www.pudn.com > Cimage.zip > IMAGIF.CPP

/* 
 * File:	imagif.cc 
 * Purpose:	Platform Independent GIF Image Class 
 * Author:	Alejandro Aguilar Sierra 
 * Created:	1995 
 * Copyright: (c) 1995, Alejandro Aguilar Sierra  
 * 
 */ 
 
// #include "stdafx.h" 
 
#include "imagif.h" 
#if CIMAGE_SUPPORT_GIF 
 
#include "imaiter.h" 
#include "gifdecod.h" 
#include  
 
// Force byte alignment (Borland) 
#if defined  __BORLANDC__ 
#pragma option -a1 
#elif defined _MSV_VER 
#pragma option /Zp1 
#endif 
 
//#include  
//static ofstream log("x.log"); 
 
#ifdef _DEBUG 
#define new DEBUG_NEW 
#undef THIS_FILE 
static char THIS_FILE[] = __FILE__; 
#endif 
 
////////////////////////// AD - for interlace /////////////////////////////// 
int interlaced, iypos, istep, iheight, ipass; 
///////////////////////////////////////////////////////////////////////////// 
 
#define GIFBUFTAM 16384 
 
struct rgb { byte r,g,b; }; 
 
////////////////////////// AD - for transparency /////////////////////////////// 
static struct { 
  byte transpcolflag:1; 
  byte userinputflag:1; 
  byte dispmeth:3; 
  byte res:3; 
  byte delaytimehi; 
  byte delaytimelo; 
  byte transpcolindex; 
} gifgce; 
 
static struct {                 /* Logic Screen Descriptor  */ 
  char header[6];        /* Firma and version */ 
  USHORT scrwidth; 
  USHORT scrheight; 
  char pflds; 
  char bcindx; 
  char pxasrat; 
} dscgif; 
 
static struct {             /* Image Descriptor */ 
  USHORT l; 
  USHORT t; 
  USHORT w; 
  USHORT h; 
  byte   pf; 
} image; 
 
static struct {           /*   Tabla de colores  */ 
  SHORT colres; /* color resolution */ 
  SHORT sogct;  /* size of global color table */ 
  rgb paleta[256];    /*  paleta  */ 
} TabCol; 
 
static CImageIterator* iter; 
static FILE *f; 
 
static  int ibf = GIFBUFTAM+1; 
static  byte buf[GIFBUFTAM]; 
 
int out_line(unsigned char *pixels, int linelen); 
 
BOOL CImageGIF::ReadFile(const CString& imageFileName) 
{ 
  if (imageFileName != "") 
    filename = imageFileName; 
//  puts("Empezando... "); 
 
  if ((f = fopen((const char *)filename, "rb"))==NULL) { 
 //		printf("no se pudo abrir!"); 
	return FALSE; 
  } 
 
	fread((char*)&dscgif,/*sizeof(dscgif)*/13,1,f); 
	 //if (strncmp(dscgif.header,"GIF8",3)!=0) { 
	 if (strncmp(dscgif.header,"GIF8",4)!=0) { 
//		puts("no es la firma!"); 
		return FALSE; 
	 } 
 
////////////////////////// AD - for interlace /////////////////////////////// 
 
	 //TabCol.sogct = 1<<((dscgif.pflds & 0x0007) + 0x0001); 
	 //TabCol.colres = (dscgif.pflds>>6) & 7 + 1; 
	 TabCol.sogct = 1 << (dscgif.pflds & 0x07)+1; 
	 TabCol.colres = ((int)(dscgif.pflds & 0x70) >> 3) + 1; 
 
	 // Global colour map? 
 
	 if (dscgif.pflds & 0x80) 
	 { 
		fread((char*)TabCol.paleta,/*sizeof(struct rgb)*/3*TabCol.sogct,1,f); 
		//log << "Global colour map" << endl; 
	 } 
 
	 char ch; 
 
loop: 
 
	 if (fread(&ch, 1, 1, f) <= 0) 
		goto done; 
 
	 if (ch == '!')                     // extension 
	 { 
		unsigned char count; 
		unsigned char fc; 
 
		//log << "EXTENSION: "; 
 
		if (fread(&fc, 1, 1, f) <= 0)   // function-code 
			goto done; 
 
		//log << hex << (int)fc << dec << endl; 
 
		//////////////// AD - for transparency ////////////////////////// 
		if (fc == 0xF9) 
		{ 
			//log << "Transparent" << endl; 
 
			if (fread(&count, 1, 1, f) <= 0) 
				goto done; 
			if (fread(&gifgce, 1, /*sizeof(gifgce)*/4, f) != count) 
				goto done; 
 
			if (gifgce.transpcolflag) 
				bgindex = gifgce.transpcolindex; 
 
		/////////////////////////////////////////////////////////////////// 
		} 
 
		while (fread(&count, 1, 1, f) && count) 
		{ 
			//log << "Skipping " << count << " bytes" << endl; 
			fseek(f, count, SEEK_CUR); 
		} 
 
		goto loop; 
	 } 
 
	 else if (ch == ',')                 // image 
	 { 
		fread((char*)&image,/*sizeof(image)*/9,1,f); 
		//log << "Image header" << endl; 
 
		// Local colour map? 
 
		if (image.pf & 0x80) 
		{ 
			TabCol.sogct = 1 << ((image.pf & 0x07) +1); 
			fread((char*)TabCol.paleta,/*sizeof(struct rgb)*/3*TabCol.sogct,1,f); 
			//log << "Local colour map" << endl; 
		} 
 
		Create(image.w, image.h, 8); 
 
		if ((image.pf & 0x80) || (dscgif.pflds & 0x80)) 
		{ 
			unsigned char r[256], g[256], b[256]; 
 
			int i, has_white = 0; 
 
			for (i=0; i < TabCol.sogct; i++) 
			{ 
				r[i] = TabCol.paleta[i].r; 
				g[i] = TabCol.paleta[i].g; 
				b[i] = TabCol.paleta[i].b; 
 
				if (RGB(r[i],g[i],b[i]) == 0xFFFFFF) 
					has_white = 1; 
			} 
 
			// Make transparency colour black... 
			if (bgindex != -1) 
				r[bgindex] = g[bgindex] = b[bgindex] = 0; 
 
			// Fill in with white // AD 
			if (bgindex != -1) 
			{ 
				while (i < 256) 
				{ 
					has_white = 1; 
					r[i] = g[i] = b[i] = 255; 
					i++; 
				} 
			} 
 
			// Force last colour to white...   // AD 
			if ((bgindex != -1) && !has_white) 
				r[255] = g[255] = b[255] = 255; 
 
			SetPalette((bgindex != -1 ? 256 : TabCol.sogct), r, g, b); 
			//log << "Set colour map" << endl; 
		} 
 
		iter = new CImageIterator(this); 
		iter->Upset(); 
		int badcode; 
		ibf = GIFBUFTAM+1; 
		GIFDecoder gifdec; 
 
		interlaced = image.pf & 0x40; 
		iheight = image.h; 
		istep = 8; 
		iypos = 0; 
		ipass = 0; 
 
		//if (interlaced) log << "Interlaced" << endl; 
 
		gifdec.decoder(GetWidth(), badcode); 
		delete iter; 
		goto loop; 
	 } 
 
done: 
 
	 fclose(f); 
 
  return TRUE; 
} 
 
int get_byte() 
{ 
  if (ibf>=GIFBUFTAM) { 
	 fread(buf,GIFBUFTAM,1,f); 
	 ibf = 0; 
  } 
 
  return buf[ibf++]; 
} 
 
int out_line(unsigned char *pixels, int linelen) 
{ 
////////////////////////// AD - for interlace /////////////////////////////// 
  if (interlaced) 
  { 
	 iter->SetY(iheight-iypos-1); 
	 iter->SetRow(pixels, linelen); 
 
	 if ((iypos += istep) >= iheight) 
	 { 
		do 
			{ 
				if (ipass++ > 0) 
					istep /= 2; 
 
				iypos = istep / 2; 
			} 
			  while (iypos > iheight); 
	 } 
 
	 return 0; 
  } 
  else 
///////////////////////////////////////////////////////////////////////////// 
  if (iter->ItOK()) { 
	 iter->SetRow(pixels, linelen); 
	 (void)iter->PrevRow(); 
	 return 0; 
  } 
  else { 
//	 puts("chafeo"); 
	 return -1; 
  } 
} 
 
#endif 	//	 CIMAGE_SUPPORT_GIF