/* Copyright (C) 1996 Aladdin Enterprises.  All rights reserved.
  
  This file is part of Aladdin Ghostscript.
  
  Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
  or distributor accepts any responsibility for the consequences of using it,
  or for whether it serves any particular purpose or works at all, unless he
  or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
  License (the "License") for full details.
  
  Every copy of Aladdin Ghostscript must include a copy of the License,
  normally in a plain ASCII text file named PUBLIC.  The License grants you
  the right to copy, modify and redistribute Aladdin Ghostscript, but only
  under certain conditions described in the License.  Among other things, the
  License requires that the copyright notice and this notice be preserved on
  all copies.
*/

/* gdevrrgb.c */
/* RGB device with "render algorithm" */
#include "gdevprn.h"

/*
 * This is a 32-bit device in which each pixel holds 24 bits of RGB and 8
 * (actually 4) bits of "render algorithm".  It is not useful in itself, but
 * it is a good example of (1) how to handle "render algorithm" information
 * and (2) how to implement a printer device with a non-standard memory
 * device as its underlying buffer.
 */

/* Define default device parameters. */
#ifndef X_DPI
#  define X_DPI 300
#endif
#ifndef Y_DPI
#  define Y_DPI 300
#endif

/* The device descriptor */
private dev_proc_open_device(rrgb_open);
private dev_proc_map_rgb_color(rrgb_map_rgb_color);
private dev_proc_map_color_rgb(rrgb_map_color_rgb);
private dev_proc_print_page(rrgb_print_page);
private const gx_device_procs rrgb_procs =
  prn_color_procs(rrgb_open, gdev_prn_output_page, gdev_prn_close,
		  rrgb_map_rgb_color, rrgb_map_color_rgb);

gx_device_printer far_data gs_rrgb_device =
{ prn_device_body(gx_device_printer, rrgb_procs, "rrgb",
	DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	X_DPI, Y_DPI,
	0,0,0,0,			/* margins */
	3,32,255,255,256,256, rrgb_print_page)
};

/* Buffer device implementation */
private dev_proc_make_buffer_device(rrgb_make_buffer_device);
private dev_proc_strip_copy_rop(rrgb_strip_copy_rop);

#define ppdev ((gx_device_printer *)pdev)

/* Open the device.  We redefine this only so we can reset */
/* make_buffer_device. */
private int
rrgb_open(gx_device *pdev)
{	ppdev->printer_procs.make_buffer_device = rrgb_make_buffer_device;
	return gdev_prn_open(pdev);
}

/* Color mapping */
private gx_color_index
rrgb_map_rgb_color(gx_device *dev,
  gx_color_value r, gx_color_value g, gx_color_value b)
{	return gx_color_value_to_byte(b) +
	  ((uint)gx_color_value_to_byte(g) << 8) +
	    ((ulong)gx_color_value_to_byte(r) << 16);
}
private int
rrgb_map_color_rgb(gx_device *dev, gx_color_index color,
  gx_color_value prgb[3])
{	prgb[0] = gx_color_value_from_byte((color >> 16) & 0xff);
	prgb[1] = gx_color_value_from_byte((color >> 8) & 0xff);
	prgb[2]	= gx_color_value_from_byte(color & 0xff);
	return 0;
}

/* Print the page.  Just copy the bits to the file. */
private int
rrgb_print_page(gx_device_printer *pdev, FILE *prn_stream)
{	/* Just dump the bits on the file. */
	int line_size = gdev_mem_bytes_per_scan_line((gx_device *)pdev);
	byte *in = (byte *)gs_malloc(line_size, 1, "rrgb_print_page");
	int lnum;

	if ( in == 0 )
	  return_error(gs_error_VMerror);
	for ( lnum = 0; lnum < pdev->height; ++lnum )
	  {	byte *data;
		gdev_prn_get_bits(pdev, lnum, in, &data);
		fwrite(data, 1, line_size, prn_stream);
	  }
	gs_free((char *)in, line_size, 1, "rrgb_print_page");
	return 0;
}

/* Reimplement the buffer device so that it stores the "render algorithm" */
/* in the top byte of each pixel. */
private int
rrgb_make_buffer_device(gx_device_memory *mdev,
  gx_device *target, gs_memory_t *mem, bool for_band)
{	int code = gx_default_make_buffer_device(mdev, target, mem, for_band);

	if ( code < 0 )
	  return code;
	mdev->std_procs.strip_copy_rop = rrgb_strip_copy_rop;
	return code;
}

/* Reimplement copy_rop so it saves the "render algorithm". */
/* This is messy: we have to copy each (partial) scan line from the */
/* 32-bit representation into a 24-bit buffer, do the operation, */
/* and then write it back.  The code is modeled on the default */
/* implementation in gdevmrop.c (q.v.). */
private void
rrgb_copy_4to3(byte *dest, const byte *src, int width)
{	const byte *p = src;
	byte *q = dest;
	int n;

	for ( n = width; n > 0; p += 4, q += 3, --n )
	  q[0] = p[1], q[1] = p[2], q[2] = p[3];
}
private void
rrgb_copy_3to4(byte *dest, const byte *src, int width, byte upper)
{	const byte *p = src;
	byte *q = dest;
	int n;

	for ( n = width; n > 0; p += 3, q += 4, --n )
	  q[0] = upper, q[1] = p[0], q[2] = p[1], q[3] = p[2];
}
int
rrgb_strip_copy_rop(gx_device *dev,
  const byte *sdata, int sourcex, uint sraster, gx_bitmap_id id,
  const gx_color_index *scolors,
  const gx_strip_bitmap *textures, const gx_color_index *tcolors,
  int x, int y, int width, int height,
  int phase_x, int phase_y, gs_logical_operation_t lop)
{	gs_rop3_t rop = lop_rop(lop);
	const gx_device_memory *mdproto = gdev_mem_device_for_bits(24);
	gs_memory_t *mem = &gs_memory_default;
	gx_device_memory mdev;
	bool
	  uses_d = rop3_uses_D(rop),
	  copy_s = rop3_uses_S(rop) && scolors == NULL,
	  copy_t = rop3_uses_T(rop) && tcolors == NULL;
	byte *srow = 0;
	byte *trow = 0;
	const byte *srdata;
	int sx;
	gx_strip_bitmap tsubst;
	const gx_strip_bitmap *tptr;
	int tx;
	int code;
	int py;

	gs_make_mem_device(&mdev, mdproto, 0, -1, dev);
	mdev.width = width;
	mdev.height = 1;
	mdev.bitmap_memory = mem;
	code = (*dev_proc(&mdev, open_device))((gx_device *)&mdev);
	if ( code < 0 )
	  return code;
	if ( copy_s )
	  { srow = gs_alloc_bytes(mem, width * 3, "rrgb source buffer");
	    if ( srow == 0 )
	      { code = gs_note_error(gs_error_VMerror);
	        goto x;
	      }
	  }
	if ( copy_t )
	  { trow = gs_alloc_bytes(mem, textures->rep_width * 3,
				  "rrgb texture buffer");
	    if ( trow == 0 )
	      { code = gs_note_error(gs_error_VMerror);
	        goto x;
	      }
	  }
	for ( py = y; py < y + height; ++py )
	  { byte *ddata = scan_line_base((gx_device_memory *)dev, y) + x * 4;

	    if ( uses_d )
	      { rrgb_copy_4to3(scan_line_base(&mdev, 0), ddata, width);
	      }
	    if ( copy_s )
	      { rrgb_copy_4to3(srow, sdata + sourcex * 4, width);
		srdata = srow, sx = 0;
	      }
	    else
	      srdata = sdata + y * sraster, sx = sourcex;
	    if ( copy_t )
	      { tsubst = *textures;
		rrgb_copy_4to3(trow,
			       tsubst.data + ((py + phase_y) %
				 tsubst.rep_height) * tsubst.raster,
			       textures->rep_width);
		tsubst.data = trow;
		tsubst.size.x = tsubst.rep_width;
		tsubst.size.y = 1;
		tsubst.id = gx_no_bitmap_id;
		tsubst.rep_height = 1;
		tx = py / tsubst.rep_height * tsubst.rep_shift;
		tptr = &tsubst;
	      }
	    else
	      tptr = textures, tx = 0;
	    code = (*dev_proc(&mdev, strip_copy_rop))((gx_device *)&mdev,
			srdata, sx, 0 /*unused*/, gx_no_bitmap_id, scolors,
			tptr, tcolors, 0, 0, width, 1,
			phase_x + tx, phase_y + py, lop);
	    if ( code < 0 )
	      break;
	    rrgb_copy_3to4(ddata, scan_line_base(&mdev, 0), width,
			   (lop >> lop_ral_shift) & lop_ral_mask);
	  }
x:	gs_free_object(mem, trow, "rrgb texture buffer");
	gs_free_object(mem, srow, "rrgb source buffer");
	(*dev_proc(&mdev, close_device))((gx_device *)&mdev);
	return code;
}
