/*
 * jcapimin.c
 *
 * Copyright (C) 1994-1998, 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_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
{
  int i;
  /* Guard against version mismatches between library and caller. */
  cinfo->mem = NULL;		/* so jpeg_destroy knows mem mgr not called */

  /* For debugging purposes, we zero the whole master structure.
   * But the application has already set the err pointer, and may have set
   * client_data, so we have to save and restore those fields.
   * Note: if application hasn't set client_data, tools like Purify may
   * complain here.
   */
  {
    struct jpeg_error_mgr * err = cinfo->err;
    MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
    cinfo->err = err;
  }

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

  /* Zero out pointers to permanent structures. */
  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->script_space = NULL;

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


/*
 * 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++) {
      /* 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);
}