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/*
    This file contains the routines necessary to manipulate an image
    of 8 bit data that do not need to know about the image file format
*/

#include <stream.h>
#include <stdio.h>

#include "for.h++"

#include "long_image.h++"


/* the constructor when the image is built */
long_image::long_image 
    ( 
    const create_image_type cit ,	// marker that the image is being created
    const card n_rows , 		// the number of rows in the image
    const card n_cols , 		// the number of collumns in the image
    const FILE * image_file ,	// file for image
    const card w_width = 1 ,	// window width
    const card w_length = 1 	// window length
    )
    : ( CREATE , image_file , n_rows , n_cols , w_width , w_length )
    {
    /* check that the constructor is called correctly */
    if ( cit != CREATE )
	{
	cerr << "constructor for long_image being called in obscure way\n";
	abort();
	}
    
    /* allocate space for image */
    image_buffer = new long [ n_rows*n_cols ];

    /* allocate space for dope vector */
    image_rows = new long * [ n_rows ];
    /* allocate space for window dope vector */
    window_rows = new long * [ w_length ];

    /* initialize dope vector */
    FOR(int i1 = 0 ; i1 < n_rows; i1++)
	{
	image_rows[i1] = image_buffer + i1*n_cols;
	}
    ENDFOR

    /* set up the protection  so the image can be written */
    prot = CAN_WRITE;

    /* initialize function pointers */
    next = &uninitialized_next;
    prev = &uninitialized_prev;
    get_w_e_pointer = &uninitialized_get_w_e;
    write_w_e_pointer = &uninitialized_write_w_e;
    }


/* functions for function pointers */

/* this version of next assumes the window has been initialized */
int 
long_image::initialized_next ()
    {
    // if at the end of a row
    if ( collumn + window_width == number_cols )
	{
	// if at the end of the image
	if ( row + window_length == number_rows )
	    {
	    return 0;
	    }
	// otherwise go to the beginning of the next row
	collumn = 0;
	row++;
	// reset the pointers in the window
	FOR(int i1 = 0 ; i1 < window_length ; i1++)
	    {
	    window_rows[i1] = image_rows[row + i1];
	    }
	ENDFOR
	// return successfully
	return 1;
	}
    // otherwise move along row
    collumn++;
    // move the pointers in the window
    FOR(int i1 = 0 ; i1 < window_length ; i1++)
	{
	window_rows[i1]++;
	}
    ENDFOR
    // return successfully
    return 1;
    }

/* this version of prev assumes the window has been initialized */
int 
long_image::initialized_prev ()
    {
    // if at beginning of a row
    if ( collumn == 0 )
	{
	// if at the beginning of the image
	if ( row == 0 )
	    {
	    return 0;
	    }
	// otherwise go to the end of the previous row
	collumn = number_cols - window_width;
	row--;
	// reset the pointers in the window
	FOR(int i1 = 0 ; i1 < window_length ; i1++)
	    {
	    window_rows[i1] = image_rows[row + i1] + collumn;
	    }
	ENDFOR
	// return successfully
	return 1;
	}
    // otherwise move back on the row
    collumn--;
    // move the pointers in the window
    FOR(int i1 = 0 ; i1 < window_length ; i1++)
	{
	window_rows[i1]--;
	}
    ENDFOR
    // return successfully
    return 1;
    }

/* this version of next initializes the window */
int 
long_image::uninitialized_next ()
    {
    // check that the window fits in the image
    if ( (window_width > number_cols) || (window_length > number_rows) )
	{
	return 0;
	}

    // set row and collumn to 0
    row = 0;
    collumn = 0;

    // set the window row pointers
    FOR(int i1 = 0 ; i1 < window_length ; i1++)
	{
	window_rows[i1] = image_rows[row + i1];
	}
    ENDFOR

    // set the function pointers
    next = &initialized_next;
    prev = &initialized_prev;
    get_w_e_pointer = &initialized_get_w_e;
    write_w_e_pointer = &initialized_write_w_e;

    // set the window status
    window_status = INITIALIZED;
    return 1;
    }

/* this version of prev initializes the window */
int 
long_image::uninitialized_prev ()
    {
    // check that the window fits in the image
    if ( (window_width > number_cols) || (window_length > number_rows) )
	{
	return 0;
	}

    // set row and collumn to bottom right of image
    row = number_rows - window_length;
    collumn = number_cols - window_width;
    // set the window row pointers
    FOR(int i1 = 0 ; i1 < window_length ; i1++)
	{
	window_rows[i1] = image_rows[row + i1] + collumn;
	}
    ENDFOR

    // set the function pointers
    next = &initialized_next;
    prev = &initialized_prev;
    get_w_e_pointer = &initialized_get_w_e;
    write_w_e_pointer = &initialized_write_w_e;

    // set the window status
    window_status = INITIALIZED;
    return 1;
    }

// this version of next says that applying the next operation is impossible
int
long_image::impossible_next ( )
    {
    cerr << "Trying to apply the next operation to an image for which it is impossible!\n";
    return 0;
    }

// this version of prev says that applying the next operation is impossible
int
long_image::impossible_prev ( )
    {
    cerr << "Trying to apply the prev operation to an image for which it is impossible!\n";
    return 0;
    }

/* uninitialized version of get_w_e will just die */
long 
long_image::uninitialized_get_w_e ( const card i , const card j )
    {
    cerr << "Trying to get an element of an uninitialized window\n";
    cerr << "The element was " << i << "," << j << "\n";
    abort ();
    return 0;
    }

/* initialized version of get_w_e */
long 
long_image::initialized_get_w_e ( const card i , const card j )
    {
    // check that i,j is in the window
    if ( ( i >= window_length ) || ( j >= window_width ) )
	{
	cerr << "Tried to access element outside window\n";
	cerr << "Window size " << window_length << "," << window_width << "\n";
	cerr << "Accessed " << i << "," << j << "\n";
	abort ();
	return 0;
	}
    
    // otherwise return the element
    return window_rows[i][j];
    }

/* uninitialized version of write_w_e will just die */
void 
long_image::uninitialized_write_w_e ( const card i , const card j , const long value )
    {
    cerr << "Trying to write to an element of an uninitialized window\n";
    cerr << "Trying to write " << value << "\n";
    cerr << "To " << i << "," << j << "\n";
    abort ();
    }

/* initialized version of write_w_e */
void 
long_image::initialized_write_w_e ( const card i , const card j , const long value)
    {
    // check that i,j is in the window
    if ( ( i >= window_length ) || ( j >= window_width ) )
	{
	cerr << "Tried to access element outside window\n";
	cerr << "Window size " << window_length << "," << window_width << "\n";
	cerr << "Accessed " << i << "," << j << "\n";
	abort ();
	}
    
    // otherwise set the element
    window_rows[i][j] = value;
    }

/*
    move in row n steps 
    returns 1 when that motion is legal 0 otherwise
*/
int 
long_image::move_collumn ( const int n ) 
    {
    // the version in image does the checking and most of the work
    int result = image_class::move_collumn ( n );

    // if the move was successful move the window
    if ( result == 1 )
	{
	FOR(int i1 = 0 ; i1 < window_length ; i1++)
	    {
	    window_rows[i1] += n;
	    }
	ENDFOR
	}

    return result;
    }

/*
    move in collumn n steps
    returns 1 when that motion is legal 0 otherwise
*/
int 
long_image::move_row ( const int n ) 
    {
    // the version in image does the checking and most of the work
    int result = image_class::move_row ( n );

    // if the move was successful move the window
    if ( result == 1 )
	{
	FOR(int i1 = 0 ; i1 < window_length ; i1++)
	    {
	    window_rows[i1] = image_rows[row + i1] + collumn ;
	    }
	ENDFOR
	}

    return result;
    }


/*
    move to specified row
*/
void 
long_image::move_to_row ( const card n ) 
    {
    // the version in image does the checking and most of the work
    image_class::move_to_row ( n );

    // move the window to the specified place
    FOR(int i1 = 0 ; i1 < window_length ; i1++)
	{
	window_rows[i1] = image_rows[row + i1] + collumn ;
	}
    ENDFOR
    }


/*
    move to specified collumn
*/
void 
long_image::move_to_collumn ( const card n ) 
    {
    // the version in image does the checking and most of the work
    image_class::move_to_collumn ( n );

    // move the window to the specified place
    FOR(int i1 = 0 ; i1 < window_length ; i1++)
	{
	window_rows[i1] = image_rows[row + i1] + collumn ;
	}
    ENDFOR
    }

/*
    Gets a pointer to a row
    of the image
*/
const long * 
long_image::get_row( card row )
    {
    // Checks to make sure request is legal
    if ( row >= number_rows )
	{
	cerr << "Tried to accesses row " << row;
	cerr << " when image only has " << number_rows << " rows!\n";
	abort();
	}
    if ( image_status == UNINITIALIZED )
	{
	cerr << "Trying to read row from unitialized image!\n";
	abort();
	}
    if ( (prot != CAN_READ) && (prot != CAN_READ_AND_WRITE) )
	{
	cerr << "Trying to access a row of an image protected against reading!\n";
	abort();
	}
    
    return image_rows[row];
    }

/*
    Change the size of a window
    causes the window to become uninitialized
*/
void 
long_image::resize_window ( card width , card length )
    {

    // set the window
    window_width = width;
    window_length = length;
    window_status = UNINITIALIZED;

    /* allocate space for window dope vector */
    window_rows = new long * [ window_length ];

    /* reset function pointers */
    next = &uninitialized_next;
    prev = &uninitialized_prev;
    get_w_e_pointer = &uninitialized_get_w_e;
    write_w_e_pointer = &uninitialized_write_w_e;
    }

/*
    Causes the window to cover the entire image.
    Allows one to access any part of the image with window operations
*/
void 
long_image::window_entire_image ( )
    {
    // set up the window
    window_width = number_cols;
    window_length = number_rows;
    window_status = INITIALIZED;
    // make the window dope vector an alias for the image dope vector
    window_rows = image_rows;

    // set up function pointers so next and previous impossible
    next = &impossible_next;
    prev = &impossible_prev;
    // access functions
    get_w_e_pointer = &initialized_get_w_e;
    write_w_e_pointer = &initialized_write_w_e;
    }
/*
Copyright (C) 1986, David Sher in the University of Rochester
Permission is granted to any individual or institution to use, copy, or
redistribute this software so long as it is not sold for profit, provided
this copyright notice is retained.
*/
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