Category : C Source Code
Archive   : GIF_LIB.ZIP
Filename : DEV2GIF.C

/*****************************************************************************
* "Gif-Lib" - Yet another gif library. *
* *
* Written by: Gershon Elber IBM PC Ver 0.1, Jun. 1989 *
******************************************************************************
* Module to dump graphic devices into a GIF file. Current supported devices: *
* 1. Hercules. *
******************************************************************************
* History: *
* 22 Jun 89 - Version 1.0 by Gershon Elber. *
*****************************************************************************/

#include
#include
#include
#include
#include "gif_lib.h"

#define PROGRAM_NAME "GIF_LIBRARY"
#define VERSION "á Version 1.0, "

static int GraphDriver = HERCMONO, /* Device parameters */
GraphMode = HERCMONOHI,
ScreenXMax = 720,
ScreenYMax = 348,
ScreenColorBits = 1;
static unsigned int ScreenBase;

static char *VersionStr =
PROGRAM_NAME
" IBMPC "
VERSION
" Gershon Elber, "
__DATE__ ", " __TIME__ "\n"
"(C) Copyright 1989 Gershon Elber, Non commercial use only.\n";

static void GetScanLine(PixelType *ScanLine, int Y);
static int HandleGifError(GifFileType *GifFile);

/******************************************************************************
* Dump the given Device, into given File as GIF format: *
* Return 0 on success, -1 if device not supported, or GIF-LIB error number. *
* See graphics.h for exact definition of GraphDriver/Mode. *
******************************************************************************/
int DumpScreen(char *FileName, int ReqGraphDriver, int ReqGraphMode)
{
int i;
static PixelType *ScanLine;
static GifColorType HerculesColorMap[2] = { { 0, 0, 0 },
{ 255, 255, 255 } };
GifFileType *GifFile;

switch (ReqGraphDriver) { /* return on non supported screens */
case HERCMONO:
ScreenXMax = 720;
ScreenYMax = 350;
ScreenColorBits = 1;
ScreenBase = 0xb000;
break;
default:
return -1;
}

ScanLine = (PixelType *) malloc(sizeof(PixelType) * ScreenXMax);

GraphDriver = ReqGraphDriver;
GraphMode = ReqGraphMode;

if ((GifFile = EGifOpenFileName(FileName, FALSE)) == NULL) {
free((char *) ScanLine);
return HandleGifError(GifFile);
}

if (EGifPutScreenDesc(GifFile, ScreenXMax, ScreenYMax, ScreenColorBits,
0, ScreenColorBits, HerculesColorMap) == ERROR) {
free((char *) ScanLine);
return HandleGifError(GifFile);
}

if (EGifPutImageDesc(GifFile, 0, 0, ScreenXMax, ScreenYMax, FALSE, 1,
NULL) == ERROR) {
free((char *) ScanLine);
return HandleGifError(GifFile);
}

for (i=0; i GetScanLine(ScanLine, i);
if (EGifPutLine(GifFile, ScanLine, ScreenXMax) == ERROR) {
free((char *) ScanLine);
return HandleGifError(GifFile);
}
}

if (EGifCloseFile(GifFile) == ERROR) {
free((char *) ScanLine);
return HandleGifError(GifFile);
}

free((char *) ScanLine);
return 0;
}

/******************************************************************************
* Update the given scan line buffer with the pixel levels of the Y line. *
* This routine is device specific, so make sure you know was you are doing *
******************************************************************************/
static void GetScanLine(PixelType *ScanLine, int Y)
{
unsigned char ScreenByte;
int i, j, k;
unsigned int Offset, Bit;

switch (GraphDriver) {
case HERCMONO:
Offset = 0x2000 * (Y % 4) + (Y / 4) * (ScreenXMax / 8);
/* In one scan lines we have ScreenXMax / 8 bytes: */
for (i=0, k=0; i ScreenByte = (unsigned char) peekb(ScreenBase, Offset++);
for (j=0, Bit = 0x80; j<8; j++) {
ScanLine[k++] = (ScreenByte & Bit ? 1 : 0);
Bit >>= 1;
}
}
break;
default:
break;
}
}

/******************************************************************************
* Handle last GIF error. Try to close the file and free all allocated memory. *
******************************************************************************/
static int HandleGifError(GifFileType *GifFile)
{
int i = GifLastError();

if (EGifCloseFile(GifFile) == ERROR) {
GifLastError();
}
return i;
}