事情是这样的，本人在编译3D游戏编程大师技巧中的程序是遇到了一个关于位图读取函数int Load_Bitmap_File的lseek问题。
我使用以下位图读取函数读取位图事报错如下：
int Load_Bitmap_File(BITMAP_FILE_PTR bitmap, char *filename)
{
// this function opens a bitmap file and loads the data into bitmap int file_handle, // the file handle
index; // looping index UCHAR *temp_buffer = NULL; // used to convert 24 bit images to 16 bit
OFSTRUCT file_data; // the file data information // open the file if it exists
if ((file_handle = OpenFile(filename,&file_data,OF_READ))==-)
return(); // now load the bitmap file header
_lread(file_handle, &bitmap->bitmapfileheader,sizeof(BITMAPFILEHEADER)); // test if this is a bitmap file
if (bitmap->bitmapfileheader.bfType!=BITMAP_ID)
{
// close the file
_lclose(file_handle); // return error
return();
} // end if // now we know this is a bitmap, so read in all the sections // first the bitmap infoheader // now load the bitmap file header
_lread(file_handle, &bitmap->bitmapinfoheader,sizeof(BITMAPINFOHEADER)); // now load the color palette if there is one
if (bitmap->bitmapinfoheader.biBitCount == )
{
_lread(file_handle, &bitmap->palette,MAX_COLORS_PALETTE*sizeof(PALETTEENTRY)); // now set all the flags in the palette correctly and fix the reversed
// BGR RGBQUAD data format
for (index=; index < MAX_COLORS_PALETTE; index++)
{
// reverse the red and green fields
int temp_color = bitmap->palette[index].peRed;
bitmap->palette[index].peRed = bitmap->palette[index].peBlue;
bitmap->palette[index].peBlue = temp_color; // always set the flags word to this
bitmap->palette[index].peFlags = PC_NOCOLLAPSE;
} // end for index } // end if // finally the image data itself
_lseek(file_handle,-(int)(bitmap->bitmapinfoheader.biSizeImage),SEEK_END); // now read in the image
if (bitmap->bitmapinfoheader.biBitCount== || bitmap->bitmapinfoheader.biBitCount==)
{
// delete the last image if there was one
if (bitmap->buffer)
free(bitmap->buffer); // allocate the memory for the image
if (!(bitmap->buffer = (UCHAR *)malloc(bitmap->bitmapinfoheader.biSizeImage)))
{
// close the file
_lclose(file_handle); // return error
return();
} // end if // now read it in
_lread(file_handle,bitmap->buffer,bitmap->bitmapinfoheader.biSizeImage); } // end if
else
if (bitmap->bitmapinfoheader.biBitCount==)
{
// allocate temporary buffer to load 24 bit image
if (!(temp_buffer = (UCHAR *)malloc(bitmap->bitmapinfoheader.biSizeImage)))
{
// close the file
_lclose(file_handle); // return error
return();
} // end if // allocate final 16 bit storage buffer
if (!(bitmap->buffer=(UCHAR *)malloc(*bitmap->bitmapinfoheader.biWidth*bitmap->bitmapinfoheader.biHeight)))
{
// close the file
_lclose(file_handle); // release working buffer
free(temp_buffer); // return error
return();
} // end if // now read the file in
_lread(file_handle,temp_buffer,bitmap->bitmapinfoheader.biSizeImage); // now convert each 24 bit RGB value into a 16 bit value
for (index=; index < bitmap->bitmapinfoheader.biWidth*bitmap->bitmapinfoheader.biHeight; index++)
{
// build up 16 bit color word
USHORT color; // build pixel based on format of directdraw surface
if (dd_pixel_format==DD_PIXEL_FORMAT555)
{
// extract RGB components (in BGR order), note the scaling
UCHAR blue = (temp_buffer[index* + ] >> ),
green = (temp_buffer[index* + ] >> ),
red = (temp_buffer[index* + ] >> );
// use the 555 macro
color = _RGB16BIT555(red,green,blue);
} // end if 555
else
if (dd_pixel_format==DD_PIXEL_FORMAT565)
{
// extract RGB components (in BGR order), note the scaling
UCHAR blue = (temp_buffer[index* + ] >> ),
green = (temp_buffer[index* + ] >> ),
red = (temp_buffer[index* + ] >> ); // use the 565 macro
color = _RGB16BIT565(red,green,blue); } // end if 565 // write color to buffer
((USHORT *)bitmap->buffer)[index] = color; } // end for index // finally write out the correct number of bits
bitmap->bitmapinfoheader.biBitCount=; // release working buffer
free(temp_buffer); } // end if 24 bit
else
{
// serious problem
return(); } // end else #if 0
// write the file info out
printf("\nfilename:%s \nsize=%d \nwidth=%d \nheight=%d \nbitsperpixel=%d \ncolors=%d \nimpcolors=%d",
filename,
bitmap->bitmapinfoheader.biSizeImage,
bitmap->bitmapinfoheader.biWidth,
bitmap->bitmapinfoheader.biHeight,
bitmap->bitmapinfoheader.biBitCount,
bitmap->bitmapinfoheader.biClrUsed,
bitmap->bitmapinfoheader.biClrImportant);
#endif // close the file
_lclose(file_handle); // flip the bitmap
Flip_Bitmap(bitmap->buffer,
bitmap->bitmapinfoheader.biWidth*(bitmap->bitmapinfoheader.biBitCount/),
bitmap->bitmapinfoheader.biHeight); // return success
return(); } // end Load_Bitmap_File
编译运行会产生以下问题
查lseek函数介绍也没有发现问题。
http://c.biancheng.net/cpp/html/236.html
然后就查找_lseek()函数在新版本有什么变化。没有查到
http://www.educity.cn/wenda/493024.html
去google搜索到许多人遇到问题，但是没有解决办法。
http://www.debugease.com/vc/2006166.html
还搜到一个人说是因为OS是vista也没说具体解决办法。
https://social.msdn.microsoft.com/Forums/vstudio/en-US/2dde18b1-fe36-4679-8ed2-ee61beee4af3/moves-a-file-pointer-to-the-specified-location?forum=vsdebug
最终在百度知道找到一个答案，就说了一句话把lseek（）函数注释掉。。我开始怎么没想到。
解决办法：将
_lseek(file_handle,-(int)(bitmap->bitmapinfoheader.biSizeImage),SEEK_END); 注释掉，我也不知道会产生什么影响，但是错误解决了。暂时先这样解决吧