/*****************************************************************************
*   "Gif-Lib" - Yet another gif library.				     *
*									     *
* Written by:  Gershon Elber			IBM PC Ver 0.1,	Jul. 1989    *
******************************************************************************
* Program to rotate image 90 degrees to the right/left or flip the image     *
* horizintally/vertically (mirror).					     *
* Options:								     *
* -r : rotate 90 degrees to the right (default).			     *
* -l : rotate 90 degrees to the left.					     *
* -x : Mirror the image horizontally (first line switch places with last).   *
* -y : Mirror the image vertically (first column switch places with last).   *
* -h : on line help							     *
******************************************************************************
* History:								     *
* 10 Jul 89 - Version 1.0 by Gershon Elber.				     *
*****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <alloc.h>
#include <string.h>
#include "gif_lib.h"
#include "getarg.h"

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

enum {
    FLIP_NONE,
    FLIP_RIGHT,
    FLIP_LEFT,
    FLIP_HORIZ,
    FLIP_VERT
};

extern unsigned int
    _stklen = 16384;			      /* Increase default stack size */

static char
    *VersionStr =
	PROGRAM_NAME
	"	IBMPC "
	VERSION
	"	Gershon Elber,	"
	__DATE__ ",   " __TIME__ "\n"
	"(C) Copyright 1989 Gershon Elber, Non commercial use only.\n";
static char
    *CtrlStr =
	PROGRAM_NAME
	" r%- l%- x%- y%- h%- GifFile!*s";
static char
    *ProgramName;

/* Make some variables global, so we could access them faster: */
static int
    ImageNum = 0;

static int LoadImage(GifFileType *GifFile, RowType **ImageBuffer);
static int DumpImage(GifFileType *GifFile, RowType *ImageBuffer,
				int Width, int Height, int FlipDirection);
static void QuitGifError(GifFileType *GifFileIn, GifFileType *GifFileOut);

/******************************************************************************
* Interpret the command line and scan the given GIF file.		      *
******************************************************************************/
void main(int argc, char **argv)
{
    int	i, Error, NumFiles, ExtCode, FlipDirection,
	RightFlag = FALSE, LeftFlag = FALSE,
	HorizFlag = FALSE, VertFlag = FALSE, HelpFlag = FALSE;
    GifRecordType RecordType;
    ByteType *Extension;
    char **FileName = NULL;
    RowType *ImageBuffer;
    GifFileType *GifFileIn = NULL, *GifFileOut = NULL;

    if (strlen(ProgramName = argv[0]) == 0)		    /* DOS 3.x only! */
	ProgramName = PROGRAM_NAME;	  /* Do something reasonable for 2.x */

    if ((Error = GAGetArgs(argc, argv, CtrlStr,
		&RightFlag, &LeftFlag, &HorizFlag, &VertFlag, &HelpFlag,
		&NumFiles, &FileName)) != FALSE ||
		(NumFiles > 1 && !HelpFlag)) {
	if (Error) GAPrintErrMsg(Error);
	else
	if (NumFiles > 1)
	    MESSAGE("Error in command line parsing - one GIF file please\n");
	GAPrintHowTo(CtrlStr);
	exit(1);
    }

    if (HelpFlag) {
	fprintf(stderr, VersionStr);
	GAPrintHowTo(CtrlStr);
	exit(0);
    }

    if ((i = (RightFlag != 0) + (LeftFlag != 0) +
	     (HorizFlag != 0) + (VertFlag != 0)) > 1)
	EXIT("Only one of -r, -l, -x, -y please\n");
    if (i == 0) FlipDirection = FLIP_RIGHT;	      /* Make it the default */
    else {
	if (RightFlag) FlipDirection = FLIP_RIGHT;
	if (LeftFlag) FlipDirection = FLIP_LEFT;
	if (HorizFlag) FlipDirection = FLIP_HORIZ;
	if (VertFlag) FlipDirection = FLIP_VERT;
    }

    if (NumFiles == 1) {
	if ((GifFileIn = DGifOpenFileName(*FileName)) == NULL)
	    QuitGifError(GifFileIn, GifFileOut);
    }
    else {
	/* Use the stdin instead: */
	if ((GifFileIn = DGifOpenFileHandle(0)) == NULL)
	    QuitGifError(GifFileIn, GifFileOut);
    }

    /* Open stdout for the output file: */
    if ((GifFileOut = EGifOpenFileHandle(1)) == NULL)
	QuitGifError(GifFileIn, GifFileOut);

    if (RightFlag || LeftFlag) {
	/* Dump out same screen information, but flip Screen Width/Height: */
	if (EGifPutScreenDesc(GifFileOut,
	    GifFileIn -> SHeight, GifFileIn -> SWidth,
	    GifFileIn -> SColorResolution, GifFileIn -> SBackGroundColor,
	    GifFileIn -> SBitsPerPixel, GifFileIn -> SColorMap) == ERROR)
	    QuitGifError(GifFileIn, GifFileOut);
    }
    else {
	/* Dump out exactly same screen information: */
	if (EGifPutScreenDesc(GifFileOut,
	    GifFileIn -> SWidth, GifFileIn -> SHeight,
	    GifFileIn -> SColorResolution, GifFileIn -> SBackGroundColor,
	    GifFileIn -> SBitsPerPixel, GifFileIn -> SColorMap) == ERROR)
	    QuitGifError(GifFileIn, GifFileOut);
    }

    /* Scan the content of the GIF file and load the image(s) in: */
    do {
	if (DGifGetRecordType(GifFileIn, &RecordType) == ERROR)
	    QuitGifError(GifFileIn, GifFileOut);

	switch (RecordType) {
	    case IMAGE_DESC_RECORD_TYPE:
		if (DGifGetImageDesc(GifFileIn) == ERROR)
		    QuitGifError(GifFileIn, GifFileOut);
		if (GifFileIn -> IInterlace)
		    EXIT("Cannt flip interlaced images - use GifInter first\n");

		/* Put the image descriptor to out file: */
		if (RightFlag) {
		    /* Rotate to the right: */
		    if (EGifPutImageDesc(GifFileOut,
			GifFileIn -> SHeight - GifFileIn -> IHeight -
						GifFileIn -> ITop,
			GifFileIn -> ILeft,
			GifFileIn -> IHeight, GifFileIn -> IWidth,
			FALSE, GifFileIn -> IBitsPerPixel,
			GifFileIn -> IColorMap) == ERROR)
			    QuitGifError(GifFileIn, GifFileOut);
		}
		else
		if (LeftFlag) {
		    /* Rotate to the left: */
		    if (EGifPutImageDesc(GifFileOut,
			GifFileIn -> ITop,
			GifFileIn -> SWidth - GifFileIn -> IWidth -
						GifFileIn -> ILeft,
			GifFileIn -> IHeight, GifFileIn -> IWidth,
			FALSE, GifFileIn -> IBitsPerPixel,
			GifFileIn -> IColorMap) == ERROR)
			    QuitGifError(GifFileIn, GifFileOut);
		}
		else {
		    /* No rotation - only flipping vert. or horiz.: */
		    if (EGifPutImageDesc(GifFileOut,
			GifFileIn -> ILeft, GifFileIn -> ITop,
			GifFileIn -> IWidth, GifFileIn -> IHeight,
			FALSE, GifFileIn -> IBitsPerPixel,
			GifFileIn -> IColorMap) == ERROR)
			    QuitGifError(GifFileIn, GifFileOut);
		}

		/* Load the image (either Interlaced or not), and dump it    */
		/* fliped as requrested by Flags:			     */
		if (LoadImage(GifFileIn, &ImageBuffer) == ERROR)
		    QuitGifError(GifFileIn, GifFileOut);
		if (DumpImage(GifFileOut, ImageBuffer, GifFileIn -> IWidth,
				GifFileIn -> IHeight, FlipDirection) == ERROR)
		    QuitGifError(GifFileIn, GifFileOut);
		break;
	    case EXTENSION_RECORD_TYPE:
		/* Skip any extension blocks in file: */
		if (DGifGetExtension(GifFileIn, &ExtCode, &Extension) == ERROR)
		    QuitGifError(GifFileIn, GifFileOut);
		if (EGifPutExtension(GifFileOut, ExtCode, Extension[0],
							Extension) == ERROR)
		    QuitGifError(GifFileIn, GifFileOut);

		/* No support to more than one extension blocks, so discard: */
		while (Extension != NULL) {
		    if (DGifGetExtensionNext(GifFileIn, &Extension) == ERROR)
			QuitGifError(GifFileIn, GifFileOut);
		}
		break;
	    case TERMINATE_RECORD_TYPE:
		break;
	    default:		     /* Should be traps by DGifGetRecordType */
		break;
	}
    }
    while (RecordType != TERMINATE_RECORD_TYPE);

    if (DGifCloseFile(GifFileIn) == ERROR)
	QuitGifError(GifFileIn, GifFileOut);
    if (EGifCloseFile(GifFileOut) == ERROR)
	QuitGifError(GifFileIn, GifFileOut);
}

/******************************************************************************
* Routine to read Image out. The image can be Non interlaced only.	      *
* The memory required to hold the image is allocate by the routine itself.    *
* Return OK if succesful, ERROR otherwise.				      *
******************************************************************************/
static int LoadImage(GifFileType *GifFile, RowType **ImageBufferPtr)
{
    int Size, i;
    RowType *ImageBuffer;

    /* Allocate the image as vector of column of rows. We cannt allocate     */
    /* the all screen at once, as this broken minded CPU can allocate up to  */
    /* 64k at a time and our image can be bigger than that:		     */
    if ((ImageBuffer = (RowType *)
	malloc(GifFile -> IHeight * sizeof(RowType *))) == NULL)
	    EXIT("Failed to allocate memory required, aborted");

    Size = GifFile -> IWidth * sizeof(PixelType);   /* One row size in bytes */
    for (i=0; i<GifFile -> IHeight; i++) {
	/* Allocate the rows: */
	if ((ImageBuffer[i] = (RowType) malloc(Size)) == NULL)
	    EXIT("Failed to allocate memory required, aborted\n");
    }

    *ImageBufferPtr = ImageBuffer;

    fprintf(stderr, "\n%s: Image %d at (%d, %d) [%dx%d]:     ",
	ProgramName, ++ImageNum, GifFile -> ILeft, GifFile -> ITop,
				 GifFile -> IWidth, GifFile -> IHeight);

    for (i=0; i<GifFile -> IHeight; i++) {
	fprintf(stderr, "\b\b\b\b%-4d", i);
	if (DGifGetLine(GifFile, ImageBuffer[i], GifFile -> IWidth)
		== ERROR) return ERROR;
    }

    return OK;
}

/******************************************************************************
* Routine to dump image out. The given Image buffer should always hold the    *
* image sequencially, and Width & Height hold image dimensions BEFORE flip.   *
* Image will be dumped according to FlipDirection.			      *
* Once dumped, the memory holding the image is freed.			      *
* Return OK if succesful, ERROR otherwise.				      *
******************************************************************************/
static int DumpImage(GifFileType *GifFile, RowType *ImageBuffer,
				int Width, int Height, int FlipDirection)
{
    int i, j, Count;
    RowType Line;			    /* New scan line is copied to it */

    /* Allocate scan line that will fit both image width and height: */
    if ((Line = (RowType) malloc((Width > Height ? Width : Height)
						* sizeof(PixelType))) == NULL)
	EXIT("Failed to allocate memory required, aborted\n");

    switch (FlipDirection) {
	case FLIP_RIGHT:
	    for (Count=Width, i=0; i<Width; i++) {
		fprintf(stderr, "\b\b\b\b%-4d", Count--);
		for (j=0; j<Height; j++)
		    Line[j] = ImageBuffer[Height - j - 1][i];
		if (EGifPutLine(GifFile, Line, Height) == ERROR) return ERROR;
	    }
	    break;
	case FLIP_LEFT:
	    for (i=Width-1; i>=0; i--) {
		fprintf(stderr, "\b\b\b\b%-4d", i + 1);
		for (j=0; j<Height; j++)
		    Line[j] = ImageBuffer[j][i];
		if (EGifPutLine(GifFile, Line, Height) == ERROR) return ERROR;
	    }
	    break;
	case FLIP_HORIZ:
	    for (i=Height-1; i>=0; i--) {
		fprintf(stderr, "\b\b\b\b%-4d", i);
		if (EGifPutLine(GifFile, ImageBuffer[i], Width) == ERROR)
		    return ERROR;
	    }
	    break;
	case FLIP_VERT:
	    for (Count=Height, i=0; i<Height; i++) {
		fprintf(stderr, "\b\b\b\b%-4d", Count--);
		for (j=0; j<Width; j++)
		    Line[j] = ImageBuffer[i][Width - j - 1];
		if (EGifPutLine(GifFile, Line, Width) == ERROR) return ERROR;
	    }
	    break;
    }

    /* Free the memory used for this image, and the temporary scan line: */
    for (i=0; i<Height; i++) free((char *) ImageBuffer[i]);
    free((char *) ImageBuffer);

    free((char *) Line);

    return OK;
}

/******************************************************************************
* Close both input and output file (if open), and exit.			      *
******************************************************************************/
static void QuitGifError(GifFileType *GifFileIn, GifFileType *GifFileOut)
{
    PrintGifError();
    if (GifFileIn != NULL) DGifCloseFile(GifFileIn);
    if (GifFileOut != NULL) EGifCloseFile(GifFileOut);
    exit(1);
}