9. 視圖矩陣（錄影機）

#include<d3d9.h>      

#include<d3dx9.h>      

#pragma comment(lib, "d3d9.lib")      

#pragma comment(lib, "d3dx9.lib")      

#define WINDOW_CLASS    "UGPDX"      

#define WINDOW_NAME     "View Matrix"      

#define WINDOW_WIDTH    640      

#define WINDOW_HEIGHT   480      

// Function Prototypes...      

bool InitializeD3D(HWND hWnd, bool fullscreen);      

bool InitializeObjects();      

void RenderScene();      

void Shutdown();      

// Direct3D object and device.      

LPDIRECT3D9 g_D3D = NULL;      

LPDIRECT3DDEVICE9 g_D3DDevice = NULL;      

D3DXMATRIX g_projection;      

D3DXMATRIX g_ViewMatrix;      

// Vertex buffer to hold the geometry.      

LPDIRECT3DVERTEXBUFFER9 g_VertexBuffer = NULL;      

// A structure for our custom vertex type      

struct stD3DVertex      

{      

float x, y, z;      

unsigned long color;      

};      

// Our custom FVF, which describes our custom vertex structure      

#define D3DFVF_VERTEX (D3DFVF_XYZ | D3DFVF_DIFFUSE)      

LRESULT WINAPI MsgProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)      

{      

switch(msg)      

{      

case WM_DESTROY:      

PostQuitMessage(0);      

return 0;      

break;      

case WM_KEYUP:      

if(wParam == VK_ESCAPE) PostQuitMessage(0);      

break;      

}      

return DefWindowProc(hWnd, msg, wParam, lParam);      

}      

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE prevhInst, LPSTR cmdLine, int show)      

{      

// Register the window class      

WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, MsgProc, 0L, 0L,      

GetModuleHandle(NULL), NULL, NULL, NULL, NULL,      

WINDOW_CLASS, NULL };      

RegisterClassEx(&wc);      

// Create the application's window      

HWND hWnd = CreateWindow(WINDOW_CLASS, WINDOW_NAME, WS_OVERLAPPEDWINDOW,      

100, 100, WINDOW_WIDTH, WINDOW_HEIGHT, GetDesktopWindow(),      

NULL, wc.hInstance, NULL);      

// Initialize Direct3D      

if(InitializeD3D(hWnd, false))      

{      

// Show the window      

ShowWindow(hWnd, SW_SHOWDEFAULT);      

UpdateWindow(hWnd);      

// Enter the message loop      

MSG msg;      

ZeroMemory(&msg, sizeof(msg));      

while(msg.message != WM_QUIT)      

{      

if(PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))      

{      

TranslateMessage(&msg);      

DispatchMessage(&msg);      

}      

else      

RenderScene();      

}      

}      

// Release any and all resources.      

Shutdown();      

// Unregister our window.      

UnregisterClass(WINDOW_CLASS, wc.hInstance);      

return 0;      

}      

bool InitializeD3D(HWND hWnd, bool fullscreen)      

{      

D3DDISPLAYMODE displayMode;      

// Create the D3D object.      

g_D3D = Direct3DCreate9(D3D_SDK_VERSION);      

if(g_D3D == NULL) return false;      

// Get the desktop display mode.      

if(FAILED(g_D3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &displayMode)))      

return false;      

// Set up the structure used to create the D3DDevice      

D3DPRESENT_PARAMETERS d3dpp;      

ZeroMemory(&d3dpp, sizeof(d3dpp));      

if(fullscreen)      

{      

d3dpp.Windowed = FALSE;      

d3dpp.BackBufferWidth = WINDOW_WIDTH;      

d3dpp.BackBufferHeight = WINDOW_HEIGHT;      

}      

else      

d3dpp.Windowed = TRUE;      

d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;      

d3dpp.BackBufferFormat = displayMode.Format;      

// Create the D3DDevice      

if(FAILED(g_D3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,      

D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &g_D3DDevice)))      

{      

return false;      

}      

// Set the projection matrix. 透視投影矩陣      

D3DXMatrixPerspectiveFovLH(&g_projection, 45.0f, WINDOW_WIDTH/WINDOW_HEIGHT,      

0.1f, 1000.0f);      

g_D3DDevice->SetTransform(D3DTS_PROJECTION, &g_projection);      

// Define camera information. 視圖矩陣（錄影機）      

D3DXVECTOR3 cameraPos(0.0f, 0.0f, -5.0f);      

D3DXVECTOR3 lookAtPos(0.0f, 0.0f, 0.0f);      

D3DXVECTOR3 upDir(0.0f, 1.0f, 0.0f);      

// Build view matrix.      

D3DXMatrixLookAtLH(&g_ViewMatrix, &cameraPos,      

&lookAtPos, &upDir);      

// Apply the view (camera).      

g_D3DDevice->SetTransform(D3DTS_VIEW, &g_ViewMatrix);      

//沒有設定世界矩陣，是以物體預設在（0,0,0）顯示      

// Set default rendering states.      

g_D3DDevice->SetRenderState(D3DRS_LIGHTING, FALSE);      

g_D3DDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);      

// Initialize any objects we will be displaying.      

if(!InitializeObjects()) return false;      

return true;      

}      

bool InitializeObjects()      

{      

// Fill in our structure to draw an object.      

// x, y, z, color.      

stD3DVertex objData[] =      

{      

{-0.3f, -0.3f, 0.0f, D3DCOLOR_XRGB(255,255,0)},      

{0.3f, -0.3f, 0.0f, D3DCOLOR_XRGB(255,0,0)},      

{0.0f, 0.3f, 0.0f, D3DCOLOR_XRGB(0,0,255)}      

};      

// Create the vertex buffer.      

if(FAILED(g_D3DDevice->CreateVertexBuffer(3 * sizeof(stD3DVertex), 0,      

D3DFVF_VERTEX, D3DPOOL_DEFAULT, &g_VertexBuffer, NULL))) return false;      

// Fill the vertex buffer.      

void *ptr;      

if(FAILED(g_VertexBuffer->Lock(0, sizeof(objData), (void**)&ptr, 0))) return false;      

memcpy(ptr, objData, sizeof(objData));      

g_VertexBuffer->Unlock();      

return true;      

}      

void RenderScene()      

{      

// Clear the backbuffer.      

g_D3DDevice->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,0), 1.0f, 0);      

// Begin the scene.  Start rendering.      

g_D3DDevice->BeginScene();      

// Bind data to the stream, set fvf so D3D knows how our data      

// is made up, then render the object.      

g_D3DDevice->SetStreamSource(0, g_VertexBuffer, 0, sizeof(stD3DVertex));      

g_D3DDevice->SetFVF(D3DFVF_VERTEX);      

g_D3DDevice->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 1);      

// End the scene.  Stop rendering.      

g_D3DDevice->EndScene();      

// Display the scene.      

g_D3DDevice->Present(NULL, NULL, NULL, NULL);      

}      

void Shutdown()      

{      

if(g_D3DDevice != NULL) g_D3DDevice->Release();      

if(g_D3D != NULL) g_D3D->Release();      

if(g_VertexBuffer != NULL) g_VertexBuffer->Release();      

}