DirectX camera question

sasho648 0 Newbie Poster

12 Years Ago

I want to make a mouse controlled camera the problem is that i want to rotate over the space not the current object but I don't know how to calculate the changes on view transformation. Here is the code example:

D3DXMatrixLookAtLH(&matView,
                       &D3DXVECTOR3 (0.0f, 0.0f, CurCamRot.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
//The CurCamRot have 3 values the first 2 are the x,y rotation from the mouse the 3 value is the deep(it's working) I want to know where to place CurCamRot.x and CurCamRot.y

And here is the full code:

#include "stdafx.h"
#include "DX3D-Test.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
#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600

// global declarations
LPDIRECT3D9 d3d;    // the pointer to our Direct3D interface
LPDIRECT3DDEVICE9 d3ddev;    // the pointer to the device class
LPDIRECT3DVERTEXBUFFER9 v_buffer = NULL;    // the pointer to the vertex buffer
LPDIRECT3DINDEXBUFFER9 i_buffer = NULL;
HANDLE DirectX(0);

// function prototypes
void initD3D(HWND hWnd);    // sets up and initializes Direct3D
unsigned long __stdcall render_frame(void* lp);    // renders a single frame
void cleanD3D(void);    // closes Direct3D and releases memory
void init_graphics(void);    // 3D declarations

D3DXVECTOR3 CurCamRot(0.0f,0.0f,15.0f);
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);

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

    // enter the main loop:

    MSG msg;

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

        if(msg.message == WM_QUIT) {
			TerminateThread(DirectX, 0);
			break;
		}
            
    }

    // clean up DirectX and COM
    cleanD3D();

    return msg.wParam;
}


// this is the main message handler for the program
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static bool rot=false;
	static POINT mouse;
    switch(message)
    {
        case WM_DESTROY:
            {
                PostQuitMessage(0);
                return 0;
            } break;
		case WM_MOUSEMOVE:
			{
				TRACKMOUSEEVENT MyEvent;
				MyEvent.cbSize=sizeof(TRACKMOUSEEVENT);
				MyEvent.dwFlags=TME_LEAVE;
				MyEvent.hwndTrack=hWnd;
				MyEvent.dwHoverTime=0;
				TrackMouseEvent(&MyEvent);
			if(wParam==MK_LBUTTON)
			{
				if(!rot) {
					rot=true;
					GetCursorPos(&mouse);
				}
				else {
					POINT Curr;
					GetCursorPos(&Curr);
					CurCamRot.y+=(mouse.x-Curr.x)*0.01f;
					CurCamRot.x+=(mouse.y-Curr.y)*0.01f;
					GetCursorPos(&mouse);
				}
				//MessageBoxA(hWnd,"The program can't find any TRAOD levels!","Error!",MB_OK|MB_ICONHAND);
			}
			}
			break;
		case WM_MOUSELEAVE:
			if(!rot)
				break;
		case WM_LBUTTONUP:
				rot=false;
			break;
		case WM_MOUSEWHEEL:
			{
				CurCamRot.z-=GET_WHEEL_DELTA_WPARAM(wParam)*0.001f;
			}
			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.BackBufferCount = 2;

    // 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

    d3ddev->SetRenderState(D3DRS_LIGHTING, FALSE);    // turn off the 3D lighting
	d3ddev->SetRenderState(D3DRS_CULLMODE, D3DCULL_CCW);    // turn off culling
    d3ddev->SetRenderState(D3DRS_ZENABLE, TRUE);    // turn on the z-buffer
	DirectX=CreateThread(0,0,render_frame,0,0,0);

}

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

    d3ddev->BeginScene();

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

    // SET UP THE PIPELINE

   // D3DXMATRIX matRotateY;    // a matrix to store the rotation information
	//D3DXMATRIX matRotateX;

    // build a matrix to rotate the model based on the increasing float value
   // D3DXMatrixRotationY(&matRotateY, CurCamRot.y);
	//D3DXMatrixRotationX(&matRotateX, CurCamRot.x);

    // tell Direct3D about our matrix
    //d3ddev->SetTransform(D3DTS_WORLD, &(matRotateY * matRotateX));

    D3DXMATRIX matView;    // the view transform matrix

    D3DXMatrixLookAtLH(&matView,
                       &D3DXVECTOR3 (0.0f, 0.0f, CurCamRot.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 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
                               900.0f);    // the far view-plane

    d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection);    // set the projection

    // select the vertex buffer to display
    d3ddev->SetStreamSource(0, v_buffer, 0, sizeof(CUSTOMVERTEX));
	d3ddev->SetIndices(i_buffer);

    // copy the vertex buffer to the back buffer
    d3ddev->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, 16, 0, 24);

    d3ddev->EndScene();

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

unsigned long __stdcall render_frame(void* lp) {
	while(TRUE)
		render_frame();
}

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


// this is the function that puts the 3D models into video RAM
void init_graphics(void)
{
    // create the vertices using the CUSTOMVERTEX struct
    CUSTOMVERTEX vertices[] = 
    {
        { -3.0f, 3.0f, -3.0f, D3DCOLOR_XRGB(0, 0, 255), },
        { 3.0f, 3.0f, -3.0f, D3DCOLOR_XRGB(0, 255, 0), },
        { -3.0f, -3.0f, -3.0f, D3DCOLOR_XRGB(255, 0, 0), },
        { 3.0f, -3.0f, -3.0f, D3DCOLOR_XRGB(0, 255, 255), },
        { -3.0f, 3.0f, 3.0f, D3DCOLOR_XRGB(0, 0, 255), },
        { 3.0f, 3.0f, 3.0f, D3DCOLOR_XRGB(255, 0, 0), },
        { -3.0f, -3.0f, 3.0f, D3DCOLOR_XRGB(0, 255, 0), },
        { 3.0f, -3.0f, 3.0f, D3DCOLOR_XRGB(0, 255, 255), },

		{ -3.0f, 3.0f, -6.0f, D3DCOLOR_XRGB(0, 0, 255), },
        { 3.0f, 3.0f, -6.0f, D3DCOLOR_XRGB(0, 255, 0), },
        { -3.0f, -3.0f, -6.0f, D3DCOLOR_XRGB(255, 0, 0), },
        { 3.0f, -3.0f, -6.0f, D3DCOLOR_XRGB(0, 255, 255), },
        { -3.0f, 3.0f, 0.0f, D3DCOLOR_XRGB(0, 0, 255), },
        { 3.0f, 3.0f, 0.0f, D3DCOLOR_XRGB(255, 0, 0), },
        { -3.0f, -3.0f, 0.0f, D3DCOLOR_XRGB(0, 255, 0), },
        { 3.0f, -3.0f, 0.0f, D3DCOLOR_XRGB(0, 255, 255), },
    };

    // create a vertex buffer interface called v_buffer
    d3ddev->CreateVertexBuffer(16*sizeof(CUSTOMVERTEX),
                               0,
                               CUSTOMFVF,
                               D3DPOOL_MANAGED,
                               &v_buffer,
                               NULL);

    VOID* pVoid;    // a void pointer

    // lock v_buffer and load the vertices into it
    v_buffer->Lock(0, 0, (void**)&pVoid, 0);
    memcpy(pVoid, vertices, sizeof(vertices));
    v_buffer->Unlock();

	// create the indices using an int array
    short indices[] =
    {
        0, 1, 2,    // side 1
        2, 1, 3,
        4, 0, 6,    // side 2
        6, 0, 2,
        7, 5, 6,    // side 3
        6, 5, 4,
        3, 1, 7,    // side 4
        7, 1, 5,
        4, 5, 0,    // side 5
        0, 5, 1,
        3, 7, 2,    // side 6
        2, 7, 6,
		8, 9, 10,    // side 1
        10, 9, 11,
        12, 8, 14,    // side 2
        14, 8, 10,
        15, 13, 14,    // side 3
        14, 13, 12,
        11, 9, 15,    // side 4
        15, 9, 13,
        12, 13, 8,    // side 5
        8, 13, 9,
        11, 15, 10,    // side 6
        10, 15, 14,
    };

    // create an index buffer interface called i_buffer
    d3ddev->CreateIndexBuffer(72*sizeof(short),
                              0,
                              D3DFMT_INDEX16,
                              D3DPOOL_MANAGED,
                              &i_buffer,
                              NULL);

    // lock i_buffer and load the indices into it
    i_buffer->Lock(0, 0, (void**)&pVoid, 0);
    memcpy(pVoid, indices, sizeof(indices));
    i_buffer->Unlock();
}

c++

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