URL https://opencores.org/ocsvn/or1k/or1k/trunk
Subversion Repositories or1k

[/] [or1k/] [trunk/] [insight/] [tk/] [generic/] [tkCanvLine.c] - Blame information for rev 1780

Go to most recent revision | Details | Compare with Previous | View Log

/*
 * 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.
 *
 * RCS: @(#) $Id: tkCanvLine.c,v 1.1.1.1 2002-01-16 10:25:51 markom Exp $
 */
 
#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_GetGCColor(tkwin, mask, &gcValues, linePtr->fg, NULL);
        gcValues.line_width = 0;
        arrowGC = Tk_GetGCColor(tkwin, mask, &gcValues, linePtr->fg, NULL);
    }
    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;
}
Browse

Tools

Subversion Repositories or1k

[/] [or1k/] [trunk/] [insight/] [tk/] [generic/] [tkCanvLine.c] - Blame information for rev 1780

Line No.	Rev	Author	Line
1	578	markom	`/*`
2			`* tkCanvLine.c --`
3			`*`
4			`* This file implements line items for canvas widgets.`
5			`*`
6			`* Copyright (c) 1991-1994 The Regents of the University of California.`
7			`* Copyright (c) 1994-1995 Sun Microsystems, Inc.`
8			`*`
9			`* See the file "license.terms" for information on usage and redistribution`
10			`* of this file, and for a DISCLAIMER OF ALL WARRANTIES.`
11			`*`
12			`* RCS: @(#) $Id: tkCanvLine.c,v 1.1.1.1 2002-01-16 10:25:51 markom Exp $`
13			`*/`
14
15			`#include <stdio.h>`
16			`#include "tkInt.h"`
17			`#include "tkPort.h"`
18
19			`/*`
20			`* The structure below defines the record for each line item.`
21			`*/`
22
23			`typedef struct LineItem {`
24			`Tk_Item header; /* Generic stuff that's the same for all`
25			`* types. MUST BE FIRST IN STRUCTURE. */`
26			`Tk_Canvas canvas; /* Canvas containing item. Needed for`
27			`* parsing arrow shapes. */`
28			`int numPoints; /* Number of points in line (always >= 2). */`
29			`double coordPtr; / Pointer to malloc-ed array containing`
30			`* x- and y-coords of all points in line.`
31			`* X-coords are even-valued indices, y-coords`
32			`* are corresponding odd-valued indices. If`
33			`* the line has arrowheads then the first`
34			`* and last points have been adjusted to refer`
35			`* to the necks of the arrowheads rather than`
36			`* their tips. The actual endpoints are`
37			`* stored in the *firstArrowPtr and`
38			`* lastArrowPtr, if they exist. /`
39			`int width; /* Width of line. */`
40			`XColor fg; / Foreground color for line. */`