picbuf.c

/*
   Copyright (c) 1991 - 1994 Heinz W. Werntges.  All rights reserved.
   Distributed by Free Software Foundation, Inc.

This file is part of HP2xx.

HP2xx 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, Version 2 or later, for full details.

Everyone is granted permission to copy, modify and redistribute
HP2xx, 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 HP2xx 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.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/

/** picbuf.c: Part of hp2xx project dealing with the picture buffer
 **
 ** 91/01/19  V 1.00  HWW  Derived from hptopcl.c
 ** 91/01/29  V 1.01  HWW  Tested on SUN
 ** 91/02/15  V 1.02  HWW  stdlib.h supported
 ** 91/02/20  V 1.03a HWW  minor mod. in fread(); adaptation to
 **			   new HPGL_Pt structures in tmpfile_to_PicBuf()
 ** 91/06/09  V 1.04  HWW  new options acknowledged; minimal changes
 ** 91/10/15  V 1.05  HWW  ANSI_C
 ** 91/11/20  V 1.06  HWW  "SPn;" consequences
 ** 92/02/17  V 1.07b HWW  Preparations for font support
 ** 92/05/24  V 2.00c HWW  Color supported! Fonts ok now; "init" bug fixed
 ** 92/06/08  V 2.00d HWW  GIVE_BACK: 5 --> 8; free_PicBuf() debugged
 ** 92/12/24  V 2.00e HWW  plot_RowBuf() augmented to bit REsetting
 ** 93/04/02  V 2.01a HWW  Always use four bit planes in color mode!
 **			   Out-dated "DotBlock" concept replaced by "char".
 ** 94/02/14  V 2.10  HWW  New parameter structs; restructured
 **			   Improved cleanup & error handling
 ** 00/07/16          MK   Modify pensize correction in size_Pixbuf
 **                        for new .1 pixel pensize unit scheme (G.B.)
 **/


#include <stdio.h>
#include <stdlib.h>
#ifndef _NO_VCL
#include <unistd.h>
#endif
#include <string.h>
#include <math.h>
#include "bresnham.h"
#include "murphy.h"
#include "pendef.h"
#include "lindef.h"
#include "picbuf.h"
#include "hp2xx.h"
#include "hpgl.h"


static RowBuf *first_buf = NULL, *last_buf = NULL;

static int X_Offset = 0;
static int Y_Offset = 0;

#ifndef SEEK_SET
#define SEEK_SET 0
#endif



static void swapout_RowBuf(RowBuf * row, const PicBuf * picbuf)
{
	if (fseek
	    (picbuf->sd, (long) row->index * picbuf->nb * picbuf->depth,
	     SEEK_SET)) {
		PError("swapout_RowBuf (on seek)");
		exit(ERROR);
	}

	if ((int)
	    fwrite((char *) row->buf, (size_t) picbuf->nb,
		   (size_t) picbuf->depth, picbuf->sd)
	    != picbuf->depth) {
		PError("swapout_RowBuf (on write)");
		exit(ERROR);
	}
}



static void swapin_RowBuf(RowBuf * row, const PicBuf * picbuf)
{
	if (fseek
	    (picbuf->sd, (long) row->index * picbuf->nb * picbuf->depth,
	     SEEK_SET)) {
		PError("swapin_RowBuf (on seek)");
		exit(ERROR);
	}

	if ((int)
	    fread((char *) row->buf, (size_t) picbuf->nb,
		  (size_t) picbuf->depth, picbuf->sd)
	    != picbuf->depth) {
		PError("swapin_RowBuf (on read)");
		exit(ERROR);
	}
}





static void link_RowBuf(RowBuf * act, RowBuf * prev)
{
	if (prev == NULL) {	/* Make act the new "first_buf"   */
		if (first_buf == NULL) {
			first_buf = act;
			act->next = act->prev = NULL;
			return;
		}
		act->next = first_buf;
		act->prev = NULL;
		first_buf->prev = act;
		first_buf = act;
	} else {		/* Squeeze act between prev & prev->next */

		if ((act->next = prev->next) != NULL)
			act->next->prev = act;
		act->prev = prev;
		prev->next = act;
	}
}





static void unlink_RowBuf(RowBuf * act)
{
	if ((act->prev == NULL) && (act->next == NULL))
		return;

	if (act->prev)
		act->prev->next = act->next;
	else
		first_buf = act->next;

	if (act->next)
		act->next->prev = act->prev;
	else
		last_buf = act->prev;

	act->next = act->prev = NULL;
}




RowBuf *get_RowBuf(const PicBuf * pb, int index)
{
	RowBuf *row;

	if (pb == NULL)
		return NULL;
	if (index < 0 || index >= pb->nr) {
		Eprintf("get_RowBuf: Illegal y (%d not in [0, %d])\n",
			index, pb->nr - 1);
		return NULL;
	}

	row = pb->row + index;

/**
 ** If swapped, load first. Put into first position, if not already there:
 **/
	if ((row->prev == NULL) && (row->next == NULL)) {
		swapout_RowBuf(last_buf, pb);
		row->buf = last_buf->buf;
		unlink_RowBuf(last_buf);	/* Mark as swapped       */
		swapin_RowBuf(row, pb);
		link_RowBuf(row, NULL);	/* Put in first position */
	} else if (row->prev != NULL) {
		unlink_RowBuf(row);
		link_RowBuf(row, NULL);	/* Put in first position */
	}
	/* else: Leave it in first position */

	return row;
}





static void plot_RowBuf(RowBuf * rowbuf, int x, int depth,
			PEN_C color_index)
/**
 ** Write color index into pixel x of given row buffer
 **/
{
	int i, Mask;
	Byte *addr;

	if (rowbuf == NULL)
		return;
/**
 ** Color_index is either the low bit (b/w) or the low nybble (color)
 ** rowbuf->buf is either a sequence of such bits or nybbles.
 ** High bits show left, low bits show right.
 **
 ** This is a time-critical step, so code here is compact,
 ** but not easily readable...
 **/

	if (depth == 1) {
		if (color_index > 1)
			color_index = 1;
		Mask = 0x80;
		if ((i = x & 0x07) != 0) {
			Mask >>= i;
			if (i != 7)
				color_index <<= (7 - i);
		} else
			color_index <<= 7;
		addr = rowbuf->buf + (x >> 3);
	} else if (depth == 4) {
		Mask = 0xF0;
		if ((x & 0x01) != 0)
			Mask >>= 4;
		else
			color_index <<= 4;
		addr = rowbuf->buf + (x >> 1);
	} else {
		addr = rowbuf->buf + x;
		Mask = 0x00;
	}
	if (depth < 8) {
		*addr &= ~Mask;
		*addr |= color_index;
	} else
		*addr = (Byte) color_index;
}





int index_from_RowBuf(const RowBuf * rowbuf, int x, const PicBuf * pb)
/**
 ** Return color index of pixel x in given row
 **/
{
	int i, Mask, color_index;
	Byte *addr;

	if (pb->depth == 1) {
		Mask = 0x80;
		if ((i = x & 0x07) != 0)
			Mask >>= i;
		addr = rowbuf->buf + (x >> 3);
		return (*addr & Mask) ? xxForeground : xxBackground;
	} else if (pb->depth == 4) {
		Mask = 0xF0;
		if ((x & 0x01) != 0)
			Mask >>= 4;
		addr = rowbuf->buf + (x >> 1);
		color_index = *addr & Mask;
		if ((x & 0x01) == 0)
			color_index >>= 4;
		return color_index;
	} else {
		addr = rowbuf->buf + x;
		color_index = *addr;
		return color_index;
	}
}





static void
HPcoord_to_dotcoord(const HPGL_Pt * HP_P, DevPt * DevP, const OUT_PAR * po)
{
	DevP->x = (int) ((HP_P->x - po->xmin) * po->HP_to_xdots);
	DevP->y = (int) ((HP_P->y - po->ymin) * po->HP_to_ydots);
}



void size_PicBuf(const GEN_PAR * pg, const OUT_PAR * po, int *p_rows,
		 int *p_cols)
{
	HPGL_Pt HP_Pt;
	DevPt D_Pt;
	int maxps;

	HP_Pt.x = po->xmax;
	HP_Pt.y = po->ymax;
	HPcoord_to_dotcoord(&HP_Pt, &D_Pt, po);
	/* Pensize correction */
/*  maxps= (int)(1. + pg->maxpensize *po->HP_to_xdots/0.025); */
	maxps = 1 + ceil(pg->maxpensize * po->HP_to_xdots / 0.025);
	X_Offset = maxps / 2;
	Y_Offset = maxps / 2;

/*   printf("maxps = %d\n",maxps);*/
	*p_cols = D_Pt.x + maxps + 1;
	*p_rows = D_Pt.y + maxps + 1;
}


PicBuf *allocate_PicBuf(const GEN_PAR * pg, int n_rows, int n_cols)
/**
 ** Here we allocate the picture buffer. This memory is used by all raster
 ** modes. It is organized in rows (scan lines). Rows which do not
 ** end on a byte boundary will be right-padded with "background" bits.
 **
 ** If colors are active, there will always be "four bit" layers per row,
 ** even if you need only three colors.
 ** These layers are implemented by allocating longer rows
 ** (regular length times number of bit planes per pel (depth)).
 **
 ** We try to allocate all row buffers from main memory first.
 ** If allocation fails, we first free a few lines (see constant GIVE_BACK)
 ** to avoid operation close to the dyn. memory limit,
 ** and then initiate swapping to a file.
 **/
{
	PicBuf *pb;
	RowBuf *prev, *act;
	int nr, not_allocated;
#define	GIVE_BACK 8

	if ((pb = (PicBuf *) malloc(sizeof(*pb))) == NULL) {
		Eprintf("Cannot malloc() PicBuf structure\n");
		return NULL;
	}

	pb->nr = n_rows;
	pb->nc = n_cols;
	pb->sd = NULL;
	pb->sf_name = NULL;
	pb->row = NULL;
	first_buf = NULL;	/* Re-init for multiple-file    */
	last_buf = NULL;	/* applications                 */

/**
 ** Number of buffer bytes per row:
 **
 ** Example:
 **
 ** dot range (horiz.): 0...2595 ==> 2596 dots per row, pb->nc=2096 ==>
 ** 	[2596 bits / 8 bits per byte]
 ** ==> 324 DotBlocks + 4 bits which require another whole byte (!)
 **/

	pb->nb = (pb->nc >> 3);
	if (pb->nc & 7)
		pb->nb++;

/**
 ** Auto-detection of depth (# bits per pel):
 **
 ** B/W mode      (1 bit per pel, Foreground & Background),
 ** or color mode (4 bits per pel)
 **/

	pb->depth = (pg->is_color) ? 4 : 1;
	if (pg->is_color && pg->maxcolor > 15) {
		pb->depth = 8;
		if (!pg->quiet)
			fprintf(stderr, "using 8bpp picbuf for NP>15\n");
	}
/**
 ** Allocate a (large) array of RowBuf structures: One for each scan line.
 ** !!! The NULL initialization done implicitly by calloc() is crucial !!!
 **/

	if ((pb->row =
	     (RowBuf *) calloc((unsigned) pb->nr, sizeof(RowBuf)))
	    == NULL) {
		Eprintf("Cannot calloc() %d RowBuf structures\n", pb->nr);
		free_PicBuf(pb);
		return NULL;
	}

/**
 ** Now try to allocate as many buffers as possible. Double-link all RowBuf's
 ** which succeed in buffer allocation, leave the rest isolated (swapping
 ** candidates!)
 **/

	not_allocated = 0;
	prev = (RowBuf *) NULL;
	for (nr = 0, act = pb->row; nr < pb->nr; nr++, act++) {
		act->prev = act->next = NULL;
		act->index = nr;
		if ((act->buf =
		     (Byte *) calloc((unsigned) (pb->nb * pb->depth),
				     1)) == NULL)
			not_allocated++;
		else {
			link_RowBuf(act, prev);
			prev = act;
			last_buf = act;
		}
	}

/**
 ** Prepare swapping
 **/

	if (not_allocated) {
		if (last_buf->index > GIVE_BACK)
			for (nr = 0; nr < GIVE_BACK; nr++) {
				/* Return some memory for internal use */
				free((char *) last_buf->buf);
				unlink_RowBuf(last_buf);
				not_allocated++;
		} else {
			Eprintf
			    ("\nNot enough memory for swapping -- sorry!\n");
			free_PicBuf(pb);
			return NULL;
		}

		Eprintf("\nCouldn't allocate %d out of %d row buffers.\n",
			not_allocated, pb->nr);
		Eprintf("Swapping to disk...\n");
		pb->sf_name = pg->swapfile;
		if ((pb->sd = fopen(pb->sf_name, WRITE_BIN)) == NULL) {
			Eprintf("Couldn't open swap file '%s'\n",
				pb->sf_name);
			PError("hp2xx");
			free_PicBuf(pb);
			return NULL;
		}

/**
 ** Init. swap file data to background color (0), using a shortcut by
 ** assuming that all data are stored without gaps. Thus, instead of
 ** row-by-row operation, we simply write a sufficient number of 0 rows
 ** into the swap file sequentially.
 **/

		for (nr = 0; nr < pb->nr; nr++)
			if ((int)
			    fwrite((char *) pb->row[0].buf,
				   (size_t) pb->nb, (size_t) pb->depth,
				   pb->sd)
			    != pb->depth) {
				Eprintf("Couldn't clear swap file!\n");
				PError("hp2xx");
				free_PicBuf(pb);
				return NULL;
			}
	}
	return pb;
}




void free_PicBuf(PicBuf * pb)
/**
 ** De-allocate all row buffers and the picture puffer struct,
 ** remove the swap file (if any).
 **/
{
	RowBuf *row;
	int i;

	if (pb == NULL)
		return;

	if (pb->sd) {
		fclose(pb->sd);
		pb->sd = NULL;
#ifdef VAX
		delete(pb->sf_name);
#else
		unlink(pb->sf_name);
#endif
	}
	for (i = 0; i < pb->nr; i++) {
		row = &(pb->row[i]);
		if (row != NULL
		    && (row->prev != NULL || row->next != NULL))
			free((char *) row->buf);
	}
	free((char *) pb->row);
	free((char *) pb);
}





void plot_PicBuf(PicBuf * pb, DevPt * pt, PEN_C color_index)
{
	if ((pt->x + X_Offset) < 0 || pt->x > (pb->nc - X_Offset)) {
		Eprintf("plot_PicBuf: Illegal x (%d not in [0, %d])\n",
			pt->x + X_Offset, pb->nc);
		return;
	}
	if ((pt->y + Y_Offset) < 0 || pt->y > (pb->nr - Y_Offset)) {
		Eprintf("plot_PicBuf: Illegal y (%d not in [0, %d])\n",
			pt->y + Y_Offset, pb->nr);
		return;
	}
	plot_RowBuf(get_RowBuf(pb, pt->y + Y_Offset), pt->x + X_Offset,
		    pb->depth, color_index);
}




int index_from_PicBuf(const PicBuf * pb, const DevPt * pt)
{
	if (pt->x < 0 || pt->x > pb->nc) {
		Eprintf
		    ("index_from_PicBuf: Illegal x (%d not in [0, %d])\n",
		     pt->x, pb->nc);
		return 0;
	}
	return index_from_RowBuf(get_RowBuf(pb, pt->y), pt->x, pb);
}


static void dot_PicBuf(DevPt * p0, int pensize, PEN_C pencolor,
		       PicBuf * pb)
{

	DevPt pt;

	int dd = 3 - (pensize);
	int dx = 0;
	int dy = pensize / 2;

	for (; dx <= dy; dx++) {
		for (pt.x = p0->x - dx, pt.y = p0->y + dy;
		     pt.x <= p0->x + dx; pt.x++)
			plot_PicBuf(pb, &pt, pencolor);

		for (pt.x = p0->x - dx, pt.y = p0->y - dy;
		     pt.x <= p0->x + dx; pt.x++)
			plot_PicBuf(pb, &pt, pencolor);

		for (pt.x = p0->x - dy, pt.y = p0->y + dx;
		     pt.x <= p0->x + dy; pt.x++)
			plot_PicBuf(pb, &pt, pencolor);

		for (pt.x = p0->x - dy, pt.y = p0->y - dx;
		     pt.x <= p0->x + dy; pt.x++)
			plot_PicBuf(pb, &pt, pencolor);

		if (dd < 0) {
			dd += (4 * dx) + 6;
		} else {
			dd += 4 * (dx - dy) + 10;
			dy--;
		}
	}
}


static void
line_PicBuf(DevPt * p0, DevPt * p1, PEN_W pensize, PEN_C pencolor,
	    int consecutive, const OUT_PAR * po)
    /**
     ** Rasterize a vector (draw a line in the picture buffer), using the
     ** Bresenham algorithm.
     **/
{
	PicBuf *pb = po->picbuf;
	DevPt *p_act;
	DevPt t0, t1, t2, t3;
	double len, xoff, yoff;
	int dx, dy;
	int linewidth = (int) ceil(pensize * po->HP_to_xdots / 0.025);	/* convert to pixel space */
/*
   printf("pensize = %0.3f mm, linewidth = %d pixels\n",pensize,linewidth); 
*/
	if (linewidth == 0)	/* No pen selected! */
		return;

	if (pencolor == xxBackground)	/* No drawable color!       */
		return;

	if (linewidth == 1) {	/* Thin lines of any attitude */
		p_act = bresenham_init(p0, p1);
		do {
			plot_PicBuf(pb, p_act, pencolor);
		} while (bresenham_next() != BRESENHAM_ERR);
		return;
	}

	if ((p1->x == p0->x) && (p1->y == p0->y)) {	/* No Movement Dot Only */
		if (!po->simplewidths) dot_PicBuf(p0, linewidth, pencolor, pb);
		return;
	}

	if (po->simplewidths) { /* use simple pre-3.4.3 Bresenham hack */
	
	DevPt pt;	
		p_act = bresenham_init (p0, p1);

		do
			{
			plot_PicBuf (pb, p_act, pencolor);

			pt = *p_act;
			pt.x++;	plot_PicBuf (pb, &pt, pencolor);
			pt.y++; plot_PicBuf (pb, &pt, pencolor);
			pt.x--; plot_PicBuf (pb, &pt, pencolor);

			if (pensize > 2)
				{
				pt = *p_act;
				pt.x += 2;	plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
			
			if (pensize > 3)	/* expecting 4 ... 9	*/
				{
				pt = *p_act;
				pt.x += 3;	plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
			}

			if (pensize > 7)	/* who knows	*/
				{
				pt = *p_act;
				pt.x += 4;	plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
			}
			if (pensize > 12)	/* who knows	*/
				{
				pt = *p_act;
				pt.x += 5;	plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
			}
			if (pensize > 15)	/* who knows	*/
				{
				pt = *p_act;
				pt.x += 6;	plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.y++;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
				pt.x--;		plot_PicBuf (pb, &pt, pencolor);
			}
			}
		} while (bresenham_next() != BRESENHAM_ERR);
 
	} else { /* use wide-line Bresenham algorithm for more precise widths */

	murphy_init(pb, pencolor);	/* Wide Lines */
	murphy_wideline(*p0, *p1, linewidth, (consecutive >1?1:0));

	if (pensize > 0.35) {
		switch (CurrentLineAttr.End) {
		case LAE_square:
			dx = p0->x - p1->x;
			dy = p0->y - p1->y;
			len = HYPOT(dx, dy);
			xoff = 0.5 *(dx / len);
			yoff = 0.5 *(dy / len);
			t0.x = p0->x + linewidth*xoff;
			t0.y = p0->y + linewidth*yoff;
                	murphy_wideline(*p0, t0, linewidth, 0);
			t1.x = p1->x - linewidth*xoff;
			t1.y = p1->y - linewidth*yoff;
			murphy_wideline(*p1, t1, linewidth, 0);
			break;
		case LAE_butt:
		default:
			break;
		case LAE_triangular:
			dx = p0->x - p1->x;
			dy = p0->y - p1->y;
			len = HYPOT(dx, dy);
			xoff = 0.5 * fabs(dx / len);
			yoff = 0.5 * fabs(dy / len);
			t0.x = p0->x - (linewidth - 1) * xoff;
			t0.y = p0->y - (linewidth - 1) * yoff;
			t1.x = p0->x + (linewidth - 1) * yoff;
			t1.y = p0->y - (linewidth - 1) * xoff;
			t2.x = p0->x + (linewidth - 1) * xoff;
			t2.y = p0->y + (linewidth - 1) * yoff;
			t3.x = p0->x - (linewidth - 1) * yoff;
			t3.y = p0->y + (linewidth - 1) * xoff;
			polygon_PicBuf(t1, t3, t0, t2, pencolor, pb);
			t0.x = p1->x - (linewidth - 1) * xoff;
			t0.y = p1->y - (linewidth - 1) * yoff;
			t1.x = p1->x + (linewidth - 1) * yoff;
			t1.y = p1->y - (linewidth - 1) * xoff;
			t2.x = p1->x + (linewidth - 1) * xoff;
			t2.y = p1->y + (linewidth - 1) * yoff;
			t3.x = p1->x - (linewidth - 1) * yoff;
			t3.y = p1->y + (linewidth - 1) * xoff;
			polygon_PicBuf(t1, t3, t0, t2, pencolor, pb);
			break;
		case LAE_round:
			dot_PicBuf(p0, linewidth, pencolor, pb);
			dot_PicBuf(p1, linewidth, pencolor, pb);
			break;
		}
	} else {
		dot_PicBuf(p0, linewidth, pencolor, pb);	/* lines upto 0.35 always have round ends */
		dot_PicBuf(p1, linewidth, pencolor, pb);
	}
	} /* simple or true wide-line Bresenham */
}

void polygon_PicBuf(DevPt p4, DevPt p2, DevPt p1, DevPt p3, PEN_C pencolor,
		    PicBuf * pb)
{

	DevPt polygon[8];
	int xmin, ymin, xmax, ymax;
	int start, end, tmp;
	DevPt p_act;
	double denominator;
	double A1, B1, C1, A2, B2, C2;
	int scany;
	int segx, numlines;
	int i, j, k;
/*
fprintf (stderr,"in polydraw: (%d,%d) (%d,%d) (%d,%d) (%d,%d)\n",p1.x,p1.y,p2.x,p2.y,p3.x,p3.y,
p4.x,p4.y);
*/
	polygon[0] = p1;
	polygon[1] = p2;
	polygon[2] = p2;
	polygon[3] = p3;
	polygon[4] = p3;
	polygon[5] = p4;
	polygon[6] = p4;
	polygon[7] = p1;
/*
fprintf(stderr,"pline0 %d %d - %d %d\n",polygon[0].x,polygon[0].y,polygon[1].x,polygon[1].y);
fprintf(stderr,"pline1 %d %d - %d %d\n",polygon[2].x,polygon[2].y,polygon[3].x,polygon[3].y);
fprintf(stderr,"pline2 %d %d - %d %d\n",polygon[4].x,polygon[4].y,polygon[5].x,polygon[5].y);
fprintf(stderr,"pline3 %d %d - %d %d\n",polygon[6].x,polygon[6].y,polygon[7].x,polygon[7].y);
*/

	xmin = MIN(p1.x, p2.x);
	xmin = MIN(xmin, p3.x);
	xmin = MIN(xmin, p4.x);
	xmax = MAX(p1.x, p2.x);
	xmax = MAX(xmax, p3.x);
	xmax = MAX(xmax, p4.x);
	ymin = MIN(p1.y, p2.y);
	ymin = MIN(ymin, p3.y);
	ymin = MIN(ymin, p4.y);
	ymax = MAX(p1.y, p2.y);
	ymax = MAX(ymax, p3.y);
	ymax = MAX(ymax, p4.y);

/*
xmin=xmin-2;
xmax=xmax+2;
*/

	numlines = 1 + ymax - ymin;

/* start at lowest y , run scanlines parallel x across polygon */
/* looking for intersections with edges */

	for (i = 0; i <= numlines; i++) {	/* for all scanlines ... */
		k = -1;
		start = end = 0;
		scany = ymin + i;
/*
if(scany >= ymax || scany<=ymin) {
continue;
}
*/
/* coefficients for current scan line */
		A1 = 0.;
		B1 = (double) (xmin - xmax);
		C1 = (double) (scany * (xmax - xmin));

		for (j = 0; j <= 6; j = j + 2) {	/*for all polygon edges */
			if ((scany < MIN(polygon[j].y, polygon[j + 1].y))
			    || (scany >
				MAX(polygon[j].y, polygon[j + 1].y)))
				continue;

/* coefficients for this edge */
			A2 = (double) (polygon[j + 1].y - polygon[j].y);
			B2 = (double) (polygon[j].x - polygon[j + 1].x);
			C2 = (double) (polygon[j].x *
				       (polygon[j].y - polygon[j + 1].y) +
				       polygon[j].y * (polygon[j + 1].x -
						       polygon[j].x));

/*determine coordinates of intersection */
			denominator = A1 * B2 - A2 * B1;
			if (fabs(denominator) > 1.e-5) {	/* zero means parallel lines */

				segx = (int) ((B1 * C2 - B2 * C1) / denominator);	/*x coordinate of intersection */

/*fprintf(stderr,"seg x,y= %d %d\n",segx,segy);*/
				if ((segx > xmax) || (segx < xmin) ||
				    (segx <
				     MIN(polygon[j].x, polygon[j + 1].x))
				    || (segx >
					MAX(polygon[j].x,
					    polygon[j + 1].x))) {
/*fprintf(stderr,"intersection  at %d %d is not within (%d,%d)-(%d,%d)\n",segx,segy,polygon[j].x,polygon[j].y,polygon[j+1].x,polygon[j+1].y )
; */
				} else {

					k++;
					if (k == 0) {
						start = segx;
					} else if (segx != start) {
						end = segx;
					} else if (k > 0)
						k--;
				}	/* if crossing withing range */
			}
			/*if not parallel */
		}		/*next edge */
		if (k >= 1) {
			if (start > end) {
				tmp = end;
				end = start;
				start = tmp;
			}
/*fprintf(stderr,"fillline %d %d - %d %d\n",start.x,start.y,end.x,end.y);*/
			for (p_act.x = start, p_act.y = scany;
			     p_act.x <= end; p_act.x++)
				plot_PicBuf(pb, &p_act, pencolor);
		}
	}			/* next scanline */

}

void tmpfile_to_PicBuf(const GEN_PAR * pg, const OUT_PAR * po)
/**
 ** Interface to higher-level routines:
 **   Assuming a valid picture buffer, read the drawing commands from
 **   the temporary file, transform HP_GL coordinates into dot coordinates,
 **   and draw (rasterize) vectors.
 **/
{
	HPGL_Pt pt1;
	static DevPt ref = { 0, 0 };
	DevPt next;
	PlotCmd cmd;
	static int consecutive = 0;
	int pen_no = 1;

	if (!pg->quiet)
		Eprintf("\nPlotting in buffer\n");

	rewind(pg->td);

	while ((cmd = PlotCmd_from_tmpfile()) != CMD_EOF)
		switch (cmd) {
		case NOP:
			consecutive = -1;
			break;
		case SET_PEN:
			if ((pen_no = fgetc(pg->td)) == EOF) {
				PError("Unexpected end of temp. file");
				exit(ERROR);
			}
			consecutive = -1;
			break;
		case DEF_PW:
			if (!load_pen_width_table(pg->td,0)) {
				PError("Unexpected end of temp. file");
				exit(ERROR);
			}
			consecutive = -1;
			break;
		case DEF_PC:
			if (load_pen_color_table(pg->td,0) < 0) {
				PError("Unexpected end of temp. file");
				exit(ERROR);
			}
			consecutive = -1;
			break;
		case DEF_LA:
			if (load_line_attr(pg->td,0) < 0) {
				PError("Unexpected end of temp. file");
				exit(ERROR);
			}
			consecutive = -1;
			break;
		case MOVE_TO:
			HPGL_Pt_from_tmpfile(&pt1);
			HPcoord_to_dotcoord(&pt1, &ref, po);
			consecutive = -1;
			break;
		case DRAW_TO:
			HPGL_Pt_from_tmpfile(&pt1);
			HPcoord_to_dotcoord(&pt1, &next, po);
			line_PicBuf(&ref, &next, pt.width[pen_no],
				    pt.color[pen_no], consecutive, po);
			memcpy(&ref, &next, sizeof(ref));
			consecutive++;
			break;
		case PLOT_AT:
			HPGL_Pt_from_tmpfile(&pt1);
			HPcoord_to_dotcoord(&pt1, &ref, po);
			line_PicBuf(&ref, &ref, pt.width[pen_no],
				    pt.color[pen_no], consecutive, po);
			consecutive = -1;
			break;

		default:
			Eprintf("Illegal cmd in temp. file!\n");
			exit(ERROR);
		}
}