DirectX 学习笔记 四、索引缓冲

#pragma comment(lib, "d3d9.lib")
#pragma comment(lib, "d3dx9.lib")

#include <windows.h>
#include <d3d9.h>
#include <d3dx9.h>

IDirect3D9*                             g_pD3D    = NULL;               // D3D接口指针
IDirect3DDevice9*               g_pDevice = NULL;               // D3D设备指针
IDirect3DVertexBuffer9* g_pVB     = NULL;               // 顶点缓冲区
IDirect3DIndexBuffer9*  g_pIB     = NULL;               // 索引缓冲区

LPSTR   szClassName             = "dx";                                       // 窗口类名
LPSTR   szWindowName    = "dx_IndexBuffer";           // 窗口标题名
int             nWidth                  = 300;                                  // 窗口宽度
int             nHeight                 = 300;                                  // 窗口高度

// 声明顶点结构体
struct Vertex
{
        float x, y, z;
        DWORD color;
        static const DWORD FVF;
};

// 顶点渲染格式
const DWORD Vertex::FVF = D3DFVF_XYZ | D3DFVF_DIFFUSE;

//------------------------------------------------------------------------
// 初始化D3D
//------------------------------------------------------------------------
BOOL InitD3D(HWND hWnd)
{
        // 取得D3D接口指针
        if (NULL == (g_pD3D = Direct3DCreate9(D3D_SDK_VERSION)))
        {
                MessageBox(NULL, "Direct3DCreate9 failed!", NULL, NULL);
                return FALSE;
        }

        // 取得主设备显示模式
        D3DDISPLAYMODE d3ddm;
        g_pD3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &d3ddm);

        // 检测硬件顶点渲染
        D3DCAPS9 caps;
        g_pD3D->GetDeviceCaps(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, &caps);

        int vp = 0;
        if (caps.DevCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT)
                vp = D3DCREATE_HARDWARE_VERTEXPROCESSING;
        else
                vp = D3DCREATE_SOFTWARE_VERTEXPROCESSING;

        // 填充创建D3D设备的结构体
        D3DPRESENT_PARAMETERS d3dpp;
        ZeroMemory(&d3dpp, sizeof(d3dpp));
        d3dpp.Windowed = TRUE;
        d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
        d3dpp.BackBufferFormat = d3ddm.Format;

        // 创建D3D设备
        if (FAILED(g_pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL,
                hWnd, vp, &d3dpp, &g_pDevice)))
        {
                MessageBox(NULL, "CreateDevice failed!", NULL, NULL);
                return FALSE;
        }

        // 禁用背面剔除，即正反面都渲染
        g_pDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);

        // 禁用灯光
        g_pDevice->SetRenderState(D3DRS_LIGHTING, FALSE);

        return TRUE;
}

//------------------------------------------------------------------------
// 初始化几何信息
//------------------------------------------------------------------------
BOOL InitGeometry()
{
        // 定义顶点数组
        Vertex vertices[] = 
        {
                { -0.5f, -0.5f, 1.0f, D3DCOLOR_XRGB(0, 0, 255), },
                { 0.5f, -0.5f, 1.0f, D3DCOLOR_XRGB(0, 255, 0), },
                { 0.0f, 0.5f, 0.5f, D3DCOLOR_XRGB(255, 0, 0), },
                { 0.0f, -0.5f, 0.0f, D3DCOLOR_XRGB(255, 255, 0), },
        };

        // 定义索引序列
        WORD indices[] = { 0, 2, 1, 0, 3, 2, 0, 1, 3, 1, 2, 3 };

        // 创建顶点缓冲区
        g_pDevice->CreateVertexBuffer(sizeof(vertices), 
                0, Vertex::FVF, D3DPOOL_DEFAULT, &g_pVB, NULL);

        // 把顶点数据存入顶点缓冲区
        void* pVertices;
        g_pVB->Lock(0, sizeof(vertices), (void**)&pVertices, 0);
        memcpy(pVertices, vertices, sizeof(vertices));
        g_pVB->Unlock();

        // 创建索引缓冲区
        g_pDevice->CreateIndexBuffer(sizeof(indices),
                0, D3DFMT_INDEX16, D3DPOOL_DEFAULT, &g_pIB, NULL);

        // 把索引数据存入索引缓冲区
        void* pIndices;
        g_pIB->Lock(0, sizeof(indices), (void**)&pIndices, 0);
        memcpy(pIndices, indices, sizeof(indices));
        g_pIB->Unlock();

        return TRUE;
}

//------------------------------------------------------------------------
// 清除资源
//------------------------------------------------------------------------
void Cleanup()
{
        if (g_pIB != NULL)
                g_pIB->Release();

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

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

        if (g_pD3D != NULL)
                g_pD3D->Release();
}

//------------------------------------------------------------------------
// 渲染场景
//------------------------------------------------------------------------
void Render()
{
        if (g_pDevice == NULL)
                return;

        // 清除后置缓冲区
        g_pDevice->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);

        // 开始渲染
        g_pDevice->BeginScene();

        // 渲染顶点
        g_pDevice->SetFVF(Vertex::FVF);
        g_pDevice->SetStreamSource(0, g_pVB, 0, sizeof(Vertex));
        g_pDevice->SetIndices(g_pIB);
        g_pDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, 4, 0, 4);

        // 结束渲染
        g_pDevice->EndScene();

        // 显示后置缓冲区的画面
        g_pDevice->Present(NULL, NULL, NULL, NULL);
}

//------------------------------------------------------------------------
// 消息处理
//------------------------------------------------------------------------
LRESULT CALLBACK MsgProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
        switch(msg)
        {
        case WM_PAINT:
                Render();
                break;

        case WM_DESTROY:
                PostQuitMessage(0);
                break;
        }

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

//------------------------------------------------------------------------
// Windows主函数
//------------------------------------------------------------------------
INT WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
        // 注册窗口类
        WNDCLASS wc;
        wc.style                 = CS_VREDRAW | CS_HREDRAW;
        wc.cbClsExtra    = 0;
        wc.cbWndExtra    = 0;
        wc.hInstance     = hInstance;
        wc.hIcon                 = LoadIcon(NULL, IDI_APPLICATION);
        wc.hCursor               = LoadCursor(NULL, IDC_ARROW);
        wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
        wc.lpfnWndProc   = MsgProc;
        wc.lpszClassName = szClassName;
        wc.lpszMenuName  = NULL;

        if (!RegisterClass(&wc))
        {
                MessageBox(NULL, "RegisterClass failed!", NULL, NULL);
                return FALSE;
        }

        // 获取窗口居中位置
        RECT rect;
        GetWindowRect(GetDesktopWindow(), &rect);
        int left = (rect.right - rect.left - nWidth)/2;
        int top = (rect.bottom - rect.top - nHeight)/2;

        // 创建窗口
        HWND hWnd = CreateWindow(szClassName, szWindowName, 
                WS_OVERLAPPEDWINDOW, left, top, nWidth, nHeight, 
                NULL, NULL, wc.hInstance, NULL);

        if(!hWnd)
        {
                MessageBox(NULL, "CreateWindow failed!", NULL, NULL);
                return FALSE;
        }

        // 初始化D3D
        if (InitD3D(hWnd))
        {
                // 初始化几何信息
                if (InitGeometry())
                {
                        // 显示窗口
                        ShowWindow(hWnd, SW_SHOWDEFAULT);
                        UpdateWindow(hWnd);

                        // 消息循环
                        MSG msg;
                        ZeroMemory(&msg, sizeof(msg));
                        while (msg.message != WM_QUIT)
                        {
                                if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
                                {
                                        TranslateMessage(&msg);
                                        DispatchMessage(&msg);
                                }
                        }
                }
        }

        Cleanup();
        UnregisterClass(szClassName, wc.hInstance);
        return 0;
}