/* Copyright (C) 1992, 1995, 1996, 1997, 1998, 1999 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
  to anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given
  to you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
*/

/*$RCSfile: gxicolor.c,v $ $Revision: 1.2.2.1 $ */
/* Color image rendering */
#include "gx.h"
#include "memory_.h"
#include "gpcheck.h"
#include "gserrors.h"
#include "gxfixed.h"
#include "gxfrac.h"
#include "gxarith.h"
#include "gxmatrix.h"
#include "gsccolor.h"
#include "gspaint.h"
#include "gzstate.h"
#include "gxdevice.h"
#include "gxcmap.h"
#include "gxdcconv.h"
#include "gxdcolor.h"
#include "gxistate.h"
#include "gxdevmem.h"
#include "gxcpath.h"
#include "gximage.h"

typedef union {
    byte v[GS_IMAGE_MAX_COLOR_COMPONENTS];
#define BYTES_PER_BITS32 4
#define BITS32_PER_COLOR_SAMPLES\
  ((GS_IMAGE_MAX_COLOR_COMPONENTS + BYTES_PER_BITS32 - 1) / BYTES_PER_BITS32)
    bits32 all[BITS32_PER_COLOR_SAMPLES];	/* for fast comparison */
} color_samples;

/* ------ Strategy procedure ------ */

/* Check the prototype. */
iclass_proc(gs_image_class_4_color);

private irender_proc(image_render_color);
irender_proc_t
gs_image_class_4_color(gx_image_enum * penum)
{
    if (penum->use_mask_color) {
	/*
	 * Scale the mask colors to match the scaling of each sample to
	 * a full byte, and set up the quick-filter parameters.
	 */
	int i;
	color_samples mask, test;
	bool exact = penum->spp <= BYTES_PER_BITS32;

	memset(&mask, 0, sizeof(mask));
	memset(&test, 0, sizeof(test));
	for (i = 0; i < penum->spp; ++i) {
	    byte v0, v1;
	    byte match = 0xff;

	    gx_image_scale_mask_colors(penum, i);
	    v0 = (byte)penum->mask_color.values[2 * i];
	    v1 = (byte)penum->mask_color.values[2 * i + 1];
	    while ((v0 & match) != (v1 & match))
		match <<= 1;
	    mask.v[i] = match;
	    test.v[i] = v0 & match;
	    exact &= (v0 == match && (v1 | match) == 0xff);
	}
	penum->mask_color.mask = mask.all[0];
	penum->mask_color.test = test.all[0];
	penum->mask_color.exact = exact;
    } else {
	penum->mask_color.mask = 0;
	penum->mask_color.test = ~0;
    }
    return image_render_color;
}

/* ------ Rendering procedures ------ */

/* Test whether a color is transparent. */
private bool
mask_color_matches(const byte *v, const gx_image_enum *penum,
		   int num_components)
{
    int i;

    for (i = num_components * 2, v += num_components - 1; (i -= 2) >= 0; --v)
	if (*v < penum->mask_color.values[i] ||
	    *v > penum->mask_color.values[i + 1]
	    )
	    return false;
    return true;
}

/* Render a color image with 8 or fewer bits per sample. */
private int
image_render_color(gx_image_enum *penum_orig, const byte *buffer, int data_x,
		   uint w, int h, gx_device * dev)
{
    const gx_image_enum *const penum = penum_orig; /* const within proc */
    gx_image_clue *const clues = penum_orig->clues; /* not const */
    const gs_imager_state *pis = penum->pis;
    gs_logical_operation_t lop = penum->log_op;
    gx_dda_fixed_point pnext;
    image_posture posture = penum->posture;
    fixed xprev, yprev;
    fixed pdyx, pdyy;		/* edge of parallelogram */
    int vci, vdi;
    const gs_color_space *pcs = penum->pcs;
    cs_proc_remap_color((*remap_color)) = pcs->type->remap_color;
    gs_client_color cc;
    bool device_color = penum->device_color;
    const gx_color_map_procs *cmap_procs = gx_get_cmap_procs(pis, dev);
    cmap_proc_rgb((*map_3)) = cmap_procs->map_rgb;
    cmap_proc_cmyk((*map_4)) =
	(penum->alpha ? cmap_procs->map_rgb_alpha : cmap_procs->map_cmyk);
    bits32 mask = penum->mask_color.mask;
    bits32 test = penum->mask_color.test;
    gx_image_clue *pic = &clues[0];
#define pdevc (&pic->dev_color)
    gx_image_clue *pic_next = &clues[1];
#define pdevc_next (&pic_next->dev_color)
    gx_image_clue empty_clue;
    gx_image_clue clue_temp;
    int spp = penum->spp;
    const byte *psrc_initial = buffer + data_x * spp;
    const byte *psrc = psrc_initial;
    const byte *rsrc = psrc + spp; /* psrc + spp at start of run */
    fixed xrun;			/* x ditto */
    fixed yrun;			/* y ditto */
    int irun;			/* int x/rrun */
    color_samples run;		/* run value */
    color_samples next;		/* next sample value */
    const byte *bufend = psrc + w;
    bool use_cache = spp * penum->bps <= 12;
    int code = 0, mcode = 0;

    if (h == 0)
	return 0;
    pnext = penum->dda.pixel0;
    xrun = xprev = dda_current(pnext.x);
    yrun = yprev = dda_current(pnext.y);
    pdyx = dda_current(penum->dda.row.x) - penum->cur.x;
    pdyy = dda_current(penum->dda.row.y) - penum->cur.y;
    switch (posture) {
	case image_portrait:
	    vci = penum->yci, vdi = penum->hci;
	    irun = fixed2int_var_rounded(xrun);
	    break;
	case image_landscape:
	    vci = penum->xci, vdi = penum->wci;
	    irun = fixed2int_var_rounded(yrun);
	    break;
	default:
	    break;
    }

    if_debug5('b', "[b]y=%d data_x=%d w=%d xt=%f yt=%f\n",
	      penum->y, data_x, w, fixed2float(xprev), fixed2float(yprev));
    memset(&run, 0, sizeof(run));
    memset(&next, 0, sizeof(next));
    /* Ensure that we don't get any false dev_color_eq hits. */
    if (use_cache) {
	color_set_pure(&empty_clue.dev_color, gx_no_color_index);
	pic = &empty_clue;
    }
    cs_full_init_color(&cc, pcs);
    run.v[0] = ~psrc[0];	/* force remap */
    while (psrc < bufend) {
	dda_next(pnext.x);
	dda_next(pnext.y);
#define CLUE_HASH3(penum, next)\
  &clues[(next.v[0] + (next.v[1] << 2) + (next.v[2] << 4)) & 255];
#define CLUE_HASH4(penum, next)\
  &clues[(next.v[0] + (next.v[1] << 2) + (next.v[2] << 4) +\
		 (next.v[3] << 6)) & 255]

	if (spp == 4) {		/* may be CMYK or RGBA */
	    next.v[0] = psrc[0];
	    next.v[1] = psrc[1];
	    next.v[2] = psrc[2];
	    next.v[3] = psrc[3];
	    psrc += 4;
map4:	    if (next.all[0] == run.all[0])
		goto inc;
	    if (use_cache) {
		pic_next = CLUE_HASH4(penum, next);
		if (pic_next->key == next.all[0])
		    goto f;
		/*
		 * If we are really unlucky, pic_next == pic,
		 * so mapping this color would clobber the one
		 * we're about to use for filling the run.
		 */
		if (pic_next == pic) {
		    clue_temp = *pic;
		    pic = &clue_temp;
		}
		pic_next->key = next.all[0];
	    }
	    /* Check for transparent color. */
	    if ((next.all[0] & mask) == test &&
		(penum->mask_color.exact ||
		 mask_color_matches(next.v, penum, 4))
		) {
		color_set_null(pdevc_next);
		goto mapped;
	    }
	    if (device_color) {
		(*map_4)(byte2frac(next.v[0]), byte2frac(next.v[1]),
			 byte2frac(next.v[2]), byte2frac(next.v[3]),
			 pdevc_next, pis, dev,
			 gs_color_select_source);
		goto mapped;
	    }
	    decode_sample(next.v[3], cc, 3);
	    if_debug1('B', "[B]cc[3]=%g\n", cc.paint.values[3]);
do3:	    decode_sample(next.v[0], cc, 0);
	    decode_sample(next.v[1], cc, 1);
	    decode_sample(next.v[2], cc, 2);
	    if_debug3('B', "[B]cc[0..2]=%g,%g,%g\n",
		      cc.paint.values[0], cc.paint.values[1],
		      cc.paint.values[2]);
	} else if (spp == 3) {	    /* may be RGB */
	    next.v[0] = psrc[0];
	    next.v[1] = psrc[1];
	    next.v[2] = psrc[2];
	    psrc += 3;
	    if (next.all[0] == run.all[0])
		goto inc;
	    if (use_cache) {
		pic_next = CLUE_HASH3(penum, next);
		if (pic_next->key == next.all[0])
		    goto f;
		/* See above re the following check. */
		if (pic_next == pic) {
		    clue_temp = *pic;
		    pic = &clue_temp;
		}
		pic_next->key = next.all[0];
	    }
	    /* Check for transparent color. */
	    if ((next.all[0] & mask) == test &&
		(penum->mask_color.exact ||
		 mask_color_matches(next.v, penum, 3))
		) {
		color_set_null(pdevc_next);
		goto mapped;
	    }
	    if (device_color) {
		(*map_3)(byte2frac(next.v[0]), byte2frac(next.v[1]),
			 byte2frac(next.v[2]),
			 pdevc_next, pis, dev,
			 gs_color_select_source);
		goto mapped;
	    }
	    goto do3;
	} else if (penum->alpha) {
	    if (spp == 2) {	/* might be Gray + alpha */
		next.v[2] = next.v[1] = next.v[0] = psrc[0];
		next.v[3] = psrc[1];
		psrc += 2;
		goto map4;
	    } else if (spp == 5) {	/* might be CMYK + alpha */
		/* Convert CMYK to RGB. */
		frac rgb[3];

		color_cmyk_to_rgb(byte2frac(psrc[0]), byte2frac(psrc[1]),
				  byte2frac(psrc[2]), byte2frac(psrc[3]),
				  pis, rgb);
		/*
		 * It seems silly to do all this converting between
		 * fracs and bytes, but that's what the current
		 * APIs require.
		 */
		next.v[0] = frac2byte(rgb[0]);
		next.v[1] = frac2byte(rgb[1]);
		next.v[2] = frac2byte(rgb[2]);
		next.v[3] = psrc[4];
		psrc += 5;
		goto map4;
	    }
	} else {		/* DeviceN */
	    int i;

	    use_cache = false;	/* should do in initialization */
	    if (!memcmp(psrc, run.v, spp)) {
		psrc += spp;
		goto inc;
	    }
	    memcpy(next.v, psrc, spp);
	    psrc += spp;
	    if ((next.all[0] & mask) == test &&
		(penum->mask_color.exact ||
		 mask_color_matches(next.v, penum, spp))
		) {
		color_set_null(pdevc_next);
		goto mapped;
	    }
	    for (i = 0; i < spp; ++i)
		decode_sample(next.v[i], cc, i);
#ifdef DEBUG
	    if (gs_debug_c('B')) {
		dprintf2("[B]cc[0..%d]=%g", spp - 1,
			 cc.paint.values[0]);
		for (i = 1; i < spp; ++i)
		    dprintf1(",%g", cc.paint.values[i]);
		dputs("\n");
	    }
#endif
	}
	mcode = remap_color(&cc, pcs, pdevc_next, pis, dev,
			   gs_color_select_source);
	if (mcode < 0)
	    goto fill;
mapped:	if (pic == pic_next)
	    goto fill;
f:	if_debug7('B', "[B]0x%x,0x%x,0x%x,0x%x -> %ld,%ld,0x%lx\n",
		  next.v[0], next.v[1], next.v[2], next.v[3],
		  pdevc_next->colors.binary.color[0],
		  pdevc_next->colors.binary.color[1],
		  (ulong) pdevc_next->type);
	/* Even though the supplied colors don't match, */
	/* the device colors might. */
	if (dev_color_eq(*pdevc, *pdevc_next))
	    goto set;
fill:	/* Fill the region between */
	/* xrun/irun and xprev */
	switch (posture) {
	case image_portrait:
	    {		/* Rectangle */
		int xi = irun;
		int wi =
		    (irun = fixed2int_var_rounded(xprev)) - xi;

		if (wi < 0)
		    xi += wi, wi = -wi;
		if (wi > 0)
		    code = gx_fill_rectangle_device_rop(xi, vci, wi, vdi,
							pdevc, dev, lop);
		xrun = xprev;	/* for sake of final run */
	    }
	    break;
	case image_landscape:
	    {		/* 90 degree rotated rectangle */
		int yi = irun;
		int hi =
		    (irun = fixed2int_var_rounded(yprev)) - yi;

		if (hi < 0)
		    yi += hi, hi = -hi;
		if (hi > 0)
		    code = gx_fill_rectangle_device_rop(vci, yi, vdi, hi,
							pdevc, dev, lop);
		yrun = yprev;	/* for sake of final run */
	    }
	    break;
	default:
	    {		/* Parallelogram */
		code = (*dev_proc(dev, fill_parallelogram))
		    (dev, xrun, yrun,
		     xprev - xrun, yprev - yrun, pdyx, pdyy,
		     pdevc, lop);
		xrun = xprev;
		yrun = yprev;
	    }
	}
	if (code < 0)
	    goto err;
	rsrc = psrc;
	if ((code = mcode) < 0) {
	    /* Invalidate any partially built cache entry. */
	    if (use_cache)
		pic_next->key = ~next.all[0];
	    goto err;
	}
	if (use_cache)
	    pic = pic_next;
	else {
	    gx_image_clue *ptemp = pic;

	    pic = pic_next;
	    pic_next = ptemp;
	}
set:	run = next;
inc:	xprev = dda_current(pnext.x);
	yprev = dda_current(pnext.y);	/* harmless if no skew */
    }
    /* Fill the last run. */
    code = (*dev_proc(dev, fill_parallelogram))
	(dev, xrun, yrun, xprev - xrun, yprev - yrun, pdyx, pdyy, pdevc, lop);
    return (code < 0 ? code : 1);
    /* Save position if error, in case we resume. */
err:
    penum_orig->used.x = (rsrc - spp - psrc_initial) / spp;
    penum_orig->used.y = 0;
    return code;
}
