c++ - 如何防止 DirectX Sprite 在将其移出屏幕时被删除

Question

所以我试图学习如何在 directX 中制作 Sprite 并下载了一个示例文件，但是示例中有一个错误我无法克服并且必须知道如何修复，只要附加到窗口的 Sprite 是移出屏幕并返回到被移出屏幕的 Sprite 部分，直到我释放鼠标左键后才重新绘制。我阅读了 RenderFrame() 函数中的所有内容，希望找到一些可以更改的设置，但没有成功。

Here是该问题的示例动画(出于某种奇怪的原因，我在我的视频中找不到任何没有 502 错误的文件共享服务。)

这是源代码:

// main.cpp : Defines the entry point for the application.
//
#include <windows.h>
#include "C:\Program Files\Microsoft DirectX SDK (August 2008)\Include\D3dx9core.h"
#include "C:\Documents and Settings\Death\My Documents\Downloads\DXSprite\DXSprite\resource.h"

//-----------------------------------------------------------------------------
// GLOBALS
//-----------------------------------------------------------------------------
HWND g_hWnd = NULL;
LPDIRECT3D9 g_pD3D = NULL;
LPDIRECT3DDEVICE9 g_pD3DDevice = NULL;
ID3DXSprite * g_pD3DXSprite = NULL;
LPDIRECT3DTEXTURE9 g_pTexture = NULL;
const int SCREEN_WIDTH = 800;
const int SCREEN_HEIGHT = 600;

//-----------------------------------------------------------------------------
// PROTOTYPES
//-----------------------------------------------------------------------------
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
               LPSTR lpCmdLine, int nCmdShow);
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
HRESULT InitializeD3D       ( );
void RenderFrame            ( );

//-----------------------------------------------------------------------------
//    Name: WinMain()
// Desc: The application's entry point
//-----------------------------------------------------------------------------
int WINAPI WinMain( HINSTANCE hInstance,
                HINSTANCE hPrevInstance,
                LPSTR     lpCmdLine,
                int       nCmdShow )
{
WNDCLASSEX  winClass;
MSG         uMsg;
HRESULT     hr;

memset(&uMsg,0,sizeof(uMsg));

winClass.lpszClassName = "MY_WINDOWS_CLASS";
winClass.cbSize        = sizeof(WNDCLASSEX);
winClass.style         = CS_HREDRAW | CS_VREDRAW;
winClass.lpfnWndProc   = WindowProc;
winClass.hInstance     = hInstance;
winClass.hIcon         = LoadIcon(hInstance, (LPCTSTR)IDC_DXSPRITE);
winClass.hIconSm       = LoadIcon(hInstance, (LPCTSTR)IDC_DXSPRITE);
winClass.hCursor       = LoadCursor(NULL, IDC_ARROW);
winClass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
winClass.lpszMenuName  = NULL;
winClass.cbClsExtra    = 0;
winClass.cbWndExtra    = 0;

if( !RegisterClassEx(&winClass) )
    return E_FAIL;

g_hWnd = CreateWindowEx( NULL, "MY_WINDOWS_CLASS",
                         "Direct3D 9 - ID3DXSprite Example",
                         WS_OVERLAPPEDWINDOW | WS_VISIBLE,
                         0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, NULL, NULL, hInstance, NULL );

if( g_hWnd == NULL )
    return E_FAIL;

ShowWindow( g_hWnd, nCmdShow );
UpdateWindow( g_hWnd );

//----------------------------------------------------------------
// Create the DirectX device
//----------------------------------------------------------------
if (FAILED( InitializeD3D()))
    return 0;


//----------------------------------------------------------------
// CREATE THE ID3DXSprite
//----------------------------------------------------------------

// Create the ID3DXSprite interface object
hr = D3DXCreateSprite(g_pD3DDevice, &g_pD3DXSprite );
if( FAILED(hr) )
    return hr;


//----------------------------------------------------------------
// LOAD THE TEXTURE FOR THE SPRITE
//----------------------------------------------------------------

// --------------------------------------------------------
// Load the texture.  I decided to use the extended
// version of the texture loading function just to show what
// it would look like.
// The texture was created with Photoshop with a transparent
// background to start with.  Then line cross hairs were added.
//
// Note - If you don't use a texture image that has a power of
// 2 size for the width or height then the image may not load
// properly.  This image is 256x256.
//
D3DXCreateTextureFromFileEx(
    g_pD3DDevice,
    "C:\\Documents and Settings\\Death\\My Documents\\Downloads\\DXSprite\\DXSprite\\sarah.jpg",                // Our texture image!
    D3DX_DEFAULT,               // width
    D3DX_DEFAULT,               // height
    D3DX_DEFAULT,               // MIP levels
    0,                          // usage
    D3DFMT_DXT1,                // texture format
    D3DPOOL_MANAGED,            // mem pool
    D3DX_DEFAULT,               // filter
    D3DX_DEFAULT,               // MIP filter
    0,                          // transparent color key
    NULL,                       // image info struct
    NULL,                       // palette
    &g_pTexture);               // the returned texture, if success

if ( FAILED(hr) )
    return hr;





// ---------
// Main Loop
// ---------
while( uMsg.message != WM_QUIT )
{
RenderFrame();
    if( PeekMessage( &uMsg, NULL, 0, 0, PM_REMOVE ) )
    {
        TranslateMessage( &uMsg );
        DispatchMessage( &uMsg );
    }
}

// -------------------------
// Release directx resources
// -------------------------
if (g_pD3DXSprite)
{
    g_pD3DXSprite->Release();
    g_pD3DXSprite = NULL;
}

if (g_pTexture)
{
    g_pTexture->Release();
    g_pTexture = NULL;
}

if (g_pD3DDevice)
{
    g_pD3DDevice->Release();
    g_pD3DDevice = NULL;
}




UnregisterClass( "MY_WINDOWS_CLASS", winClass.hInstance );

return (int)uMsg.wParam;
}

//-----------------------------------------------------------------------------
// Name: WindowProc()
// Desc: The window's message handler
//-----------------------------------------------------------------------------
LRESULT CALLBACK WindowProc( HWND   hWnd,
                         UINT   msg,
                         WPARAM wParam,
                         LPARAM lParam )
{

switch( msg )
{
    case WM_KEYDOWN:
    {
        switch( wParam )
        {
            case VK_ESCAPE:
                PostQuitMessage(0);
                break;

        }
    }
    break;

    case WM_CLOSE:
    {
        PostQuitMessage(0);
    }

    case WM_DESTROY:
    {
        PostQuitMessage(0);
    }
    break;

    default:
    {
        return DefWindowProc( hWnd, msg, wParam, lParam );
    }
    break;
}

return 0;
}

//-----------------------------------------------------------------------------
// Name: InitializeD3D()
// Desc: Create DirectX interface objects 
//       Initialize the view matrix.
//       Setup render states that will not need changing throughout
//       the life of the application.
//-----------------------------------------------------------------------------
HRESULT InitializeD3D( ) 
{
HRESULT hr;

// Create a direct 3D interface object
g_pD3D = Direct3DCreate9( D3D_SDK_VERSION );

if( g_pD3D == NULL )
{
    // TO DO: Respond to failure of Direct3DCreate9
    return E_FAIL;
}

D3DDISPLAYMODE d3ddm;

if( FAILED( hr = g_pD3D->GetAdapterDisplayMode( D3DADAPTER_DEFAULT, &d3ddm ) ) )
{
    // TO DO: Respond to failure of GetAdapterDisplayMode
    return hr;
}


//
if( FAILED( hr = g_pD3D->CheckDeviceFormat( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL,
                                            d3ddm.Format, D3DUSAGE_DEPTHSTENCIL,
                                            D3DRTYPE_SURFACE, D3DFMT_D16 ) ) )
{
    if( hr == D3DERR_NOTAVAILABLE )
        // POTENTIAL PROBLEM: We need at least a 16-bit z-buffer!
        return hr;
}

//
// Do we support hardware vertex processing? If so, use it.
// If not, downgrade to software.
//

D3DCAPS9 d3dCaps;

if( FAILED( hr = g_pD3D->GetDeviceCaps( D3DADAPTER_DEFAULT,
                                   D3DDEVTYPE_HAL, &d3dCaps ) ) )
{
    // TO DO: Respond to failure of GetDeviceCaps
    return hr;
}

DWORD dwBehaviorFlags = 0;

if( d3dCaps.VertexProcessingCaps != 0 )
    dwBehaviorFlags |= D3DCREATE_HARDWARE_VERTEXPROCESSING;
else
    dwBehaviorFlags |= D3DCREATE_SOFTWARE_VERTEXPROCESSING;

//
// Everything checks out - create a simple, windowed device.
//

D3DPRESENT_PARAMETERS d3dpp;
memset(&d3dpp, 0, sizeof(d3dpp));

d3dpp.BackBufferFormat       = d3ddm.Format;
d3dpp.SwapEffect             = D3DSWAPEFFECT_DISCARD;
d3dpp.Windowed               = TRUE;
d3dpp.EnableAutoDepthStencil = TRUE;
d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
d3dpp.PresentationInterval   = D3DPRESENT_INTERVAL_IMMEDIATE;

// Attempt to create a HAL device, end app on failure just to keep things
// simple.  In other words we are not trying to create a REF device if the
// HAL fails.
if( FAILED( hr = g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, g_hWnd,
                                  dwBehaviorFlags, &d3dpp, &g_pD3DDevice ) ) )
{
    // Should respond to failure of creating the hardware device.
    return hr;
}


// If we get here everything worked!
return S_OK;
}


//-----------------------------------------------------------------------------
// Name: RenderFrame()
// Desc: Draw the image to the framebuffer.
//-----------------------------------------------------------------------------
void RenderFrame( )
{
if (!g_pD3DDevice && !g_pD3DXSprite && !g_pTexture)
    return;


// Clear the frame & depth buffer ready for drawing (Black color)
g_pD3DDevice->Clear( 0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER,  0x00000000, 1.0f, 0 );

g_pD3DDevice->BeginScene();
{
    //-------------------------
    // Render the sprite
    //

    D3DXVECTOR3 vecPos = D3DXVECTOR3(0,0,0);

    if (g_pD3DXSprite && g_pTexture)
    {
        g_pD3DXSprite->Begin( D3DXSPRITE_ALPHABLEND );
        g_pD3DXSprite->Draw(g_pTexture, NULL, NULL, &vecPos, 0xffffffff);
        g_pD3DXSprite->End();
    }


}
g_pD3DDevice->EndScene();


// Frame buffer to Front buffer
g_pD3DDevice->Present( NULL, NULL, NULL, NULL );

}

Answer 1

This answer也是您问题的答案。您可以通过使用以下代码 ( #include <ctime> ) 在循环中输出当前时间来验证在拖动窗口时消息循环是否未运行:

// ---------
// Main Loop
// ---------
while( uMsg.message != WM_QUIT )
{
    std::time_t time = std::time(0);
    OutputDebugStringA(ctime(&time));
    // ... 

这里是答案:

There are a number of modal operations that happen on windows. Win32 Modal operations refer to functions that put an application into a "mode" by starting their own event processing loop until the mode finishes. Common application modes include drag and drop operations, move/size operations, anytime a dialog pops up that needs input before the application can continue.

So what is happening is: Your message loop is NOT being run. Your window recieved a WM_LBUTTONDOWN message that you passed to DefWindowProc. DefWindowProc determined that the user was trying to size or move the window interactively and entered a sizing/moving modal function. This function is in a message processing loop watching for mouse messages so that It can intercept them to provide the interactive sizing experience, and will only exit when the sizing operation completes - typically by the user releasing the held button, or by pressing escape.

You get notified of this - DefWindowProc sends a WM_ENTERSIZEMOVE and WM_EXITSIZEMOVE messages as it enters and exits the modal event processing loop.

To continue to generate "idle" messages, typically create a timer (SetTimer) before calling a modal function - or when getting a message that DefWindowProc is entering a modal function - the modal loop will continue to dispatch WM_TIMER messages... and call the idle proc from the timer message handler. Destroy the timer when the modal function returns.

原始答案:

我看到一些 DX 应用程序显示出这种行为，而另一些则没有。不仅仅是 Sprite ，从屏幕外拖出的整个矩形都是黑色的。这意味着这是一个窗口重绘问题。

尝试在 WindowProc 中拦截 WM_MOVING 并调用 RedrawWindow