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.bmp loader failing

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hey everyone. Please help me. I am trying to finish my .bmp bitmap loader class as part of my game engine, but it is giving me memory errors. For reading in data, I am using ''CreateFile'' and ''ReadFile''. I hope you are familiar with these two I/O functions. Anyway, here is my code: Header File: #ifndef _KwamiBitMapBMP_H #define _KwamiBitMapBMP_H #include #include #include #include class KwamiBitMapBMP { protected: struct KwamiBMP { BITMAPFILEHEADER bitmapfileheader; BITMAPINFOHEADER bitmapinfoheader; unsigned short *bitmaphold; }; HANDLE file; bool result; public: KwamiBitMapBMP(); void LoadBMP(HWND handle,apstring filename); void UnloadBMP(); unsigned short *bitmapholdtemp; KwamiBMP *bmap; unsigned long *bit; }; #endif Source File: #include "KwamiBitMapBMP.h" KwamiBitMapBMP::KwamiBitMapBMP() { bmap->bitmapfileheader.bfSize=0; bmap->bitmapfileheader.bfReserved1=0; bmap->bitmapfileheader.bfReserved2=0; bmap->bitmapfileheader.bfOffBits=0; bmap->bitmapfileheader.bfType=0x4D42; bmap->bitmapinfoheader.biSize=0; bmap->bitmapinfoheader.biWidth=0; bmap->bitmapinfoheader.biHeight=0; bmap->bitmapinfoheader.biPlanes=1; bmap->bitmapinfoheader.biBitCount=16; bmap->bitmapinfoheader.biCompression=BI_RGB; bmap->bitmapinfoheader.biSizeImage=0; bmap->bitmapinfoheader.biXPelsPerMeter=0; bmap->bitmapinfoheader.biYPelsPerMeter=0; bmap->bitmapinfoheader.biClrUsed=0; bmap->bitmapinfoheader.biClrImportant=0; bitmapholdtemp=NULL; bmap->bitmaphold=NULL; } void KwamiBitMapBMP::LoadBMP(HWND handle,apstring filename) { file=CreateFile(filename.c_str(),GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_READONLY,NULL); if(file==INVALID_HANDLE_VALUE) MessageBox(handle,"This file or path specified is invalid","KwamiBitMapBMP",MB_OK); else { result=ReadFile(file,&bmap->bitmapfileheader,sizeof(BITMAPFILEHEADER),bit,NULL); if(result==false) MessageBox(handle,"Unable to read file properly.","KwamiBitMapBMP",MB_OK); else { if(bmap->bitmapfileheader.bfType!=0x4D42) MessageBox(handle, "Requested file is not a .bmp file.","KwamiBitMapBMP",MB_OK); else { ReadFile(file,&bmap->bitmapinfoheader,sizeof(BITMAPINFOHEADER),bit,NULL); if(bmap->bitmapinfoheader.biBitCount==8) MessageBox(handle,"The KwamiEngine does not support 8bit bitmaps","KwamiBitMapBMP",MB_OK); else { UnloadBMP(); bmap->bitmaphold=(unsigned short*)malloc(bmap->bitmapinfoheader.biSizeImage); ReadFile(file,&bmap->bitmaphold,bmap->bitmapinfoheader.biSizeImage,bit,NULL); bitmapholdtemp=bmap->bitmaphold; } } } } } void KwamiBitMapBMP::UnloadBMP() { delete bmap->bitmaphold; delete bitmapholdtemp; bmap->bitmaphold=NULL; bitmapholdtemp=NULL; } ''unsigned long *bit'' is just a temporary pointer that I don''t use, but need for ReadFile().When I try to load in a bitmap in my client program, I get memory errors. I am not sure what I am doing wrong. Please help me. thanks a lot Edem Attiogbe

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The bitmap file format has always caused me trouble for some odd reason (both loading and saving). I recommend that you use FreeImage to load images, or D3DXCreateTextureFromFile or similar DirectX functions.

FreeImage is a free, easy to use image loading and saving library.

FreeImage

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This may not be exactly what you''re looking for, but it works. It''s out of MS IDX book. You may have seen it before:

BOOL Sprite::LoadImage( LPDIRECTDRAWSURFACE lpDDS, LPSTR szImage ){

HBITMAP hbm;
HDC hdcImage = NULL;
HDC hdcSurf = NULL;
BOOL bReturn = FALSE;
DDSURFACEDESC ddsd;

ZeroMemory( &ddsd, sizeof( ddsd ) );
ddsd.dwSize = sizeof( ddsd );

if ( FAILED( lpDDS->GetSurfaceDesc( &ddsd ) ) )
{
goto Exit;
}

// If the pixel format isn''t some flavor of RGB,
// we can''t handle it.
if ( ( ddsd.ddpfPixelFormat.dwFlags != DDPF_RGB ) ||
( ddsd.ddpfPixelFormat.dwRGBBitCount < 16 ) )

{
OutputDebugString( "Nonpalettized RGB mode required.\n" );
goto Exit;
}

// Try loading the image.
hbm = ( HBITMAP )::LoadImage( NULL, szImage,
IMAGE_BITMAP, ddsd.dwWidth,
ddsd.dwHeight, LR_LOADFROMFILE | LR_CREATEDIBSECTION);

if ( hbm == NULL )
{
OutputDebugString("Couldn''t find the resource.\n" );
goto Exit;
}

// Create a DC and select the image into it.
hdcImage = CreateCompatibleDC( NULL );
SelectObject( hdcImage, hbm );

// Get a DC for the surface.
if ( FAILED( lpDDS->GetDC( &hdcSurf ) ) )
{
OutputDebugString( "Couldn''t get a DC.\n");
goto Exit;
}

// The BitBlt will perform format conversion as necessary.
if ( BitBlt( hdcSurf, 0, 0, ddsd.dwWidth, ddsd.dwHeight,
hdcImage, 0, 0, SRCCOPY ) == FALSE )
{
OutputDebugString( "Blt failed.\n" );
goto Exit;
}
// Success.
bReturn = TRUE;

Exit:
// Clean up everything.
if ( hdcSurf )
lpDDS->ReleaseDC( hdcSurf );
if ( hdcImage )
DeleteDC( hdcImage );
if ( hbm )
DeleteObject( hbm );

return bReturn;
}
void App::ReleaseObjects( void )
{
sprite.Destroy();
if ( lpDD != NULL )
{
if ( lpDDSPrimary != NULL )
{
lpDDSPrimary->Release();
lpDDSPrimary = NULL;
}
lpDD->Release();
lpDD = NULL;
}

}

BOOL App::Fail( HWND hwnd, char *szMsg )
{
ReleaseObjects();
OutputDebugString( szMsg );
DestroyWindow( hwnd );
return FALSE;
}

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thanks for your help mutex and j_north. j_north, actually, I rather not use the LoadImage function. I rather write my own bitmap loader, but I know that is another alternative. mutex, I checked out that webpage, and it looks good. I just want to understand why my code isn''t working properly, so that I can learn from my mistakes. If you guys or anybody else can look at my code, that would be appriciated. once again, thanks for all your help.

Edem Attiogbe

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I figured it out. all I forgot to do was allocate memory for my KwamiBMP with the ''new'' keyword. thanks for your help mutex and j_north. I still have some other bugs to iron out though.

Edem Attiogbe

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