#include <u.h>#include <libc.h>#include <bio.h>#include <ctype.h>#include "../common/common.h"#include "tr2post.h" BOOLEAN drawflag = FALSE;BOOLEAN	inpath = FALSE;			/* TRUE if we're putting pieces together */ voidcover(double, double){} voiddrawspline(Biobufhdr *Bp, int flag) {	/* flag!=1 connect end points */	int x[100], y[100];	int i, N;/* * * Spline drawing routine for Postscript printers. The complicated stuff is * handled by procedure Ds, which should be defined in the library file. I've * seen wrong implementations of troff's spline drawing, so fo the record I'll * write down the parametric equations and the necessary conversions to Bezier * cubic splines (as used in Postscript). * * * Parametric equation (x coordinate only): * * *	    (x2 - 2 * x1 + x0)    2                    (x0 + x1) *	x = ------------------ * t   + (x1 - x0) * t + --------- *		    2					   2 * * * The coefficients in the Bezier cubic are, * * *	A = 0 *	B = (x2 - 2 * x1 + x0) / 2 *	C = x1 - x0 * * * while the current point is, * *	current-point = (x0 + x1) / 2 * * Using the relationships given in the Postscript manual (page 121) it's easy to * see that the control points are given by, * * *	x0' = (x0 + 5 * x1) / 6 *	x1' = (x2 + 5 * x1) / 6 *	x2' = (x1 + x2) / 2 * * * where the primed variables are the ones used by curveto. The calculations * shown above are done in procedure Ds using the coordinates set up in both * the x[] and y[] arrays. * * A simple test of whether your spline drawing is correct would be to use cip * to draw a spline and some tangent lines at appropriate points and then print * the file. * */ 	for (N=2; N<sizeof(x)/sizeof(x[0]); N++)		if (Bgetfield(Bp, 'd', &x[N], 0)<=0 || Bgetfield(Bp, 'd', &y[N], 0)<=0)			break; 	x[0] = x[1] = hpos;	y[0] = y[1] = vpos; 	for (i = 1; i < N; i++) {		x[i+1] += x[i];		y[i+1] += y[i];	} 	x[N] = x[N-1];	y[N] = y[N-1]; 	for (i = ((flag!=1)?0:1); i < ((flag!=1)?N-1:N-2); i++) {		endstring();		if (pageon())			Bprint(Bstdout, "%d %d %d %d %d %d Ds\n", x[i], y[i], x[i+1], y[i+1], x[i+2], y[i+2]);/*		if (dobbox == TRUE) {		/* could be better *//*	    		cover((double)(x[i] + x[i+1])/2,(double)-(y[i] + y[i+1])/2);/*	    		cover((double)x[i+1], (double)-y[i+1]);/*	    		cover((double)(x[i+1] + x[i+2])/2, (double)-(y[i+1] + y[i+2])/2);/*		} */	} 	hpos = x[N];			/* where troff expects to be */	vpos = y[N];} voiddraw(Biobufhdr *Bp) { 	int r, x1, y1, x2, y2, i;	int d1, d2; 	drawflag = TRUE;	r = Bgetrune(Bp);	switch(r) {	case 'l':		if (Bgetfield(Bp, 'd', &x1, 0)<=0 || Bgetfield(Bp, 'd', &y1, 0)<=0 || Bgetfield(Bp, 'r', &i, 0)<=0)			error(FATAL, "draw line function, destination coordinates not found.\n"); 		endstring();		if (pageon())			Bprint(Bstdout, "%d %d %d %d Dl\n", hpos, vpos, hpos+x1, vpos+y1);		hpos += x1;		vpos += y1;		break;	case 'c':		if (Bgetfield(Bp, 'd', &d1, 0)<=0)			error(FATAL, "draw circle function, diameter coordinates not found.\n"); 		endstring();		if (pageon())			Bprint(Bstdout, "%d %d %d %d De\n", hpos, vpos, d1, d1);		hpos += d1;		break;	case 'e':		if (Bgetfield(Bp, 'd', &d1, 0)<=0 || Bgetfield(Bp, 'd', &d2, 0)<=0)			error(FATAL, "draw ellipse function, diameter coordinates not found.\n"); 		endstring();		if (pageon())			Bprint(Bstdout, "%d %d %d %d De\n", hpos, vpos, d1, d2);		hpos += d1;		break;	case 'a':		if (Bgetfield(Bp, 'd', &x1, 0)<=0 || Bgetfield(Bp, 'd', &y1, 0)<=0 || Bgetfield(Bp, 'd', &x2, 0)<=0 || Bgetfield(Bp, 'd', &y2, 0)<=0)			error(FATAL, "draw arc function, coordinates not found.\n"); 		endstring();		if (pageon())			Bprint(Bstdout, "%d %d %d %d %d %d Da\n", hpos, vpos, x1, y1, x2, y2);		hpos += x1 + x2;		vpos += y1 + y2;		break;	case 'q':		drawspline(Bp, 1);		break;	case '~':		drawspline(Bp, 2);		break;	default:		error(FATAL, "unknown draw function <%c>\n", r);		break;	}} voidbeginpath(char *buf, int copy) { /* * Called from devcntrl() whenever an "x X BeginPath" command is read. It's used * to mark the start of a sequence of drawing commands that should be grouped * together and treated as a single path. By default the drawing procedures in * *drawfile treat each drawing command as a separate object, and usually start * with a newpath (just as a precaution) and end with a stroke. The newpath and * stroke isolate individual drawing commands and make it impossible to deal with * composite objects. "x X BeginPath" can be used to mark the start of drawing * commands that should be grouped together and treated as a single object, and * part of what's done here ensures that the PostScript drawing commands defined * in *drawfile skip the newpath and stroke, until after the next "x X DrawPath" * command. At that point the path that's been built up can be manipulated in * various ways (eg. filled and/or stroked with a different line width). * * Color selection is one of the options that's available in parsebuf(), * so if we get here we add *colorfile to the output file before doing * anything important. * */	if (inpath == FALSE) {		endstring();	/*	getdraw();	*/	/*	getcolor(); */		Bprint(Bstdout, "gsave\n");		Bprint(Bstdout, "newpath\n");		Bprint(Bstdout, "%d %d m\n", hpos, vpos);		Bprint(Bstdout, "/inpath true def\n");		if ( copy == TRUE )			Bprint(Bstdout, "%s\n", buf);		inpath = TRUE;	}} static void parsebuf(char*); voiddrawpath(char *buf, int copy) { /* * * Called from devcntrl() whenever an "x X DrawPath" command is read. It marks the * end of the path started by the last "x X BeginPath" command and uses whatever * has been passed along in *buf to manipulate the path (eg. fill and/or stroke * the path). Once that's been done the drawing procedures are restored to their * default behavior in which each drawing command is treated as an isolated path. * The new version (called after "x X DrawPath") has copy set to FALSE, and calls * parsebuf() to figure out what goes in the output file. It's a feeble attempt * to free users and preprocessors (like pic) from having to know PostScript. The * comments in parsebuf() describe what's handled. * * In the early version a path was started with "x X BeginObject" and ended with * "x X EndObject". In both cases *buf was just copied to the output file, and * was expected to be legitimate PostScript that manipulated the current path. * The old escape sequence will be supported for a while (for Ravi), and always * call this routine with copy set to TRUE. *  * */ 	if ( inpath == TRUE ) {		if ( copy == TRUE )			Bprint(Bstdout, "%s\n", buf);		else			parsebuf(buf);		Bprint(Bstdout, "grestore\n");		Bprint(Bstdout, "/inpath false def\n");/*		reset();		*/		inpath = FALSE;	}}  /*****************************************************************************/ static voidparsebuf(char *buf){	char	*p;			/* usually the next token */	char *q;	int		gsavelevel = 0;		/* non-zero if we've done a gsave */ /* * * Simple minded attempt at parsing the string that followed an "x X DrawPath" * command. Everything not recognized here is simply ignored - there's absolutely * no error checking and what was originally in buf is clobbered by strtok(). * A typical *buf might look like, * *	gray .9 fill stroke * * to fill the current path with a gray level of .9 and follow that by stroking the * outline of the path. Since unrecognized tokens are ignored the last example * could also be written as, * *	with gray .9 fill then stroke * * The "with" and "then" strings aren't recognized tokens and are simply discarded. * The "stroke", "fill", and "wfill" force out appropriate PostScript code and are * followed by a grestore. In otherwords changes to the grahics state (eg. a gray * level or color) are reset to default values immediately after the stroke, fill, * or wfill tokens. For now "fill" gets invokes PostScript's eofill operator and * "wfill" calls fill (ie. the operator that uses the non-zero winding rule). * * The tokens that cause temporary changes to the graphics state are "gray" (for * setting the gray level), "color" (for selecting a known color from the colordict * dictionary defined in *colorfile), and "line" (for setting the line width). All * three tokens can be extended since strncmp() makes the comparison. For example * the strings "line" and "linewidth" accomplish the same thing. Colors are named * (eg. "red"), but must be appropriately defined in *colorfile. For now all three * tokens must be followed immediately by their single argument. The gray level * (ie. the argument that follows "gray") should be a number between 0 and 1, with * 0 for black and 1 for white. * * To pass straight PostScript through enclose the appropriate commands in double * quotes. Straight PostScript is only bracketed by the outermost gsave/grestore * pair (ie. the one from the initial "x X BeginPath") although that's probably * a mistake. Suspect I may have to change the double quote delimiters. * */	p = buf;	for( ; p != nil ; p = q ) {		if( q = strchr(p, ' ') ) {			*q++ = '\0';		} 		if ( gsavelevel == 0 ) {			Bprint(Bstdout, "gsave\n");			gsavelevel++;		}		if ( strcmp(p, "stroke") == 0 ) {			Bprint(Bstdout, "closepath stroke\ngrestore\n");			gsavelevel--;		} else if ( strcmp(p, "openstroke") == 0 ) {			Bprint(Bstdout, "stroke\ngrestore\n");			gsavelevel--;		} else if ( strcmp(p, "fill") == 0 ) {			Bprint(Bstdout, "eofill\ngrestore\n");			gsavelevel--;		} else if ( strcmp(p, "wfill") == 0 ) {			Bprint(Bstdout, "fill\ngrestore\n");			gsavelevel--;		} else if ( strcmp(p, "sfill") == 0 ) {			Bprint(Bstdout, "eofill\ngrestore\ngsave\nstroke\ngrestore\n");			gsavelevel--;		} else if ( strncmp(p, "gray", strlen("gray")) == 0 ) {			if( q ) {				p = q;				if ( q = strchr(p, ' ') )					*q++ = '\0';				Bprint(Bstdout, "%s setgray\n", p);			}		} else if ( strncmp(p, "color", strlen("color")) == 0 ) {			if( q ) {				p = q;				if ( q = strchr(p, ' ') )					*q++ = '\0';				Bprint(Bstdout, "/%s setcolor\n", p);			}		} else if ( strncmp(p, "line", strlen("line")) == 0 ) {			if( q ) {				p = q;				if ( q = strchr(p, ' ') )					*q++ = '\0';				Bprint(Bstdout, "%s resolution mul 2 div setlinewidth\n", p);			}		} else if ( strncmp(p, "reverse", strlen("reverse")) == 0 )			Bprint(Bstdout, "reversepath\n");		else if ( *p == '"' ) {			for ( ; gsavelevel > 0; gsavelevel-- )				Bprint(Bstdout, "grestore\n");			if ( q != nil )				*--q = ' ';			if ( (q = strchr(p, '"')) != nil ) {				*q++ = '\0';				Bprint(Bstdout, "%s\n", p);			}		}	} 	for ( ; gsavelevel > 0; gsavelevel-- )		Bprint(Bstdout, "grestore\n"); }