直接控制24位位图的象素(E)[2]

	delete m_pdib;

file: cdib.h -- cdib class header file

// cdib.h declaration for inside visual c++ cdib class

#ifndef _inside_visual_cpp_cdib
#define _inside_visual_cpp_cdib

class cdib : public cobject
{
	enum alloc {noalloc, crtalloc, heapalloc};
	declare_serial(cdib)
public:
	lpvoid m_lpvcolortable;
	hbitmap m_hbitmap;
	lpbyte m_lpimage;  // starting address of dib bits
	lpbitmapinfoheader m_lpbmih; //  buffer containing the bitmapinfoheader
private:
	hglobal m_hglobal; // for external windows we need to free;
	                   //  could be allocated by this class or allocated externally
	alloc m_nbmihalloc;
	alloc m_nimagealloc;
	dword m_dwsizeimage; // of bits -- not bitmapinfoheader or bitmapfileheader
	int m_ncolortableentries;
	
	handle m_hfile;
	handle m_hmap;
	lpvoid m_lpvfile;
	hpalette m_hpalette;
public:
	cdib();
	cdib(csize size, int nbitcount);	// builds bitmapinfoheader
	~cdib();
	int getsizeimage() {return m_dwsizeimage;}
	int getsizeheader()
		{return sizeof(bitmapinfoheader) + sizeof(rgbquad) * m_ncolortableentries;}
	csize getdimensions();
	bool attachmapfile(const char* strpathname, bool bshare = false);
	bool copytomapfile(const char* strpathname);
	bool attachmemory(lpvoid lpvmem, bool bmustdelete = false, hglobal hglobal = null);
	bool draw(cdc* pdc, cpoint origin, csize size);  // until we implemnt createdibsection
	hbitmap createsection(cdc* pdc = null);
	uint usepalette(cdc* pdc, bool bbackground = false);
	bool makepalette();
	bool setsystempalette(cdc* pdc);
	bool compress(cdc* pdc, bool bcompress = true); // false means decompress
	hbitmap createbitmap(cdc* pdc);
	bool read(cfile* pfile);
	bool readsection(cfile* pfile, cdc* pdc = null);
	bool write(cfile* pfile);
	void serialize(carchive& ar);
	void empty();
private:
	void detachmapfile();
	void computepalettesize(int nbitcount);
	void computemetrics();
};
#endif // _inside_visual_cpp_cdib

file: cdib.cpp -- cdib class definitions

// cdib.cpp
// new version for win32
#include "stdafx.h"
#include "cdib.h"

#ifdef _debug
#define new debug_new
#undef this_file
static char this_file[] = __file__;
#endif

implement_serial(cdib, cobject, 0);

cdib::cdib()
{
	m_hfile = null;
	m_hbitmap = null;
	m_hpalette = null;
	m_nbmihalloc = m_nimagealloc = noalloc;
	empty();
}

cdib::cdib(csize size, int nbitcount)
{
	m_hfile = null;
	m_hbitmap = null;
	m_hpalette = null;
	m_nbmihalloc = m_nimagealloc = noalloc;
	empty();
	computepalettesize(nbitcount);
	m_lpbmih = (lpbitmapinfoheader) new 
		char[sizeof(bitmapinfoheader) + sizeof(rgbquad) * m_ncolortableentries];
	m_nbmihalloc = crtalloc;
	m_lpbmih->bisize = sizeof(bitmapinfoheader);
	m_lpbmih->biwidth = size.cx;
	m_lpbmih->biheight = size.cy;
	m_lpbmih->biplanes = 1;
	m_lpbmih->bibitcount = nbitcount;
	m_lpbmih->bicompression = bi_rgb;
	m_lpbmih->bisizeimage = 0;
	m_lpbmih->bixpelspermeter = 0;
	m_lpbmih->biypelspermeter = 0;
	m_lpbmih->biclrused = m_ncolortableentries;
	m_lpbmih->biclrimportant = m_ncolortableentries;
	computemetrics();
	memset(m_lpvcolortable, 0, sizeof(rgbquad) * m_ncolortableentries);
	m_lpimage = null;  // no data yet
}

cdib::~cdib()
{
	empty();
}

csize cdib::getdimensions()
{	
	if(m_lpbmih == null) return csize(0, 0);
	return csize((int) m_lpbmih->biwidth, (int) m_lpbmih->biheight);
}

bool cdib::attachmapfile(const char* strpathname, bool bshare) // for reading
{
	// if we open the same file twice, windows treats it as 2 separate files
	// doesn't work with rare bmp files where # palette entries > biclrused
	handle hfile = ::createfile(strpathname, generic_write | generic_read,
		bshare ? file_share_read : 0,
		null, open_existing, file_attribute_normal, null);
	assert(hfile != invalid_handle_value);
	dword dwfilesize = ::getfilesize(hfile, null);
	handle hmap = ::createfilemapping(hfile, null, page_readwrite, 0, 0, null);
	dword dwerr = ::getlasterror();
	if(hmap == null) {
		afxmessagebox("empty bitmap file");
		return false;
	}
	lpvoid lpvfile = ::mapviewoffile(hmap, file_map_write, 0, 0, 0); // map whole file
	assert(lpvfile != null);
	if(((lpbitmapfileheader) lpvfile)->bftype != 0x4d42) {
		afxmessagebox("invalid bitmap file");
		detachmapfile();
		return false;
	}
	attachmemory((lpbyte) lpvfile + sizeof(bitmapfileheader));
	m_lpvfile = lpvfile;
	m_hfile = hfile;
	m_hmap = hmap;
	return true;
}

bool cdib::copytomapfile(const char* strpathname)
{
	// copies dib to a new file, releases prior pointers
	// if you previously used createsection, the hbitmap will be null (and unusable)
	bitmapfileheader bmfh;
	bmfh.bftype = 0x4d42;  // 'bm'
	bmfh.bfsize = m_dwsizeimage + sizeof(bitmapinfoheader) +
			sizeof(rgbquad) *