⟦598514e0a⟧

TextFile

/*
 * Copyright (c) 1987, 1989 University of Maryland
 * Department of Computer Science.  All rights reserved.
 * Permission to copy for any purpose is hereby granted
 * so long as this copyright notice remains intact.
 */

/*
 * Sample device driver page loop.
 * Here are the functions you must write.
 * The particular lines to change are indicated with `:::'.
 */

char	*DVIFileName;		/* name of input DVI file */

/*
 * Do some sort of device-dependent fiddling with fonts
 * as they are read from the DVI file.
 */
struct font *
DefineFont(name, dvimag, dvidsz)
	char *name;
	i32 dvimag, dvidsz;
{
	struct font *f;
	char *path;

:::	f = GetFont(name, dvimag, dvidsz, PrintEngine, &path);
	if (f == NULL) {
		GripeCannotGetFont(name, dvimag, dvidsz, PrintEngine, path);
		return (NULL);
	}
:::	f->f_un.f_int = NextFontNumber++;
	return (f);
}

/*
 * Start a new page (interpreter found a DVI_BOP).
 */
void
BeginPage()
{

:::	(void) printf("start new page\n");
:::	dev_hh = dev_vv = somewhere;
}

/*
 * End the page (interpreter found a DVI_EOP).
 */
EndPage()
{

:::	(void) printf("end the page\n");
}

/*
 * Perform a \special.
 * This version ignores all, with a warning.
 */
void
DoSpecial(len)
	i32 len;
{

	error(0, 0, "warning: ignoring \\special");
	(void) fseek(stdin, (long)len, 1);
}

/*
 * Set a rule at dvi_hh, dvi_vv.
 */
void
SetRule(h, w)
	i32 h, w;
{

:::	DRAW A RULE, height h, width w AT dvi_hh,dvi_vv
}

/*
 * Check the range of a character, to be sure the device can handle it.
 * Called for DVI_SET and DVI_PUT opcodes only.
 */
int
CheckChar(c)
	i32 c;
{

	if ((ui32)c > 127) {
		error(0, 0, "Warning: character code %ld too big for XXX",
		    (long)c);
		return (1);
	}
	return (0);
}

/*
 * Main page loop.  This reads one page of the DVI file.
 * Returns 1 for EOP and 0 for end of last page (POST).
 */
int
PageLoop()
{
	static struct font NoFont;	/* font with zero pspace, etc */
	register int c;
	register i32 p;
	register struct font *f = &NoFont;
	register FILE *fp = ds.ds_fp;
:::	LOCAL VARIABLE DECLARATIONS
	int doingpage = 0, advance;

:::	if (ReversePages)
		if (ds.ds_prevpage == -1)
			return (0);	/* `the first shall be last' */
		else
			(void) fseek(fp, ds.ds_prevpage, 0);

	/*
	 * This would be a `for (;;)', but that makes the function
	 * crawl off the right of the screen.
	 *
	 * We handle ordinary characters early, as they are the
	 * most common opcodes in DVI files, and doing so makes the
	 * loop run faster.
	 */
loop:
	c = fgetbyte(fp);
	if (DVI_IsChar(c)) {
		register struct glyph *g;

		p = c;
		advance = 1;
do_char:
		g = GLYPH(f, p);
		if (!GVALID(g)) {
			GripeBadGlyph(p, f);
			goto loop;
		}
		if ((g->g_flags & GF_SEEN) == 0) {
			g->g_pixwidth = fromSP(g->g_tfmwidth);
			g->g_flags |= GF_SEEN;
:::			LOAD GLYPH (p,f,g) INTO DEVICE IF NECESSARY
		}
:::		SET DEVICE POSITION (to dvi_hh, dvi_vv) IF NECESSARY
:::		SET DEVICE FONT (e.g., to f->f_un.f_int) IF NECESSARY
:::		PUT CHARACTER p IN FONT f
:::		ADJUST NOTION OF DEVICE POSITION IF NECESSARY
		if (advance) {
			dvi_h += g->g_tfmwidth;
			dvi_hh += g->g_pixwidth;
			p = fromSP(dvi_h);
			FIXDRIFT(dvi_hh, p);
		}
		goto loop;
	}

	if (c == EOF)		/* unexpected end of DVI file */
		GripeUnexpectedDVIEOF();

	/*
	 * Gather up a parameter, if known.
	 */
	switch (DVI_OpLen(c)) {

	case DPL_NONE:
		break;

	case DPL_SGN1:
		p = fgetbyte(fp);
		p = Sign8(p);
		break;

	case DPL_SGN2:
		fGetWord(fp, p);
		p = Sign16(p);
		break;

	case DPL_SGN3:
		fGet3Byte(fp, p);
		p = Sign24(p);
		break;

	case DPL_SGN4:
		fGetLong(fp, p);
		break;

	case DPL_UNS1:
		p = fgetbyte(fp);
		p = UnSign8(p);
		break;

	case DPL_UNS2:
		fGetWord(fp, p);
		p = UnSign16(p);
		break;

	case DPL_UNS3:
		fGet3Byte(fp, p);
		p = UnSign24(p);
		break;

	default:
		panic("DVI_OpLen(%d) = %d", c, DVI_OpLen(c));
		/* NOTREACHED */
	}

	/*
	 * Now switch on the type.
	 */
	switch (DVI_DT(c)) {

	case DT_SET:
		advance = 1;
:::		if (CheckChar(p))	...delete this if all characters OK
:::			goto loop;
		goto do_char;

	case DT_PUT:
		advance = 0;
:::		if (CheckChar(p))
:::			goto loop;
		goto do_char;

	case DT_SETRULE:
		DVIRule(SetRule, 1);
		goto loop;

	case DT_PUTRULE:
		DVIRule(SetRule, 0);
		goto loop;

	case DT_NOP:
		goto loop;

	case DT_BOP:
		if (doingpage)
			GripeUnexpectedOp("BOP (already in page)");
		DVIBeginPage(BeginPage);
		doingpage = 1;
		goto loop;

	case DT_EOP:
		if (!doingpage)
			GripeUnexpectedOp("EOP (no BOP)");
		EndPage();
		return (1);

	case DT_PUSH:
		*ds.ds_sp++ = ds.ds_cur;
		goto loop;

	case DT_POP:
		ds.ds_cur = *--ds.ds_sp;
		goto loop;

	case DT_W0:
		p = dvi_w;
		goto right;

	case DT_W:
		dvi_w = p;
		goto right;

	case DT_X0:
		p = dvi_x;
		goto right;

	case DT_X:
		dvi_x = p;
		goto right;

	case DT_RIGHT:
right:
		dvi_h += p;
		if (F_SMALLH(f, p)) {
			dvi_hh += fromSP(p);
			p = fromSP(dvi_h);
			FIXDRIFT(dvi_hh, p);
		} else
			dvi_hh = fromSP(dvi_h);
		goto loop;

	case DT_Y0:
		p = dvi_y;
		goto down;

	case DT_Y:
		dvi_y = p;
		goto down;

	case DT_Z0:
		p = dvi_z;
		goto down;

	case DT_Z:
		dvi_z = p;
		goto down;

	case DT_DOWN:
down:
		dvi_v += p;
		if (F_SMALLV(f, p)) {
			dvi_vv += fromSP(p);
			p = fromSP(dvi_v);
			FIXDRIFT(dvi_vv, p);
		} else
			dvi_vv = fromSP(dvi_v);
		goto loop;

	case DT_FNTNUM:
		f = DVIFindFont((i32)(c - DVI_FNTNUM0));
		goto loop;

	case DT_FNT:
		f = DVIFindFont(p);
		goto loop;

	case DT_XXX:
		DoSpecial(p);
		goto loop;

	case DT_FNTDEF:
		SkipFontDef(fp);
		goto loop;

	case DT_PRE:
		GripeUnexpectedOp("PRE");
		/* NOTREACHED */

	case DT_POST:
		if (doingpage) {
			GripeUnexpectedOp("POST (no EOP)");
			/* NOTREACHED */
		}
		return (0);

	case DT_POSTPOST:
		GripeUnexpectedOp("POSTPOST");
		/* NOTREACHED */

	case DT_UNDEF:
		GripeUndefinedOp(c);
		/* NOTREACHED */

	default:
		panic("DVI_DT(%d) = %d", c, DVI_DT(c));
		/* NOTREACHED */
	}
	/* NOTREACHED */
}

main(argc, argv)
	int argc;
	char **argv;
{
:::	DECLARATIONS

	ProgName = *argv;
	ds.ds_usermag = 1000;
:::	ds.ds_maxdrift = 3;
:::	ReversePages = 0;
	DVIFileName = "`stdin'";

:::	PARSE OPTIONS

:::	OPEN INPUT FILE

:::	DVISetState(stdin, DefineFont, dpi, xoff, yoff);

:::	SET INITIAL DEVICE STATE

	while (PageLoop())
		/* void */;

:::	FINISH DEVICE OUTPUT

:::	exit(0);
}
DataMuseum.dk

DKUUG/EUUG Conference tapes

⟦598514e0a⟧ TextFile

Derivation

TextFile
