/*
 * This software is copyrighted as noted below.  It may be freely copied,
 * modified, and redistributed, provided that the copyright notice is 
 * preserved on all copies.
 * 
 * There is no warranty or other guarantee of fitness for this software,
 * it is provided solely "as is".  Bug reports or fixes may be sent
 * to the author, who may or may not act on them as he desires.
 *
 * You may not include this software in a program or other software product
 * without supplying the source, or without informing the end-user that the 
 * source is available for no extra charge.
 *
 * If you modify this software, you should include a notice giving the
 * name of the person performing the modification, the date of modification,
 * and the reason for such modification.
 *
 *  Modified at BRL 16-May-88 by Mike Muuss to avoid Alliant STDC desire
 *  to have all "void" functions so declared.
 *
 *  2002-12-19: Fix maths wrapping bugs. Alan Cox <alan@redhat.com>
 */
/* 
 * Runput.c - General purpose Run Length Encoding.
 * 
 * Author:	Spencer W. Thomas
 * 		Computer Science Dept.
 * 		University of Utah
 * Date:	Mon Aug  9 1982
 * Copyright (c) 1982,1986 Spencer W. Thomas
 * 
 * $Id: Runput.c,v 3.0.1.1 1992/01/28 18:17:40 spencer Exp $
 * 
 * Modified by:	Todd W. Fuqua
 * 	Date:	Jul 22 1984
 * convert to new RLE format to make room for larger frame buffers
 */

/* THIS IS WAY OUT OF DATE.  See rle.5.
 * The output file format is:
 * 
 * Word 0:	A "magic" number.  The top byte of the word contains
 *		the letter 'R' or the letter 'W'.  'W' indicates that
 *		only black and white information was saved.  The bottom
 *		byte is one of the following:
 *	' ':	Means a straight "box" save, -S flag was given.
 *	'B':	Image saved with background color, clear screen to
 *		background before restoring image.
 *	'O':	Image saved in overlay mode.
 * 
 * Words 1-6:	The structure
 * {     short   xpos,			Lower left corner
 *             ypos,
 *             xsize,			Size of saved box
 *             ysize;
 *     char    rgb[3];			Background color
 *     char    map;			flag for map presence
 * }
 * 
 * If the map flag is non-zero, then the color map will follow as 
 * 3*256 16 bit words, first the red map, then the green map, and
 * finally the blue map.
 * 
 * Following the setup information is the Run Length Encoded image.
 * Each instruction consists of a 4-bit opcode, a 12-bit datum and
 * possibly one or more following words (all words are 16 bits).  The
 * instruction opcodes are:
 * 
 * SkipLines (1):   The bottom 10 bits are an unsigned number to be added to
 *		    current Y position.
 * 
 * SetColor (2):    The datum indicates which color is to be loaded with
 * 		    the data described by the following ByteData and
 * 		    RunData instructions.  0->red, 1->green, 2->blue.  The
 * 		    operation also resets the X position to the initial
 * 		    X (i.e. a carriage return operation is performed).
 * 
 * SkipPixels (3):  The bottom 10 bits are an unsigned number to be
 * 		    added to the current X position.
 * 
 * ByteData (5):    The datum is one less than the number of bytes of
 * 		    color data following.  If the number of bytes is
 * 		    odd, a filler byte will be appended to the end of
 * 		    the byte string to make an integral number of 16-bit
 * 		    words.  The bytes are in PDP-11 order.  The X
 * 		    position is incremented to follow the last byte of
 * 		    data.
 * 
 * RunData (6):	    The datum is one less than the run length.  The
 * 		    following word contains (in its lower 8 bits) the
 * 		    color of the run.  The X position is incremented to
 * 		    follow the last byte in the run.
 */

#include    <string.h>
#include	<stdio.h>

#include	"rle_put.h"
#include	"rle.h"
#include	"rle_code.h"
#include    "vaxshort.h"
#include    "Runput.h"

#define UPPER 255			/* anything bigger ain't a byte */

/*
 * Macros to make writing instructions with correct byte order easier.
 */
/* Write a two-byte value in little_endian order. */
#define	put16(a)    (putc((a)&0xff,rle_fd),putc((char)(((a)>>8)&0xff),rle_fd))

/* short instructions */
#define mk_short_1(oper,a1)		/* one argument short */ \
    putc(oper,rle_fd), putc((char)a1,rle_fd)

#define mk_short_2(oper,a1,a2)		/* two argument short */ \
    putc(oper,rle_fd), putc((char)a1,rle_fd), put16(a2)

/* long instructions */
#define mk_long_1(oper,a1)		/* one argument long */ \
    putc((char)(LONG|oper),rle_fd), putc('\0', rle_fd), put16(a1)

#define mk_long_2(oper,a1,a2)		/* two argument long */ \
    putc((char)(LONG|oper),rle_fd), putc('\0', rle_fd), \
    put16(a1), put16(a2)

/* choose between long and short format instructions */
/* NOTE: these macros can only be used where a STATEMENT is legal */

#define mk_inst_1(oper,a1)		/* one argument inst */ \
    if (a1>UPPER) (mk_long_1(oper,a1)); else (mk_short_1(oper,a1))

#define mk_inst_2(oper,a1,a2)		/* two argument inst */ \
    if (a1>UPPER) (mk_long_2(oper,a1,a2)); else (mk_short_2(oper,a1,a2))

/* 
 * Opcode definitions
 */
#define	    RSkipLines(n)   	    mk_inst_1(RSkipLinesOp,(n))

#define	    RSetColor(c)	    mk_short_1(RSetColorOp,(c))
				    /* has side effect of performing */
				    /* "carriage return" action */

#define	    RSkipPixels(n)	    mk_inst_1(RSkipPixelsOp,(n))

#define	    RNewLine		    RSkipLines(1)

#define	    RByteData(n)	    mk_inst_1(RByteDataOp,n)
					/* followed by ((n+1)/2)*2 bytes */
					/* of data.  If n is odd, last */
					/* byte will be ignored */
					/* "cursor" is left at pixel */
					/* following last pixel written */

#define	    RRunData(n,c)	    mk_inst_2(RRunDataOp,(n),(c))
					/* next word contains color data */
					/* "cursor" is left at pixel after */
					/* end of run */

#define     REOF		    mk_inst_1(REOFOp,0)
					/* Really opcode only */

/*****************************************************************
 * TAG( RunSetup )
 * Put out initial setup data for RLE files.
 */
void
RunSetup(rle_hdr * the_hdr)
{
    struct XtndRsetup setup;
    register FILE * rle_fd = the_hdr->rle_file;

    put16( RLE_MAGIC );

    if ( the_hdr->background == 2 )
	setup.h_flags = H_CLEARFIRST;
    else if ( the_hdr->background == 0 )
	setup.h_flags = H_NO_BACKGROUND;
    else
	setup.h_flags = 0;
    if ( the_hdr->alpha )
	setup.h_flags |= H_ALPHA;
    if ( the_hdr->comments != NULL && *the_hdr->comments != NULL )
	setup.h_flags |= H_COMMENT;

    setup.h_ncolors = the_hdr->ncolors;
    setup.h_pixelbits = 8;		/* Grinnell dependent */
    if ( the_hdr->ncmap > 0 && the_hdr->cmap == NULL )
    {
	fprintf( stderr,
       "%s: Color map of size %d*%d specified, but not supplied, writing %s\n",
		 the_hdr->cmd, the_hdr->ncmap, (1 << the_hdr->cmaplen),
		 the_hdr->file_name );
	the_hdr->ncmap = 0;
    }
    setup.h_cmaplen = the_hdr->cmaplen;	/* log2 of color map size */
    setup.h_ncmap = the_hdr->ncmap;	/* no of color channels */
    vax_pshort(setup.hc_xpos,the_hdr->xmin);
    vax_pshort(setup.hc_ypos,the_hdr->ymin);
    vax_pshort(setup.hc_xlen,the_hdr->xmax - the_hdr->xmin + 1);
    vax_pshort(setup.hc_ylen,the_hdr->ymax - the_hdr->ymin + 1);
    fwrite((char *)&setup, SETUPSIZE, 1, rle_fd);
    if ( the_hdr->background != 0 )
    {
	register int i;
	register rle_pixel *background;
	register int *bg_color;

	overflow_add(the_hdr->ncolors,1);
	background = (rle_pixel *)malloc( (unsigned)(the_hdr->ncolors + 1) );
	/* 
	 * If even number of bg color bytes, put out one more to get to 
	 * 16 bit boundary.
	 */
	bg_color = the_hdr->bg_color;
	for ( i = 0; i < the_hdr->ncolors; i++ )
	    background[i] =  *bg_color++;
	/* Extra byte, if written, should be 0. */
	background[i] = 0;
	fwrite((char *)background, (the_hdr->ncolors / 2) * 2 + 1, 1, rle_fd);
	free( background );
    }
    else
	putc( '\0', rle_fd );
    if (the_hdr->ncmap > 0)
    {
	/* Big-endian machines are harder */
	register int i, nmap = (1 << the_hdr->cmaplen) *
			       the_hdr->ncmap;
	register char *h_cmap = (char *)malloc2( nmap, 2 );
	if ( h_cmap == NULL )
	{
	    fprintf( stderr,
	     "%s: Malloc failed for color map of size %d, writing %s\n",
		     the_hdr->cmd, nmap, the_hdr->file_name );
	    exit( 1 );
	}
	for ( i = 0; i < nmap; i++ )
	    vax_pshort( &h_cmap[i*2], the_hdr->cmap[i] );

	fwrite( h_cmap, nmap, 2, rle_fd );
	free( h_cmap );
    }

    /* Now write out comments if given */
    if ( setup.h_flags & H_COMMENT )
    {
	int comlen;
	register CONST_DECL char ** com_p;

	/* Get the total length of comments */
	comlen = 0;
	for ( com_p = the_hdr->comments; *com_p != NULL; com_p++ )
	    comlen += 1 + strlen( *com_p );

	put16( comlen );
	for ( com_p = the_hdr->comments; *com_p != NULL; com_p++ )
	    fwrite( *com_p, 1, strlen( *com_p ) + 1, rle_fd );

	if ( comlen & 1 )	/* if odd length, round up */
	    putc( '\0', rle_fd );
    }
}

/*****************************************************************
 * TAG( RunSkipBlankLines )
 * Skip one or more blank lines in the RLE file.
 */
void
RunSkipBlankLines(int nblank, rle_hdr * the_hdr)
{
    register FILE * rle_fd = the_hdr->rle_file;
    RSkipLines(nblank);
}

/*****************************************************************
 * TAG( RunSetColor )
 * Select a color and do carriage return.
 * color: 0 = Red, 1 = Green, 2 = Blue.
 */
void
RunSetColor(int c, rle_hdr * the_hdr)
{
    register FILE * rle_fd = the_hdr->rle_file;
    RSetColor(c);
}

/*****************************************************************
 * TAG( RunSkipPixels )
 * Skip a run of background.
 */

/* ARGSUSED */
void
RunSkipPixels(int nskip, int last, int wasrun, rle_hdr * the_hdr)
{
    register FILE * rle_fd = the_hdr->rle_file;
    if (! last && nskip > 0)
    {
	RSkipPixels(nskip);
    }
}

/*****************************************************************
 * TAG( RunNewScanLine )
 * Perform a newline action.  Since CR is implied by the Set Color
 * operation, only generate code if the newline flag is true.
 */
void
RunNewScanLine(int flag, rle_hdr * the_hdr)
{
    register FILE * rle_fd = the_hdr->rle_file;
    if (flag)
    {
	RNewLine;
    }
}

/*****************************************************************
 * TAG( Runputdata )
 * Put one or more pixels of byte data into the output file.
 */
void
Runputdata(rle_pixel * buf, int n, rle_hdr * the_hdr)
{
    register FILE * rle_fd = the_hdr->rle_file;
    if (n == 0)
	return;

    RByteData(n-1);
    fwrite((char *)buf, n, 1, rle_fd);
    if ( n & 1 )
	putc( 0, rle_fd );
}

/*****************************************************************
 * TAG( Runputrun )
 * Output a single color run.
 */

/* ARGSUSED */
void
Runputrun(int color, int n, int last, rle_hdr * the_hdr)
{
    register FILE * rle_fd = the_hdr->rle_file;
    RRunData(n-1,color);
}


/*****************************************************************
 * TAG( RunputEof )
 * Output an EOF opcode
 */
void
RunputEof(rle_hdr * the_hdr)
{
    register FILE * rle_fd = the_hdr->rle_file;
    REOF;
}
