/* 
 * 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 */ 
