坐标系与基本图元（8）

坐标系与基本图元（8）

全屏幕显示

游戏程序通常都是运行在全屏幕模式下，进行全屏显示的关键是使用全屏显示的渲染设备。创建全屏显示模式渲染设备同窗口模式渲染设备基本相同，区别是将d3dpp.Windowed设置为FALSE，告诉Direct3D系统，将要创建的是全屏模式渲染设备。此外，还需要明确指定后台缓冲区的大小和格式，这和创建窗口模式渲染设备是不相同的，在创建窗口模式渲染设备时可将后台缓冲区格式设置为D3DFMT_UNKNOWN，后台缓冲区大小也可取默认值，而在创建全屏模式渲染设备时这些都需要明确指定。

首先调用函数GetAdapterDisplayMode()获得显示器当前的显示模式：

Retrieves the current display mode of the adapter.

HRESULT GetAdapterDisplayMode(
  UINT Adapter,
  D3DDISPLAYMODE * pMode
);

Parameters

Adapter

[in] Ordinal number that denotes the display adapter to query. D3DADAPTER_DEFAULT is always the primary display adapter.

pMode

[in, out] Pointer to a D3DDISPLAYMODE structure, to be filled with information describing the current adapter's mode.

Return Values

If the method succeeds, the return value is D3D_OK.

If Adapter is out of range or pMode is invalid, this method returns D3DERR_INVALIDCALL.

Remarks

IDirect3D9::GetAdapterDisplayMode will not return the correct format when the display is in an extended format, such as 2:10:10:10. Instead, it returns the format X8R8G8B8.

Describes the display mode.

typedef struct D3DDISPLAYMODE {
    UINT Width;
    UINT Height;
    UINT RefreshRate;
    D3DFORMAT Format;
} D3DDISPLAYMODE, *LPD3DDISPLAYMODE;

Members

Width

Screen width, in pixels.

Height

Screen height, in pixels.

RefreshRate

Refresh rate. The value of 0 indicates an adapter default.

Format

Member of the D3DFORMAT enumerated type, describing the surface format of the display mode.

运行截图：

完整源代码：

#include <d3d9.h>

#define CLASS_NAME    "GameApp"

#define release_com(p)    do { if(p) { (p)->Release(); (p) = NULL; } } while(0)

IDirect3D9*                g_d3d;
IDirect3DDevice9*        g_device;
IDirect3DVertexBuffer9* g_vertex_buffer;

struct sCustomVertex
{
    float x, y, z, rhw;
    DWORD color;
};

#define D3DFVF_CUSTOM_VERTEX (D3DFVF_XYZRHW | D3DFVF_DIFFUSE) 

void init_vertices()
{
    sCustomVertex vertices[] =
    {
        { 100.0f,  650.0f, 0.5f, 1.0f, 0xffff0000, },
        { 500.0f,  100.0f, 0.5f, 1.0f, 0xff00ff00, }, 
        { 900.0f,  650.0f, 0.5f, 1.0f, 0xff0000ff, },
    };

    // push vertex data into vertex buffer

    g_device->CreateVertexBuffer(sizeof(vertices), 0, D3DFVF_CUSTOM_VERTEX, D3DPOOL_DEFAULT, &g_vertex_buffer, NULL);

    void* ptr;

    g_vertex_buffer->Lock(0, sizeof(vertices), (void**)&ptr, 0);
    memcpy(ptr, vertices, sizeof(vertices));
    g_vertex_buffer->Unlock();
}

bool init_d3d(HWND hwnd)
{
    g_d3d = Direct3DCreate9(D3D_SDK_VERSION);

    if(g_d3d == NULL)
        return false;

    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory(&d3dpp, sizeof(d3dpp));

    D3DDISPLAYMODE display_mode;
    g_d3d->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &display_mode);

    d3dpp.Windowed            = FALSE;
    d3dpp.SwapEffect        = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferWidth    = display_mode.Width;
    d3dpp.BackBufferHeight    = display_mode.Height;
    d3dpp.BackBufferFormat    = display_mode.Format;
    
    if(FAILED(g_d3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hwnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                                  &d3dpp, &g_device)))
    {
        return false;
    }

    init_vertices();

    return true;
}

void cleanup()
{    
    release_com(g_vertex_buffer);
    release_com(g_device);
    release_com(g_d3d);
}

void render()
{    
    g_device->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(5, 5, 5), 1.0f, 0);    

    g_device->BeginScene();

    g_device->SetStreamSource(0, g_vertex_buffer, 0, sizeof(sCustomVertex));
    g_device->SetFVF(D3DFVF_CUSTOM_VERTEX);    
    g_device->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 1);

    g_device->EndScene();

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

LRESULT WINAPI WinProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
    case WM_KEYDOWN:
        switch(wParam)
        {    
        case VK_ESCAPE:
            DestroyWindow(hwnd);
            break;
        }    
        break;

    case WM_DESTROY:        
        PostQuitMessage(0);
        return 0;
    }

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

int WINAPI WinMain(HINSTANCE inst, HINSTANCE, LPSTR, INT)
{
    WNDCLASSEX wc;

    wc.cbSize            = sizeof(WNDCLASSEX);
    wc.style            = CS_CLASSDC;
    wc.lpfnWndProc        = WinProc;
    wc.cbClsExtra        = 0;
    wc.cbWndExtra        = 0;
    wc.hInstance        = inst;
    wc.hIcon            = NULL;
    wc.hCursor            = NULL;
    wc.hbrBackground    = NULL;
    wc.lpszMenuName        = NULL;
    wc.lpszClassName    = CLASS_NAME;
    wc.hIconSm            = NULL;

    if(! RegisterClassEx(&wc))
        return -1;

    HWND hwnd = CreateWindow(CLASS_NAME, "Direct3D App", WS_OVERLAPPEDWINDOW, 200, 100, 600, 500,
                             NULL, NULL, wc.hInstance, NULL);

    if(hwnd == NULL)
        return -1;

    if(init_d3d(hwnd))
    {
        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);
            }
                
            render();
        }
    }

    cleanup();

    UnregisterClass(CLASS_NAME, wc.hInstance);    

    return 0;
}