/* Copyright (C) 1997, 1998 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.
 */

/*$Id: gdevpsds.c $ */
/* Image processing streams for PostScript and PDF writers */
#include "gx.h"
#include "memory_.h"
#include "gserrors.h"
#include "gxdcconv.h"
#include "gdevpsds.h"

/* ---------------- Convert between 1/2/4 and 8 bits ---------------- */
gs_private_st_simple(st_1248_state, stream_1248_state, "stream_1248_state");

/* Initialize the state. */
private int
s_1_init(stream_state * st)
{
    stream_1248_state *const ss = (stream_1248_state *) st;

    ss->left = ss->samples_per_row;
    ss->bits_per_sample = 1;
    return 0;
}
private int
s_2_init(stream_state * st)
{
    stream_1248_state *const ss = (stream_1248_state *) st;

    ss->left = ss->samples_per_row;
    ss->bits_per_sample = 2;
    return 0;
}
private int
s_4_init(stream_state * st)
{
    stream_1248_state *const ss = (stream_1248_state *) st;

    ss->left = ss->samples_per_row;
    ss->bits_per_sample = 4;
    return 0;
}

/* Process one buffer. */
#define BEGIN_1248\
	stream_1248_state * const ss = (stream_1248_state *)st;\
	const byte *p = pr->ptr;\
	const byte *rlimit = pr->limit;\
	byte *q = pw->ptr;\
	byte *wlimit = pw->limit;\
	uint left = ss->left;\
	int status;\
	int n
#define END_1248\
	pr->ptr = p;\
	pw->ptr = q;\
	ss->left = left;\
	return status

/* N-to-8 expansion */
#define FOREACH_N_8(in, nout)\
	status = 0;\
	for ( ; p < rlimit; left -= n, q += n, ++p ) {\
	  byte in = p[1];\
	  n = min(left, nout);\
	  if ( wlimit - q < n ) {\
	    status = 1;\
	    break;\
	  }\
	  switch ( n ) {\
	    case 0: left = ss->samples_per_row; --p; continue;
#define END_FOREACH_N_8\
	  }\
	}
private int
s_N_8_process(stream_state * st, stream_cursor_read * pr,
	      stream_cursor_write * pw, bool last)
{
    BEGIN_1248;

    switch (ss->bits_per_sample) {

	case 1:{
		FOREACH_N_8(in, 8)
	case 8:
		q[8] = (byte) - (in & 1);
	case 7:
		q[7] = (byte) - ((in >> 1) & 1);
	case 6:
		q[6] = (byte) - ((in >> 2) & 1);
	case 5:
		q[5] = (byte) - ((in >> 3) & 1);
	case 4:
		q[4] = (byte) - ((in >> 4) & 1);
	case 3:
		q[3] = (byte) - ((in >> 5) & 1);
	case 2:
		q[2] = (byte) - ((in >> 6) & 1);
	case 1:
		q[1] = (byte) - (in >> 7);
		END_FOREACH_N_8;
	    }
	    break;

	case 2:{
		static const byte b2[4] =
		{0x00, 0x55, 0xaa, 0xff};

		FOREACH_N_8(in, 4)
	case 4:
		q[4] = b2[in & 3];
	case 3:
		q[3] = b2[(in >> 2) & 3];
	case 2:
		q[2] = b2[(in >> 4) & 3];
	case 1:
		q[1] = b2[in >> 6];
		END_FOREACH_N_8;
	    }
	    break;

	case 4:{
		static const byte b4[16] =
		{
		    0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
		    0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff
		};

		FOREACH_N_8(in, 2)
	case 2:
		q[2] = b4[in & 0xf];
	case 1:
		q[1] = b4[in >> 4];
		END_FOREACH_N_8;
	    }
	    break;

	default:
	    return ERRC;
    }

    END_1248;
}

/* 8-to-N reduction */
#define FOREACH_8_N(out, nin)\
	byte out;\
	status = 1;\
	for ( ; q < wlimit; left -= n, p += n, ++q ) {\
	  n = min(left, nin);\
	  if ( rlimit - p < n ) {\
	    status = 0;\
	    break;\
	  }\
	  out = 0;\
	  switch ( n ) {\
	    case 0: left = ss->samples_per_row; --q; continue;
#define END_FOREACH_8_N\
	    q[1] = out;\
	  }\
	}
private int
s_8_N_process(stream_state * st, stream_cursor_read * pr,
	      stream_cursor_write * pw, bool last)
{
    BEGIN_1248;

    switch (ss->bits_per_sample) {

	case 1:{
		FOREACH_8_N(out, 8)
	case 8:
		out = p[8] >> 7;
	case 7:
		out |= (p[7] >> 7) << 1;
	case 6:
		out |= (p[6] >> 7) << 2;
	case 5:
		out |= (p[5] >> 7) << 3;
	case 4:
		out |= (p[4] >> 7) << 4;
	case 3:
		out |= (p[3] >> 7) << 5;
	case 2:
		out |= (p[2] >> 7) << 6;
	case 1:
		out |= p[1] & 0x80;
		END_FOREACH_8_N;
	    }
	    break;

	case 2:{
		FOREACH_8_N(out, 4)
	case 4:
		out |= p[4] >> 6;
	case 3:
		out |= (p[3] >> 6) << 2;
	case 2:
		out |= (p[2] >> 6) << 4;
	case 1:
		out |= p[1] & 0xc0;
		END_FOREACH_8_N;
	    }
	    break;

	case 4:{
		FOREACH_8_N(out, 2)
	case 2:
		out |= p[2] >> 4;
	case 1:
		out |= p[1] & 0xf0;
		END_FOREACH_8_N;
	    }
	    break;

	default:
	    return ERRC;
    }

    END_1248;
}

const stream_template s_1_8_template =
{
    &st_1248_state, s_1_init, s_N_8_process, 1, 8
};
const stream_template s_2_8_template =
{
    &st_1248_state, s_2_init, s_N_8_process, 1, 4
};
const stream_template s_4_8_template =
{
    &st_1248_state, s_4_init, s_N_8_process, 1, 2
};

const stream_template s_8_1_template =
{
    &st_1248_state, s_1_init, s_8_N_process, 8, 1
};
const stream_template s_8_2_template =
{
    &st_1248_state, s_2_init, s_8_N_process, 4, 1
};
const stream_template s_8_4_template =
{
    &st_1248_state, s_4_init, s_8_N_process, 2, 1
};

/* ---------------- CMYK => RGB conversion ---------------- */

private_st_C2R_state();

/* Process one buffer. */
private int
s_C2R_process(stream_state * st, stream_cursor_read * pr,
	      stream_cursor_write * pw, bool last)
{
    stream_C2R_state *const ss = (stream_C2R_state *) st;
    const byte *p = pr->ptr;
    const byte *rlimit = pr->limit;
    byte *q = pw->ptr;
    byte *wlimit = pw->limit;

    for (; rlimit - p >= 4 && wlimit - q >= 3; p += 4, q += 3) {
	byte bc = p[1], bm = p[2], by = p[3], bk = p[4];
	frac rgb[3];

	color_cmyk_to_rgb(byte2frac(bc), byte2frac(bm), byte2frac(by),
			  byte2frac(bk), ss->pis, rgb);
	q[1] = frac2byte(rgb[0]);
	q[2] = frac2byte(rgb[1]);
	q[3] = frac2byte(rgb[2]);
    }
    pr->ptr = p;
    pw->ptr = q;
    return (rlimit - p < 4 ? 0 : 1);
}

const stream_template s_C2R_template =
{
    &st_C2R_state, 0 /*NULL */ , s_C2R_process, 4, 3
};

/* ---------------- Downsampling ---------------- */

private void
s_Downsample_set_defaults(register stream_state * st)
{
    stream_Downsample_state *const ss =
	(stream_Downsample_state *) st;

    s_Downsample_set_defaults_inline(ss);
}

/* Subsample */
/****** DOESN'T IMPLEMENT padY YET ******/

gs_private_st_simple(st_Subsample_state, stream_Subsample_state,
		     "stream_Subsample_state");

/* Initialize the state. */
private int
s_Subsample_init(stream_state * st)
{
    stream_Subsample_state *const ss = (stream_Subsample_state *) st;

    ss->x = ss->y = 0;
    return 0;
}

/* Process one buffer. */
private int
s_Subsample_process(stream_state * st, stream_cursor_read * pr,
		    stream_cursor_write * pw, bool last)
{
    stream_Subsample_state *const ss = (stream_Subsample_state *) st;
    const byte *p = pr->ptr;
    const byte *rlimit = pr->limit;
    byte *q = pw->ptr;
    byte *wlimit = pw->limit;
    int spp = ss->Colors;
    int width = ss->Columns;
    int xf = ss->XFactor, yf = ss->YFactor;
    int xf2 = xf / 2, yf2 = yf / 2;
    int xlimit = (width / xf) * xf;
    int xlast = (ss->padX && xlimit < width ? xlimit + (width % xf) / 2 : -1);
    int x = ss->x, y = ss->y;
    int status = 0;

    for (; rlimit - p >= spp; p += spp) {
	if (y == yf2 && ((x % xf == xf2 && x < xlimit) || x == xlast)) {
	    if (wlimit - q < spp) {
		status = 1;
		break;
	    }
	    memcpy(q + 1, p + 1, spp);
	    q += spp;
	}
	if (++x == width) {
	    x = 0;
	    if (++y == yf) {
		y = 0;
	    }
	}
    }
    pr->ptr = p;
    pw->ptr = q;
    ss->x = x, ss->y = y;
    return status;
}

const stream_template s_Subsample_template =
{
    &st_Subsample_state, s_Subsample_init, s_Subsample_process, 4, 4,
    0 /* NULL */, s_Downsample_set_defaults
};

/* Average */

private_st_Average_state();

/* Initialize the state. */
private int
s_Average_init(stream_state * st)
{
    stream_Average_state *const ss = (stream_Average_state *) st;

    ss->sum_size =
	ss->Colors * ((ss->Columns + ss->XFactor - 1) / ss->XFactor);
    ss->copy_size = ss->sum_size -
	(ss->padX || (ss->Columns % ss->XFactor == 0) ? 0 : ss->Colors);
    ss->sums =
	(uint *)gs_alloc_byte_array(st->memory, ss->sum_size,
				    sizeof(uint), "Average sums");
    if (ss->sums == 0)
	return ERRC;	/****** WRONG ******/
    memset(ss->sums, 0, ss->sum_size * sizeof(uint));
    return s_Subsample_init(st);
}

/* Release the state. */
private void
s_Average_release(stream_state * st)
{
    stream_Average_state *const ss = (stream_Average_state *) st;

    gs_free_object(st->memory, ss->sums, "Average sums");
}

/* Process one buffer. */
private int
s_Average_process(stream_state * st, stream_cursor_read * pr,
		  stream_cursor_write * pw, bool last)
{
    stream_Average_state *const ss = (stream_Average_state *) st;
    const byte *p = pr->ptr;
    const byte *rlimit = pr->limit;
    byte *q = pw->ptr;
    byte *wlimit = pw->limit;
    int spp = ss->Colors;
    int width = ss->Columns;
    int xf = ss->XFactor, yf = ss->YFactor;
    int x = ss->x, y = ss->y;
    uint *sums = ss->sums;
    int status = 0;

top:
    if (y == yf || (last && p >= rlimit && ss->padY && y != 0)) {
	/* We're copying averaged values to the output. */
	int ncopy = min(ss->copy_size - x, wlimit - q);

	if (ncopy) {
	    int scale = xf * y;

	    while (--ncopy >= 0)
		*++q = (byte) (sums[x++] / scale);
	}
	if (x < ss->copy_size) {
	    status = 1;
	    goto out;
	}
	/* Done copying. */
	x = y = 0;
	memset(sums, 0, ss->sum_size * sizeof(uint));
    }
    while (rlimit - p >= spp) {
	uint *bp = sums + x / xf * spp;
	int i;

	for (i = spp; --i >= 0;)
	    *bp++ += *++p;
	if (++x == width) {
	    x = 0;
	    ++y;
	    goto top;
	}
    }
out:
    pr->ptr = p;
    pw->ptr = q;
    ss->x = x, ss->y = y;
    return status;
}

const stream_template s_Average_template =
{
    &st_Average_state, s_Average_init, s_Average_process, 4, 4,
    s_Average_release, s_Downsample_set_defaults
};
