#include<windows.h>
#include"CreateDIBfromFile248.h"

int CreateDIBfromFile248(char *lpFileName,LPVOID *lppPixel,LPBITMAPINFO *lppBmpInfo,CDF type)
{
	HANDLE fh;
	DWORD dwFileSize,dwReadSize;
	LPBYTE lpbuf;

	LPBITMAPFILEHEADER lpbmpfh;
	LPBITMAPINFO lpbmpInfo;

	LPBYTE lpbmpPixel;
	LPRGBQUAD lpColorTable;
	int bitCount,nColorTable,iWidth,iHeight,iLenSrc,iLenDst,x,y;

	fh=CreateFile(lpFileName,GENERIC_READ,0,NULL,
		OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
	if(fh==INVALID_HANDLE_VALUE){
		MessageBox(NULL,"ファイルが開けません",lpFileName,MB_OK);
		return -1;
	}
	dwFileSize=GetFileSize(fh,NULL);
	lpbuf=(LPBYTE)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,dwFileSize);
	ReadFile(fh,lpbuf,dwFileSize,&dwReadSize,NULL);
	CloseHandle(fh);

	lpbmpfh=(LPBITMAPFILEHEADER)lpbuf;
	lpbmpInfo=(LPBITMAPINFO)(lpbuf+sizeof(BITMAPFILEHEADER));
	bitCount=lpbmpInfo->bmiHeader.biBitCount;
	if(lpbmpfh->bfType!=('M'<<8)+'B' || (bitCount!=24 && bitCount!=8)){
		HeapFree(GetProcessHeap(),0,lpbuf);
   		MessageBox(NULL,"24 or 8 ビットBMPファイルしか読み込めません",lpFileName,MB_OK);
		return -2;
	}

	lpbmpPixel=lpbuf + lpbmpfh->bfOffBits;
	iWidth=lpbmpInfo->bmiHeader.biWidth;
	iHeight=lpbmpInfo->bmiHeader.biHeight;

	if(type==CT && bitCount!=8) type=BY;
	else if(type==DEF){
		if(bitCount==24) type=BY;
		else if(bitCount==8) type=CT;
	}

	if(iWidth*(bitCount/8)%4) iLenSrc=iWidth*(bitCount/8)+(4-iWidth*(bitCount/8)%4);
	else iLenSrc=iWidth*(bitCount/8);
	if(iWidth*(type/8)%4) iLenDst=iWidth*(type/8)+(4-iWidth*(type/8)%4);
	else iLenDst=iWidth*(type/8);

	*lppPixel=HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,iLenDst*iHeight);
	if(type==CT) *lppBmpInfo=(LPBITMAPINFO)HeapAlloc(GetProcessHeap(),
		HEAP_ZERO_MEMORY,sizeof(BITMAPINFO)+255*4);
	else *lppBmpInfo=(LPBITMAPINFO)HeapAlloc(GetProcessHeap(),
		HEAP_ZERO_MEMORY,sizeof(BITMAPINFO));

	switch(bitCount){
		case 24:
			for(y=0;y<iHeight;y++) 				for(x=0;x<iWidth;x++) 					CopyMemory(*(LPBYTE*)lppPixel+x*(type/8)+y*iLenDst, 						lpbmpPixel+x*3+y*iLenSrc,3); 			break; 		case 8: 			nColorTable=lpbmpInfo->bmiHeader.biClrUsed;
			if(nColorTable==0) nColorTable=256;
			lpColorTable=lpbmpInfo->bmiColors;
			switch(type){
				case DW: case BY:
					for(y=0;y<iHeight;y++) 						for(x=0;x<iWidth;x++) 							CopyMemory(*(LPBYTE*)lppPixel+x*(type/8)+y*iLenDst, 								lpColorTable+lpbmpPixel[x+y*iLenSrc],3); 					break; 				case CT: 					for(y=0;y<iHeight;y++) 						for(x=0;x<iWidth;x++) 							(*(LPBYTE*)lppPixel)[x+y*iLenDst]=lpbmpPixel[x+y*iLenSrc]; 					for(x=0;x<nColorTable;x++) 						(*lppBmpInfo)->bmiColors[x]=lpColorTable[x];
					break;
			}
			break;
	}
	CopyMemory(*lppBmpInfo,&lpbmpInfo->bmiHeader,sizeof(BITMAPINFOHEADER));
	(*lppBmpInfo)->bmiHeader.biBitCount=type;

	HeapFree(GetProcessHeap(),0,lpbuf);
	return iLenDst;
}

void DeleteDIB(LPVOID *lppPixel,LPBITMAPINFO *lppBmpInfo)
{
	if(*lppPixel!=NULL){
		HeapFree(GetProcessHeap(),0,*lppPixel);
		*lppPixel=NULL;
	}
	if(*lppBmpInfo!=NULL){
		HeapFree(GetProcessHeap(),0,*lppBmpInfo);
		*lppBmpInfo=NULL;
	}
}