/* libpnm4.c - pnm utility library part 4
**
** Copyright (C) 1988 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#include "pnm.h"
#include "rast.h"
#include "mallocvar.h"

/*
** Semi-work-alike versions of some Sun pixrect routines.  Just enough
** for rasterfile reading and writing to work.
*/

struct pixrect*
mem_create( w, h, depth )
    int w, h, depth;
{
    struct pixrect* p;
    struct mpr_data* m;

    MALLOCVAR(p);
    if ( p == NULL )
        return NULL;
    p->pr_ops = NULL;
    p->pr_size.x = w;
    p->pr_size.y = h;
    p->pr_depth = depth;
    MALLOCVAR(m);
    if ( m == NULL )
    {
        free( p );
        return NULL;
    }
    p->pr_data = m;

    /* According to the documentation, linebytes is supposed to be rounded
    ** up to a longword (except on 386 boxes).  However, this turns out
    ** not to be the case.  In reality, all of Sun's code rounds up to
    ** a short, not a long.
    */
    m->md_linebytes = ( w * depth + 15 ) / 16 * 2;
    m->md_offset.x = 0;
    m->md_offset.y = 0;
    m->md_flags = 0;
    MALLOCARRAY(m->md_image, m->md_linebytes * h );
    if ( m->md_image == NULL )
    {
        free( m );
        free( p );
        return NULL;
    }

    return p;
}



void
mem_free( p )
    struct pixrect* p;
{
    free( p->pr_data->md_image );
    free( p->pr_data );
    free( p );
}



int
pr_dump( p, out, colormap, type, copy_flag )
    struct pixrect* p;
    FILE* out;
    colormap_t* colormap;
    int type, copy_flag;
{
    struct rasterfile h;
    int size, besize, count;
    unsigned char* beimage;
    unsigned char* bp;
    unsigned char c, pc;
    int i, j;

    h.ras_magic = RAS_MAGIC;
    h.ras_width = p->pr_size.x;
    h.ras_height = p->pr_size.y;
    h.ras_depth = p->pr_depth;

    h.ras_type = type;
    switch ( type )
    {
    case RT_OLD:
        pm_error( "This program does not know the Old rasterfile type" );

    case RT_FORMAT_TIFF:
        pm_error( "This program does not know the TIFF rasterfile type" );

    case RT_FORMAT_IFF:
        pm_error( "This program does not know the IFF rasterfile type" );

    case RT_EXPERIMENTAL:
        pm_error( "This program does not know the Experimental "
                  "rasterfile type" );

    case RT_STANDARD:
    case RT_FORMAT_RGB:
        /* Ignore hP->ras_length. */
        h.ras_length = p->pr_size.y * p->pr_data->md_linebytes;
        break;

    case RT_BYTE_ENCODED:
        size = p->pr_size.y * p->pr_data->md_linebytes;
        bp = p->pr_data->md_image;
        MALLOCARRAY(beimage, size * 3 / 2);  /* worst case */
        if ( beimage == NULL )
            return PIX_ERR;
        besize = 0;
        count = 0;
        for ( i = 0; i < size; ++i )
        {
            c = *bp++;
            if ( count > 0 )
            {
                if ( pc != c )
                {
                    if ( count == 1 && pc == 128 )
                    {
                        beimage[besize++] = 128;
                        beimage[besize++] = 0;
                        count = 0;
                    }
                    else if ( count > 2 || pc == 128 )
                    {
                        beimage[besize++] = 128;
                        beimage[besize++] = count - 1;
                        beimage[besize++] = pc;
                        count = 0;
                    }
                    else
                    {
                        for ( j = 0; j < count; ++j )
                            beimage[besize++] = pc;
                        count = 0;
                    }
                }
            }
            pc = c;
            ++count;
            if ( count == 256 )
            {
                beimage[besize++] = 128;
                beimage[besize++] = count - 1;
                beimage[besize++] = c;
                count = 0;
            }
        }
        if ( count > 0 )
        {
            if ( count == 1 && c == 128 )
            {
                beimage[besize++] = 128;
                beimage[besize++] = 0;
            }
            if ( count > 2 || c == 128 )
            {
                beimage[besize++] = 128;
                beimage[besize++] = count - 1;
                beimage[besize++] = c;
            }
            else
            {
                for ( j = 0; j < count; ++j )
                    beimage[besize++] = c;
            }
        }
        h.ras_length = besize;
        break;

    default:
        pm_error( "unknown rasterfile type" );
    }

    if ( colormap == NULL )
    {
        h.ras_maptype = RMT_NONE;
        h.ras_maplength = 0;
    }
    else
    {
        h.ras_maptype = colormap->type;
        switch ( colormap->type )
        {
        case RMT_EQUAL_RGB:
            h.ras_maplength = colormap->length * 3;
            break;

        case RMT_RAW:
            h.ras_maplength = colormap->length;
            break;

        default:
            pm_error( "unknown colormap type" );
        }
    }

    if ( pm_writebiglong( out, h.ras_magic ) == -1 )
        return PIX_ERR;
    if ( pm_writebiglong( out, h.ras_width ) == -1 )
        return PIX_ERR;
    if ( pm_writebiglong( out, h.ras_height ) == -1 )
        return PIX_ERR;
    if ( pm_writebiglong( out, h.ras_depth ) == -1 )
        return PIX_ERR;
    if ( pm_writebiglong( out, h.ras_length ) == -1 )
        return PIX_ERR;
    if ( pm_writebiglong( out, h.ras_type ) == -1 )
        return PIX_ERR;
    if ( pm_writebiglong( out, h.ras_maptype ) == -1 )
        return PIX_ERR;
    if ( pm_writebiglong( out, h.ras_maplength ) == -1 )
        return PIX_ERR;

    if ( colormap != NULL )
    {
        switch ( colormap->type )
        {
        case RMT_EQUAL_RGB:
            if ( fwrite( colormap->map[0], 1, colormap->length, out ) !=
                 colormap->length )
                return PIX_ERR;
            if ( fwrite( colormap->map[1], 1, colormap->length, out ) !=
                 colormap->length )
                return PIX_ERR;
            if ( fwrite( colormap->map[2], 1, colormap->length, out ) !=
                 colormap->length )
                return PIX_ERR;
            break;

        case RMT_RAW:
            if ( fwrite( colormap->map[0], 1, colormap->length, out ) !=
                 colormap->length )
                return PIX_ERR;
            break;
        }
    }

    switch ( type )
    {
    case RT_STANDARD:
    case RT_FORMAT_RGB:
        if ( fwrite( p->pr_data->md_image, 1, h.ras_length, out ) !=
             h.ras_length )
            return PIX_ERR;
        break;

    case RT_BYTE_ENCODED:
        if ( fwrite( beimage, 1, besize, out ) != besize )
        {
            free( beimage );
            return PIX_ERR;
        }
        free( beimage );
        break;
    }

    return 0;
}



int
pr_load_header(FILE * const ifP, struct rasterfile * const headerP) {

    {
        long magic;

        pm_readbiglong(ifP, &magic);
        if (magic != RAS_MAGIC)
            pm_error("Wrong magic number for a RAST file");
    }
    {
        long width;
        pm_readbiglong(ifP, &width);

        if (width < 0)
            pm_error("Negative width in RAST header");
        else
            headerP->ras_width = width;
    }
    {
        long height;
        pm_readbiglong(ifP, &height);

        if (height < 0)
            pm_error("Negative height in RAST header");
        else
            headerP->ras_height = height;
    }
    {
        long depth;
        pm_readbiglong(ifP, &depth);

        if (depth < 0)
            pm_error("Negative depth in RAST header");
        else
            headerP->ras_depth = depth;
    }
    {
        long length;
        pm_readbiglong(ifP, &length);

        if (length < 0)
            pm_error("Negative length in RAST header");
        else
            headerP->ras_length = length;
    }
    pm_readbiglong(ifP, &headerP->ras_type);

    pm_readbiglong(ifP, &headerP->ras_maptype);
    {
        long mapLength;
        pm_readbiglong(ifP, &mapLength);

        if (mapLength < 0)
            pm_error("Negative map length in RAST header");
        else
            headerP->ras_maplength = mapLength;
    }
    return 0;
}



int
pr_load_colormap( in, hP, colormap )
    FILE* in;
    struct rasterfile* hP;
    colormap_t* colormap;
{
    if ( colormap == NULL || hP->ras_maptype == RMT_NONE )
    {
        int i;

        for ( i = 0; i < hP->ras_maplength; ++i )
            if ( getc( in ) == EOF )
                return PIX_ERR;
    }
    else
    {
        colormap->type = hP->ras_maptype;
        switch ( hP->ras_maptype )
        {
        case RMT_EQUAL_RGB:
            colormap->length = hP->ras_maplength / 3;
            MALLOCARRAY( colormap->map[0], colormap->length );
            if ( colormap->map[0] == NULL )
                return PIX_ERR;
            MALLOCARRAY( colormap->map[1], colormap->length );
            if ( colormap->map[1] == NULL )
            {
                free( colormap->map[0] );
                return PIX_ERR;
            }
            MALLOCARRAY( colormap->map[2], colormap->length );
            if ( colormap->map[2] == NULL )
            {
                free( colormap->map[0] );
                free( colormap->map[1] );
                return PIX_ERR;
            }
            if ( fread( colormap->map[0], 1, colormap->length, in ) !=
                 colormap->length ||
                 fread( colormap->map[1], 1, colormap->length, in ) !=
                 colormap->length ||
                 fread( colormap->map[2], 1, colormap->length, in ) !=
                 colormap->length )
            {
                free( colormap->map[0] );
                free( colormap->map[1] );
                free( colormap->map[2] );
                return PIX_ERR;
            }
            break;

        case RMT_RAW: {
            size_t bytesRead;

            colormap->length = hP->ras_maplength;
            MALLOCARRAY( colormap->map[0], colormap->length );
            if ( colormap->map[0] == NULL )
                return PIX_ERR;
            colormap->map[2] = colormap->map[1] = colormap->map[0];
            bytesRead = fread( colormap->map[0], 1, hP->ras_maplength, in );
            if ( bytesRead != hP->ras_maplength )
            {
                free( colormap->map[0] );
                return PIX_ERR;
            }
        }
            break;

        default:
            pm_error( "unknown colormap type" );
        }
    }
    return 0;
}



struct pixrect*
pr_load_image( in, hP, colormap )
    FILE* in;
    struct rasterfile* hP;
    colormap_t* colormap;
{
    struct pixrect* p;
    unsigned char* beimage;
    register unsigned char* bep;
    register unsigned char* bp;
    register unsigned char c;
    int i;
    register int j, count;

    p = mem_create( hP->ras_width, hP->ras_height, hP->ras_depth );
    if ( p == NULL )
        return NULL;

    switch ( hP->ras_type )
    {
    case RT_OLD:
        pm_error( "This program does not know the Old rasterfile type" );

    case RT_FORMAT_TIFF:
        pm_error( "This program does not know the TIFF rasterfile type" );

    case RT_FORMAT_IFF:
        pm_error( "This program does not know the IFF rasterfile type" );

    case RT_EXPERIMENTAL:
        pm_error( "This program does not know the Experimental "
                  "rasterfile type" );

    case RT_STANDARD:
    case RT_FORMAT_RGB:
        /* Ignore hP->ras_length. */
        i = p->pr_size.y * p->pr_data->md_linebytes;
        if ( fread( p->pr_data->md_image, 1, i, in ) != i )
        {
            mem_free( p );
            return NULL;
        }
        break;

    case RT_BYTE_ENCODED:
        MALLOCARRAY( beimage, hP->ras_length );
        if ( beimage == NULL )
        {
            mem_free( p );
            return NULL;
        }
        if ( fread( beimage, 1, hP->ras_length, in ) != hP->ras_length )
        {
            mem_free( p );
            free( beimage );
            return NULL;
        }
        bep = beimage;
        bp = p->pr_data->md_image;
        for ( i = 0; i < hP->ras_length; )
        {
            c = *bep++;
            if ( c == 128 )
            {
                count = ( *bep++ ) + 1;
                if ( count == 1 )
                {
                    *bp++ = 128;
                    i += 2;
                }
                else
                {
                    c = *bep++;
                    for ( j = 0; j < count; ++j )
                        *bp++ = c;
                    i += 3;
                }
            }
            else
            {
                *bp++ = c;
                ++i;
            }
        }
        free( beimage );
        break;

    default:
        pm_error( "unknown rasterfile type" );
    }

    return p;
}