/*

 * wrtarga.c

 *

 * This file was part of the Independent JPEG Group's software:

 * Copyright (C) 1991-1996, Thomas G. Lane.

 * libjpeg-turbo Modifications:

 * Copyright (C) 2017, D. R. Commander.

 * For conditions of distribution and use, see the accompanying README.ijg

 * file.

 *

 * This file contains routines to write output images in Targa format.

 *

 * 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 Lee Daniel Crocker.

 */

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

#ifdef TARGA_SUPPORTED

/*

 * To support 12-bit JPEG data, we'd have to scale output down to 8 bits.

 * This is not yet implemented.

 */

#if BITS_IN_JSAMPLE != 8

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

#endif

/* Private version of data destination object */

typedef struct {

  struct djpeg_dest_struct pub; /* public fields */

  char *iobuffer;               /* physical I/O buffer */

  JDIMENSION buffer_width;      /* width of one row */

} tga_dest_struct;

typedef tga_dest_struct *tga_dest_ptr;

LOCAL(void)

write_header(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, int num_colors)

/* Create and write a Targa header */

{

  char targaheader[18];

  /* Set unused fields of header to 0 */

  MEMZERO(targaheader, sizeof(targaheader));

  if (num_colors > 0) {

    targaheader[1] = 1;         /* color map type 1 */

    targaheader[5] = (char)(num_colors & 0xFF);

    targaheader[6] = (char)(num_colors >> 8);

    targaheader[7] = 24;        /* 24 bits per cmap entry */

  }

  targaheader[12] = (char)(cinfo->output_width & 0xFF);

  targaheader[13] = (char)(cinfo->output_width >> 8);

  targaheader[14] = (char)(cinfo->output_height & 0xFF);

  targaheader[15] = (char)(cinfo->output_height >> 8);

  targaheader[17] = 0x20;       /* Top-down, non-interlaced */

  if (cinfo->out_color_space == JCS_GRAYSCALE) {

    targaheader[2] = 3;         /* image type = uncompressed grayscale */

    targaheader[16] = 8;        /* bits per pixel */

  } else {                      /* must be RGB */

    if (num_colors > 0) {

      targaheader[2] = 1;       /* image type = colormapped RGB */

      targaheader[16] = 8;

    } else {

      targaheader[2] = 2;       /* image type = uncompressed RGB */

      targaheader[16] = 24;

    }

  }

  if (JFWRITE(dinfo->output_file, targaheader, 18) != (size_t)18)

    ERREXIT(cinfo, JERR_FILE_WRITE);

}

/*

 * Write some pixel data.

 * In this module rows_supplied will always be 1.

 */

METHODDEF(void)

put_pixel_rows(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,

               JDIMENSION rows_supplied)

/* used for unquantized full-color output */

{

  tga_dest_ptr dest = (tga_dest_ptr)dinfo;

  register JSAMPROW inptr;

  register char *outptr;

  register JDIMENSION col;

  inptr = dest->pub.buffer[0];

  outptr = dest->iobuffer;

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

    outptr[0] = (char)GETJSAMPLE(inptr[2]); /* RGB to BGR order */

    outptr[1] = (char)GETJSAMPLE(inptr[1]);

    outptr[2] = (char)GETJSAMPLE(inptr[0]);

    inptr += 3, outptr += 3;

  }

  (void)JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);

}

METHODDEF(void)

put_gray_rows(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,

              JDIMENSION rows_supplied)

/* used for grayscale OR quantized color output */

{

  tga_dest_ptr dest = (tga_dest_ptr)dinfo;

  register JSAMPROW inptr;

  register char *outptr;

  register JDIMENSION col;

  inptr = dest->pub.buffer[0];

  outptr = dest->iobuffer;

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

    *outptr++ = (char)GETJSAMPLE(*inptr++);

  }

  (void)JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);

}

/*

 * Write some demapped pixel data when color quantization is in effect.

 * For Targa, this is only applied to grayscale data.

 */

METHODDEF(void)

put_demapped_gray(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,

                  JDIMENSION rows_supplied)

{

  tga_dest_ptr dest = (tga_dest_ptr)dinfo;

  register JSAMPROW inptr;

  register char *outptr;

  register JSAMPROW color_map0 = cinfo->colormap[0];

  register JDIMENSION col;

  inptr = dest->pub.buffer[0];

  outptr = dest->iobuffer;

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

    *outptr++ = (char)GETJSAMPLE(color_map0[GETJSAMPLE(*inptr++)]);

  }

  (void)JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);

}

/*

 * Startup: write the file header.

 */

METHODDEF(void)

start_output_tga(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)

{

  tga_dest_ptr dest = (tga_dest_ptr)dinfo;

  int num_colors, i;

  FILE *outfile;

  if (cinfo->out_color_space == JCS_GRAYSCALE) {

    /* Targa doesn't have a mapped grayscale format, so we will */

    /* demap quantized gray output.  Never emit a colormap. */

    write_header(cinfo, dinfo, 0);

    if (cinfo->quantize_colors)

      dest->pub.put_pixel_rows = put_demapped_gray;

    else

      dest->pub.put_pixel_rows = put_gray_rows;

  } else if (cinfo->out_color_space == JCS_RGB) {

    if (cinfo->quantize_colors) {

      /* We only support 8-bit colormap indexes, so only 256 colors */

      num_colors = cinfo->actual_number_of_colors;

      if (num_colors > 256)

        ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors);

      write_header(cinfo, dinfo, num_colors);

      /* Write the colormap.  Note Targa uses BGR byte order */

      outfile = dest->pub.output_file;

      for (i = 0; i < num_colors; i++) {

        putc(GETJSAMPLE(cinfo->colormap[2][i]), outfile);

        putc(GETJSAMPLE(cinfo->colormap[1][i]), outfile);

        putc(GETJSAMPLE(cinfo->colormap[0][i]), outfile);

      }

      dest->pub.put_pixel_rows = put_gray_rows;

    } else {

      write_header(cinfo, dinfo, 0);

      dest->pub.put_pixel_rows = put_pixel_rows;

    }

  } else {

    ERREXIT(cinfo, JERR_TGA_COLORSPACE);

  }

}

/*

 * Finish up at the end of the file.

 */

METHODDEF(void)

finish_output_tga(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)

{

  /* Make sure we wrote the output file OK */

  fflush(dinfo->output_file);

  if (ferror(dinfo->output_file))

    ERREXIT(cinfo, JERR_FILE_WRITE);

}

/*

 * Re-calculate buffer dimensions based on output dimensions.

 */

METHODDEF(void)

calc_buffer_dimensions_tga(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)

{

  tga_dest_ptr dest = (tga_dest_ptr)dinfo;

  dest->buffer_width = cinfo->output_width * cinfo->output_components;

}

/*

 * The module selection routine for Targa format output.

 */

GLOBAL(djpeg_dest_ptr)

jinit_write_targa(j_decompress_ptr cinfo)

{

  tga_dest_ptr dest;

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

  dest = (tga_dest_ptr)

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

                                sizeof(tga_dest_struct));

  dest->pub.start_output = start_output_tga;

  dest->pub.finish_output = finish_output_tga;

  dest->pub.calc_buffer_dimensions = calc_buffer_dimensions_tga;

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

  jpeg_calc_output_dimensions(cinfo);

  /* Create I/O buffer. */

  dest->pub.calc_buffer_dimensions(cinfo, (djpeg_dest_ptr)dest);

  dest->iobuffer = (char *)

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

                                (size_t)(dest->buffer_width * sizeof(char)));

  /* Create decompressor output buffer. */

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

    ((j_common_ptr)cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION)1);

  dest->pub.buffer_height = 1;

  return (djpeg_dest_ptr)dest;

}

#endif /* TARGA_SUPPORTED */