【游戏开发】Directx9绘制两条白色线段

//Direct3D9头文件
#include <d3d9.h>

//宏定义窗口类名字
#define WINDOW_CLASS "UGPDX"

//宏定义窗口名字
#define WINDOW_NAME "Drawing Lines"

//设置和创建Direct3D
bool InitializeD3D(HWND hWnd, bool fullscreen);

//创建将要绘制在屏幕上的物体
bool InitializeObjects();

//渲染图形
void RenderScene();

//在程序退出时清除程序
void Shutdown();

//分别将Direct3D对象和Direct3D设备对象置为空
LPDIRECT3D9 g_D3D = NULL;
LPDIRECT3DDEVICE9 g_D3DDevice = NULL;

//将顶点缓存置为空
LPDIRECT3DVERTEXBUFFER9 g_VertexBuffer = NULL;

//定义Direct3D顶点结构
struct stD3DVertex
{
    //xyz坐标
	float x, y, z;

    //颜色
	unsigned long color;
};

//宏定义灵活顶点格式
#define D3DFVF_VERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE);

bool InitializeObject()
{
    //指定颜色为白色
	unsigned long col = D3DCOLOR_XRGB(255, 255, 255);

    //为了创建2条线段，需要指定4个点，以及每个点的x，y，z位置坐标和颜色值
	stD3DVertex objData[] = {
		{ 420.0f, 150.0f, 0.5f, col, },
		{ 420.0f, 350.0f, 0.5f, col, },
		{ 220.0f, 150.0f, 0.5f, col, },
		{ 220.0f, 350.0f, 0.5f, col, },
	};
    //创建顶点缓存保存数据
	if (FAILED(g_D3DDevice->CreateVertexBuffer(sizeof(objData), 0,
		D3DFVF_VERTEX, D3DPOOL_DEFAULT, &g_VertexBuffer, NULL)))return false;

    //声明一个指针，Lock()函数可以获取一个指向顶点缓存中已分配内存的指针，进而操作该指针
	void *ptr;

    //锁定顶点缓存
	if (FAILED(g_VertexBuffer->Lock(0, sizeof(objData), (void**)&ptr, 0)))return false;

    //将数据复制到顶点缓存中
	memcpy(ptr, objData, sizeof(objData));

    //将顶点缓存设置为准备就绪
	g_VertexBuffer->Unlock();

	return true;
}

void RenderScene()
{
    //清屏
	g_D3DDevice->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);

    //开始渲染
	g_D3DDevice->BeginScene();
    
    //将顶点设置为渲染流
	g_D3DDevice->SetStreamSource(0, g_VertexBuffer, 0, sizeof(stD3DVertex));

    //设置顶点格式FVF
	g_D3DDevice->SetFVF(D3DFVF_VERTEX);

    //绘制出当前设置为流的顶点缓存内容
	g_D3DDevice->DrawPrimitive(D3DPT_LINELIST, 0, 2);

    //结束渲染
	g_D3DDevice->EndScene();
    
    //显示
	g_D3DDevice->Present(NULL, NULL, NULL, NULL);
}

void Shutdown()
{
    //释放D3D设备对象
	if (g_D3DDevice != NULL)g_D3DDevice->Release();

    //释放D3D对象
	if (g_D3D != NULL)g_D3D->Release();

    //释放顶点缓存
	if (g_VertexBuffer != NULL)g_VertexBuffer->Release();

    //分别置为空
	g_D3DDevice = NULL;
	g_D3D = NULL;
	g_VertexBuffer = NULL;
}

//完整代码：

#include <Windows.h>
#include <d3d9.h>

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

#define WINDOW_CLASS "UGPDX"
#define WINDOW_NAME "Drawing Lines"

bool InitializeD3D(HWND hWnd, bool fullscreen);
bool InitializeObjects();
void RenderScene();
void Shutdown();

LPDIRECT3D9 g_D3D = NULL;
LPDIRECT3DDEVICE9 g_D3DDevice = NULL;

LPDIRECT3DVERTEXBUFFER9 g_VertexBuffer = NULL;

struct stD3DVertex
{
	float x, y, z;
	unsigned long color;
};

#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 hInstance,HINSTANCE hPrevInstanace,
	PSTR szCmdLine,int iCmdShow)
{
	WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, MsgProc, 0, 0, GetModuleHandle(NULL), NULL,
		NULL, NULL, NULL, WINDOW_CLASS, NULL };
	RegisterClassEx(&wc);
	HWND hWnd = CreateWindow(WINDOW_CLASS, WINDOW_NAME, WS_OVERLAPPEDWINDOW,
		100, 100, 640, 480, GetDesktopWindow(), NULL, wc.hInstance, NULL);
	if (InitializeD3D(hWnd, false))
	{
		ShowWindow(hWnd, SW_SHOWDEFAULT);
		UpdateWindow(hWnd);

		MSG msg;
		ZeroMemory(&msg, sizeof(msg));
		while (msg.message != WM_QUIT)
		{
			if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
			{
				TranslateMessage(&msg);
				DispatchMessage(&msg);
			}
			else
			{
				RenderScene();
			}
		}
	}
	
	
	Shutdown();
	UnregisterClass(WINDOW_CLASS, wc.hInstance);
	return 0;
}

bool InitializeD3D(HWND hWnd, bool fullscreen)
{
	D3DDISPLAYMODE displayMode;
	g_D3D = Direct3DCreate9(D3D_SDK_VERSION);
	if (g_D3D == NULL)return false;
	if (FAILED(g_D3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &displayMode)))
		return false;
	D3DPRESENT_PARAMETERS d3dpp;
	ZeroMemory(&d3dpp, sizeof(d3dpp));
	if (fullscreen)
	{
		d3dpp.Windowed = FALSE;
		d3dpp.BackBufferWidth = 640;
		d3dpp.BackBufferHeight = 480;
	}
	else
		d3dpp.Windowed = TRUE;
	d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
	d3dpp.BackBufferFormat = displayMode.Format;
	if (FAILED(g_D3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
		D3DCREATE_HARDWARE_VERTEXPROCESSING, &d3dpp,
		&g_D3DDevice)))return false;
	if (!InitializeObjects())return false;
	return true;
}

bool InitializeObjects()
{
	unsigned long col = D3DCOLOR_XRGB(255, 255, 255);
	stD3DVertex objData[] = {
		{ 420.0f, 150.0f, 0.5f, col, },
		{ 420.0f, 350.0f, 0.5f, col, },
		{ 220.0f, 150.0f, 0.5f, col, },
		{ 220.0f, 350.0f, 0.5f, col, },
	};
	if (FAILED(g_D3DDevice->CreateVertexBuffer(sizeof(objData), 0,
		D3DFVF_VERTEX, D3DPOOL_DEFAULT, &g_VertexBuffer, NULL)))return false;
	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()
{
	g_D3DDevice->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
	g_D3DDevice->BeginScene();
	g_D3DDevice->SetStreamSource(0, g_VertexBuffer, 0, sizeof(stD3DVertex));
	g_D3DDevice->SetFVF(D3DFVF_VERTEX);
	g_D3DDevice->DrawPrimitive(D3DPT_LINELIST, 0, 2);
	g_D3DDevice->EndScene();
	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();
	g_D3DDevice = NULL;
	g_D3D = NULL;
	g_VertexBuffer = NULL;
}