gusucode.com > VC++ 图片浏览器的设计与实现+设计文档源码程序 > VC++ 图片浏览器的设计与实现+设计文档源码程序/code/PictView/Lib/Gif.cpp
//Download by http://www.NewXing.com
// Gif.cpp: implementation of the CGif class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include <io.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include "Gif.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////////////////////////////////
// Global variables
//
GIF89 Gif89 = {-1,-1,-1,0};
GIFSCREEN GifScreen;
static unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F,
0x001F, 0x003F, 0x007F, 0x00FF,
0x01FF, 0x03FF, 0x07FF, 0x0FFF,
0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CGif::CGif()
{
ZeroDataBlock = FALSE;
m_strGIFError = "No Error"; // yet
m_pDib = NULL;
cur_accum = 0;
cur_bits = 0;
maxbits = BITS;
maxmaxcode = (code_int)1 << BITS;
free_ent = 0;
clear_flg = 0;
m_pDib = NULL;
}
CGif::CGif(CDib *pDib)
{
ZeroDataBlock = FALSE;
m_strGIFError = "No Error"; // yet
m_pDib = NULL;
cur_accum = 0;
cur_bits = 0;
maxbits = BITS;
maxmaxcode = (code_int)1 << BITS;
free_ent = 0;
clear_flg = 0;
m_pDib = NULL;
SetDib(pDib);
}
CGif::~CGif()
{
if (m_pDib != NULL)
delete m_pDib;
}
// free allocate memory
void CGif::FreeBuffer(BYTE *Buffer)
{
delete[] Buffer;
}
// get error string
CString CGif::GetErrorString()
{
return m_strGIFError;
}
// load gif file
BOOL CGif::Load(LPCTSTR lpstrFileName)
{
UINT uWidth, uHeight, uWidthDW;
// read the GIF to a packed buffer of RGB bytes
BYTE *lpTmpBuffer = ReadGIFFile(lpstrFileName, &uWidth, &uHeight);
if (lpTmpBuffer == NULL)
return FALSE;
// do this before DWORD-alignment!!!
// swap red and blue for display
BGRFromRGB(lpTmpBuffer, uWidth, uHeight);
// now DWORD-align for display
BYTE *lpBuffer = MakeDwordAlign(lpTmpBuffer, uWidth, uHeight, &uWidthDW);
FreeBuffer(lpTmpBuffer);
// flip for display
VertFlipBuf(lpBuffer, uWidthDW, uHeight);
BITMAPINFOHEADER bmiHeader;
bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmiHeader.biWidth = uWidth;
bmiHeader.biHeight = uHeight;
bmiHeader.biPlanes = 1;
bmiHeader.biBitCount = 24;
bmiHeader.biCompression = BI_RGB;
bmiHeader.biSizeImage = 0;
bmiHeader.biXPelsPerMeter = 0;
bmiHeader.biYPelsPerMeter = 0;
bmiHeader.biClrUsed = 0;
bmiHeader.biClrImportant = 0;
// Allocate enough memory for the new CF_DIB, and copy bits
DWORD dwHeaderSize = sizeof(BITMAPINFOHEADER);
DWORD dwBitsSize = WIDTHBYTES(uWidth*24) * uHeight;
HDIB hDIB = GlobalAlloc(GHND, dwHeaderSize + dwBitsSize);
if (hDIB == NULL)
return FALSE;
LPBYTE lpDIB = (LPBYTE)GlobalLock(hDIB);
memcpy(lpDIB, (LPBYTE)&bmiHeader, dwHeaderSize);
memcpy(FindDIBBits((LPBYTE)lpDIB), lpBuffer, dwBitsSize);
FreeBuffer(lpBuffer);
if (m_pDib != NULL)
delete m_pDib;
m_pDib = new CDib();
m_pDib->Attach(hDIB);
return TRUE;
}
// save gif file
BOOL CGif::Save(LPCTSTR lpstrFileName, CDib* pDib)
{
if (pDib == NULL)
pDib = m_pDib;
if (pDib == NULL)
return FALSE;
HDIB hDib = CopyHandle(pDib->GetHandle());
if (hDib == NULL)
return FALSE;
CDib* pDibTmp = new CDib;
pDibTmp->Attach(hDib);
//if (pDibTmp->GetBitCount() != 24)
// pDibTmp->ConvertFormat(24);
UINT uWidth = pDibTmp->GetWidth();
UINT uHeight = pDibTmp->GetHeight();
// convert to 8-bit image
if (pDibTmp->GetBitCount() != 8)
pDibTmp->ColorQuantize(8);
// get 256 color r, g, b
PALETTEENTRY PaletteColors[256];
pDibTmp->GetPalette()->GetPaletteEntries(0, 256, PaletteColors);
int red[256], blue[256], green[256];
for (int i=0;i<256;i++)
{
red[i] = PaletteColors[i].peRed;
green[i] = PaletteColors[i].peGreen;
blue[i] = PaletteColors[i].peBlue;
}
// convert from DIB format (DWORD aligned, vertically flipped, red and blue swapped)
BYTE *tmp = ClearDwordAlign(pDibTmp->GetBitsPtr(), uWidth, uHeight, 8);
if (tmp == NULL)
return FALSE;
// convert from DIB
VertFlipBuf(tmp, uWidth, uHeight);
BOOL bSuccess = WriteGIFFile(lpstrFileName,
tmp, uWidth, uHeight,
0, // background color
red, green, blue);
delete pDibTmp;
FreeBuffer(tmp);
return bSuccess;
}
LPBYTE CGif::ReadGIFFile(LPCTSTR lpstrFileName, UINT *uWidth, UINT *uHeight)
{
BYTE buf[16];
BYTE c;
BYTE localColorMap[3][MAXCOLORMAPSIZE];
int useGlobalColormap;
int bitPixel;
int imageCount =0;
char version[4];
FILE *fd;
int w=0;
int h=0;
CString strFileName = lpstrFileName;
if (strFileName.IsEmpty())
{
m_strGIFError="No Name Given";
return NULL;
}
BYTE *bigBuf;
fd=fopen(lpstrFileName,"rb");
if (fd==NULL)
{
m_strGIFError="Cant open GIF :\n" + strFileName;
return NULL;
}
// read GIF file header
if (!ReadOK(fd,buf,6))
{
m_strGIFError="Error reading GIF Magic #\n"+strFileName;
fclose(fd);
return NULL;
}
// need the string "GIF" in the header
if (strncmp((char *)buf,"GIF",3)!=0)
{
m_strGIFError="Error, "+strFileName+" is not a valid .GIF file";
fclose(fd);
return NULL;
}
strncpy(version,(char *)(buf+3),3);
version[3]='\0';
// only handle v 87a and 89a
if ((strcmp(version,"87a")!=0)&&(strcmp(version,"89a")!=0))
{
m_strGIFError="Error, Bad GIF Version number";
fclose(fd);
return NULL;
}
// screen description
if (!ReadOK(fd,buf,7))
{
m_strGIFError="Error, failed to GIF read screen descriptor.\nGiving up";
fclose(fd);
return NULL;
}
GifScreen.Width = LM_to_uint((BYTE)buf[0],(BYTE)buf[1]);
GifScreen.Height = LM_to_uint((BYTE)buf[2],(BYTE)buf[3]);
GifScreen.BitPixel = 2 << ((BYTE)buf[4] & 0x07);
GifScreen.ColorResolution = ((((BYTE)buf[4] & 0x70) >> 3) + 1);
GifScreen.BackGround= (BYTE)buf[5]; // background color...
GifScreen.AspectRatio= (BYTE)buf[6];
// read colormaps
if (BitSet((BYTE)buf[4],LOCALCOLORMAP))
{
if (!ReadColorMap(fd,GifScreen.BitPixel,GifScreen.ColorMap))
{
m_strGIFError="Error reading GIF colormap";
fclose(fd);
return NULL;
}
}
// non-square pixels, so what?
if ((GifScreen.AspectRatio!=0 ) && (GifScreen.AspectRatio!=49))
{
m_strGIFError="Non-square pixels in GIF image.\nIgnoring that fact...";
}
// there can be multiple images in a GIF file... uh?
// what the hell do we do with multiple images?
// so, we'll be interested in just the first image, cause we're lazy
for(;;)
{
// read a byte;
if (!ReadOK(fd,&c,1))
{
m_strGIFError="Unexpected EOF in GIF.\nGiving up";
fclose(fd);
return NULL;
}
// image terminator
if (c==';')
{
}
if (c=='!')
{
if (!ReadOK(fd,&c,1))
{
m_strGIFError="Error on extension read.\nGiving up";
fclose(fd);
return NULL;
}
DoExtension(fd,c);
continue;
}
if (c!=',')
{
// Ignoring c
continue;
}
// read image header
if (!ReadOK(fd,buf,9))
{
m_strGIFError="Error on dimension read\nGiving up";
fclose(fd);
return NULL;
}
useGlobalColormap=!BitSet((BYTE)buf[8],LOCALCOLORMAP);
bitPixel=1<<(((BYTE)buf[8]&0x07)+1);
// let's see if we have enough mem to continue?
long bufsize;
if ((int)buf[5]>4)
{
//AfxMessageBox("This GIF file claims to be > 2000 bytes wide!",MB_OK | MB_ICONINFORMATION);
}
if ((int)buf[7]>4)
{
//AfxMessageBox("This GIF file claims to be > 2000 bytes high!",MB_OK | MB_ICONINFORMATION);
}
w=LM_to_uint((BYTE)buf[4],(BYTE)buf[5]);
h=LM_to_uint((BYTE)buf[6],(BYTE)buf[7]);
if ((w<0) || (h<0))
{
m_strGIFError="Negative image dimensions!\nGiving up";
fclose(fd);
return NULL;
}
bufsize=(long)w*(long)h;
bufsize*=3;
bigBuf= (BYTE *) new char [bufsize];
if (bigBuf==NULL)
{
m_strGIFError="Out of Memory in GIFRead";
fclose(fd);
return NULL;
}
if (!useGlobalColormap)
{
if (!ReadColorMap(fd,bitPixel,localColorMap))
{
m_strGIFError="Error reading GIF colormap\nGiving up";
delete [] bigBuf;
fclose(fd);
return NULL;
}
//read image
if (!ReadImage(fd, bigBuf, w, h, localColorMap, BitSet((BYTE)buf[8],INTERLACE)))
{
m_strGIFError="Error reading GIF file\nLocalColorMap\nGiving up";
delete [] bigBuf;
fclose(fd);
return NULL;
}
}
else
{
if (!ReadImage(fd, bigBuf, w, h, GifScreen.ColorMap, BitSet((BYTE)buf[8],INTERLACE)))
{
m_strGIFError="Error reading GIF file\nGIFScreen Colormap\nGiving up";
delete [] bigBuf;
fclose(fd);
return NULL;
}
}
break;
}
*uWidth=w;
*uHeight=h;
fclose(fd);
return bigBuf;
}
int CGif::ReadColorMap(FILE *fd, int number, BYTE buffer[3][MAXCOLORMAPSIZE])
{
int i;
BYTE rgb[3];
for (i=0;i < number; ++i)
{
if (!ReadOK(fd,rgb,sizeof(rgb)))
{
return FALSE;
}
buffer[CM_RED][i]=rgb[0];
buffer[CM_GREEN][i]=rgb[1];
buffer[CM_BLUE][i]=rgb[2];
}
return TRUE;
}
int CGif::DoExtension(FILE *fd, int label)
{
static char buf[256];
char *str;
switch(label)
{
case 0x01 :
str="Plain Text Ext";
break;
case 0xff :
str= "Appl ext";
break;
case 0xfe :
str="Comment Ext";
while (GetDataBlock(fd,(BYTE *)buf)!=0);
return FALSE;
case 0XF9 :
str="Graphic Ctrl Ext";
(void)GetDataBlock(fd,(BYTE *)buf);
Gif89.disposal =(buf[0]>>2) &0x7;
Gif89.inputFlag =(buf[0]>>1) &0x1;
Gif89.delayTime =LM_to_uint(buf[1],buf[2]);
if ((buf[0]&0x1)!=0)
Gif89.transparent=buf[3];
while (GetDataBlock(fd,(BYTE *)buf)!=0);
return FALSE;
default :
str=buf;
sprintf(buf,"UNKNOWN (0x%02x)",label);
break;
}
while (GetDataBlock(fd,(BYTE *)buf)!=0);
return FALSE;
}
int CGif::GetDataBlock(FILE *fd, BYTE *buf)
{
BYTE count;
if (!ReadOK(fd,&count,1))
{
//m_strGIFError="Error in GIF DataBlock Size";
return -1;
}
ZeroDataBlock=count==0;
if ((count!=0) && (!ReadOK(fd,buf,count)))
{
//m_strGIFError="Error reading GIF datablock";
return -1;
}
return count;
}
int CGif::GetCode(FILE *fd, int code_size, int flag)
{
static BYTE buf[280];
static int curbit, lastbit, done, last_byte;
int i,j,ret;
BYTE count;
if (flag)
{
curbit=0;
lastbit=0;
done=FALSE;
return 0;
}
if ((curbit+code_size) >=lastbit)
{
if (done)
{
if (curbit >=lastbit)
{
//m_strGIFError="Ran off the end of my bits";
return 0;
}
return -1;
}
buf[0]=buf[last_byte-2];
buf[1]=buf[last_byte-1];
if ((count=GetDataBlock(fd,&buf[2]))==0)
done=TRUE;
last_byte=2+count;
curbit=(curbit - lastbit) + 16;
lastbit = (2+count)*8;
}
ret=0;
for (i=curbit,j=0; j<code_size;++i,++j)
ret|=((buf[i/8]&(1<<(i% 8)))!=0)<<j;
curbit+=code_size;
return ret;
}
int CGif::LZWReadByte(FILE *fd, int flag, int input_code_size)
{
static int fresh=FALSE;
int code, incode;
static int code_size, set_code_size;
static int max_code, max_code_size;
static int firstcode, oldcode;
static int clear_code, end_code;
static unsigned short next[1<<MAX_LZW_BITS];
static BYTE vals[1<<MAX_LZW_BITS];
static BYTE stack [1<<(MAX_LZW_BITS+1)];
static BYTE *sp;
register int i;
if (flag)
{
set_code_size=input_code_size;
code_size=set_code_size+1;
clear_code=1<<set_code_size;
end_code = clear_code+1;
max_code = clear_code+2;
max_code_size=2*clear_code;
GetCode(fd,0,TRUE);
fresh=TRUE;
for(i=0;i<clear_code;++i)
{
next[i]=0;
vals[i]=i;
}
for (;i<(1<<MAX_LZW_BITS);++i)
next[i]=vals[0]=0;
sp=stack;
return 0;
}
else if (fresh)
{
fresh=FALSE;
do
{
firstcode=oldcode=GetCode(fd,code_size,FALSE);
} while (firstcode==clear_code);
return firstcode;
}
if (sp > stack)
return *--sp;
while ((code= GetCode(fd,code_size,FALSE)) >=0)
{
if (code==clear_code)
{
for (i=0;i<clear_code;++i)
{
next[i]=0;
vals[i]=i;
}
for (;i<(1<<MAX_LZW_BITS);++i)
next[i]=vals[i]=0;
code_size=set_code_size+1;
max_code_size=2*clear_code;
max_code=clear_code+2;
sp=stack;
firstcode=oldcode=GetCode(fd,code_size,FALSE);
return firstcode;
}
else if (code==end_code)
{
int count;
BYTE buf[260];
if (ZeroDataBlock)
{
//AfxMessageBox("ZeroDataBlock!");
//return -2;//##NEO##
return 11; //原来是return 2,但是在打开Photoshop 7.0从
//test_pics中8_256.pcx转存为GIF的图片时，
//会出现ZeoDataBlock错误，但如果不理会仍能正常显示
}
while ((count=GetDataBlock(fd,buf)) >0);
if (count!=0)
{
AfxMessageBox("Missing EOD in GIF data stream (common occurrence)",MB_OK);
return -2;
}
}
incode = code;
if (code >= max_code)
{
*sp++=firstcode;
code=oldcode;
}
while (code >=clear_code)
{
*sp++=vals[code];
if (code==(int)next[code])
{
//m_strGIFError="Circular table entry, big GIF Error!";
return -1;
}
code=next[code];
}
*sp++ = firstcode=vals[code];
if ((code=max_code) <(1<<MAX_LZW_BITS))
{
next[code]=oldcode;
vals[code]=firstcode;
++max_code;
if ((max_code >=max_code_size) &&
(max_code_size < (1<<MAX_LZW_BITS)))
{
max_code_size*=2;
++code_size;
}
}
oldcode=incode;
if (sp > stack)
return *--sp;
}
return code;
}
BOOL CGif::ReadImage(FILE *fd, BYTE * bigMemBuf, int width, int height,
BYTE cmap[3][MAXCOLORMAPSIZE], int interlace)
{
BYTE c;
int color;
int xpos=0, ypos=0, pass=0;
long curidx;
if (!ReadOK(fd,& c,1))
{
return FALSE;
}
if (LZWReadByte(fd,TRUE,c)<0)
{
return FALSE;
}
while ((color=LZWReadByte(fd,FALSE,c))>=0)
{
curidx=(long)xpos+(long)ypos*(long)width;
curidx*=3;
*(bigMemBuf+curidx)=cmap[0][color];
*(bigMemBuf+curidx+1)=cmap[1][color];
*(bigMemBuf+curidx+2)=cmap[2][color];
++xpos;
if (xpos==width)
{
xpos=0;
if (interlace)
{
switch (pass)
{
case 0:
case 1:
ypos+=8; break;
case 2:
ypos+=4; break;
case 3:
ypos+=2; break;
}
if (ypos>=height)
{
++pass;
switch (pass)
{
case 1: ypos=4;break;
case 2: ypos=2;break;
case 3: ypos=1;break;
default : goto fini;
}
}
}
else
{
++ypos;
}
}
if (ypos >=height)
break;
}
fini :
ASSERT(LZWReadByte(fd,FALSE,c)>=0);
return TRUE;
}
////////////
//
// GIF writing section
//
////////////
/*
* Bump the 'curx' and 'cury' to point to the next pixel
*/
void CGif::BumpPixel()
{
/*
* Bump the current X position
*/
++curx;
if( curx == Width ) {
curx = 0;
++cury;
}
}
/*******************************************************************************
* Return the next pixel from the image
*******************************************************************************/
int CGif::GIFNextPixel( )
{
unsigned long index;
int r;
if( CountDown == 0 )
return EOF;
--CountDown;
index= (unsigned long)curx + (unsigned long)cury * (unsigned long)Width;
r = *(buffer+index);
BumpPixel();
return r;
}
/*******************************************************************************
* here's the entry point.
* file ptr, screen width, height, background color, bits per pixel and
* arrays of color values (0-255)
*******************************************************************************/
BOOL CGif::WriteGIFFile(LPCTSTR lpstrFileName,
BYTE* buf,
int GWidth,
int GHeight,
int BackGround,
int Red[], int Green[], int Blue[])
{
FILE *fp;
int B;
int RWidth, RHeight;
int LeftOfs, TopOfs;
int Resolution;
int ColorMapSize;
int InitCodeSize;
int i;
int BitsPerPixel = 8;
fp=fopen(lpstrFileName,"wb");
if (fp==NULL)
{
m_strGIFError="Can't open GIF for writing";
return FALSE;
}
ColorMapSize = 1 << BitsPerPixel;
buffer=buf;
RWidth = Width = GWidth;
RHeight = Height = GHeight;
LeftOfs = TopOfs = 0;
cur_accum = 0;
cur_bits = 0;
Resolution = BitsPerPixel;
CountDown = (long)Width * (long) Height;
if (BitsPerPixel <=1)
InitCodeSize=2;
else
InitCodeSize = BitsPerPixel;
curx = cury =0;
fwrite("GIF87a",1,6,fp);
Putword(RWidth,fp);
Putword(RHeight,fp);
B=0x80;
B |=(Resolution -1) << 5;
B |=(BitsPerPixel - 1);
fputc(B,fp);
fputc(BackGround,fp);
fputc(0,fp);
for(i=0; i<ColorMapSize; ++i)
{
fputc(Red[i],fp);
fputc(Green[i],fp);
fputc(Blue[i],fp);
}
fputc(',',fp);
Putword(LeftOfs,fp);
Putword(TopOfs,fp);
Putword(Width,fp);
Putword(Height,fp);
fputc(0x00,fp);
/*
* Write out the initial code size
*/
fputc( InitCodeSize, fp );
/*
* Go and actually compress the data
*/
compress( InitCodeSize+1, fp);
/*
* Write out a Zero-length packet (to end the series)
*/
fputc( 0, fp );
/*
* Write the GIF file terminator
*/
fputc( ';', fp );
/*
* And close the file
*/
fclose( fp );
return TRUE;
}
/*******************************************************************************
* Write out a word to the GIF file
*******************************************************************************/
void CGif::Putword(int w, FILE *fp )
{
fputc( w & 0xff, fp );
fputc( (w / 256) & 0xff, fp );
}
/***************************************************************************
*
* GIF Image compression section
*
* Lempel-Ziv compression based on 'compress'. GIF modifications by
* David Rowley (mgardi@watdcsu.waterloo.edu)
*
***************************************************************************/
void CGif::compress( int init_bits, FILE* outfile)
{
register long fcode;
register code_int i /* = 0 */;
register int c;
register code_int ent;
register code_int disp;
register int hshift;
/*
* Set up the globals: g_init_bits - initial number of bits
* g_outfile - pointer to output file
*/
g_init_bits = init_bits;
g_outfile = outfile;
/*
* Set up the necessary values
*/
clear_flg = 0;
maxcode = MAXCODE(n_bits = g_init_bits);
ClearCode = (1 << (init_bits - 1));
EOFCode = ClearCode + 1;
free_ent = ClearCode + 2;
char_init();
ent = GIFNextPixel( );
hshift = 0;
for ( fcode = (long) HSIZE; fcode < 65536L; fcode *= 2L )
++hshift;
hshift = 8 - hshift; /* set hash code range bound */
cl_hash( (count_int) HSIZE); /* clear hash table */
output( (code_int)ClearCode );
while ( (c = GIFNextPixel( )) != EOF )
{ /* } */
fcode = (long) (((long) c << maxbits) + ent);
i = (((code_int)c << hshift) ^ ent); /* xor hashing */
if ( htab[i] == fcode ) {
ent = codetab[i];
continue;
} else if ( (long)htab[i] < 0 ) /* empty slot */
goto nomatch;
disp = HSIZE - i; /* secondary hash (after G. Knott) */
if ( i == 0 )
disp = 1;
probe:
if ( (i -= disp) < 0 )
i += HSIZE;
if ( htab[i] == fcode ) {
ent = codetab[i];
continue;
}
if ( (long)htab[i] > 0 )
goto probe;
nomatch:
output ( (code_int) ent );
ent = c;
if ( free_ent < maxmaxcode )
{ /* } */
codetab[i] = free_ent++; /* code -> hashtable */
htab[i] = fcode;
} else
cl_block();
}
/*
* Put out the final code.
*/
output( (code_int)ent );
output( (code_int) EOFCode );
}
/*****************************************************************
* TAG( output )
*
* Output the given code.
* Inputs:
* code: A n_bits-bit integer. If == -1, then EOF. This assumes
* that n_bits =< (long)wordsize - 1.
* Outputs:
* Outputs code to the file.
* Assumptions:
* Chars are 8 bits long.
* Algorithm:
* Maintain a BITS character long buffer (so that 8 codes will
* fit in it exactly). Use the VAX insv instruction to insert each
* code in turn. When the buffer fills up empty it and start over.
*/
void CGif::output( code_int code)
{
cur_accum &= masks[ cur_bits ];
if( cur_bits > 0 )
cur_accum |= ((long)code << cur_bits);
else
cur_accum = code;
cur_bits += n_bits;
while( cur_bits >= 8 )
{
char_out( (unsigned int)(cur_accum & 0xff) );
cur_accum >>= 8;
cur_bits -= 8;
}
/*
* If the next entry is going to be too big for the code size,
* then increase it, if possible.
*/
if ( free_ent > maxcode || clear_flg )
{
if( clear_flg )
{
maxcode = MAXCODE (n_bits = g_init_bits);
clear_flg = 0;
}
else
{
++n_bits;
if ( n_bits == maxbits )
maxcode = maxmaxcode;
else
maxcode = MAXCODE(n_bits);
}
}
if( code == EOFCode )
{
/*
* At EOF, write the rest of the buffer.
*/
while( cur_bits > 0 )
{
char_out( (unsigned int)(cur_accum & 0xff) );
cur_accum >>= 8;
cur_bits -= 8;
}
flush_char();
fflush( g_outfile );
if( ferror( g_outfile ) )
{
AfxMessageBox("Write Error in GIF file",MB_OK);
}
}
}
void CGif::cl_block()
{
cl_hash((count_int)HSIZE);
free_ent=ClearCode+2;
clear_flg=1;
output((code_int)ClearCode);
}
void CGif::cl_hash(register count_int hsize)
{
register count_int *htab_p = htab+hsize;
register long i;
register long m1 = -1L;
i = hsize - 16;
do
{
*(htab_p-16)=m1;
*(htab_p-15)=m1;
*(htab_p-14)=m1;
*(htab_p-13)=m1;
*(htab_p-12)=m1;
*(htab_p-11)=m1;
*(htab_p-10)=m1;
*(htab_p-9)=m1;
*(htab_p-8)=m1;
*(htab_p-7)=m1;
*(htab_p-6)=m1;
*(htab_p-5)=m1;
*(htab_p-4)=m1;
*(htab_p-3)=m1;
*(htab_p-2)=m1;
*(htab_p-1)=m1;
htab_p-=16;
} while ((i-=16) >=0);
for (i+=16;i>0;--i)
*--htab_p=m1;
}
/*******************************************************************************
* GIF specific
*******************************************************************************/
void CGif::char_init()
{
a_count=0;
}
void CGif::char_out(int c)
{
accum[a_count++]=c;
if (a_count >=254)
flush_char();
}
void CGif::flush_char()
{
if (a_count > 0)
{
fputc(a_count,g_outfile);
fwrite(accum,1,a_count,g_outfile);
a_count=0;
}
}
//
// copies BYTE buffer into DWORD-aligned BYTE buffer
// return addr of new buffer
//
BYTE* CGif::MakeDwordAlign(BYTE *dataBuf, UINT widthPix, UINT height, UINT *uiOutWidthBytes) // bytes!!!
{
////////////////////////////////////////////////////////////
// what's going on here? this certainly means trouble
if (dataBuf==NULL)
return NULL;
////////////////////////////////////////////////////////////
// how big is the smallest DWORD-aligned buffer that we can use?
UINT uiWidthBytes;
uiWidthBytes = WIDTHBYTES(widthPix * 24);
DWORD dwNewsize=(DWORD)((DWORD)uiWidthBytes *
(DWORD)height);
BYTE *pNew;
////////////////////////////////////////////////////////////
// alloc and open our new buffer
pNew=(BYTE *)new BYTE[dwNewsize];
if (pNew==NULL)
{
return NULL;
}
////////////////////////////////////////////////////////////
// copy row-by-row
UINT uiInWidthBytes = widthPix * 3;
UINT uiCount;
for (uiCount=0;uiCount < height;uiCount++)
{
BYTE * bpInAdd;
BYTE * bpOutAdd;
ULONG lInOff;
ULONG lOutOff;
lInOff=uiInWidthBytes * uiCount;
lOutOff=uiWidthBytes * uiCount;
bpInAdd= dataBuf + lInOff;
bpOutAdd= pNew + lOutOff;
memcpy(bpOutAdd,bpInAdd,uiInWidthBytes);
}
*uiOutWidthBytes=uiWidthBytes;
return pNew;
}
//
// vertically flip a buffer
// note, this operates on a buffer of widthBytes bytes, not pixels!!!
//
BOOL CGif::VertFlipBuf(BYTE * inbuf, UINT widthBytes, UINT height)
{
BYTE *tb1;
BYTE *tb2;
if (inbuf==NULL)
return FALSE;
UINT bufsize;
bufsize=widthBytes;
tb1= (BYTE *)new BYTE[bufsize];
if (tb1==NULL) {
return FALSE;
}
tb2= (BYTE *)new BYTE [bufsize];
if (tb1==NULL)
{
return FALSE;
}
UINT row_cnt;
ULONG off1=0;
ULONG off2=0;
for (row_cnt=0;row_cnt<(height+1)/2;row_cnt++)
{
off1=row_cnt*bufsize;
off2=((height-1)-row_cnt)*bufsize;
memcpy(tb1,inbuf+off1,bufsize);
memcpy(tb2,inbuf+off2,bufsize);
memcpy(inbuf+off1,tb2,bufsize);
memcpy(inbuf+off2,tb1,bufsize);
}
delete [] tb1;
delete [] tb2;
return TRUE;
}
//
// swap Rs and Bs
//
// Note! this does its stuff on buffers with a whole number of pixels
// per data row!!
//
BOOL CGif::BGRFromRGB(BYTE *buf, UINT widthPix, UINT height)
{
if (buf==NULL)
return FALSE;
UINT col, row;
for (row=0;row<height;row++)
{
for (col=0;col<widthPix;col++)
{
LPBYTE pRed, pGrn, pBlu;
pRed = buf + row * widthPix * 3 + col * 3;
pGrn = buf + row * widthPix * 3 + col * 3 + 1;
pBlu = buf + row * widthPix * 3 + col * 3 + 2;
// swap red and blue
BYTE tmp;
tmp = *pRed;
*pRed = *pBlu;
*pBlu = tmp;
}
}
return TRUE;
}
BYTE* CGif::ClearDwordAlign(BYTE *inBuf, UINT widthPix, UINT height, UINT nBpp)
{
if (inBuf==NULL)
return FALSE;
BYTE *tmp;
tmp=(BYTE *)new BYTE[height * widthPix * nBpp/8];
if (tmp==NULL)
return NULL;
UINT row;
for (row=0;row<height;row++)
{
memcpy((tmp+row * widthPix * nBpp/8),
(inBuf + row * WIDTHBYTES(widthPix * nBpp)),
widthPix * nBpp/8);
}
return tmp;
}