Initial revision

1 files changed, 1623 insertions, 0 deletions

diff --git a/generic/tkCanvLine.c b/generic/tkCanvLine.c
new file mode 100644
index 0000000..97cd1f5
--- /dev/null
+++ b/generic/tkCanvLine.c
@@ -0,0 +1,1623 @@
+/* 
+ * tkCanvLine.c --
+ *
+ *	This file implements line items for canvas widgets.
+ *
+ * Copyright (c) 1991-1994 The Regents of the University of California.
+ * Copyright (c) 1994-1995 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution
+ * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * SCCS: @(#) tkCanvLine.c 1.46 97/04/25 16:51:02
+ */
+
+#include <stdio.h>
+#include "tkInt.h"
+#include "tkPort.h"
+
+/*
+ * The structure below defines the record for each line item.
+ */
+
+typedef struct LineItem  {
+    Tk_Item header;		/* Generic stuff that's the same for all
+				 * types.  MUST BE FIRST IN STRUCTURE. */
+    Tk_Canvas canvas;		/* Canvas containing item.  Needed for
+				 * parsing arrow shapes. */
+    int numPoints;		/* Number of points in line (always >= 2). */
+    double *coordPtr;		/* Pointer to malloc-ed array containing
+				 * x- and y-coords of all points in line.
+				 * X-coords are even-valued indices, y-coords
+				 * are corresponding odd-valued indices. If
+				 * the line has arrowheads then the first
+				 * and last points have been adjusted to refer
+				 * to the necks of the arrowheads rather than
+				 * their tips.  The actual endpoints are
+				 * stored in the *firstArrowPtr and
+				 * *lastArrowPtr, if they exist. */
+    int width;			/* Width of line. */
+    XColor *fg;			/* Foreground color for line. */
+    Pixmap fillStipple;		/* Stipple bitmap for filling line. */
+    int capStyle;		/* Cap style for line. */
+    int joinStyle;		/* Join style for line. */
+    GC gc;			/* Graphics context for filling line. */
+    GC arrowGC;			/* Graphics context for drawing arrowheads. */
+    Tk_Uid arrow;		/* Indicates whether or not to draw arrowheads:
+				 * "none", "first", "last", or "both". */
+    float arrowShapeA;		/* Distance from tip of arrowhead to center. */
+    float arrowShapeB;		/* Distance from tip of arrowhead to trailing
+				 * point, measured along shaft. */
+    float arrowShapeC;		/* Distance of trailing points from outside
+				 * edge of shaft. */
+    double *firstArrowPtr;	/* Points to array of PTS_IN_ARROW points
+				 * describing polygon for arrowhead at first
+				 * point in line.  First point of arrowhead
+				 * is tip.  Malloc'ed.  NULL means no arrowhead
+				 * at first point. */
+    double *lastArrowPtr;	/* Points to polygon for arrowhead at last
+				 * point in line (PTS_IN_ARROW points, first
+				 * of which is tip).  Malloc'ed.  NULL means
+				 * no arrowhead at last point. */
+    int smooth;			/* Non-zero means draw line smoothed (i.e.
+				 * with Bezier splines). */
+    int splineSteps;		/* Number of steps in each spline segment. */
+} LineItem;
+
+/*
+ * Number of points in an arrowHead:
+ */
+
+#define PTS_IN_ARROW 6
+
+/*
+ * Prototypes for procedures defined in this file:
+ */
+
+static int		ArrowheadPostscript _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, LineItem *linePtr,
+			    double *arrowPtr));
+static void		ComputeLineBbox _ANSI_ARGS_((Tk_Canvas canvas,
+			    LineItem *linePtr));
+static int		ConfigureLine _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, Tk_Item *itemPtr, int argc,
+			    char **argv, int flags));
+static int		ConfigureArrows _ANSI_ARGS_((Tk_Canvas canvas,
+			    LineItem *linePtr));
+static int		CreateLine _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, struct Tk_Item *itemPtr,
+			    int argc, char **argv));
+static void		DeleteLine _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, Display *display));
+static void		DisplayLine _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, Display *display, Drawable dst,
+			    int x, int y, int width, int height));
+static int		LineCoords _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, Tk_Item *itemPtr,
+			    int argc, char **argv));
+static int		LineToArea _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double *rectPtr));
+static double		LineToPoint _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double *coordPtr));
+static int		LineToPostscript _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, Tk_Item *itemPtr, int prepass));
+static int		ParseArrowShape _ANSI_ARGS_((ClientData clientData,
+			    Tcl_Interp *interp, Tk_Window tkwin, char *value,
+			    char *recordPtr, int offset));
+static char *		PrintArrowShape _ANSI_ARGS_((ClientData clientData,
+			    Tk_Window tkwin, char *recordPtr, int offset,
+			    Tcl_FreeProc **freeProcPtr));
+static void		ScaleLine _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double originX, double originY,
+			    double scaleX, double scaleY));
+static void		TranslateLine _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double deltaX, double deltaY));
+
+/*
+ * Information used for parsing configuration specs.  If you change any
+ * of the default strings, be sure to change the corresponding default
+ * values in CreateLine.
+ */
+
+static Tk_CustomOption arrowShapeOption = {ParseArrowShape,
+	PrintArrowShape, (ClientData) NULL};
+static Tk_CustomOption tagsOption = {Tk_CanvasTagsParseProc,
+    Tk_CanvasTagsPrintProc, (ClientData) NULL
+};
+
+static Tk_ConfigSpec configSpecs[] = {
+    {TK_CONFIG_UID, "-arrow", (char *) NULL, (char *) NULL,
+	"none", Tk_Offset(LineItem, arrow), TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_CUSTOM, "-arrowshape", (char *) NULL, (char *) NULL,
+	"8 10 3", Tk_Offset(LineItem, arrowShapeA),
+	TK_CONFIG_DONT_SET_DEFAULT, &arrowShapeOption},
+    {TK_CONFIG_CAP_STYLE, "-capstyle", (char *) NULL, (char *) NULL,
+	"butt", Tk_Offset(LineItem, capStyle), TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_COLOR, "-fill", (char *) NULL, (char *) NULL,
+	"black", Tk_Offset(LineItem, fg), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_JOIN_STYLE, "-joinstyle", (char *) NULL, (char *) NULL,
+	"round", Tk_Offset(LineItem, joinStyle), TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_BOOLEAN, "-smooth", (char *) NULL, (char *) NULL,
+	"0", Tk_Offset(LineItem, smooth), TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_INT, "-splinesteps", (char *) NULL, (char *) NULL,
+	"12", Tk_Offset(LineItem, splineSteps), TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_BITMAP, "-stipple", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(LineItem, fillStipple), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_CUSTOM, "-tags", (char *) NULL, (char *) NULL,
+	(char *) NULL, 0, TK_CONFIG_NULL_OK, &tagsOption},
+    {TK_CONFIG_PIXELS, "-width", (char *) NULL, (char *) NULL,
+	"1", Tk_Offset(LineItem, width), TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
+	(char *) NULL, 0, 0}
+};
+
+/*
+ * The structures below defines the line item type by means
+ * of procedures that can be invoked by generic item code.
+ */
+
+Tk_ItemType tkLineType = {
+    "line",				/* name */
+    sizeof(LineItem),			/* itemSize */
+    CreateLine,				/* createProc */
+    configSpecs,			/* configSpecs */
+    ConfigureLine,			/* configureProc */
+    LineCoords,				/* coordProc */
+    DeleteLine,				/* deleteProc */
+    DisplayLine,			/* displayProc */
+    0,					/* alwaysRedraw */
+    LineToPoint,			/* pointProc */
+    LineToArea,				/* areaProc */
+    LineToPostscript,			/* postscriptProc */
+    ScaleLine,				/* scaleProc */
+    TranslateLine,			/* translateProc */
+    (Tk_ItemIndexProc *) NULL,		/* indexProc */
+    (Tk_ItemCursorProc *) NULL,		/* icursorProc */
+    (Tk_ItemSelectionProc *) NULL,	/* selectionProc */
+    (Tk_ItemInsertProc *) NULL,		/* insertProc */
+    (Tk_ItemDCharsProc *) NULL,		/* dTextProc */
+    (Tk_ItemType *) NULL		/* nextPtr */
+};
+
+/*
+ * The Tk_Uid's below refer to uids for the various arrow types:
+ */
+
+static Tk_Uid noneUid = NULL;
+static Tk_Uid firstUid = NULL;
+static Tk_Uid lastUid = NULL;
+static Tk_Uid bothUid = NULL;
+
+/*
+ * The definition below determines how large are static arrays
+ * used to hold spline points (splines larger than this have to
+ * have their arrays malloc-ed).
+ */
+
+#define MAX_STATIC_POINTS 200
+
+/*
+ *--------------------------------------------------------------
+ *
+ * CreateLine --
+ *
+ *	This procedure is invoked to create a new line item in
+ *	a canvas.
+ *
+ * Results:
+ *	A standard Tcl return value.  If an error occurred in
+ *	creating the item, then an error message is left in
+ *	interp->result;  in this case itemPtr is left uninitialized,
+ *	so it can be safely freed by the caller.
+ *
+ * Side effects:
+ *	A new line item is created.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+CreateLine(interp, canvas, itemPtr, argc, argv)
+    Tcl_Interp *interp;			/* Interpreter for error reporting. */
+    Tk_Canvas canvas;			/* Canvas to hold new item. */
+    Tk_Item *itemPtr;			/* Record to hold new item;  header
+					 * has been initialized by caller. */
+    int argc;				/* Number of arguments in argv. */
+    char **argv;			/* Arguments describing line. */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    int i;
+
+    if (argc < 4) {
+	Tcl_AppendResult(interp, "wrong # args: should be \"",
+		Tk_PathName(Tk_CanvasTkwin(canvas)), " create ",
+		itemPtr->typePtr->name, " x1 y1 x2 y2 ?x3 y3 ...? ?options?\"",
+		(char *) NULL);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Carry out initialization that is needed to set defaults and to
+     * allow proper cleanup after errors during the the remainder of
+     * this procedure.
+     */
+
+    linePtr->canvas = canvas;
+    linePtr->numPoints = 0;
+    linePtr->coordPtr = NULL;
+    linePtr->width = 1;
+    linePtr->fg = None;
+    linePtr->fillStipple = None;
+    linePtr->capStyle = CapButt;
+    linePtr->joinStyle = JoinRound;
+    linePtr->gc = None;
+    linePtr->arrowGC = None;
+    if (noneUid == NULL) {
+	noneUid = Tk_GetUid("none");
+	firstUid = Tk_GetUid("first");
+	lastUid = Tk_GetUid("last");
+	bothUid = Tk_GetUid("both");
+    }
+    linePtr->arrow = noneUid;
+    linePtr->arrowShapeA = (float)8.0;
+    linePtr->arrowShapeB = (float)10.0;
+    linePtr->arrowShapeC = (float)3.0;
+    linePtr->firstArrowPtr = NULL;
+    linePtr->lastArrowPtr = NULL;
+    linePtr->smooth = 0;
+    linePtr->splineSteps = 12;
+
+    /*
+     * Count the number of points and then parse them into a point
+     * array.  Leading arguments are assumed to be points if they
+     * start with a digit or a minus sign followed by a digit.
+     */
+
+    for (i = 4; i < (argc-1); i+=2) {
+	if ((!isdigit(UCHAR(argv[i][0]))) &&
+		((argv[i][0] != '-')
+		|| ((argv[i][1] != '.') && !isdigit(UCHAR(argv[i][1]))))) {
+	    break;
+	}
+    }
+    if (LineCoords(interp, canvas, itemPtr, i, argv) != TCL_OK) {
+	goto error;
+    }
+    if (ConfigureLine(interp, canvas, itemPtr, argc-i, argv+i, 0) == TCL_OK) {
+	return TCL_OK;
+    }
+
+    error:
+    DeleteLine(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas)));
+    return TCL_ERROR;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * LineCoords --
+ *
+ *	This procedure is invoked to process the "coords" widget
+ *	command on lines.  See the user documentation for details
+ *	on what it does.
+ *
+ * Results:
+ *	Returns TCL_OK or TCL_ERROR, and sets interp->result.
+ *
+ * Side effects:
+ *	The coordinates for the given item may be changed.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+LineCoords(interp, canvas, itemPtr, argc, argv)
+    Tcl_Interp *interp;			/* Used for error reporting. */
+    Tk_Canvas canvas;			/* Canvas containing item. */
+    Tk_Item *itemPtr;			/* Item whose coordinates are to be
+					 * read or modified. */
+    int argc;				/* Number of coordinates supplied in
+					 * argv. */
+    char **argv;			/* Array of coordinates: x1, y1,
+					 * x2, y2, ... */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    char buffer[TCL_DOUBLE_SPACE];
+    int i, numPoints;
+
+    if (argc == 0) {
+	double *coordPtr;
+	int numCoords;
+
+	numCoords = 2*linePtr->numPoints;
+	if (linePtr->firstArrowPtr != NULL) {
+	    coordPtr = linePtr->firstArrowPtr;
+	} else {
+	    coordPtr = linePtr->coordPtr;
+	}
+	for (i = 0; i < numCoords; i++, coordPtr++) {
+	    if (i == 2) {
+		coordPtr = linePtr->coordPtr+2;
+	    }
+	    if ((linePtr->lastArrowPtr != NULL) && (i == (numCoords-2))) {
+		coordPtr = linePtr->lastArrowPtr;
+	    }
+	    Tcl_PrintDouble(interp, *coordPtr, buffer);
+	    Tcl_AppendElement(interp, buffer);
+	}
+    } else if (argc < 4) {
+	Tcl_AppendResult(interp,
+		"too few coordinates for line: must have at least 4",
+		(char *) NULL);
+	return TCL_ERROR;
+    } else if (argc & 1) {
+	Tcl_AppendResult(interp,
+		"odd number of coordinates specified for line",
+		(char *) NULL);
+	return TCL_ERROR;
+    } else {
+	numPoints = argc/2;
+	if (linePtr->numPoints != numPoints) {
+	    if (linePtr->coordPtr != NULL) {
+		ckfree((char *) linePtr->coordPtr);
+	    }
+	    linePtr->coordPtr = (double *) ckalloc((unsigned)
+		    (sizeof(double) * argc));
+	    linePtr->numPoints = numPoints;
+	}
+	for (i = argc-1; i >= 0; i--) {
+	    if (Tk_CanvasGetCoord(interp, canvas, argv[i],
+		    &linePtr->coordPtr[i]) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	}
+
+	/*
+	 * Update arrowheads by throwing away any existing arrow-head
+	 * information and calling ConfigureArrows to recompute it.
+	 */
+
+	if (linePtr->firstArrowPtr != NULL) {
+	    ckfree((char *) linePtr->firstArrowPtr);
+	    linePtr->firstArrowPtr = NULL;
+	}
+	if (linePtr->lastArrowPtr != NULL) {
+	    ckfree((char *) linePtr->lastArrowPtr);
+	    linePtr->lastArrowPtr = NULL;
+	}
+	if (linePtr->arrow != noneUid) {
+	    ConfigureArrows(canvas, linePtr);
+	}
+	ComputeLineBbox(canvas, linePtr);
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ConfigureLine --
+ *
+ *	This procedure is invoked to configure various aspects
+ *	of a line item such as its background color.
+ *
+ * Results:
+ *	A standard Tcl result code.  If an error occurs, then
+ *	an error message is left in interp->result.
+ *
+ * Side effects:
+ *	Configuration information, such as colors and stipple
+ *	patterns, may be set for itemPtr.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+ConfigureLine(interp, canvas, itemPtr, argc, argv, flags)
+    Tcl_Interp *interp;		/* Used for error reporting. */
+    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
+    Tk_Item *itemPtr;		/* Line item to reconfigure. */
+    int argc;			/* Number of elements in argv.  */
+    char **argv;		/* Arguments describing things to configure. */
+    int flags;			/* Flags to pass to Tk_ConfigureWidget. */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    XGCValues gcValues;
+    GC newGC, arrowGC;
+    unsigned long mask;
+    Tk_Window tkwin;
+
+    tkwin = Tk_CanvasTkwin(canvas);
+    if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc, argv,
+	    (char *) linePtr, flags) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * A few of the options require additional processing, such as
+     * graphics contexts.
+     */
+
+    if (linePtr->fg == NULL) {
+	newGC = arrowGC = None;
+    } else {
+	gcValues.foreground = linePtr->fg->pixel;
+	gcValues.join_style = linePtr->joinStyle;
+	if (linePtr->width < 0) {
+	    linePtr->width = 1;
+	}
+	gcValues.line_width = linePtr->width;
+	mask = GCForeground|GCJoinStyle|GCLineWidth;
+	if (linePtr->fillStipple != None) {
+	    gcValues.stipple = linePtr->fillStipple;
+	    gcValues.fill_style = FillStippled;
+	    mask |= GCStipple|GCFillStyle;
+	}
+	if (linePtr->arrow == noneUid) {
+	    gcValues.cap_style = linePtr->capStyle;
+	    mask |= GCCapStyle;
+	}
+	newGC = Tk_GetGC(tkwin, mask, &gcValues);
+	gcValues.line_width = 0;
+	arrowGC = Tk_GetGC(tkwin, mask, &gcValues);
+    }
+    if (linePtr->gc != None) {
+	Tk_FreeGC(Tk_Display(tkwin), linePtr->gc);
+    }
+    if (linePtr->arrowGC != None) {
+	Tk_FreeGC(Tk_Display(tkwin), linePtr->arrowGC);
+    }
+    linePtr->gc = newGC;
+    linePtr->arrowGC = arrowGC;
+
+    /*
+     * Keep spline parameters within reasonable limits.
+     */
+
+    if (linePtr->splineSteps < 1) {
+	linePtr->splineSteps = 1;
+    } else if (linePtr->splineSteps > 100) {
+	linePtr->splineSteps = 100;
+    }
+
+    /*
+     * Setup arrowheads, if needed.  If arrowheads are turned off,
+     * restore the line's endpoints (they were shortened when the
+     * arrowheads were added).
+     */
+
+    if ((linePtr->firstArrowPtr != NULL) && (linePtr->arrow != firstUid)
+	    && (linePtr->arrow != bothUid)) {
+	linePtr->coordPtr[0] = linePtr->firstArrowPtr[0];
+	linePtr->coordPtr[1] = linePtr->firstArrowPtr[1];
+	ckfree((char *) linePtr->firstArrowPtr);
+	linePtr->firstArrowPtr = NULL;
+    }
+    if ((linePtr->lastArrowPtr != NULL) && (linePtr->arrow != lastUid)
+	    && (linePtr->arrow != bothUid)) {
+	int i;
+
+	i = 2*(linePtr->numPoints-1);
+	linePtr->coordPtr[i] = linePtr->lastArrowPtr[0];
+	linePtr->coordPtr[i+1] = linePtr->lastArrowPtr[1];
+	ckfree((char *) linePtr->lastArrowPtr);
+	linePtr->lastArrowPtr = NULL;
+    }
+    if (linePtr->arrow != noneUid) {
+	if ((linePtr->arrow != firstUid) && (linePtr->arrow != lastUid)
+		&& (linePtr->arrow != bothUid)) {
+	    Tcl_AppendResult(interp, "bad arrow spec \"",
+		    linePtr->arrow, "\": must be none, first, last, or both",
+		    (char *) NULL);
+	    linePtr->arrow = noneUid;
+	    return TCL_ERROR;
+	}
+	ConfigureArrows(canvas, linePtr);
+    }
+
+    /*
+     * Recompute bounding box for line.
+     */
+
+    ComputeLineBbox(canvas, linePtr);
+
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * DeleteLine --
+ *
+ *	This procedure is called to clean up the data structure
+ *	associated with a line item.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Resources associated with itemPtr are released.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+DeleteLine(canvas, itemPtr, display)
+    Tk_Canvas canvas;			/* Info about overall canvas widget. */
+    Tk_Item *itemPtr;			/* Item that is being deleted. */
+    Display *display;			/* Display containing window for
+					 * canvas. */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+
+    if (linePtr->coordPtr != NULL) {
+	ckfree((char *) linePtr->coordPtr);
+    }
+    if (linePtr->fg != NULL) {
+	Tk_FreeColor(linePtr->fg);
+    }
+    if (linePtr->fillStipple != None) {
+	Tk_FreeBitmap(display, linePtr->fillStipple);
+    }
+    if (linePtr->gc != None) {
+	Tk_FreeGC(display, linePtr->gc);
+    }
+    if (linePtr->arrowGC != None) {
+	Tk_FreeGC(display, linePtr->arrowGC);
+    }
+    if (linePtr->firstArrowPtr != NULL) {
+	ckfree((char *) linePtr->firstArrowPtr);
+    }
+    if (linePtr->lastArrowPtr != NULL) {
+	ckfree((char *) linePtr->lastArrowPtr);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ComputeLineBbox --
+ *
+ *	This procedure is invoked to compute the bounding box of
+ *	all the pixels that may be drawn as part of a line.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The fields x1, y1, x2, and y2 are updated in the header
+ *	for itemPtr.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+ComputeLineBbox(canvas, linePtr)
+    Tk_Canvas canvas;			/* Canvas that contains item. */
+    LineItem *linePtr;			/* Item whose bbos is to be
+					 * recomputed. */
+{
+    double *coordPtr;
+    int i, width;
+
+    coordPtr = linePtr->coordPtr;
+    linePtr->header.x1 = linePtr->header.x2 = (int) *coordPtr;
+    linePtr->header.y1 = linePtr->header.y2 = (int) coordPtr[1];
+
+    /*
+     * Compute the bounding box of all the points in the line,
+     * then expand in all directions by the line's width to take
+     * care of butting or rounded corners and projecting or
+     * rounded caps.  This expansion is an overestimate (worst-case
+     * is square root of two over two) but it's simple.  Don't do
+     * anything special for curves.  This causes an additional
+     * overestimate in the bounding box, but is faster.
+     */
+
+    for (i = 1, coordPtr = linePtr->coordPtr+2; i < linePtr->numPoints;
+	    i++, coordPtr += 2) {
+	TkIncludePoint((Tk_Item *) linePtr, coordPtr);
+    }
+    width = linePtr->width;
+    if (width < 1) {
+	width = 1;
+    }
+    linePtr->header.x1 -= width;
+    linePtr->header.x2 += width;
+    linePtr->header.y1 -= width;
+    linePtr->header.y2 += width;
+
+    /*
+     * For mitered lines, make a second pass through all the points.
+     * Compute the locations of the two miter vertex points and add
+     * those into the bounding box.
+     */
+
+    if (linePtr->joinStyle == JoinMiter) {
+	for (i = linePtr->numPoints, coordPtr = linePtr->coordPtr; i >= 3;
+		i--, coordPtr += 2) {
+	    double miter[4];
+	    int j;
+    
+	    if (TkGetMiterPoints(coordPtr, coordPtr+2, coordPtr+4,
+		    (double) width, miter, miter+2)) {
+		for (j = 0; j < 4; j += 2) {
+		    TkIncludePoint((Tk_Item *) linePtr, miter+j);
+		}
+	    }
+	}
+    }
+
+    /*
+     * Add in the sizes of arrowheads, if any.
+     */
+
+    if (linePtr->arrow != noneUid) {
+	if (linePtr->arrow != lastUid) {
+	    for (i = 0, coordPtr = linePtr->firstArrowPtr; i < PTS_IN_ARROW;
+		    i++, coordPtr += 2) {
+		TkIncludePoint((Tk_Item *) linePtr, coordPtr);
+	    }
+	}
+	if (linePtr->arrow != firstUid) {
+	    for (i = 0, coordPtr = linePtr->lastArrowPtr; i < PTS_IN_ARROW;
+		    i++, coordPtr += 2) {
+		TkIncludePoint((Tk_Item *) linePtr, coordPtr);
+	    }
+	}
+    }
+
+    /*
+     * Add one more pixel of fudge factor just to be safe (e.g.
+     * X may round differently than we do).
+     */
+
+    linePtr->header.x1 -= 1;
+    linePtr->header.x2 += 1;
+    linePtr->header.y1 -= 1;
+    linePtr->header.y2 += 1;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * DisplayLine --
+ *
+ *	This procedure is invoked to draw a line item in a given
+ *	drawable.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	ItemPtr is drawn in drawable using the transformation
+ *	information in canvas.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+DisplayLine(canvas, itemPtr, display, drawable, x, y, width, height)
+    Tk_Canvas canvas;			/* Canvas that contains item. */
+    Tk_Item *itemPtr;			/* Item to be displayed. */
+    Display *display;			/* Display on which to draw item. */
+    Drawable drawable;			/* Pixmap or window in which to draw
+					 * item. */
+    int x, y, width, height;		/* Describes region of canvas that
+					 * must be redisplayed (not used). */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    XPoint staticPoints[MAX_STATIC_POINTS];
+    XPoint *pointPtr;
+    XPoint *pPtr;
+    double *coordPtr;
+    int i, numPoints;
+
+    if (linePtr->gc == None) {
+	return;
+    }
+
+    /*
+     * Build up an array of points in screen coordinates.  Use a
+     * static array unless the line has an enormous number of points;
+     * in this case, dynamically allocate an array.  For smoothed lines,
+     * generate the curve points on each redisplay.
+     */
+
+    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
+	numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
+    } else {
+	numPoints = linePtr->numPoints;
+    }
+
+    if (numPoints <= MAX_STATIC_POINTS) {
+	pointPtr = staticPoints;
+    } else {
+	pointPtr = (XPoint *) ckalloc((unsigned) (numPoints * sizeof(XPoint)));
+    }
+
+    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
+	numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
+		linePtr->numPoints, linePtr->splineSteps, pointPtr,
+		(double *) NULL);
+    } else {
+	for (i = 0, coordPtr = linePtr->coordPtr, pPtr = pointPtr;
+		i < linePtr->numPoints;  i += 1, coordPtr += 2, pPtr++) {
+	    Tk_CanvasDrawableCoords(canvas, coordPtr[0], coordPtr[1],
+		    &pPtr->x, &pPtr->y);
+	}
+    }
+
+    /*
+     * Display line, the free up line storage if it was dynamically
+     * allocated.  If we're stippling, then modify the stipple offset
+     * in the GC.  Be sure to reset the offset when done, since the
+     * GC is supposed to be read-only.
+     */
+
+    if (linePtr->fillStipple != None) {
+	Tk_CanvasSetStippleOrigin(canvas, linePtr->gc);
+	Tk_CanvasSetStippleOrigin(canvas, linePtr->arrowGC);
+    }
+    XDrawLines(display, drawable, linePtr->gc, pointPtr, numPoints,
+	    CoordModeOrigin);
+    if (pointPtr != staticPoints) {
+	ckfree((char *) pointPtr);
+    }
+
+    /*
+     * Display arrowheads, if they are wanted.
+     */
+
+    if (linePtr->firstArrowPtr != NULL) {
+	TkFillPolygon(canvas, linePtr->firstArrowPtr, PTS_IN_ARROW,
+		display, drawable, linePtr->gc, NULL);
+    }
+    if (linePtr->lastArrowPtr != NULL) {
+	TkFillPolygon(canvas, linePtr->lastArrowPtr, PTS_IN_ARROW,
+		display, drawable, linePtr->gc, NULL);
+    }
+    if (linePtr->fillStipple != None) {
+	XSetTSOrigin(display, linePtr->gc, 0, 0);
+	XSetTSOrigin(display, linePtr->arrowGC, 0, 0);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * LineToPoint --
+ *
+ *	Computes the distance from a given point to a given
+ *	line, in canvas units.
+ *
+ * Results:
+ *	The return value is 0 if the point whose x and y coordinates
+ *	are pointPtr[0] and pointPtr[1] is inside the line.  If the
+ *	point isn't inside the line then the return value is the
+ *	distance from the point to the line.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static double
+LineToPoint(canvas, itemPtr, pointPtr)
+    Tk_Canvas canvas;		/* Canvas containing item. */
+    Tk_Item *itemPtr;		/* Item to check against point. */
+    double *pointPtr;		/* Pointer to x and y coordinates. */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    double *coordPtr, *linePoints;
+    double staticSpace[2*MAX_STATIC_POINTS];
+    double poly[10];
+    double bestDist, dist;
+    int numPoints, count;
+    int changedMiterToBevel;	/* Non-zero means that a mitered corner
+				 * had to be treated as beveled after all
+				 * because the angle was < 11 degrees. */
+
+    bestDist = 1.0e36;
+
+    /*
+     * Handle smoothed lines by generating an expanded set of points
+     * against which to do the check.
+     */
+
+    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
+	numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
+	if (numPoints <= MAX_STATIC_POINTS) {
+	    linePoints = staticSpace;
+	} else {
+	    linePoints = (double *) ckalloc((unsigned)
+		    (2*numPoints*sizeof(double)));
+	}
+	numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
+		linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL,
+		linePoints);
+    } else {
+	numPoints = linePtr->numPoints;
+	linePoints = linePtr->coordPtr;
+    }
+
+    /*
+     * The overall idea is to iterate through all of the edges of
+     * the line, computing a polygon for each edge and testing the
+     * point against that polygon.  In addition, there are additional
+     * tests to deal with rounded joints and caps.
+     */
+
+    changedMiterToBevel = 0;
+    for (count = numPoints, coordPtr = linePoints; count >= 2;
+	    count--, coordPtr += 2) {
+
+	/*
+	 * If rounding is done around the first point then compute
+	 * the distance between the point and the point.
+	 */
+
+	if (((linePtr->capStyle == CapRound) && (count == numPoints))
+		|| ((linePtr->joinStyle == JoinRound)
+			&& (count != numPoints))) {
+	    dist = hypot(coordPtr[0] - pointPtr[0], coordPtr[1] - pointPtr[1])
+		    - linePtr->width/2.0;
+	    if (dist <= 0.0) {
+		bestDist = 0.0;
+		goto done;
+	    } else if (dist < bestDist) {
+		bestDist = dist;
+	    }
+	}
+
+	/*
+	 * Compute the polygonal shape corresponding to this edge,
+	 * consisting of two points for the first point of the edge
+	 * and two points for the last point of the edge.
+	 */
+
+	if (count == numPoints) {
+	    TkGetButtPoints(coordPtr+2, coordPtr, (double) linePtr->width,
+		    linePtr->capStyle == CapProjecting, poly, poly+2);
+	} else if ((linePtr->joinStyle == JoinMiter) && !changedMiterToBevel) {
+	    poly[0] = poly[6];
+	    poly[1] = poly[7];
+	    poly[2] = poly[4];
+	    poly[3] = poly[5];
+	} else {
+	    TkGetButtPoints(coordPtr+2, coordPtr, (double) linePtr->width, 0,
+		    poly, poly+2);
+
+	    /*
+	     * If this line uses beveled joints, then check the distance
+	     * to a polygon comprising the last two points of the previous
+	     * polygon and the first two from this polygon;  this checks
+	     * the wedges that fill the mitered joint.
+	     */
+
+	    if ((linePtr->joinStyle == JoinBevel) || changedMiterToBevel) {
+		poly[8] = poly[0];
+		poly[9] = poly[1];
+		dist = TkPolygonToPoint(poly, 5, pointPtr);
+		if (dist <= 0.0) {
+		    bestDist = 0.0;
+		    goto done;
+		} else if (dist < bestDist) {
+		    bestDist = dist;
+		}
+		changedMiterToBevel = 0;
+	    }
+	}
+	if (count == 2) {
+	    TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width,
+		    linePtr->capStyle == CapProjecting, poly+4, poly+6);
+	} else if (linePtr->joinStyle == JoinMiter) {
+	    if (TkGetMiterPoints(coordPtr, coordPtr+2, coordPtr+4,
+		    (double) linePtr->width, poly+4, poly+6) == 0) {
+		changedMiterToBevel = 1;
+		TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width,
+			0, poly+4, poly+6);
+	    }
+	} else {
+	    TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width, 0,
+		    poly+4, poly+6);
+	}
+	poly[8] = poly[0];
+	poly[9] = poly[1];
+	dist = TkPolygonToPoint(poly, 5, pointPtr);
+	if (dist <= 0.0) {
+	    bestDist = 0.0;
+	    goto done;
+	} else if (dist < bestDist) {
+	    bestDist = dist;
+	}
+    }
+
+    /*
+     * If caps are rounded, check the distance to the cap around the
+     * final end point of the line.
+     */
+
+    if (linePtr->capStyle == CapRound) {
+	dist = hypot(coordPtr[0] - pointPtr[0], coordPtr[1] - pointPtr[1])
+		- linePtr->width/2.0;
+	if (dist <= 0.0) {
+	    bestDist = 0.0;
+	    goto done;
+	} else if (dist < bestDist) {
+	    bestDist = dist;
+	}
+    }
+
+    /*
+     * If there are arrowheads, check the distance to the arrowheads.
+     */
+
+    if (linePtr->arrow != noneUid) {
+	if (linePtr->arrow != lastUid) {
+	    dist = TkPolygonToPoint(linePtr->firstArrowPtr, PTS_IN_ARROW,
+		    pointPtr);
+	    if (dist <= 0.0) {
+		bestDist = 0.0;
+		goto done;
+	    } else if (dist < bestDist) {
+		bestDist = dist;
+	    }
+	}
+	if (linePtr->arrow != firstUid) {
+	    dist = TkPolygonToPoint(linePtr->lastArrowPtr, PTS_IN_ARROW,
+		    pointPtr);
+	    if (dist <= 0.0) {
+		bestDist = 0.0;
+		goto done;
+	    } else if (dist < bestDist) {
+		bestDist = dist;
+	    }
+	}
+    }
+
+    done:
+    if ((linePoints != staticSpace) && (linePoints != linePtr->coordPtr)) {
+	ckfree((char *) linePoints);
+    }
+    return bestDist;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * LineToArea --
+ *
+ *	This procedure is called to determine whether an item
+ *	lies entirely inside, entirely outside, or overlapping
+ *	a given rectangular area.
+ *
+ * Results:
+ *	-1 is returned if the item is entirely outside the
+ *	area, 0 if it overlaps, and 1 if it is entirely
+ *	inside the given area.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static int
+LineToArea(canvas, itemPtr, rectPtr)
+    Tk_Canvas canvas;		/* Canvas containing item. */
+    Tk_Item *itemPtr;		/* Item to check against line. */
+    double *rectPtr;
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    double staticSpace[2*MAX_STATIC_POINTS];
+    double *linePoints;
+    int numPoints, result;
+
+    /*
+     * Handle smoothed lines by generating an expanded set of points
+     * against which to do the check.
+     */
+
+    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
+	numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
+	if (numPoints <= MAX_STATIC_POINTS) {
+	    linePoints = staticSpace;
+	} else {
+	    linePoints = (double *) ckalloc((unsigned)
+		    (2*numPoints*sizeof(double)));
+	}
+	numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
+		linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL,
+		linePoints);
+    } else {
+	numPoints = linePtr->numPoints;
+	linePoints = linePtr->coordPtr;
+    }
+
+    /*
+     * Check the segments of the line.
+     */
+
+    result = TkThickPolyLineToArea(linePoints, numPoints, 
+	    (double) linePtr->width, linePtr->capStyle, linePtr->joinStyle,
+	    rectPtr);
+    if (result == 0) {
+	goto done;
+    }
+
+    /*
+     * Check arrowheads, if any.
+     */
+
+    if (linePtr->arrow != noneUid) {
+	if (linePtr->arrow != lastUid) {
+	    if (TkPolygonToArea(linePtr->firstArrowPtr, PTS_IN_ARROW,
+		    rectPtr) != result) {
+		result = 0;
+		goto done;
+	    }
+	}
+	if (linePtr->arrow != firstUid) {
+	    if (TkPolygonToArea(linePtr->lastArrowPtr, PTS_IN_ARROW,
+		    rectPtr) != result) {
+		result = 0;
+		goto done;
+	    }
+	}
+    }
+
+    done:
+    if ((linePoints != staticSpace) && (linePoints != linePtr->coordPtr)) {
+	ckfree((char *) linePoints);
+    }
+    return result;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ScaleLine --
+ *
+ *	This procedure is invoked to rescale a line item.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The line referred to by itemPtr is rescaled so that the
+ *	following transformation is applied to all point
+ *	coordinates:
+ *		x' = originX + scaleX*(x-originX)
+ *		y' = originY + scaleY*(y-originY)
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+ScaleLine(canvas, itemPtr, originX, originY, scaleX, scaleY)
+    Tk_Canvas canvas;			/* Canvas containing line. */
+    Tk_Item *itemPtr;			/* Line to be scaled. */
+    double originX, originY;		/* Origin about which to scale rect. */
+    double scaleX;			/* Amount to scale in X direction. */
+    double scaleY;			/* Amount to scale in Y direction. */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    double *coordPtr;
+    int i;
+
+    /*
+     * Delete any arrowheads before scaling all the points (so that
+     * the end-points of the line get restored).
+     */
+
+    if (linePtr->firstArrowPtr != NULL) {
+	linePtr->coordPtr[0] = linePtr->firstArrowPtr[0];
+	linePtr->coordPtr[1] = linePtr->firstArrowPtr[1];
+	ckfree((char *) linePtr->firstArrowPtr);
+	linePtr->firstArrowPtr = NULL;
+    }
+    if (linePtr->lastArrowPtr != NULL) {
+	int i;
+
+	i = 2*(linePtr->numPoints-1);
+	linePtr->coordPtr[i] = linePtr->lastArrowPtr[0];
+	linePtr->coordPtr[i+1] = linePtr->lastArrowPtr[1];
+	ckfree((char *) linePtr->lastArrowPtr);
+	linePtr->lastArrowPtr = NULL;
+    }
+    for (i = 0, coordPtr = linePtr->coordPtr; i < linePtr->numPoints;
+	    i++, coordPtr += 2) {
+	coordPtr[0] = originX + scaleX*(*coordPtr - originX);
+	coordPtr[1] = originY + scaleY*(coordPtr[1] - originY);
+    }
+    if (linePtr->arrow != noneUid) {
+	ConfigureArrows(canvas, linePtr);
+    }
+    ComputeLineBbox(canvas, linePtr);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TranslateLine --
+ *
+ *	This procedure is called to move a line by a given amount.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The position of the line is offset by (xDelta, yDelta), and
+ *	the bounding box is updated in the generic part of the item
+ *	structure.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+TranslateLine(canvas, itemPtr, deltaX, deltaY)
+    Tk_Canvas canvas;			/* Canvas containing item. */
+    Tk_Item *itemPtr;			/* Item that is being moved. */
+    double deltaX, deltaY;		/* Amount by which item is to be
+					 * moved. */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    double *coordPtr;
+    int i;
+
+    for (i = 0, coordPtr = linePtr->coordPtr; i < linePtr->numPoints;
+	    i++, coordPtr += 2) {
+	coordPtr[0] += deltaX;
+	coordPtr[1] += deltaY;
+    }
+    if (linePtr->firstArrowPtr != NULL) {
+	for (i = 0, coordPtr = linePtr->firstArrowPtr; i < PTS_IN_ARROW;
+		i++, coordPtr += 2) {
+	    coordPtr[0] += deltaX;
+	    coordPtr[1] += deltaY;
+	}
+    }
+    if (linePtr->lastArrowPtr != NULL) {
+	for (i = 0, coordPtr = linePtr->lastArrowPtr; i < PTS_IN_ARROW;
+		i++, coordPtr += 2) {
+	    coordPtr[0] += deltaX;
+	    coordPtr[1] += deltaY;
+	}
+    }
+    ComputeLineBbox(canvas, linePtr);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ParseArrowShape --
+ *
+ *	This procedure is called back during option parsing to
+ *	parse arrow shape information.
+ *
+ * Results:
+ *	The return value is a standard Tcl result:  TCL_OK means
+ *	that the arrow shape information was parsed ok, and
+ *	TCL_ERROR means it couldn't be parsed.
+ *
+ * Side effects:
+ *	Arrow information in recordPtr is updated.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static int
+ParseArrowShape(clientData, interp, tkwin, value, recordPtr, offset)
+    ClientData clientData;	/* Not used. */
+    Tcl_Interp *interp;		/* Used for error reporting. */
+    Tk_Window tkwin;		/* Not used. */
+    char *value;		/* Textual specification of arrow shape. */
+    char *recordPtr;		/* Pointer to item record in which to
+				 * store arrow information. */
+    int offset;			/* Offset of shape information in widget
+				 * record. */
+{
+    LineItem *linePtr = (LineItem *) recordPtr;
+    double a, b, c;
+    int argc;
+    char **argv = NULL;
+
+    if (offset != Tk_Offset(LineItem, arrowShapeA)) {
+	panic("ParseArrowShape received bogus offset");
+    }
+
+    if (Tcl_SplitList(interp, value, &argc, &argv) != TCL_OK) {
+	syntaxError:
+	Tcl_ResetResult(interp);
+	Tcl_AppendResult(interp, "bad arrow shape \"", value,
+		"\": must be list with three numbers", (char *) NULL);
+	if (argv != NULL) {
+	    ckfree((char *) argv);
+	}
+	return TCL_ERROR;
+    }
+    if (argc != 3) {
+	goto syntaxError;
+    }
+    if ((Tk_CanvasGetCoord(interp, linePtr->canvas, argv[0], &a) != TCL_OK)
+	    || (Tk_CanvasGetCoord(interp, linePtr->canvas, argv[1], &b)
+		!= TCL_OK)
+	    || (Tk_CanvasGetCoord(interp, linePtr->canvas, argv[2], &c)
+		!= TCL_OK)) {
+	goto syntaxError;
+    }
+    linePtr->arrowShapeA = (float)a;
+    linePtr->arrowShapeB = (float)b;
+    linePtr->arrowShapeC = (float)c;
+    ckfree((char *) argv);
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * PrintArrowShape --
+ *
+ *	This procedure is a callback invoked by the configuration
+ *	code to return a printable value describing an arrow shape.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+    /* ARGSUSED */
+static char *
+PrintArrowShape(clientData, tkwin, recordPtr, offset, freeProcPtr)
+    ClientData clientData;	/* Not used. */
+    Tk_Window tkwin;		/* Window associated with linePtr's widget. */
+    char *recordPtr;		/* Pointer to item record containing current
+				 * shape information. */
+    int offset;			/* Offset of arrow information in record. */
+    Tcl_FreeProc **freeProcPtr;	/* Store address of procedure to call to
+				 * free string here. */
+{
+    LineItem *linePtr = (LineItem *) recordPtr;
+    char *buffer;
+
+    buffer = (char *) ckalloc(120);
+    sprintf(buffer, "%.5g %.5g %.5g", linePtr->arrowShapeA,
+	    linePtr->arrowShapeB, linePtr->arrowShapeC);
+    *freeProcPtr = TCL_DYNAMIC;
+    return buffer;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ConfigureArrows --
+ *
+ *	If arrowheads have been requested for a line, this
+ *	procedure makes arrangements for the arrowheads.
+ *
+ * Results:
+ *	Always returns TCL_OK.
+ *
+ * Side effects:
+ *	Information in linePtr is set up for one or two arrowheads.
+ *	the firstArrowPtr and lastArrowPtr polygons are allocated
+ *	and initialized, if need be, and the end points of the line
+ *	are adjusted so that a thick line doesn't stick out past
+ *	the arrowheads.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static int
+ConfigureArrows(canvas, linePtr)
+    Tk_Canvas canvas;			/* Canvas in which arrows will be
+					 * displayed (interp and tkwin
+					 * fields are needed). */
+    LineItem *linePtr;			/* Item to configure for arrows. */
+{
+    double *poly, *coordPtr;
+    double dx, dy, length, sinTheta, cosTheta, temp;
+    double fracHeight;			/* Line width as fraction of
+					 * arrowhead width. */
+    double backup;			/* Distance to backup end points
+					 * so the line ends in the middle
+					 * of the arrowhead. */
+    double vertX, vertY;		/* Position of arrowhead vertex. */
+    double shapeA, shapeB, shapeC;	/* Adjusted coordinates (see
+					 * explanation below). */
+
+    /*
+     * The code below makes a tiny increase in the shape parameters
+     * for the line.  This is a bit of a hack, but it seems to result
+     * in displays that more closely approximate the specified parameters.
+     * Without the adjustment, the arrows come out smaller than expected.
+     */
+
+    shapeA = linePtr->arrowShapeA + 0.001;
+    shapeB = linePtr->arrowShapeB + 0.001;
+    shapeC = linePtr->arrowShapeC + linePtr->width/2.0 + 0.001;
+
+    /*
+     * If there's an arrowhead on the first point of the line, compute
+     * its polygon and adjust the first point of the line so that the
+     * line doesn't stick out past the leading edge of the arrowhead.
+     */
+
+    fracHeight = (linePtr->width/2.0)/shapeC;
+    backup = fracHeight*shapeB + shapeA*(1.0 - fracHeight)/2.0;
+    if (linePtr->arrow != lastUid) {
+	poly = linePtr->firstArrowPtr;
+	if (poly == NULL) {
+	    poly = (double *) ckalloc((unsigned)
+		    (2*PTS_IN_ARROW*sizeof(double)));
+	    poly[0] = poly[10] = linePtr->coordPtr[0];
+	    poly[1] = poly[11] = linePtr->coordPtr[1];
+	    linePtr->firstArrowPtr = poly;
+	}
+	dx = poly[0] - linePtr->coordPtr[2];
+	dy = poly[1] - linePtr->coordPtr[3];
+	length = hypot(dx, dy);
+	if (length == 0) {
+	    sinTheta = cosTheta = 0.0;
+	} else {
+	    sinTheta = dy/length;
+	    cosTheta = dx/length;
+	}
+	vertX = poly[0] - shapeA*cosTheta;
+	vertY = poly[1] - shapeA*sinTheta;
+	temp = shapeC*sinTheta;
+	poly[2] = poly[0] - shapeB*cosTheta + temp;
+	poly[8] = poly[2] - 2*temp;
+	temp = shapeC*cosTheta;
+	poly[3] = poly[1] - shapeB*sinTheta - temp;
+	poly[9] = poly[3] + 2*temp;
+	poly[4] = poly[2]*fracHeight + vertX*(1.0-fracHeight);
+	poly[5] = poly[3]*fracHeight + vertY*(1.0-fracHeight);
+	poly[6] = poly[8]*fracHeight + vertX*(1.0-fracHeight);
+	poly[7] = poly[9]*fracHeight + vertY*(1.0-fracHeight);
+
+	/*
+	 * Polygon done.  Now move the first point towards the second so
+	 * that the corners at the end of the line are inside the
+	 * arrowhead.
+	 */
+
+	linePtr->coordPtr[0] = poly[0] - backup*cosTheta;
+	linePtr->coordPtr[1] = poly[1] - backup*sinTheta;
+    }
+
+    /*
+     * Similar arrowhead calculation for the last point of the line.
+     */
+
+    if (linePtr->arrow != firstUid) {
+	coordPtr = linePtr->coordPtr + 2*(linePtr->numPoints-2);
+	poly = linePtr->lastArrowPtr;
+	if (poly == NULL) {
+	    poly = (double *) ckalloc((unsigned)
+		    (2*PTS_IN_ARROW*sizeof(double)));
+	    poly[0] = poly[10] = coordPtr[2];
+	    poly[1] = poly[11] = coordPtr[3];
+	    linePtr->lastArrowPtr = poly;
+	}
+	dx = poly[0] - coordPtr[0];
+	dy = poly[1] - coordPtr[1];
+	length = hypot(dx, dy);
+	if (length == 0) {
+	    sinTheta = cosTheta = 0.0;
+	} else {
+	    sinTheta = dy/length;
+	    cosTheta = dx/length;
+	}
+	vertX = poly[0] - shapeA*cosTheta;
+	vertY = poly[1] - shapeA*sinTheta;
+	temp = shapeC*sinTheta;
+	poly[2] = poly[0] - shapeB*cosTheta + temp;
+	poly[8] = poly[2] - 2*temp;
+	temp = shapeC*cosTheta;
+	poly[3] = poly[1] - shapeB*sinTheta - temp;
+	poly[9] = poly[3] + 2*temp;
+	poly[4] = poly[2]*fracHeight + vertX*(1.0-fracHeight);
+	poly[5] = poly[3]*fracHeight + vertY*(1.0-fracHeight);
+	poly[6] = poly[8]*fracHeight + vertX*(1.0-fracHeight);
+	poly[7] = poly[9]*fracHeight + vertY*(1.0-fracHeight);
+	coordPtr[2] = poly[0] - backup*cosTheta;
+	coordPtr[3] = poly[1] - backup*sinTheta;
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * LineToPostscript --
+ *
+ *	This procedure is called to generate Postscript for
+ *	line items.
+ *
+ * Results:
+ *	The return value is a standard Tcl result.  If an error
+ *	occurs in generating Postscript then an error message is
+ *	left in interp->result, replacing whatever used
+ *	to be there.  If no error occurs, then Postscript for the
+ *	item is appended to the result.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+LineToPostscript(interp, canvas, itemPtr, prepass)
+    Tcl_Interp *interp;			/* Leave Postscript or error message
+					 * here. */
+    Tk_Canvas canvas;			/* Information about overall canvas. */
+    Tk_Item *itemPtr;			/* Item for which Postscript is
+					 * wanted. */
+    int prepass;			/* 1 means this is a prepass to
+					 * collect font information;  0 means
+					 * final Postscript is being created. */
+{
+    LineItem *linePtr = (LineItem *) itemPtr;
+    char buffer[200];
+    char *style;
+
+    if (linePtr->fg == NULL) {
+	return TCL_OK;
+    }
+
+    /*
+     * Generate a path for the line's center-line (do this differently
+     * for straight lines and smoothed lines).
+     */
+
+    if ((!linePtr->smooth) || (linePtr->numPoints <= 2)) {
+	Tk_CanvasPsPath(interp, canvas, linePtr->coordPtr, linePtr->numPoints);
+    } else {
+	if (linePtr->fillStipple == None) {
+	    TkMakeBezierPostscript(interp, canvas, linePtr->coordPtr,
+		    linePtr->numPoints);
+	} else {
+	    /*
+	     * Special hack: Postscript printers don't appear to be able
+	     * to turn a path drawn with "curveto"s into a clipping path
+	     * without exceeding resource limits, so TkMakeBezierPostscript
+	     * won't work for stippled curves.  Instead, generate all of
+	     * the intermediate points here and output them into the
+	     * Postscript file with "lineto"s instead.
+	     */
+
+	    double staticPoints[2*MAX_STATIC_POINTS];
+	    double *pointPtr;
+	    int numPoints;
+
+	    numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
+	    pointPtr = staticPoints;
+	    if (numPoints > MAX_STATIC_POINTS) {
+		pointPtr = (double *) ckalloc((unsigned)
+			(numPoints * 2 * sizeof(double)));
+	    }
+	    numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
+		    linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL,
+		    pointPtr);
+	    Tk_CanvasPsPath(interp, canvas, pointPtr, numPoints);
+	    if (pointPtr != staticPoints) {
+		ckfree((char *) pointPtr);
+	    }
+	}
+    }
+
+    /*
+     * Set other line-drawing parameters and stroke out the line.
+     */
+
+    sprintf(buffer, "%d setlinewidth\n", linePtr->width);
+    Tcl_AppendResult(interp, buffer, (char *) NULL);
+    style = "0 setlinecap\n";
+    if (linePtr->capStyle == CapRound) {
+	style = "1 setlinecap\n";
+    } else if (linePtr->capStyle == CapProjecting) {
+	style = "2 setlinecap\n";
+    }
+    Tcl_AppendResult(interp, style, (char *) NULL);
+    style = "0 setlinejoin\n";
+    if (linePtr->joinStyle == JoinRound) {
+	style = "1 setlinejoin\n";
+    } else if (linePtr->joinStyle == JoinBevel) {
+	style = "2 setlinejoin\n";
+    }
+    Tcl_AppendResult(interp, style, (char *) NULL);
+    if (Tk_CanvasPsColor(interp, canvas, linePtr->fg) != TCL_OK) {
+	return TCL_ERROR;
+    };
+    if (linePtr->fillStipple != None) {
+	Tcl_AppendResult(interp, "StrokeClip ", (char *) NULL);
+	if (Tk_CanvasPsStipple(interp, canvas, linePtr->fillStipple)
+		!= TCL_OK) {
+	    return TCL_ERROR;
+	}
+    } else {
+	Tcl_AppendResult(interp, "stroke\n", (char *) NULL);
+    }
+
+    /*
+     * Output polygons for the arrowheads, if there are any.
+     */
+
+    if (linePtr->firstArrowPtr != NULL) {
+	if (linePtr->fillStipple != None) {
+	    Tcl_AppendResult(interp, "grestore gsave\n",
+		    (char *) NULL);
+	}
+	if (ArrowheadPostscript(interp, canvas, linePtr,
+		linePtr->firstArrowPtr) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+    }
+    if (linePtr->lastArrowPtr != NULL) {
+	if (linePtr->fillStipple != None) {
+	    Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL);
+	}
+	if (ArrowheadPostscript(interp, canvas, linePtr,
+		linePtr->lastArrowPtr) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ArrowheadPostscript --
+ *
+ *	This procedure is called to generate Postscript for
+ *	an arrowhead for a line item.
+ *
+ * Results:
+ *	The return value is a standard Tcl result.  If an error
+ *	occurs in generating Postscript then an error message is
+ *	left in interp->result, replacing whatever used
+ *	to be there.  If no error occurs, then Postscript for the
+ *	arrowhead is appended to the result.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+ArrowheadPostscript(interp, canvas, linePtr, arrowPtr)
+    Tcl_Interp *interp;			/* Leave Postscript or error message
+					 * here. */
+    Tk_Canvas canvas;			/* Information about overall canvas. */
+    LineItem *linePtr;			/* Line item for which Postscript is
+					 * being generated. */
+    double *arrowPtr;			/* Pointer to first of five points
+					 * describing arrowhead polygon. */
+{
+    Tk_CanvasPsPath(interp, canvas, arrowPtr, PTS_IN_ARROW);
+    if (linePtr->fillStipple != None) {
+	Tcl_AppendResult(interp, "clip ", (char *) NULL);
+	if (Tk_CanvasPsStipple(interp, canvas, linePtr->fillStipple)
+		!= TCL_OK) {
+	    return TCL_ERROR;
+	}
+    } else {
+	Tcl_AppendResult(interp, "fill\n", (char *) NULL);
+    }
+    return TCL_OK;
+}