/*

 * wrrle.c

 *

 * Copyright (C) 1991-1996, 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 routines to write output images in RLE format.

 * The Utah Raster Toolkit library is required (version 3.1 or later).

 *

 * These routines may need modification for non-Unix environments or

 * specialized applications.  As they stand, they assume output to

 * an ordinary stdio stream.

 *

 * Based on code contributed by Mike Lijewski,

 * with updates from Robert Hutchinson.

 */



#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */



#ifdef RLE_SUPPORTED



/* rle.h is provided by the Utah Raster Toolkit. */



#include <rle.h>



/*

 * We assume that JSAMPLE has the same representation as rle_pixel,

 * to wit, "unsigned char".  Hence we can't cope with 12- or 16-bit samples.

 */



#if BITS_IN_JSAMPLE != 8

  Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */

#endif





/*

 * Since RLE stores scanlines bottom-to-top, we have to invert the image

 * from JPEG's top-to-bottom order.  To do this, we save the outgoing data

 * in a virtual array during put_pixel_row calls, then actually emit the

 * RLE file during finish_output.

 */





/*

 * For now, if we emit an RLE color map then it is always 256 entries long,

 * though not all of the entries need be used.

 */



#define CMAPBITS	8

#define CMAPLENGTH	(1<<(CMAPBITS))



typedef struct {

  struct djpeg_dest_struct pub; /* public fields */



  jvirt_sarray_ptr image;	/* virtual array to store the output image */

  rle_map *colormap;	 	/* RLE-style color map, or NULL if none */

  rle_pixel **rle_row;		/* To pass rows to rle_putrow() */



} rle_dest_struct;



typedef rle_dest_struct * rle_dest_ptr;



/* Forward declarations */

METHODDEF(void) rle_put_pixel_rows

    JPP((j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,

	 JDIMENSION rows_supplied));





/*

 * Write the file header.

 *

 * In this module it's easier to wait till finish_output to write anything.

 */



METHODDEF(void)

start_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)

{

  rle_dest_ptr dest = (rle_dest_ptr) dinfo;

  size_t cmapsize;

  int i, ci;

#ifdef PROGRESS_REPORT

  cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;

#endif



  /*

   * Make sure the image can be stored in RLE format.

   *

   * - RLE stores image dimensions as *signed* 16 bit integers.  JPEG

   *   uses unsigned, so we have to check the width.

   *

   * - Colorspace is expected to be grayscale or RGB.

   *

   * - The number of channels (components) is expected to be 1 (grayscale/

   *   pseudocolor) or 3 (truecolor/directcolor).

   *   (could be 2 or 4 if using an alpha channel, but we aren't)

   */



  if (cinfo->output_width > 32767 || cinfo->output_height > 32767)

    ERREXIT2(cinfo, JERR_RLE_DIMENSIONS, cinfo->output_width, 

	     cinfo->output_height);



  if (cinfo->out_color_space != JCS_GRAYSCALE &&

      cinfo->out_color_space != JCS_RGB)

    ERREXIT(cinfo, JERR_RLE_COLORSPACE);



  if (cinfo->output_components != 1 && cinfo->output_components != 3)

    ERREXIT1(cinfo, JERR_RLE_TOOMANYCHANNELS, cinfo->num_components);



  /* Convert colormap, if any, to RLE format. */



  dest->colormap = NULL;



  if (cinfo->quantize_colors) {

    /* Allocate storage for RLE-style cmap, zero any extra entries */

    cmapsize = cinfo->out_color_components * CMAPLENGTH * SIZEOF(rle_map);

    dest->colormap = (rle_map *) (*cinfo->mem->alloc_small)

      ((j_common_ptr) cinfo, JPOOL_IMAGE, cmapsize);

    MEMZERO(dest->colormap, cmapsize);



    /* Save away data in RLE format --- note 8-bit left shift! */

    /* Shifting would need adjustment for JSAMPLEs wider than 8 bits. */

    for (ci = 0; ci < cinfo->out_color_components; ci++) {

      for (i = 0; i < cinfo->actual_number_of_colors; i++) {

        dest->colormap[ci * CMAPLENGTH + i] =

          GETJSAMPLE(cinfo->colormap[ci][i]) << 8;

      }

    }

  }



  /* Set the output buffer to the first row */

  dest->pub.buffer = (*cinfo->mem->access_virt_sarray)

    ((j_common_ptr) cinfo, dest->image, (JDIMENSION) 0, (JDIMENSION) 1, TRUE);

  dest->pub.buffer_height = 1;



  dest->pub.put_pixel_rows = rle_put_pixel_rows;



#ifdef PROGRESS_REPORT

  if (progress != NULL) {

    progress->total_extra_passes++;  /* count file writing as separate pass */

  }

#endif

}





/*

 * Write some pixel data.

 *

 * This routine just saves the data away in a virtual array.

 */



METHODDEF(void)

rle_put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,

		    JDIMENSION rows_supplied)

{

  rle_dest_ptr dest = (rle_dest_ptr) dinfo;



  if (cinfo->output_scanline < cinfo->output_height) {

    dest->pub.buffer = (*cinfo->mem->access_virt_sarray)

      ((j_common_ptr) cinfo, dest->image,

       cinfo->output_scanline, (JDIMENSION) 1, TRUE);

  }

}



/*

 * Finish up at the end of the file.

 *

 * Here is where we really output the RLE file.

 */



METHODDEF(void)

finish_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)

{

  rle_dest_ptr dest = (rle_dest_ptr) dinfo;

  rle_hdr header;		/* Output file information */

  rle_pixel **rle_row, *red, *green, *blue;

  JSAMPROW output_row;

  char cmapcomment[80];

  int row, col;

  int ci;

#ifdef PROGRESS_REPORT

  cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;

#endif



  /* Initialize the header info */

  header = *rle_hdr_init(NULL);

  header.rle_file = dest->pub.output_file;

  header.xmin     = 0;

  header.xmax     = cinfo->output_width  - 1;

  header.ymin     = 0;

  header.ymax     = cinfo->output_height - 1;

  header.alpha    = 0;

  header.ncolors  = cinfo->output_components;

  for (ci = 0; ci < cinfo->output_components; ci++) {

    RLE_SET_BIT(header, ci);

  }

  if (cinfo->quantize_colors) {

    header.ncmap   = cinfo->out_color_components;

    header.cmaplen = CMAPBITS;

    header.cmap    = dest->colormap;

    /* Add a comment to the output image with the true colormap length. */

    sprintf(cmapcomment, "color_map_length=%d", cinfo->actual_number_of_colors);

    rle_putcom(cmapcomment, &header);

  }



  /* Emit the RLE header and color map (if any) */

  rle_put_setup(&header);



  /* Now output the RLE data from our virtual array.

   * We assume here that (a) rle_pixel is represented the same as JSAMPLE,

   * and (b) we are not on a machine where FAR pointers differ from regular.

   */



#ifdef PROGRESS_REPORT

  if (progress != NULL) {

    progress->pub.pass_limit = cinfo->output_height;

    progress->pub.pass_counter = 0;

    (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);

  }

#endif



  if (cinfo->output_components == 1) {

    for (row = cinfo->output_height-1; row >= 0; row--) {

      rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)

        ((j_common_ptr) cinfo, dest->image,

	 (JDIMENSION) row, (JDIMENSION) 1, FALSE);

      rle_putrow(rle_row, (int) cinfo->output_width, &header);

#ifdef PROGRESS_REPORT

      if (progress != NULL) {

        progress->pub.pass_counter++;

        (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);

      }

#endif

    }

  } else {

    for (row = cinfo->output_height-1; row >= 0; row--) {

      rle_row = (rle_pixel **) dest->rle_row;

      output_row = * (*cinfo->mem->access_virt_sarray)

        ((j_common_ptr) cinfo, dest->image,

	 (JDIMENSION) row, (JDIMENSION) 1, FALSE);

      red = rle_row[0];

      green = rle_row[1];

      blue = rle_row[2];

      for (col = cinfo->output_width; col > 0; col--) {

        *red++ = GETJSAMPLE(*output_row++);

        *green++ = GETJSAMPLE(*output_row++);

        *blue++ = GETJSAMPLE(*output_row++);

      }

      rle_putrow(rle_row, (int) cinfo->output_width, &header);

#ifdef PROGRESS_REPORT

      if (progress != NULL) {

        progress->pub.pass_counter++;

        (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);

      }

#endif

    }

  }



#ifdef PROGRESS_REPORT

  if (progress != NULL)

    progress->completed_extra_passes++;

#endif



  /* Emit file trailer */

  rle_puteof(&header);

  fflush(dest->pub.output_file);

  if (ferror(dest->pub.output_file))

    ERREXIT(cinfo, JERR_FILE_WRITE);

}





/*

 * The module selection routine for RLE format output.

 */



GLOBAL(djpeg_dest_ptr)

jinit_write_rle (j_decompress_ptr cinfo)

{

  rle_dest_ptr dest;



  /* Create module interface object, fill in method pointers */

  dest = (rle_dest_ptr)

      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

                                  SIZEOF(rle_dest_struct));

  dest->pub.start_output = start_output_rle;

  dest->pub.finish_output = finish_output_rle;



  /* Calculate output image dimensions so we can allocate space */

  jpeg_calc_output_dimensions(cinfo);



  /* Allocate a work array for output to the RLE library. */

  dest->rle_row = (*cinfo->mem->alloc_sarray)

    ((j_common_ptr) cinfo, JPOOL_IMAGE,

     cinfo->output_width, (JDIMENSION) cinfo->output_components);



  /* Allocate a virtual array to hold the image. */

  dest->image = (*cinfo->mem->request_virt_sarray)

    ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,

     (JDIMENSION) (cinfo->output_width * cinfo->output_components),

     cinfo->output_height, (JDIMENSION) 1);



  return (djpeg_dest_ptr) dest;

}



#endif /* RLE_SUPPORTED */

