffuse
    }

    return;
}

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

    ZeroMemory(&light, sizeof(light));    // clear out the light struct for use
    light.Type = D3DLIGHT_SPOT;    // make the light type spot 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)
    light.Range = 500.0f;    // a range of 500
    light.Attenuation0 = 0.0f;    // no constant inverse attenuation
    light.Attenuation1 = 0.125f;    // only .125 inverse attenuation
    light.Attenuation2 = 0.0f;    // no square inverse attenuation
    light.Phi = D3DXToRadian(40.0f);    // set the outer cone to 30 degrees
    light.Theta = D3DXToRadian(20.0f);    // set the inner cone to 10 degrees
    light.Falloff = 0.0f;    // use the typical falloff

    D3DVECTOR vecPosition = {0.0f, 0.0f, 30.0f};    // the position of the light
    light.Position = vecPosition;    // set the position

    D3DVECTOR vecDirection = {0.0f, 0.0f, -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

    return;
}

// this is the function that cleans up Direct3D and COM
void cleanD3D(void)
{
    meshGround->Release();    // close and release the ground mesh
	meshBox->Release();    // close and release the box mesh
    d3ddev->Release();    // close and release the 3D device
    d3d->Release();    // close and release Direct3D

	// Clean Direct-Input
	dinkeyboard->Unacquire();    // make sure the keyboard is unacquired
    din->Release();    // close DirectInput before exiting

    return;
}

// This is C2E1v_green from "The Cg Tutorial" (Addison-Wesley, ISBN
// 0321194969) by Randima Fernando and Mark J. Kilgard.  See page 38.

struct C2E1v_Output {
  float4 position : POSITION;
  float3 color    : COLOR;
};

C2E1v_Output C2E1v_green(float2 position : POSITION)
{	
  C2E1v_Output OUT;

  OUT.position = float4(position,0,1);
  OUT.color = float3(0,1,0);

  return OUT;	
}