PDIB DibOpenFile(LPSTR szFile)
{
HFILE fh;
DWORD dwLen;
DWORD dwBits;
PDIB pdib;
LPVOID p;
long i, width, height;
BYTE *row1, *row2, *temp, *bits;
fh = open(szFile, O_BINARY | O_RDONLY);
if (fh == -1)
return NULL;
pdib = DibReadBitmapInfo(fh);
if (!pdib)
return NULL;
/* How much memory do we need to hold the DIB */
dwBits = DibWidthBytes(pdib) * pdib->biHeight;
dwLen = pdib->biSize + DibPaletteSize(pdib) + dwBits;
/* Can we get more memory? */
p = realloc(pdib,dwLen);
if (!p)
{
free(pdib);
pdib = NULL;
}
else
{
pdib = (PDIB)p;
}
if (pdib)
{
/* read in the bits */
bits = (LPBYTE) pdib + (UINT)pdib->biSize + DibPaletteSize(pdib);
read(fh, bits, dwBits);
/* Flip the bits to make bitmap top-down */
width = DibWidthBytes(pdib);
height = DibHeight(pdib);
temp = (BYTE *) malloc(width);
for (i=0; i < height / 2; i++)
{
row1 = bits + (height - i - 1) * width;
row2 = bits + i * width;
memcpy(temp, row1, (size_t) width);
memcpy(row1, row2, (size_t) width);
memcpy(row2, temp, (size_t) width);
}
free(temp);
}
close(fh);
return pdib;
}
bool CxImageBMP::Decode(CxFile * hFile)
{
if (hFile == NULL) return false;
BITMAPFILEHEADER bf;
DWORD off = hFile->Tell(); //<CSC>
try {
if (hFile->Read(&bf,min(14,sizeof(bf)),1)==0) throw "Not a BMP";
if (bf.bfType != BFT_BITMAP) { //do we have a RC HEADER?
bf.bfOffBits = 0L;
hFile->Seek(off,SEEK_SET);
}
if (!DibReadBitmapInfo(hFile,&head)) throw "Error reading BMP info";
DWORD dwCompression=head.biCompression;
DWORD dwBitCount=head.biBitCount; //preserve for BI_BITFIELDS compression <Thomas Ernst>
bool bIsOldBmp = head.biSize == sizeof(BITMAPCOREHEADER);
head.biSize = sizeof(BITMAPINFOHEADER);
bool bTopDownDib = head.biHeight<0; //<Flanders> check if it's a top-down bitmap
if (bTopDownDib) head.biHeight=-head.biHeight;
if (!Create(head.biWidth,head.biHeight,head.biBitCount,CXIMAGE_FORMAT_BMP))
throw "Can't allocate memory";
info.xDPI = (long) floor(head.biXPelsPerMeter * 254.0 / 10000.0 + 0.5);
info.yDPI = (long) floor(head.biYPelsPerMeter * 254.0 / 10000.0 + 0.5);
if (info.nEscape) throw "Cancelled"; // <vho> - cancel decoding
RGBQUAD *pRgb = GetPalette();
if (pRgb){
if (bIsOldBmp){
// convert a old color table (3 byte entries) to a new
// color table (4 byte entries)
hFile->Read((void*)pRgb,DibNumColors(&head) * sizeof(RGBTRIPLE),1);
for (int i=DibNumColors(&head)-1; i>=0; i--){
pRgb[i].rgbRed = ((RGBTRIPLE *)pRgb)[i].rgbtRed;
pRgb[i].rgbBlue = ((RGBTRIPLE *)pRgb)[i].rgbtBlue;
pRgb[i].rgbGreen = ((RGBTRIPLE *)pRgb)[i].rgbtGreen;
pRgb[i].rgbReserved = (BYTE)0;
}
} else {
hFile->Read((void*)pRgb,DibNumColors(&head) * sizeof(RGBQUAD),1);
//force rgbReserved=0, to avoid problems with some WinXp bitmaps
for (unsigned int i=0; i<head.biClrUsed; i++) pRgb[i].rgbReserved=0;
}
}
if (info.nEscape) throw "Cancelled"; // <vho> - cancel decoding
switch (dwBitCount) {
case 32 :
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
if (dwCompression == BI_BITFIELDS || dwCompression == BI_RGB){
long imagesize=4*head.biHeight*head.biWidth;
BYTE* buff32=(BYTE*)malloc(imagesize);
if (buff32){
hFile->Read(buff32, imagesize,1); // read in the pixels
Bitfield2RGB(buff32,0,0,0,32);
free(buff32);
} else throw "can't allocate memory";
} else throw "unknown compression";
break;
case 24 :
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
if (dwCompression == BI_RGB){
hFile->Read(info.pImage, head.biSizeImage,1); // read in the pixels
} else throw "unknown compression";
break;
case 16 :
{
DWORD bfmask[3];
if (dwCompression == BI_BITFIELDS)
{
hFile->Read(bfmask, 12, 1);
} else {
bfmask[0]=0x7C00; bfmask[1]=0x3E0; bfmask[2]=0x1F; //RGB555
}
// bf.bfOffBits required after the bitfield mask <Cui Ying Jie>
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
// read in the pixels
hFile->Read(info.pImage, head.biHeight*((head.biWidth+1)/2)*4,1);
// transform into RGB
Bitfield2RGB(info.pImage,(WORD)bfmask[0],(WORD)bfmask[1],(WORD)bfmask[2],16);
break;
}
case 8 :
case 4 :
case 1 :
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
switch (dwCompression) {
case BI_RGB :
hFile->Read(info.pImage, head.biSizeImage,1); // read in the pixels
break;
case BI_RLE4 :
{
BYTE status_byte = 0;
BYTE second_byte = 0;
int scanline = 0;
int bits = 0;
BOOL low_nibble = FALSE;
CImageIterator iter(this);
for (BOOL bContinue = TRUE; bContinue;) {
hFile->Read(&status_byte, sizeof(BYTE), 1);
switch (status_byte) {
case RLE_COMMAND :
hFile->Read(&status_byte, sizeof(BYTE), 1);
switch (status_byte) {
case RLE_ENDOFLINE :
bits = 0;
scanline++;
low_nibble = FALSE;
break;
case RLE_ENDOFBITMAP :
bContinue=FALSE;
break;
case RLE_DELTA :
{
// read the delta values
BYTE delta_x;
BYTE delta_y;
hFile->Read(&delta_x, sizeof(BYTE), 1);
hFile->Read(&delta_y, sizeof(BYTE), 1);
// apply them
bits += delta_x / 2;
scanline += delta_y;
break;
}
default :
hFile->Read(&second_byte, sizeof(BYTE), 1);
BYTE *sline = iter.GetRow(scanline);
for (int i = 0; i < status_byte; i++) {
if (low_nibble) {
if ((DWORD)(sline+bits) < (DWORD)(info.pImage+head.biSizeImage)){
*(sline + bits) |= second_byte & 0x0F;
}
if (i != status_byte - 1)
hFile->Read(&second_byte, sizeof(BYTE), 1);
bits++;
} else {
if ((DWORD)(sline+bits) < (DWORD)(info.pImage+head.biSizeImage)){
*(sline + bits) = (BYTE)(second_byte & 0xF0);
}
}
low_nibble = !low_nibble;
}
if (((status_byte / 2) & 1 )== 1)
hFile->Read(&second_byte, sizeof(BYTE), 1);
break;
};
break;
default :
{
BYTE *sline = iter.GetRow(scanline);
hFile->Read(&second_byte, sizeof(BYTE), 1);
for (unsigned i = 0; i < status_byte; i++) {
if (low_nibble) {
if ((DWORD)(sline+bits) < (DWORD)(info.pImage+head.biSizeImage)){
*(sline + bits) |= second_byte & 0x0F;
}
bits++;
} else {
if ((DWORD)(sline+bits) < (DWORD)(info.pImage+head.biSizeImage)){
*(sline + bits) = (BYTE)(second_byte & 0xF0);
}
}
low_nibble = !low_nibble;
}
}
break;
};
}
break;
}
case BI_RLE8 :
{
BYTE status_byte = 0;
BYTE second_byte = 0;
int scanline = 0;
int bits = 0;
CImageIterator iter(this);
for (BOOL bContinue = TRUE; bContinue; ) {
hFile->Read(&status_byte, sizeof(BYTE), 1);
switch (status_byte) {
case RLE_COMMAND :
hFile->Read(&status_byte, sizeof(BYTE), 1);
switch (status_byte) {
case RLE_ENDOFLINE :
bits = 0;
scanline++;
break;
case RLE_ENDOFBITMAP :
bContinue=FALSE;
break;
case RLE_DELTA :
{
// read the delta values
BYTE delta_x;
BYTE delta_y;
hFile->Read(&delta_x, sizeof(BYTE), 1);
hFile->Read(&delta_y, sizeof(BYTE), 1);
// apply them
bits += delta_x;
scanline += delta_y;
break;
}
default :
hFile->Read((void *)(iter.GetRow(scanline) + bits), sizeof(BYTE) * status_byte, 1);
// align run length to even number of bytes
if ((status_byte & 1) == 1)
hFile->Read(&second_byte, sizeof(BYTE), 1);
bits += status_byte;
break;
};
break;
default :
BYTE *sline = iter.GetRow(scanline);
hFile->Read(&second_byte, sizeof(BYTE), 1);
for (unsigned i = 0; i < status_byte; i++) {
*(sline + bits) = second_byte;
bits++;
}
break;
};
}
break;
}
default :
throw "compression type not supported";
}
}
if (bTopDownDib) Flip(); //<Flanders>
} catch (char *message) {
strncpy(info.szLastError,message,255);
return false;
}
return true;
}
