/* Copyright (C) 1995, 2000 Aladdin Enterprises.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License version 2
  as published by the Free Software Foundation.


  This software is provided AS-IS with no warranty, either express or
  implied. That is, this program is distributed in the hope that it will 
  be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: gdevpng.c,v 1.6 2002/02/21 22:24:51 giles Exp $ */
/* PNG (Portable Network Graphics) Format.  Pronounced "ping". */
/* lpd 1999-09-24: changes PNG_NO_STDIO to PNG_NO_CONSOLE_IO for libpng
   versions 1.0.3 and later. */
/* lpd 1999-07-01: replaced remaining uses of gs_malloc and gs_free with
   gs_alloc_bytes and gs_free_object. */
/* lpd 1999-03-08: changed png.h to png_.h to allow compiling with only
   headers in /usr/include, no source code. */
/* lpd 1997-07-20: changed from using gs_malloc/png_xxx_int to png_create_xxx
 * for allocating structures, and from gs_free to png_write_destroy for
 * freeing them. */
/* lpd 1997-5-7: added PNG_LIBPNG_VER conditional for operand types of
 * dummy png_push_fill_buffer. */
/* lpd 1997-4-13: Added PNG_NO_STDIO to remove library access to stderr. */
/* lpd 1997-3-14: Added resolution (pHYs) to output. */
/* lpd 1996-6-24: Added #ifdef for compatibility with old libpng versions. */
/* lpd 1996-6-11: Edited to remove unnecessary color mapping code. */
/* lpd (L. Peter Deutsch) 1996-4-7: Modified for libpng 0.88. */
/* Original version by Russell Lang 1995-07-04 */

#include "gdevprn.h"
#include "gdevpccm.h"
#include "gscdefs.h"

#define PNG_INTERNAL
/*
 * libpng versions 1.0.3 and later allow disabling access to the stdxxx
 * files while retaining support for FILE * I/O.
 */
#define PNG_NO_CONSOLE_IO
/*
 * Earlier libpng versions require disabling FILE * I/O altogether.
 * This produces a compiler warning about no prototype for png_init_io.
 * The right thing will happen at link time, since the library itself
 * is compiled with stdio support.  Unfortunately, we can't do this
 * conditionally depending on PNG_LIBPNG_VER, because this is defined
 * in png.h.
 */
/*#define PNG_NO_STDIO*/
#include "png_.h"

/* ------ The device descriptors ------ */

/*
 * Default X and Y resolution.
 */
#define X_DPI 72
#define Y_DPI 72

private dev_proc_print_page(png_print_page);

/* Monochrome. */

const gx_device_printer gs_pngmono_device =
prn_device(prn_std_procs, "pngmono",
	   DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	   X_DPI, Y_DPI,
	   0, 0, 0, 0,		/* margins */
	   1, png_print_page);

/* 4-bit planar (EGA/VGA-style) color. */

private const gx_device_procs png16_procs =
prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
		pc_4bit_map_rgb_color, pc_4bit_map_color_rgb);
const gx_device_printer gs_png16_device = {
  prn_device_body(gx_device_printer, png16_procs, "png16",
	   DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	   X_DPI, Y_DPI,
	   0, 0, 0, 0,		/* margins */
	   3, 4, 3, 2, 4, 3, png_print_page)
};

/* 8-bit (SuperVGA-style) color. */
/* (Uses a fixed palette of 3,3,2 bits.) */

private const gx_device_procs png256_procs =
prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
		pc_8bit_map_rgb_color, pc_8bit_map_color_rgb);
const gx_device_printer gs_png256_device = {
  prn_device_body(gx_device_printer, png256_procs, "png256",
	   DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	   X_DPI, Y_DPI,
	   0, 0, 0, 0,		/* margins */
	   3, 8, 6, 6, 7, 7, png_print_page)
};

/* 8-bit gray */

private const gx_device_procs pnggray_procs =
prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
	      gx_default_gray_map_rgb_color, gx_default_gray_map_color_rgb);
const gx_device_printer gs_pnggray_device =
{prn_device_body(gx_device_printer, pnggray_procs, "pnggray",
		 DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
		 X_DPI, Y_DPI,
		 0, 0, 0, 0,	/* margins */
		 1, 8, 255, 0, 256, 0, png_print_page)
};

/* 24-bit color. */

private const gx_device_procs png16m_procs =
prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
		gx_default_rgb_map_rgb_color, gx_default_rgb_map_color_rgb);
const gx_device_printer gs_png16m_device =
prn_device(png16m_procs, "png16m",
	   DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	   X_DPI, Y_DPI,
	   0, 0, 0, 0,		/* margins */
	   24, png_print_page);


/* ------ Private definitions ------ */

/* Write out a page in PNG format. */
/* This routine is used for all formats. */
private int
png_print_page(gx_device_printer * pdev, FILE * file)
{
    gs_memory_t *mem = pdev->memory;
    int raster = gdev_prn_raster(pdev);

    /* PNG structures */
    byte *row = gs_alloc_bytes(mem, raster, "png raster buffer");
    png_struct *png_ptr =
    png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    png_info *info_ptr =
    png_create_info_struct(png_ptr);
    int height = pdev->height;
    int depth = pdev->color_info.depth;
    int y;
    int code;			/* return code */
    const char *software_key = "Software";
    char software_text[256];
    png_text text_png;

    if (row == 0 || png_ptr == 0 || info_ptr == 0) {
	code = gs_note_error(gs_error_VMerror);
	goto done;
    }
    /* set error handling */
    if (setjmp(png_ptr->jmpbuf)) {
	/* If we get here, we had a problem reading the file */
	code = gs_note_error(gs_error_VMerror);
	goto done;
    }
    code = 0;			/* for normal path */
    /* set up the output control */
    png_init_io(png_ptr, file);

    /* set the file information here */
    info_ptr->width = pdev->width;
    info_ptr->height = pdev->height;
    /* resolution is in pixels per meter vs. dpi */
    info_ptr->x_pixels_per_unit =
	(png_uint_32) (pdev->HWResolution[0] * (100.0 / 2.54));
    info_ptr->y_pixels_per_unit =
	(png_uint_32) (pdev->HWResolution[1] * (100.0 / 2.54));
    info_ptr->phys_unit_type = PNG_RESOLUTION_METER;
    info_ptr->valid |= PNG_INFO_pHYs;
    switch (depth) {
	case 24:
	    info_ptr->bit_depth = 8;
	    info_ptr->color_type = PNG_COLOR_TYPE_RGB;
	    break;
	case 8:
	    info_ptr->bit_depth = 8;
	    if (gx_device_has_color(pdev))
		info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
	    else
		info_ptr->color_type = PNG_COLOR_TYPE_GRAY;
	    break;
	case 4:
	    info_ptr->bit_depth = 4;
	    info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
	    break;
	case 1:
	    info_ptr->bit_depth = 1;
	    info_ptr->color_type = PNG_COLOR_TYPE_GRAY;
	    /* invert monocrome pixels */
	    png_set_invert_mono(png_ptr);
	    break;
    }

    /* set the palette if there is one */
    if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) {
	int i;
	int num_colors = 1 << depth;
	gx_color_value rgb[3];

	info_ptr->palette =
	    (void *)gs_alloc_bytes(mem, 256 * sizeof(png_color),
				   "png palette");
	if (info_ptr->palette == 0) {
	    code = gs_note_error(gs_error_VMerror);
	    goto done;
	}
	info_ptr->num_palette = num_colors;
	info_ptr->valid |= PNG_INFO_PLTE;
	for (i = 0; i < num_colors; i++) {
	    (*dev_proc(pdev, map_color_rgb)) ((gx_device *) pdev,
					      (gx_color_index) i, rgb);
	    info_ptr->palette[i].red = gx_color_value_to_byte(rgb[0]);
	    info_ptr->palette[i].green = gx_color_value_to_byte(rgb[1]);
	    info_ptr->palette[i].blue = gx_color_value_to_byte(rgb[2]);
	}
    }
    /* add comment */
    sprintf(software_text, "%s %d.%02d", gs_product,
	    (int)(gs_revision / 100), (int)(gs_revision % 100));
    text_png.compression = -1;	/* uncompressed */
    text_png.key = (char *)software_key;	/* not const, unfortunately */
    text_png.text = software_text;
    text_png.text_length = strlen(software_text);
    info_ptr->text = &text_png;
    info_ptr->num_text = 1;

    /* write the file information */
    png_write_info(png_ptr, info_ptr);

    /* don't write the comments twice */
    info_ptr->num_text = 0;
    info_ptr->text = NULL;

    /* Write the contents of the image. */
    for (y = 0; y < height; y++) {
	gdev_prn_copy_scan_lines(pdev, y, row, raster);
	png_write_rows(png_ptr, &row, 1);
    }

    /* write the rest of the file */
    png_write_end(png_ptr, info_ptr);

    /* if you alloced the palette, free it here */
    gs_free_object(mem, info_ptr->palette, "png palette");

  done:
    /* free the structures */
    png_destroy_write_struct(&png_ptr, &info_ptr);
    gs_free_object(mem, row, "png raster buffer");

    return code;
}

/*
 * Patch around a static reference to a never-used procedure.
 * This could be avoided if we were willing to edit pngconf.h to
 *      #undef PNG_PROGRESSIVE_READ_SUPPORTED
 */
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
#  if PNG_LIBPNG_VER >= 95
#    define PPFB_LENGTH_T png_size_t
#  else
#    define PPFB_LENGTH_T png_uint_32
#  endif
void
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer,
		     PPFB_LENGTH_T length)
{
}
#endif
