/*
 * Copyright (C) 1991, 1992, Thomas G. Lane.
 * Part of the Independent JPEG Group's software.
 * See the file Copyright for more details.
 *
 * Copyright (c) 1993 Brian C. Smith, The Regents of the University
 * of California
 * All rights reserved.
 * 
 * Copyright (c) 1994 Kongji Huang and Brian C. Smith.
 * Cornell University
 * All rights reserved.
 * 
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without written agreement is
 * hereby granted, provided that the above copyright notice and the following
 * two paragraphs appear in all copies of this software.
 * 
 * IN NO EVENT SHALL CORNELL UNIVERSITY BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF CORNELL
 * UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * CORNELL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND CORNELL UNIVERSITY HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 */

#ifndef _IO
#define _IO

/*
 * Size of the input and output buffer
 */
#define JPEG_BUF_SIZE  4096 

/*
 * The following variables keep track of the input and output
 * buffer for the JPEG data.
 */
/*
 *extern char outputBuffer[JPEG_BUF_SIZE];      output buffer              
 *extern int numOutputBytes;                    bytes in the output buffer
 */

/*
 *extern Uchar inputBuffer[JPEG_BUF_SIZE];      Input buffer for JPEG data
 *extern int numInputBytes;                     bytes in inputBuffer       
 *extern int maxInputBytes;                     Size of inputBuffer 
 *extern int inputBufferOffset;                   Offset of current byte  
 */

/*
 * the output file pointer. 
 */
/*
 *extern FILE *outFile;
 */

/*
 *--------------------------------------------------------------
 *
 * EmitByte --
 *
 *	Write a single byte out to the output buffer, and
 *	flush if it's full.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The outp[ut buffer may get flushed.
 *
 *--------------------------------------------------------------
 */
#define EmitByte(val)  {						\
    if (numOutputBytes >= JPEG_BUF_SIZE) {				\
	FlushBytes();							\
    }									\
    outputBuffer[numOutputBytes++] = (char)(val);			\
}

/*
 *--------------------------------------------------------------
 *
 * GetJpegChar, UnGetJpegChar --
 *
 *      Macros to get the next character from the input stream.
 *
 * Results:
 *      GetJpegChar returns the next character in the stream, or EOF
 *      UnGetJpegChar returns nothing.
 *
 * Side effects:
 *      A byte is consumed or put back into the inputBuffer.
 *
 *--------------------------------------------------------------
 */
/*
 *#define GetJpegChar()                                                   \
 *   ((inputBufferOffset < numInputBytes)?                               \
 *   inputBuffer[inputBufferOffset++]:                                  \
 *   (numInputBytes = 2+ReadJpegData(inputBuffer+2,JPEG_BUF_SIZE-2),    \
 *    inputBufferOffset = 2,                                            \
 *    ((inputBufferOffset < numInputBytes)?                             \
 *     inputBuffer[inputBufferOffset++]:                                \
 *     EOF)))
 */

extern int inputBufferOffset;

#define GetJpegCharInit() {inputBufferOffset = 0;}

#define GetJpegChar()                                                   \
    ((inputBufferOffset < numInputBytes)?                               \
     inputBuffer[inputBufferOffset++]:                                  \
     EOF)

#define UnGetJpegChar(ch)       (inputBuffer[--inputBufferOffset]=(ch))

/*
 *--------------------------------------------------------------
 *
 * WriteJpegChar
 *
 *      Macros to write a character to the output stream.
 *
 *--------------------------------------------------------------
 */
#define WriteJpegChar(val, outputBuffer,outputBufferOffset,numOutputBytes) \
    ((outputBufferOffset < numOutputBytes)?                            \
    outputBuffer[outputBufferOffset++]= (char)(val):                     \
    EOF)

#endif /* _IO */