/*
 * jcapimin.c
 *
 * Copyright (C) 1994-1995, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains application interface code for the compression half
 * of the JPEG library.  These are the "minimum" API routines that may be
 * needed in either the normal full-compression case or the transcoding-only
 * case.
 *
 * Most of the routines intended to be called directly by an application
 * are in this file or in jcapistd.c.  But also see jcparam.c for
 * parameter-setup helper routines, jcomapi.c for routines shared by
 * compression and decompression, and jctrans.c for the transcoding case.
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"


/*
 * Initialization of a JPEG compression object.
 * The error manager must already be set up (in case memory manager fails).
 */

GLOBAL void
jpeg_create_compress( j_compress_ptr cinfo ) {
    int i;

    /* For debugging purposes, zero the whole master structure.
     * But error manager pointer is already there, so save and restore it.
     */
    {
        struct jpeg_error_mgr * err = cinfo->err;
        MEMZERO( cinfo, SIZEOF( struct jpeg_compress_struct ) );
        cinfo->err = err;
    }
    cinfo->is_decompressor = FALSE;

    /* Initialize a memory manager instance for this object */
    jinit_memory_mgr( (j_common_ptr) cinfo );

    /* Zero out pointers to permanent structures. */
    cinfo->progress = NULL;
    cinfo->dest = NULL;

    cinfo->comp_info = NULL;

    for ( i = 0; i < NUM_QUANT_TBLS; i++ ) {
        cinfo->quant_tbl_ptrs[i] = NULL;
    }

    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
        cinfo->dc_huff_tbl_ptrs[i] = NULL;
        cinfo->ac_huff_tbl_ptrs[i] = NULL;
    }

    cinfo->input_gamma = 1.0;/* in case application forgets */

    /* OK, I'm ready */
    cinfo->global_state = CSTATE_START;
}


/*
 * Destruction of a JPEG compression object
 */

GLOBAL void
jpeg_destroy_compress( j_compress_ptr cinfo ) {
    jpeg_destroy( (j_common_ptr) cinfo );/* use common routine */
}


/*
 * Abort processing of a JPEG compression operation,
 * but don't destroy the object itself.
 */

GLOBAL void
jpeg_abort_compress( j_compress_ptr cinfo ) {
    jpeg_abort( (j_common_ptr) cinfo );/* use common routine */
}


/*
 * Forcibly suppress or un-suppress all quantization and Huffman tables.
 * Marks all currently defined tables as already written (if suppress)
 * or not written (if !suppress).  This will control whether they get emitted
 * by a subsequent jpeg_start_compress call.
 *
 * This routine is exported for use by applications that want to produce
 * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
 * since it is called by jpeg_start_compress, we put it here --- otherwise
 * jcparam.o would be linked whether the application used it or not.
 */

GLOBAL void
jpeg_suppress_tables( j_compress_ptr cinfo, boolean suppress ) {
    int i;
    JQUANT_TBL * qtbl;
    JHUFF_TBL * htbl;

    for ( i = 0; i < NUM_QUANT_TBLS; i++ ) {
        if ( ( qtbl = cinfo->quant_tbl_ptrs[i] ) != NULL ) {
            qtbl->sent_table = suppress;
        }
    }

    for ( i = 0; i < NUM_HUFF_TBLS; i++ ) {
        if ( ( htbl = cinfo->dc_huff_tbl_ptrs[i] ) != NULL ) {
            htbl->sent_table = suppress;
        }
        if ( ( htbl = cinfo->ac_huff_tbl_ptrs[i] ) != NULL ) {
            htbl->sent_table = suppress;
        }
    }
}


/*
 * Finish JPEG compression.
 *
 * If a multipass operating mode was selected, this may do a great deal of
 * work including most of the actual output.
 */

GLOBAL void
jpeg_finish_compress( j_compress_ptr cinfo ) {
    JDIMENSION iMCU_row;

    if ( ( cinfo->global_state == CSTATE_SCANNING ) ||
        ( cinfo->global_state == CSTATE_RAW_OK ) ) {
        /* Terminate first pass */
        if ( cinfo->next_scanline < cinfo->image_height ) {
            ERREXIT( cinfo, JERR_TOO_LITTLE_DATA );
        }
        ( *cinfo->master->finish_pass )( cinfo );
    } else if ( cinfo->global_state != CSTATE_WRCOEFS ) {
        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
    }
    /* Perform any remaining passes */
    while ( !cinfo->master->is_last_pass ) {
        ( *cinfo->master->prepare_for_pass )( cinfo );
        for ( iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++ ) {
            if ( cinfo->progress != NULL ) {
                cinfo->progress->pass_counter = (long) iMCU_row;
                cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
                ( *cinfo->progress->progress_monitor )( (j_common_ptr) cinfo );
            }
            /* We bypass the main controller and invoke coef controller directly;
             * all work is being done from the coefficient buffer.
             */
            if ( !( *cinfo->coef->compress_data )( cinfo, (JSAMPIMAGE) NULL ) ) {
                ERREXIT( cinfo, JERR_CANT_SUSPEND );
            }
        }
        ( *cinfo->master->finish_pass )( cinfo );
    }
    /* Write EOI, do final cleanup */
    ( *cinfo->marker->write_file_trailer )( cinfo );
    ( *cinfo->dest->term_destination )( cinfo );
    /* We can use jpeg_abort to release memory and reset global_state */
    jpeg_abort( (j_common_ptr) cinfo );
}


/*
 * Write a special marker.
 * This is only recommended for writing COM or APPn markers.
 * Must be called after jpeg_start_compress() and before
 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
 */

GLOBAL void
jpeg_write_marker( j_compress_ptr cinfo, int marker,
                   const JOCTET * dataptr, unsigned int datalen ) {
    if ( ( cinfo->next_scanline != 0 ) ||
        ( ( cinfo->global_state != CSTATE_SCANNING ) &&
         ( cinfo->global_state != CSTATE_RAW_OK ) &&
         ( cinfo->global_state != CSTATE_WRCOEFS ) ) ) {
        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
    }

    ( *cinfo->marker->write_any_marker )( cinfo, marker, dataptr, datalen );
}


/*
 * Alternate compression function: just write an abbreviated table file.
 * Before calling this, all parameters and a data destination must be set up.
 *
 * To produce a pair of files containing abbreviated tables and abbreviated
 * image data, one would proceed as follows:
 *
 *		initialize JPEG object
 *		set JPEG parameters
 *		set destination to table file
 *		jpeg_write_tables(cinfo);
 *		set destination to image file
 *		jpeg_start_compress(cinfo, FALSE);
 *		write data...
 *		jpeg_finish_compress(cinfo);
 *
 * jpeg_write_tables has the side effect of marking all tables written
 * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
 * will not re-emit the tables unless it is passed write_all_tables=TRUE.
 */

GLOBAL void
jpeg_write_tables( j_compress_ptr cinfo ) {
    if ( cinfo->global_state != CSTATE_START ) {
        ERREXIT1( cinfo, JERR_BAD_STATE, cinfo->global_state );
    }

    /* (Re)initialize error mgr and destination modules */
    ( *cinfo->err->reset_error_mgr )( (j_common_ptr) cinfo );
    ( *cinfo->dest->init_destination )( cinfo );
    /* Initialize the marker writer ... bit of a crock to do it here. */
    jinit_marker_writer( cinfo );
    /* Write them tables! */
    ( *cinfo->marker->write_tables_only )( cinfo );
    /* And clean up. */
    ( *cinfo->dest->term_destination )( cinfo );
    /* We can use jpeg_abort to release memory. */
    jpeg_abort( (j_common_ptr) cinfo );
}