/* Copyright (C) 2001-2006 artofcode LLC.
   All Rights Reserved.
  
  This file is part of GNU ghostscript

  GNU ghostscript is free software; you can redistribute it and/or
  modify it under the terms of the version 2 of the GNU General Public
  License as published by the Free Software Foundation.

  GNU ghostscript 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
  ghostscript; see the file COPYING. If not, write to the Free Software Foundation,
  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

*/

/* $Id: gxclread.c,v 1.7 2007/08/01 14:26:19 jemarch Exp $ */
/* Command list reading for Ghostscript. */
#include "memory_.h"
#include "gx.h"
#include "gp.h"			/* for gp_fmode_rb */
#include "gpcheck.h"
#include "gserrors.h"
#include "gxdevice.h"
#include "gscoord.h"		/* requires gsmatrix.h */
#include "gsdevice.h"		/* for gs_deviceinitialmatrix */
#include "gxdevmem.h"		/* must precede gxcldev.h */
#include "gxcldev.h"
#include "gxgetbit.h"
#include "gxhttile.h"
#include "gdevplnx.h"
/*
 * We really don't like the fact that gdevprn.h is included here, since
 * command lists are supposed to be usable for purposes other than printer
 * devices; but gdev_prn_colors_used and gdev_create_buf_device are
 * currently only applicable to printer devices.
 */
#include "gdevprn.h"
#include "stream.h"
#include "strimpl.h"

/* ------ Band file reading stream ------ */

/*
 * To separate banding per se from command list interpretation,
 * we make the command list interpreter simply read from a stream.
 * When we are actually doing banding, the stream filters the band file
 * and only passes through the commands for the current bands (or band
 * ranges that include a current band).
 */
typedef struct stream_band_read_state_s {
    stream_state_common;
    gx_band_page_info_t page_info;
    int band_first, band_last;
    uint left;			/* amount of data left in this run */
    cmd_block b_this;
} stream_band_read_state;

private int
s_band_read_init(stream_state * st)
{
    stream_band_read_state *const ss = (stream_band_read_state *) st;

    ss->left = 0;
    ss->b_this.band_min = 0;
    ss->b_this.band_max = 0;
    ss->b_this.pos = 0;
    clist_rewind(ss->page_bfile, false, ss->page_bfname);
    return 0;
}

private int
s_band_read_process(stream_state * st, stream_cursor_read * ignore_pr,
		    stream_cursor_write * pw, bool last)
{
    stream_band_read_state *const ss = (stream_band_read_state *) st;
    register byte *q = pw->ptr;
    byte *wlimit = pw->limit;
    clist_file_ptr cfile = ss->page_cfile;
    clist_file_ptr bfile = ss->page_bfile;
    uint left = ss->left;
    int status = 1;
    uint count;

    while ((count = wlimit - q) != 0) {
	if (left) {		/* Read more data for the current run. */
	    if (count > left)
		count = left;
	    clist_fread_chars(q + 1, count, cfile);
	    if (clist_ferror_code(cfile) < 0) {
		status = ERRC;
		break;
	    }
	    q += count;
	    left -= count;
	    process_interrupts(st->memory);
	    continue;
	}
rb:
	/*
	 * Scan for the next run for the current bands (or a band range
	 * that includes a current band).
	 */
	if (ss->b_this.band_min == cmd_band_end &&
	    clist_ftell(bfile) == ss->page_bfile_end_pos
	    ) {
	    status = EOFC;
	    break;
	} {
	    int bmin = ss->b_this.band_min;
	    int bmax = ss->b_this.band_max;
	    int64_t pos = ss->b_this.pos;

	    clist_fread_chars(&ss->b_this, sizeof(ss->b_this), bfile);
	    if (!(ss->band_last >= bmin && ss->band_first <= bmax))
		goto rb;
	    clist_fseek(cfile, pos, SEEK_SET, ss->page_cfname);
	    left = (uint) (ss->b_this.pos - pos);
	    if_debug5('l', "[l]reading for bands (%d,%d) at bfile %ld, cfile %ld, length %u\n",
		      bmin, bmax,
		      (long)(clist_ftell(bfile) - 2 * sizeof(ss->b_this)),
		      (long)pos, left);
	}
    }
    pw->ptr = q;
    ss->left = left;
    return status;
}

/* Stream template */
private const stream_template s_band_read_template = {
    &st_stream_state, s_band_read_init, s_band_read_process, 1, cbuf_size
};


/* ------ Reading/rendering ------ */

/* Forward references */

private int clist_render_init(gx_device_clist *);
private int clist_playback_file_bands(clist_playback_action action,
				      gx_device_clist_reader *cdev,
				      gx_band_page_info_t *page_info,
				      gx_device *target,
				      int band_first, int band_last,
				      int x0, int y0);
private int clist_rasterize_lines(gx_device *dev, int y, int lineCount,
				  gx_device *bdev,
				  const gx_render_plane_t *render_plane,
				  int *pmy);

/* Calculate the raster for a chunky or planar device. */
private int
clist_plane_raster(const gx_device *dev, const gx_render_plane_t *render_plane)
{
    return bitmap_raster(dev->width *
			 (render_plane && render_plane->index >= 0 ?
			  render_plane->depth : dev->color_info.depth));
}

/* Select full-pixel rendering if required for RasterOp. */
private void
clist_select_render_plane(gx_device *dev, int y, int height,
			  gx_render_plane_t *render_plane, int index)
{
    if (index >= 0) {
	gx_colors_used_t colors_used;
	int ignore_start;

	gdev_prn_colors_used(dev, y, height, &colors_used,  &ignore_start);
	if (colors_used.slow_rop)
	    index = -1;
    }
    if (index < 0)
	render_plane->index = index;
    else
	gx_render_plane_init(render_plane, dev, index);
}

/*
 * Do device setup from params stored in command list. This is only for
 * async rendering & assumes that the first command in every command list
 * is a put_params command which sets all space-related parameters to the
 * value they will have for the duration of that command list.
 */
int
clist_setup_params(gx_device *dev)
{
    gx_device_clist_reader * const crdev =
	&((gx_device_clist *)dev)->reader;
    int code = clist_render_init((gx_device_clist *)dev);
    if (code < 0)
	return code;

    code = clist_playback_file_bands(playback_action_setup,
				     crdev, &crdev->page_info, 0, 0, 0, 0, 0);

    /* put_params may have reinitialized device into a writer */
    clist_render_init((gx_device_clist *)dev);

    return code;
}

/* Copy a rasterized rectangle to the client, rasterizing if needed. */
int
clist_get_bits_rectangle(gx_device *dev, const gs_int_rect * prect,
			 gs_get_bits_params_t *params, gs_int_rect **unread)
{
    gx_device_clist_common *cdev = (gx_device_clist_common *)dev;
    gs_get_bits_options_t options = params->options;
    int y = prect->p.y;
    int end_y = prect->q.y;
    int line_count = end_y - y;
    gs_int_rect band_rect;
    int lines_rasterized;
    gx_device *bdev;
    int num_planes =
	(options & GB_PACKING_CHUNKY ? 1 :
	 options & GB_PACKING_PLANAR ? dev->color_info.num_components :
	 options & GB_PACKING_BIT_PLANAR ? dev->color_info.depth :
	 0 /****** NOT POSSIBLE ******/);
    gx_render_plane_t render_plane;
    int plane_index;
    int my;
    int code;

    if (prect->p.x < 0 || prect->q.x > dev->width ||
	y < 0 || end_y > dev->height
	)
	return_error(gs_error_rangecheck);
    if (line_count <= 0 || prect->p.x >= prect->q.x)
	return 0;

    /*
     * Calculate the render_plane from the params.  There are two cases:
     * full pixels, or a single plane.
     */
    plane_index = -1;
    if (options & GB_SELECT_PLANES) {
	/* Look for the one selected plane. */
	int i;

	for (i = 0; i < num_planes; ++i)
	    if (params->data[i]) {
		if (plane_index >= 0)  /* >1 plane requested */
		    return gx_default_get_bits_rectangle(dev, prect, params,
							 unread);
		plane_index = i;
	    }
    }
    clist_select_render_plane(dev, y, line_count, &render_plane, plane_index);
    code = gdev_create_buf_device(cdev->buf_procs.create_buf_device,
				  &bdev, cdev->target, &render_plane,
				  dev->memory, true);
    if (code < 0)
	return code;
    code = clist_rasterize_lines(dev, y, line_count, bdev, &render_plane, &my);
    if (code < 0)
	return code;
    lines_rasterized = min(code, line_count);
    /* Return as much of the rectangle as falls within the rasterized lines. */
    band_rect = *prect;
    band_rect.p.y = my;
    band_rect.q.y = my + lines_rasterized;
    code = dev_proc(bdev, get_bits_rectangle)
	(bdev, &band_rect, params, unread);
    cdev->buf_procs.destroy_buf_device(bdev);
    if (code < 0 || lines_rasterized == line_count)
	return code;
    /*
     * We'll have to return the rectangle in pieces.  Force GB_RETURN_COPY
     * rather than GB_RETURN_POINTER, and require all subsequent pieces to
     * use the same values as the first piece for all of the other format
     * options.  If copying isn't allowed, or if there are any unread
     * rectangles, punt.
     */
    if (!(options & GB_RETURN_COPY) || code > 0)
	return gx_default_get_bits_rectangle(dev, prect, params, unread);
    options = params->options;
    if (!(options & GB_RETURN_COPY)) {
	/* Redo the first piece with copying. */
	params->options = options =
	    (params->options & ~GB_RETURN_ALL) | GB_RETURN_COPY;
	lines_rasterized = 0;
    }
    {
	gs_get_bits_params_t band_params;
	uint raster = gx_device_raster(bdev, true);

	code = gdev_create_buf_device(cdev->buf_procs.create_buf_device,
				      &bdev, cdev->target, &render_plane,
				      dev->memory, true);
	if (code < 0)
	    return code;
	band_params = *params;
	while ((y += lines_rasterized) < end_y) {
	    int i;

	    /* Increment data pointers by lines_rasterized. */
	    for (i = 0; i < num_planes; ++i)
		if (band_params.data[i])
		    band_params.data[i] += raster * lines_rasterized;
	    line_count = end_y - y;
	    code = clist_rasterize_lines(dev, y, line_count, bdev,
					 &render_plane, &my);
	    if (code < 0)
		break;
	    lines_rasterized = min(code, line_count);
	    band_rect.p.y = my;
	    band_rect.q.y = my + lines_rasterized;
	    code = dev_proc(bdev, get_bits_rectangle)
		(bdev, &band_rect, &band_params, unread);
	    if (code < 0)
		break;
	    params->options = options = band_params.options;
	    if (lines_rasterized == line_count)
		break;
	}
	cdev->buf_procs.destroy_buf_device(bdev);
    }
    return code;
}

/* Copy scan lines to the client.  This is where rendering gets done. */
/* Processes min(requested # lines, # lines available thru end of band) */
private int	/* returns -ve error code, or # scan lines copied */
clist_rasterize_lines(gx_device *dev, int y, int line_count,
		      gx_device *bdev, const gx_render_plane_t *render_plane,
		      int *pmy)
{
    gx_device_clist * const cdev = (gx_device_clist *)dev;
    gx_device_clist_reader * const crdev = &cdev->reader;
    gx_device *target = crdev->target;
    uint raster = clist_plane_raster(target, render_plane);
    byte *mdata = crdev->data + crdev->page_tile_cache_size;
    int plane_index = (render_plane ? render_plane->index : -1);
    int code;

    /* Render a band if necessary, and copy it incrementally. */
    if (crdev->ymin < 0 || crdev->yplane.index != plane_index ||
	!(y >= crdev->ymin && y < crdev->ymax)
	) {
	int band_height = crdev->page_band_height;
	int band = y / band_height;
	int band_begin_line = band * band_height;
	int band_end_line = band_begin_line + band_height;
	int band_num_lines;
	gs_int_rect band_rect;

	if (band_end_line > dev->height)
	    band_end_line = dev->height;
	/* Clip line_count to current band */
	if (line_count > band_end_line - y)
	    line_count = band_end_line - y;
	band_num_lines = band_end_line - band_begin_line;

	if (y < 0 || y > dev->height)
	    return_error(gs_error_rangecheck);
	code = crdev->buf_procs.setup_buf_device
	    (bdev, mdata, raster, NULL, 0, band_num_lines, band_num_lines);
	band_rect.p.x = 0;
	band_rect.p.y = band_begin_line;
	band_rect.q.x = dev->width;
	band_rect.q.y = band_end_line;
	if (code >= 0)
	    code = clist_render_rectangle(cdev, &band_rect, bdev, render_plane,
					  true);
	/* Reset the band boundaries now, so that we don't get */
	/* an infinite loop. */
	crdev->ymin = band_begin_line;
	crdev->ymax = band_end_line;
	if (code < 0)
	    return code;
    }

    if (line_count > crdev->ymax - y)
	line_count = crdev->ymax - y;
    code = crdev->buf_procs.setup_buf_device
	(bdev, mdata, raster, NULL, y - crdev->ymin, line_count,
	 crdev->ymax - crdev->ymin);
    if (code < 0)
	return code;

    *pmy = 0;
    return line_count;
}

/* Initialize for reading. */
private int
clist_render_init(gx_device_clist *dev)
{
    gx_device_clist_reader * const crdev = &dev->reader;

    crdev->ymin = crdev->ymax = 0;
    crdev->yplane.index = -1;
    /* For normal rasterizing, pages and num_pages are zero. */
    crdev->pages = 0;
    crdev->num_pages = 0;
    return 0;
}

/*
 * Render a rectangle to a client-supplied device.  There is no necessary
 * relationship between band boundaries and the region being rendered.
 */
int
clist_render_rectangle(gx_device_clist *cdev, const gs_int_rect *prect,
		       gx_device *bdev,
		       const gx_render_plane_t *render_plane, bool clear)
{
    gx_device_clist_reader * const crdev = &cdev->reader;
    const gx_placed_page *ppages;
    int num_pages = crdev->num_pages;
    int band_height = crdev->page_band_height;
    int band_first = prect->p.y / band_height;
    int band_last = (prect->q.y - 1) / band_height;
    gx_saved_page current_page;
    gx_placed_page placed_page;
    int code = 0;
    int i;

    /* Initialize for rendering if we haven't done so yet. */
    if (crdev->ymin < 0) {
	code = clist_end_page(&cdev->writer);
	if (code < 0)
	    return code;
	code = clist_render_init(cdev);
	if (code < 0)
	    return code;
    }
    if (render_plane)
	crdev->yplane = *render_plane;
    else
	crdev->yplane.index = -1;
    if_debug2('l', "[l]rendering bands (%d,%d)\n", band_first, band_last);
    if (clear)
	dev_proc(bdev, fill_rectangle)
	    (bdev, 0, 0, bdev->width, bdev->height, gx_device_white(bdev));

    /*
     * If we aren't rendering saved pages, do the current one.
     * Note that this is the only case in which we may encounter
     * a gx_saved_page with non-zero cfile or bfile.
     */
    ppages = crdev->pages;
    if (ppages == 0) {
	current_page.info = crdev->page_info;
	placed_page.page = &current_page;
	placed_page.offset.x = placed_page.offset.y = 0;
	ppages = &placed_page;
	num_pages = 1;
    }
    for (i = 0; i < num_pages && code >= 0; ++i) {
	const gx_placed_page *ppage = &ppages[i];

	code = clist_playback_file_bands(playback_action_render,
					 crdev, &ppage->page->info,
					 bdev, band_first, band_last,
					 prect->p.x - ppage->offset.x,
					 prect->p.y);
    }
    return code;
}

/* Playback the band file, taking the indicated action w/ its contents. */
private int
clist_playback_file_bands(clist_playback_action action, 
			  gx_device_clist_reader *cdev,
			  gx_band_page_info_t *page_info, gx_device *target,
			  int band_first, int band_last, int x0, int y0)
{
    int code = 0;
    bool opened_bfile = false;
    bool opened_cfile = false;

    /* We have to pick some allocator for rendering.... */
    gs_memory_t *mem =cdev->memory;
 
    stream_band_read_state rs;

    /* setup stream */
    s_init_state((stream_state *)&rs, &s_band_read_template,
		 (gs_memory_t *)0);
    rs.band_first = band_first;
    rs.band_last = band_last;
    rs.page_info = *page_info;

    /* If this is a saved page, open the files. */
    if (rs.page_cfile == 0) {
	code = clist_fopen(rs.page_cfname,
			   gp_fmode_rb, &rs.page_cfile, cdev->bandlist_memory,
			   cdev->bandlist_memory, true);
	opened_cfile = (code >= 0);
    }
    if (rs.page_bfile == 0 && code >= 0) {
	code = clist_fopen(rs.page_bfname,
			   gp_fmode_rb, &rs.page_bfile, cdev->bandlist_memory,
			   cdev->bandlist_memory, false);
	opened_bfile = (code >= 0);
    }
    if (rs.page_cfile != 0 && rs.page_bfile != 0) {
	stream s;
	byte sbuf[cbuf_size];
	static const stream_procs no_procs = {
	    s_std_noavailable, s_std_noseek, s_std_read_reset,
	    s_std_read_flush, s_std_close, s_band_read_process
	};

	s_band_read_init((stream_state *)&rs);
	  /* The stream doesn't need a memory, but we'll need to access s.memory->gs_lib_ctx. */
	s_init(&s, mem);
	s_std_init(&s, sbuf, cbuf_size, &no_procs, s_mode_read);
	s.foreign = 1;
	s.state = (stream_state *)&rs;
	code = clist_playback_band(action, cdev, &s, target, x0, y0, mem);
    }

    /* Close the files if we just opened them. */
    if (opened_bfile && rs.page_bfile != 0)
	clist_fclose(rs.page_bfile, rs.page_bfname, false);
    if (opened_cfile && rs.page_cfile != 0)
	clist_fclose(rs.page_cfile, rs.page_cfname, false);

    return code;
}
